Diagnosis of Pregnancy

(I) THE FIRST TRIMESTER (0-12 WEEKS) (A) Symptoms: 1.Amenorrhoea : sudden cessation of a previously regular menstruation is the most common symptom denoting pregnancy. However, pregnancy may occur during lactational amenorrhoea. On the other hand, bleeding may occur early in pregnancy as in threatened abortion. Slight bleeding may occur also at the expected time of menstruation in the first 12 weeks of pregnancy but never afterwards due to separation of parts of the decidua vera. 2.Morning sickness: nausea with or without vomiting commences in the morning. It usually appears about 6 weeks after onset of the last menstrual period and usually disappears 6-12 weeks later. 3.Frequency of micturition: due to congestion and pressure on the bladder and disappear after the first trimester to reappear again near the end of pregnancy when the foetal head descends into the maternal pelvis. 4.Breast 4. symptoms: as enlargement, sensation of fullness, tingling and tenderness. 5. Appetite changes and sleepiness. (B) Signs: (I)Breast signs: 1. Increase in size and vascularity. 2. Increase pigmentation of the nipple and primary areola. 3. Appearance of the secondary areola. 4. Montgomery’s follicles. 5. Expression of colostrum. 6. Breast signs are diagnostic only in primigravidae. In multigravidae , it may be due to the previous pregnancies . (II) Uterine signs: 1. The uterus becomes enlarged, globular and soft. 2. Palmer's sign: uterine contractions felt during bimanual examination. 3. Hegar's sign: during bimanual examination, the two fingers in the anterior fornix can be approximated to fingers of the abdominal hand behind the uterus due to softening of the lower part of the uterus and its emptiness. This sign can be elicited between 6-10weeks but not after as the growing conception will fill the whole uterine cavity. (III) Cervix : soft, hypertrophied and violet. (IV) Vagina: violet, moist, warm with increased acidity. (C) Investigations: (I) Pregnancy tests: These depend on presence of human chorionic gonadotrophin (hCG) in maternal serum and urine. 1- Urine pregnancy tests : i- Agglutination Test: Latex particles, or sheep erythrocyte (tube) coated with anti-hCG. ii- Agglutination Inhibition Tests iii- Dip stick Rapid and simple tests based on enzyme-labelled monoclonal antibodies assay can detect low level of hCG in urine. Causes of false positive results: 1. Proteinuria. 2. Haematuria. 3. At time of ovulation (cross reaction with LH). 4. HCG injection for infertility treatment within the previous 30 days. 5. Thyrotoxicosis (high TSH). 6. Premature menopause (high LH & FSH). 7. Early days after delivery or abortion. 8. Trophoblastic diseases. 9. hCG secreting tumours. Causes of false negative results: 1. Missed abortion. 2. Ectopic pregnancy. 3. Too early pregnancy. 4. Urine stored too long in room temperature. 5. Interfering medications. 2- Serum pregnancy tests: (i) Radioimmunoassay of b -subunit of hCG. (ii) Radio receptor assay. 3- Enzyme- linked immunosorbent assay (ELISA). can be used for urine and serum. The pregnancy test becomes negative about: l one week after labour, l 2 weeks after abortion, and l 4 weeks after evacuation of vesicular mole. Uses of pregnancy test: 1. Diagnosis of pregnancy. 2. Diagnosis of foetal death. 3. Diagnosis of ectopic pregnancy. 4. Diagnosis and follow up of gestational trophoblastic diseases. (II) Ultrasonography: Gestational sac can be detected after 4-5 weeks of amenorrhoea. Foetal heart pulsation can be detected as early as 7 weeks. (II) THE SECOND TRIMESTER (13-28 WEEKS) (A) Symptoms: 1. Amenorrhoea. 2. Morning sickness and urinary symptoms decrease. 3.Quickening : The first sensation of the foetal movement by the mother, occurs at 18-20 weeks in primigravida and at 16-18 weeks in multiparas. 4. Abdominal enlargement. (B) Signs: 1. Breast signs: become more manifested. 2. Skin signs : Cloasma, linea nigra and striae gravidarum appear. 3. Uterine signs: i-The uterus is felt abdominally. ii-Braxton Hick's contractions: intermittent painless contractions can be felt by abdominal examination. 4-Foetal signs: i- Internal ballottement: can be elicited at 16 weeks by a push to the foetal parts with the two fingers through the anterior fornix. ii- External ballottement: can be elicited at 20 weeks by a push to the foetal parts with one hand abdominally and the other hand receiving the impulse. iii- Palpation of foetal parts and movement: by the obstetrician at 20 weeks. iv- Foetal heart sound: can be auscultated at 20-24 weeks by the Pinard's stethoscope. v- Umbilical (funic) souffle: A murmur with the same rate of FHS due to rush of blood in the umbilical arteries. It is occasionally detected when a loop of the cord lies below the stethoscope. (C) Investigations in doubtful cases. 1. Pregnancy tests. 2. Ultrasonography. X-ray: It shows the foetal skeleton starting from the 16th week of pregnancy. It has 3.been replaced by ultrasonography due to the following hazards: i- Teratogenic effects particularly before 10 weeks. ii- Chromosomal changes in the foetal gonads leading to genetic disorders in the following generations. iii- Subsequent leukaemia in childhood. (III) THE THIRD TRIMESTER (29-40 WEEKS) All signs of pregnancy become more evident. Pregnancy tests are positive, sonar and X-ray are diagnostic. Sure Signs of Pregnancy: 1. Palpation of foetal parts. 2. Palpation of foetal movements. 3. Auscultation of foetal heart sounds. 4. The occasional auscultation of the umbilical (funic) souffle. 5. Detection of foetal skeleton by X-ray. 6. Ultrasonographic detection of foetal parts, movements and /or heart movements. Differential Diagnosis of Pregnancy: (A) Early pregnancy: (I) Causes of amenorrhoea. (II) Causes of symmetrically enlarged uterus: 1- Myoma. 2- Adenomyosis. 3- Pyometra. 4- Haematometra. 5-Metropathia haemorrhagica. (III) Pelvi-abdominal swellings: 1- Ovarian swellings. 2- Tubal swellings. 3- Pelvic haematocele. 4- Full bladder. (B) Late pregnancy: 1- Myomas. 2- Ovarian neoplasm. 3- Ascitis. 4- Pseudocyesis. 5- Other causes of pelvi-abdominal mass.

diagnostic laparoscopy , DR. Alaa Mosbah ,M.D OBS&GYN

Introduction : Diagnostic laparoscopy is indicated in any situation when inspection of the abdomen will help establish a diagnosis and to define subsequent treatment. Patients that are to undergo endoscopic surgery should have a complete pre-operative evaluation prior to scheduling the surgery. The preoperative evaluation often includes laboratory and echographic exams in order to determine the clear indication for surgery. The following text describes the usual operating room set up and procedures for a diagnostic laparoscopy. Positioning of the patient / Anesthesia : The patient is transported to the operating room and general anesthesia performed. Following this, place the patient in modified dorsolithotomy position. This position is most practical for operating and allows easy mobilization of the uterus as well as access for hysteroscopy. Some operating tables may be repositioned intraoperatively, allowing the surgeon to change the angle of the legs. Special care should be taken to avoid nerve injury by mal positioning the patient, particularly along the popliteal fossa and brachial plexus. If any part of the patient is in contact with a metal object, she may be at risk of electrosurgical burns. General anesthesia is preferred for laparoscopy as it provides adequate muscle relaxation and assisted respiration particularly as the patient is in Trendelenburg position. Disinfect the vagina, paying special attention to the umbilicus. Empty the urinary bladder. Some surgeons prefer to leave a Foley catheter in place throughout the procedure. We maintain continuous Foley drainage in selected operations, such as a Burch procedure or hysterectomy. These procedures often require longer operating times and are more likely to result in injury to the bladder. For simpler procedures, we simply empty the bladder at the beginning of the operation. Place a tenaculum on the cervix and insert the uterine cannula. This cannula will allow the uterus to be manipulated and should have the capability to perform chromopertubation. Position of the operating team and equipment : The surgeon must be familiar with the mechanics and operation of each piece of equipment. Prior to anesthetizing the patient the operating team must check that the insufflator is functioning and has an adequate supply of gas, the light source is functioning, and the video equipment is in working order. This will prevent avoidable malfunctions which may result in serious complications and surgical delays. Mobile racks for camera and TV monitor, video-recorder, light-source and insufflator are available and help organize the operating room equipment. The surgeon stands on the left side of the patient, the nurse next to him and the assistant on the opposite side. From here, the surgeon is able to continuously monitor all of the equipment (insufflator, light-source, irrigation system, electric generator). Alternatively, the surgeon and his assistant may both stand to the left of the patient with the video monitor on the opposite side. The TV monitor (1 or 2) should be located so that each member of the operating team may follow the procedure. If there is only one monitor, it is best placed at the feet of the patient. Instruments : To perform a basic diagnostic laparoscopy one must have equipment to create a pneumoperitoneum, light source, video, a cable and telescope, and instruments to manipulate the uterus and adnexea. Distention media : The peritoneal cavity is a potential space which only allows visualization of the pelvic organs with adequate distention. The gases commonly used for laparoscopy are carbon dioxide (CO2) and nitrous oxide (NO2). Carbon dioxide is more readily absorbed, non-toxic, and does not support combustion. The only serious risk is that of hypercarbia which only develops at an absorption rate of greater than 100ml/min. For this reason, patients are generally hyperventilated during surgery. The intra-abdominal pressure should not rise above 15mm Hg, higher pressures will increase the absorption rate and risk of gas embolism. Carbon dioxide embolism has been reported at a rate of 1:10,000 to 1:60,000. Early diagnosis may be made by auscultating the characteristic "mill wheel" murmur. Nitrogen is less readily absorbed by body fluids and may lead to subphrenic discomfort. It is also not flammable and does not support combustion. The risk of embolism is similar to that for carbon dioxide. The surgeon must also choose between a large array of gas insufflating systems, both mechanical and electronic. The electronic system maintains the intra-peritoneal pressure at a constant pre set level. Thus the surgeon may perform the procedure without having to constantly monitor the pressures and volumes. Basic instruments · Veress' needle. · One 10-12 mm trocar to pass the laparoscope. · Two to three 5 mm trocars (through which to pass instruments). · One 10-12 mm trocar for larger instruments. · Uterine manipulator. · Laparoscopic scissors. · Atraumatic grasping forceps. · Smooth forceps designed for grasping the tubes. · Bipolar electrocoagulator. · Mobilizer (if possible with graduations). · High flow irrigation-aspiration system. · CO2 laser coupler (optional) and adequate back-stop device. Instruments for more advanced procedures · Unipolar electrocoagulator. · Two needle holders. · Clip forceps. Minimal equipment required to perform laparoscopy · High luminosity laparoscope with 10 mm trocar. · 400 W light source. · CO2 insufflator automatically regulated for pressure and flow rate. It should enable a high rate of CO2 (at least 6 l/min.). · Video camera and screen. · Irrigation-aspiration system with high flow. · Equipment for bipolar and unipolar electrosurgery. · Endoscopic instruments: scissors, 2 forceps (one atraumatic), bipolar coagulating forceps, clip forceps. · Three secondary trocars 5 mm. · One secondary trocar 10-12 mm. Operating Procedure Pneumoperitoneum Insert the Veress'' needle through a vertical, 1 cm intraumbilical incision. In general a 7cm length is sufficient although a 15cm needle is also available for very obese patients. Prior to insertion the spring mechanism is checked on the needle to help avoid visceral puncture. At this intraumbilical site the abdominal wall is thinnest with no intervening fat and the peritoneum closely underlying the fascia. To insert the Veress' needle the abdominal wall is lifted with one hand and the needle passed through the incision. Intraperitoneal placement is confirmed by injecting 5 ml of saline through the Veress' needle. The solution should flow without resistance and should not return when trying to aspirate. Next, deposit a drop of saline on the external os of the needle. It should fall into the needle hub when negative pressure is created by lifting the anterior abdominal wall. Next, insuffltate carbon dioxide at a low flow rate of 2 liters/minute, allowing the patient to adapt gradually to the pneumoperitoneum. When a pressure of 14 mm of mercury is obtained, place the machine should on automatic flow in order to maintain this pressure. Most machines will automatically adjust the flow rate (usually at a maximum flow of 6 l/min.). In rare cases adhesions or extreme obesity may limit the surgeons ability to use the Veress' needle intraumbilically. If these situations arise, the surgeon may either perform and open laparoscopy or insert the Veress' needle through the posterior vaginal fornix. Placement of trocars After attaining a sufficient pneumoperitoneum, place one 10-12 mm umbilical trocar through the Veress' needle incision. The distal tip of the trocar must be sharp. During insertion of the trocar, compress the upper abdominal wall with the free hand to make the lower abdominal wall tense, giving a firm platform against which to insert the trocar and cannula. Direct the trocar towards the pelvis to avoid injury to major vessels.The trocar should pierce the peritoneal cavity as high as possible to assure a panoramic view. Occasionally, the trocar must be placed above the umbilicus (this must be done under direct laparoscopic visualization through an initial umbilical site). Pass the laparoscope through the trocar sleeve and immediately confirm correct intraperitoneal placement. Standard diagnostic laparoscopes vary in diameter from 5-11mm. The 5mm laparoscope is adequate for inspection but is not sufficient for more complex procedures. The light source is also an essential element. In general the standard 150 watt light source is sufficient only for diagnostic laparoscopy. Complex procedures requires a more powerful light (250-400 watt halogen lamp). Next, place the patient in Trendelenburg position in order to allow for the gravitational effect to move the bowel out of the pelvic cavity. Then insert two or three 5 mm trocars under direct vision at ancillary puncture sites for instruments. These secondary trocars are inserted suprapubically, taking care to avoid the epigastric vessels laterally and the bladder medially. While inserting these ancillary trocars, angle toward the pouch of Douglas while the uterus is held in ante-version. Secondary 8-12 mm, rather than 5 mm trocars, may be useful for some procedures. Collaboration with the anesthetist The pressure of the pneumoperitoneum and the extent of the Trendelenburg position must be adapted to the hemodynamic and respiratory demands of each individual patient. Continued communication and collaboration with the anesthetist throughout the procedure is mandatory. This is extremely important because it may be necessary to reduce the Trendelenburg position, lower the intraabdominal pressure, or even convert to laparotomy at any time during the procedure. Inspection of the abdomen and pelvis It is important to approach the evaluation of the pelvis in a systematic and thorough manner. Upper abdomen Begin the inspection with the upper abdomen. Rotate the laparoscope to view the caecum and appendix, using a probe if necessary. Examine the course of the ascending colon to the hepatic flexure. Examine the right lobe of the liver and gall bladder. Sub-diaphragmatic adhesions may indicate prior pelvic inflammatory disease (Fitz-Hugh-Curtis Syndrome). Avoiding the ligamentum falciparum, the laparoscope is rotated to view the left lobe of the liver and stomach. And finally, rotate the laparoscope around to view the descending colon. Uterus, fallopian tubes Next, examine the pelvic organs starting with the uterus. Note its shape, size, position, and mobility. Noting these characteristics may guide in making the diagnosis of either uterine myomas, adenomyosis, or aberrant Mullerian duct fusion. Look at the anterior cul-de-sac and round ligaments for evidence of endometriosis. Inspect the fallopian tubes entirely with the aid of a probe or forceps. Follow the length of the tube looking for evidence of prior infection or endometriosis. Note the thickness of the wall and mobility of the ampulla. Note all peritubal adhesions, or hydrosalpinxes. In cases of infertility, after completing the inspection of the pelvic organs, proceed with chromopertubation to evaluate tubal patency (see below). A more sophisticated technique for evaluating the fallopian tube is salpingoscopy, for a more detailed examination of the tubal mucosa. Ovaries Complete the inspection of one round ligament, fallopian tube and ovary before continuing on with the opposite side. The ovary is manipulated with a probe or forceps in order to examine its entire surface and evaluate its mobility. Again note any signs of endometriosis or adhesion formation. Uterosacral ligaments Finally, examine both uterosacral ligaments and the pouch of Douglas. For a clear view it may be necessary to aspirate the free fluid. Again, this is a common site for endometriosis and adhesion formation. Chromopertubation Chromopertubation is a basic element of a diagnostic laparoscopy for infertility to assess tubal patency. Inject a dilute solution of methylene blue (1:20 solution) through the cervical cannula. Follow the passage of the liquid through the fallopian tube a verify passage of dye through the fimbria. Closure of abdominal incisions After completing the evaluation of the pelvis or endoscopic procedure, in more advanced cases, the laparoscopy is completed as follows. Remove the ancillary ports, examining the incisions internally for bleeding. Then remove the laparoscope and allow the intra-abdominal gas to escape through the sleeve. Take the patient out of Trendelenburg position in order to optimize the decompression of the pneumoperitoneum. Close the small lower abdominal incisions with non-absorbable suture to be removed in 5-7 days. It is wise to place an absorbable fascial suture in the larger >10 mm umbilical incisions followed by a cutaneous non-absorbable suture. Indication for diagnostic laparoscopy 1. Infertility. This is one of the most common indications for diagnostic laparoscopy. A variety of pertinent diagnosis my be determined at laparoscopy these include: adhesions- evidence of prior pelvic infection Structural abnormalities of the uterus, including congenital developmental abnormalities (such as a bicornuate or unicornuate uterus), and fibroids. Endometriosis Fallopian tube occlusion. A diagnostic laparoscopy may clarify the diagnosis and treatment prior to reconstructive surgery. 2. Chronic pelvic pain. The systematic evaluation of the abdomen and pelvis provided by this relatively benign surgery can provide key diagnostic information in the evaluation of a woman with chronic pelvic pain. In particular, the laparoscopy my reveal adhesions or endometriosis not visible by other diagnostic techniques. 3. Chronic Pelvic Inflammatory Disease (PID). It is essential to carefully inspect the liver and diaphragm when considering this diagnosis. 4. Endometriosis. The appearance of endometriosis varies and it is important that the laparoscopist is aware of the spectrum that one might see during a laparoscopy. Early endometriosis may appear as clear vesicles before progressing to red plaques and eventually black plaques. An intra-operative biopsy will confirm the diagnosis. Indications for an urgent diagnostic laparoscopy 1. Acute Pelvic Inflammatory Disease. If the diagnosis cannot be clearly made by the clinical presentation, a diagnostic laparoscopy may be useful the confirm this diagnosis. 2. Ectopic Pregnancy. Today, a laparoscopy for ectopic pregnancy often not only provides the diagnosis, but also allows for the immediate surgical treatment. 3. Torsion of a tube or ovary. This is often a difficult diagnosis to establish. Echography rarely provides a clear diagnosis. Again laparoscopy can both diagnose and treat this condition. Contra-indications to laparoscopy Absolute contraindications A large abdominal mass such as a fibroid or ovarian cyst An irreducible external hernia. A laparoscopy in this situation could enlarge the hernia sac and make the condition worse. Hypovolemic shock. Medical problems such as cardio-respiratory failure, obstructive airway disease, or a recent myocardial infarction. An inexperienced surgeon or a lack of proper equipment. Relative contraindications Multiple prior abdominal incisions Morbid obesity. The difficulty in creating the pneumoperitoneum may be overcome by introducing the Veress'' needle through the posterior vaginal fornix. Local skin infections may require that the locations for the abdominal incisions be altered. Generalized peritonitis Intestinal obstruction or ileus. This is a relative contra-indication because of the increased risk of bowel perforation upon entry of the Veress'' needle or trocars. Coincidental medical conditions such as ischemic heart disease, blood dyscrasias or coagulopathies. Ancillary instruments Forceps A wide range of forceps are available for laparoscopic use. It is less important to have a wide range of forceps than to have perfected the use of one or two. It is important to have at least one of each, an atraumatic forceps and a forceps with teeth for stronger traction. Scissors Scissors which pass through a 5 mm port are sufficient for general dissection. Microscissors may be preferable for adhesiolysis close to the fimbriae or in other delicate locations. It is important that one of the blades is fixed to allow gentle traction to be applied before cutting. Laser The laser will precisely destroy tissue. Both rigid and flexible systems are available. Sutures and clips Sutures Techniques for tying and applying will be discussed in later chapters. In general there are two suturing techniques that are used in laparoscopic surgery. In the first the knot is tied within the abdomen. In the second the knot is tied extracorporeally. Suturing equipment includes: a needle holder, grasping forceps, knot pusher, and needles which can be passed through a 5 mm port. Ligatures Ligatures are most easily applied by using a prepacked modified Roeder loop introduced through the standard 5mm cannula. Clips and Staples Clips and staples my be invaluable for obtaining hemostasis. Instruments are also available which will apply up to three rows of staples on either side of the line where an incision is to be made. A blade contained within the instrument makes the incision. These instruments are disposable and expensive. Although a wide range of equipment exists for performing laparoscopic surgery, it is important to master the use of the basic instruments and appreciate their full potential before expanding to the use of more complicated devices.

Contracted pelvis and cephalopelvic disproportion

Contracted pelvis and cephaopelvic disproportion Definition: a contracted pelvis is a pelvis whose shape and size are sufficiently abnormal to cause difficulty in vaginal delivery of normal (average size body ) This may occurs when : 1- One or more of the pelvic diameters is reduced enough to cause dystochia (Obstetric definition) 2- One or more of the pelvic diameters is reduced below the average by on or more centimeters (antatomical definition) CPD: or fetopelvic disproportion in presentations other than cephalic) can arise from either : 1- Diminished pelvic capacity 2- Excessive fetal size or abnormal fetal development Or more usually a combination of both In contemporary obstetric practice dystochia literally means difficult labour and is characterized by abnormal progress by labour Generally this can occurs as a result of 3 distinct causes that may exist singly in combination 1- Abnormalities in the power: a. Uterine contractility (uterine dysfunction in significantly strong or inappropriately coordinated to affect the dilate the cervix = dysfunctional labour) b. Inadequately voluntary maternal expulsive effort during the 2nd stage of labour 2- Abnormalities in the passenger: a. Abnormal presentation and / or position b. Abnormal fetal development (congenitally malformed baby) 3- Abnormalities in the passage : a. Abnormalities in size or shape of the bony pelvis (contracted pelvis) b. Abnormalities of soft tissues of the reproduction tract and other pelvic organs (soft tissue obstruction) Classification of contracted pelvis A - Pelvic inlet contraction : when the shortest onteroposterioer diameter of the inlet < 10cm or when the greatest transverse diameter is < 12cm or when the brim idea Anteroposterior diameter x 100) is < 85 Transverse diameter The Anteroposterior diameter of the pelvic inlet is commonly approximated by manually measuring the diagonal conjugate which is about 1.5cm greater therefore inlet contraction id dysnied as a diagonal conjugate < 11.5cm Contracted inlet can cause: 1- delayed desert of the fetal head or primigravida until after the onset of labour if at all. (usually the head is engaging or already engaged in the least 2 weeks of pregnancy in normal nullipara before the onset of labour 2- face and shoulder presentation (3 times more frequent) 3- cord prolpase (4-6 times more frequent) NB: contracted pelvis has no relation to breach presentation 4- in contracted pelvis, rupture of membranes the absnce of preserve of the head against the cervix and the lower uterine segment predisposes to less effective uterine contractions (inertia) B- Midpelvic contraction: 1- More common that inlet contraction 2- It usually causes transverse arrest of the head resulting in difficulty or failed midforceps and increased CS rate 3- Average midpelvic measurements are: a. Transverse (interspinous) = 10.5cm b. Anteroposterior 9from the lower border of the symphysis pubis to the junction of 54- ) = 11.5cm posterioer sagittal (from midpoint of interspinous line namely the previous point of the sacrum to the junction of S4-S5= 5cm c. The definition of midpelvic contraction is not prescise as in inlet contraction d. Midpelvic is called contracted of the sum of interspinous and posterior sagittal < 13.5cm (normally 15.5cm) e. Although these is no precise manual method for measuring medpelvic diameters its suggested to be contracted if : i. The spines are prominent (under projection) ii. The pelvic side walls are convergent iii. The sacroscietic notch is narrow normally the sacrospinopus ligament should measure at least 2 fingers breath (if < 2 fingers the notch is suggested to be narrow) iv. The intertuberous diameter is narrow. Normally the relation between ineter spinous and inter tuberous diameter is constant. However a normal intertuberous interspinous diameter C- Pelvic outlet contraction: Usually defined as an interischil tuberous diameter < 8cm with consequent narrow subpubic angle Its incidence is usually about 1% Outlet contraction without concomitant midplane contraction is rare Diminution of the intertuberous diameter with consequent narrowing of the anterior saggital triangle of the outlet forces the fetal head posterioely resulting in increased incidence of perineal lacerations A contracted outlet may constitute dystocia not so much by itself as through the after associated midpelvic contraction D- Combination of both inlet and outlet contractions generally contracted pelvis (just-minor pelvis) Etiology of pelvic contraction I-Congenital : 1- Naegel's pelvis = asymmetric or obliquely contracted pelvis due to absence of one of the sacrum 2- Robert's pelvis: transversly contracted pelvis due to absence of 2 sacral 3- High assimilation pelvis: the sacrum is made of 6 dused segments 4- Low assimilation pelvis: the sacrum is made of 4 fused segments 5- Split pelvis: absent pubic bone usually associated with extopia vesica 6- Dislocation of the hip joint II- Acquired: 1- Metabolic disease : a. Rickets in which the following types of pelvis are found: i. Flat rachitic pelvis ii. Generally contracted rachitic pelvis iii. Generally contracted flat rachitic pelvis (rachitic stigmata on top of generally contracted pelvis) b. Osteomalcia : causing trirdiate or rosette shaped or peaked pelvis 2- Vertebral column disease : a. kyphasis b. scoliosis c. spondylolthesis 3- Lower limb disease : a. Resulting inmissing or shortening of one limb during childhood or adolescence before ossification of the pelvis b. This results in pelvis obliquity (coxolgic pelvis) froctuers (accidents inflammatory TB ostcomylitis) 4- Disease of the pelvic bones: a. Fractures b. Tumours of pelvic bones MECHANISM OF LABOUR IN SOME COMMON TYPES OF CONTRACTED PELVIS I- Generally contracted pelvic (justo minor) Features: 1- Commonest type of contracted pelvic usually in short women 2- It shows gynaecoid chometers but these is propotional dimination of all diameters with funneling in 20% of cases Mechanism of labour: 1- Delayed descent and engagement 2- Marked moulding and formation 3- Extreme felxsion of the head (roader obliquity) 4- Deep transverse arrest (failure of long anterior rotation ) in OP if associated with outlet contracted (20% of cases) NB: Cord proplase is rare due to narrow spaces and fitting of the presenting parts at the pelvic brim II- Flat rachitic pelvis: Features : 1- Forward of the sacral promontory resulting in reduction of the true conjugate 2- Hyperplasia at the junction between sacral vertebra may result in false promontory 3- Divergence of the ischial tubersity and aceteabulum resulting in wide subpubic angle and increased bituveros diameter 4- Contractions occur only at the level of the inlet so if the head possed the inlet there will be more difficulty (single dimensionally contracted pelvis) Mechanism of labour: 1- Head engagement in the transverse diameter 2- Asynclitism with anterioer porful bone presentment 3- Lateral displacement of the head to bring the short biterporal diameter in the short true conjugate 4- Deflection occurs with descent 5- With further descent both asynclitism and deflection are corrected 6- rotation (2/3 circles) interiorly because the outlet is wide III- Simple flat pelvis: Features : reduced AP diameter of the inlet cavirty and outlet without rachitic stigmata Mechanism of labour: 1- At the pelvis inlet: like flat rachitic pelvis 2- At the outlet there will be: a. Extreme flexsion and moulding (reduced AP diameter at the outlet) b. Increased incidence of perineal lacerations due to backwards dispalecment of the fetal head (narrow) subpubic angle ) c. In OP: deep transverse arrest or face to pubis (short posterior rotation) IV – Funnel pelvis (contracted outlet) Causes: 1- 20% if generally contracted pelvis 2- Android pelvis 3- High assimilation pelvis 4- Spreadylo lithesis: sublaxation of the 5the labour in front of the sacral promontory resulting in downwards and backward displacement of the sacrum deep, cavity and increased inclination of the plane of the inlet and some cases may show outlet contraction resulting in funneling 5- Lunbodacrel kyphasis 6- Obliquely contracted pelvis 7- Some cases of richets & asteomalacia Mechanism of labour : 1- Extreme flexion & moulding at the outlet 2- Backwards displacement of the head due to narrow subpubic angle resulting in increased incidence of perineal laceration 3- In OP: deep transverse arrest or face to pubis Diagnosis of CP I- History 1- post history of trauma or disease that cause pelvic contractions eg Rickets osteamalacia, poliomyelitis TB fractures or thopedic surgery 2- Bad obstetric history Malpresentation repeated fetal losses and operative deliveries II- Examination: 1- General: a. Short stature b. Rachitic manifestation c. Abnormal gait (eg limbing waddling) 2- Abdominal (during pregnancy) a. Pendulous abdomen b. Scar of CS c. Malpresntation face brow shoulder presentation d. Non engaged head in last 2w of pregnancy in primigravida III- Investigation: 1- Pelvimetry : a. Clinical pelvimetry b. MRI c. Radiographic pelvimetry (x-ray CT) d. Sonographic cephalometry Cephalopelvic disproportion test Pelvimetry I- Clinical Pelvimetry 1- External Pelvimetry of the inlet 2- External Pelvimetry of the outlet - Subpubic angle (normalley 90) - measured by fingers or morris disc - normally the angle can accommodate two fingers near the apex - Bituberous diameter (normally 11Cm) : - measured by pushing the knuckles of the 4 fingers or closed first between ischil tuberosities or by pelvimeter (Thom's crossing pelvimeter) - normally this diameter can accommodates the closed first or the knuckles of the 4 fingers easily 3- Anteroposterior diameter of the outlet normally 13cm - Measured by 2 fingers in the vagina by the same method used fordiagnal conjugate 4- Posterior and anterior sagittal diameter of the outlet (normalley 102 cm) measured by Thom's pelvimeter Thom's diction: for spontaneous vaginal delivery to occur the sum of the transverse and posterior diameter of the outlet must be > 15cm NB: pelvic outlet is accessible clinically so obstetrician must not be surprised by outlet contraction during labour outlet contraction must be diagnosed during pregnancy or very early in labour in the first exam. Internal pelvimetry : - Usually done after 36 weeks - Patient in lithotomy position without anesthesia by the gloved rt hand 1- Diagnosed conjugate (normally 12-15cm) - tip of rt middle finger reaching the sacral promontory mark the point that impringes on the lower border of the symphsis pubis on the radial border of the rt index - withdraw the rt 2 fingers and measure the distance between the tip of the middle finger and that point by a ruler NB: the same method is used to measure the anetroposteriorer diameter of the outlet but tip of middle finger touches the tip of sacrum 2- palpatic the shape of the sacrum normally it is broad with cancer or flat anterior surface 3- palpable the two ischial spines and approximate distance between them : normalley it is felt not prominent or undeuley projecting with the distance between them > 10.5cm 4- palpable the coccyx: normally is mobile and can recedes back wards easily 5- palpable the sacroscpinous ligaments normally it is 2 fingers breadth (3.5cm) 6- palpable side walls of the pelvis and sacroscietic notch - normalley parallel or divergent walls with wide notch 7- the anteroposterior diameter of the pelvic outlet - Measured by the same manner as diagonal conjugate Radiological pelvimetry A- Plain x-ray: - for borderline cases of pelvic contraction 1- lateral pelvimetry is the best to be done during labour look for the following an lateral fibm - Pelvic inclination (angle between the true conjugate and anterior surface of lunbar ureterbea ) - sacral promontory (jutting or not ) - length and shape of the sacrum - sacroscitic notch (wide or narrow) - level of the head in rotation to the ischial spine - true conjugate and posterior sagital measured by a ruller after putting a scale on the film 2- inlet and outlet radiological pelvimetry is of less importance x-ray pelvimetry is of little value in cephalic presentation (clinical cephalopelvic disproportion tests are more valuable ) CT : Advantages : 1- reduced radiation exposure 2- greater accuracy and easier technique MRI : Advantages : 1- no ionizing radiation 2- accurate measurement 3- complete fetal and placental imaging 4- evaluation of soft tissue dystocia Disadvantages: 1- cost 2- time factor 3- equipments availability Cephalopelvic disproportion tests If the head is not engaged in the last 2 weeks of pregnancy CPD is suspected and can be tested by the following maneuovers in which the fetal head is used as a pelvimeter 1- Pinard's maneuver: a. The women is examined in the seminstting position to coorect pelvic inclination (the oasis of the fetus and the uterus becomes perpendicular to the brim b. The head is grasped by the left head and pushed steadily in the pelvis c. The fingers of the rt hand is in front of the symphesis pubis to determine whether the head is engaged or not and degree overlap of the head on the symphsis pubis 2- Pinard's –Muller – Kerr's bimanual maneuver: a. The women on her back with the head and shoulder slightly abducted b. The left hand described in pinard's maneuver . the idea and middle fingers of the rt hand inside the vagina to note the degree of descent of the fetal head in relation to the ischial spine and the angle between the head and posterior surface of the symphesis pubis c. If the head is not engaged the throuth of the rt hand is placed on the sympysis pubis to note any overlap of the head over it d. Gentle fundle pressure by an assistant may be helpful e. If no CPD exists the head readily enters the pelvis and vaginal delivery can be predicted f. Inability to push the head into the pelvis doesn’t necessarily indicate that vaginal delivery is impossible g. if the head flexed head overrides the symphysis pubis this will be a presumptive widen of disproportion Degrees of CP and CPD CP CPD Minor degree Minor AP diameter 9-10cm No actual CPD because uterine contractions and pelvic reserve compensate this minor degree of contraction and vaginal delivery is the rule if no associated complication The a anterior surface of the head is in line with the posterior surface of the symphysis pubis flushing of the head with the S-pubis) with contraction during labour the head is engaged Moderate degree 1st degree CPD (moderate disproportion) - AP diameter 8-9cm - Resulting I CPD - Great majority of cases of CP - Difficult to predict its outcome so managed by trial labour and CS if failed - The anterior surface of the head is in line with the anterior surface of the symp pubis (overriding of the head with symphsysis pubis) - During labour sufficient moulding and uterine contraction may allow vaginal delivery (trial of labour if failed CS) Major degree 2nd degree CPD (severe disproportion) - AP diameter 6-8cm - Results in 2nd degree CPD - With living fetus CS is absolutely indicated - With dead fetus craniotomy can be tried if experienced obstetrician is available Extreme degree - AP diameter<6cm - Correspond also to 2nd degree CPD but CS is done even with dead fetus because the AP diameter is less than the smallest diameter of the head (Bimostoid which equal 7.5cm) so the problem cant's be solved by any destructive opeartiation (even the cronioclost and cephalo tribe) - The head is projecting beyond the anterior surface of the symphesis pubis (overriding head) - Vaginal delivery of living baby is impossible and CS is the rule - Corresponds to both major and extreme degree of CP but with dead fetus craniotomy is tried in major degree and CS is the only line in extreme degree Summary : - Mild (minor ) degree CPD corresponds to minor degree of CP : spontaneous vaginal delivery is the rule forceps may be needed for short ening of the 2nd stage of labour - Moderate degree (1st degree) CPD corresponds to moderate degree CP : trial labour if failed CS - Severe degree CPD (2nd degree) corresponds to major and extreme of CP : CS is the rule for living babies. For dead babies craniotomy is trial in major degree only if trained obstetrician is available and CS is done in extreme degree even with dead baby

Placenta Praevia

*Definition: In placenta previa, the placenta is located over or very near the internal os. *Four degrees have been recognized: 1. Total placenta previa: The internal cervical os is covered completely by placenta. 2. Partial placenta previa: The internal os is partially covered by placenta. 3. Marginal placenta previa: The edge of the placenta is at the margin of the internal os. 4. Low lying placenta: The placenta is implanted in the lower uterine segment such that the placental edge actuallly does not reach the internal os but is in close proximity to it. -In vasa previa, the fetal vessels course through membranes and present at the cervical os. This is an uncommon cause of antepartum hemorrhage and is associated with a high rate of fetal death. -The degree of placenta previa will depend on the cervical dilatation at the time of examination. *Frequency -The zygote that implants very low in the uterine cavity is likely to form a placenta that lies in very close proximity to the internal cervical os. -In most cases, it does not become symptomatic until the late 2nd or 3rd trimester -It is about 1 in 200 deliveries, or 0.5 % *Etiology 1-Multiparity and advancing age increase the risk of placenta previa, the incidence of previa in women over 35 is 1 in 100 and for those over 40 it was 1 in 50. Conversely, the incidence was 1 in 300 for women aged 20 to 29 2-Prior cesarean delivery or induced abortion increases the placenta previa, it is about 3.9 % in women who had previously cesarean delivery. It is 3- 5fold increase. -The incidence increased with the number of previous cesarean sections; it was 1.9 % with two prior cesarean and 4.1 % with three or more prior cesarean deliveries. 3-Defective decidual vascularization, a possible result of inflammatory or atrophic changes, has been implicated in the development of placenta previa. 4-The relative risk of placenta previa to be increased 2-fold related to smoking. The CO hypoxemia caused compensatory placental hypertrophy. 5-A large placenta, which spreads over a larger area of the uterus, as seen with erythroblastosis and with multiple fetuses, predisposes to previa. 6-It may be associated with placenta accreta or placenta increta or percreta. Such abnormally firm attachment of the placenta might be because of poorly developed decidua in the lower uterine segment. - 5 % of women with a placenta previa had a clinically significant placenta accreta. For women with a prior cesarean section, the incidence was almost 25 %. Clinical Findings -The most characteristic event is painless hemorrhage, which usually does not appear until near the end of the second trimester or after. -Some abortions, however, may result from such an abnormal location of the developing placenta. -Frequently, bleeding has onset without warning, presenting without pain. The initial bleeding is rarely profuse. Usually it ceases spontaneously, only to recur. -In some cases, particularly those with a placenta implanted near but not over the cervical os, bleeding does not appear until the onset of labor. -The cause of hemorrhage the placenta is located over the internal os, the formation of the lower uterine segment and the dilatation of the internal os result inevitably in tearing of placental attachments. The bleeding is increased by the inability of the myometrial fibers of the lower uterine segment to contract and constrict the torn vessels. -Coagulation Defects, coagulopathy is rare with placenta previa, even when extensive separation from the implantation site has occurred. Diagnosis 1-The diagnosis can seldom be established firmly by clinical examination unless a finger is passed through the cervix and the placenta is palpated. Such examination of the cervix is done in operating room .Today, a "double set up" examination is rarely necessary. 2-Sonography ,the simplest, most precise, and safest method of placental localization is provided by (1) Transabdominal sonography, the average accuracy is about 95 %, false positive results are often a result of bladder distention. Therefore, ultrasonic scans in apparently positive cases should be repeated after emptying the bladder. (2) The use of transvaginal ultrasonograpby improved diagnostic accuracy to visualize the internal os in all cases, in contrast to only 70 % using transabdominal equipment. 93 % positive predictive value and 98 % negative predictive value for TVS. (3) Transperineal sonograrphy allow visualization of the internal os in all cases examined. (4) Magnetic Resonance Imaging to visualize placental abnormalities including placenta previa It is unlikely that this will replace ultrasonic scanning routine evaluation in the near future. Placental "Migration" - Placentas that lie close to the internal cervical os, but not over it, during the second trimester, or even early in the third trimester; are very unlikely to persist as previa. 1-Low lying placenta not covering the internal os, previa did not persist and hemorrhage was not encountered. 2-Of those placenta covering the os at midpregnancy, about 40 % persisted as a previa. -The mechanism of placental movement is not completely understood. The term migration is clearly a misnomer -The apparent movement of the low lying placenta relative to the internal os probably results from inability to precisely define this relationship in a 3 -dimensional manner using 2 dimensional sonography in early pregnancy. This difficulty is coupled with differential growth of lower and upper myometrial segments. Management -Women with a placenta previa may be considered as follows: (1) Those in whom the fetus is preterm but there is no pressing need for delivery, (2) Those in whom the fetus is reasonably mature, (3) Those in labor, and (4) Those in whom hemorrhage is so severe as to mandate delivery despite fetal immaturity. (1) Management of the pregnancy complicated by placenta previa and a preterm fetus, but with no active bleeding, consists of hospitalization. The mother and her family must be prepared to transport her to the hospital immediately. Delivery - Cesarean section is the accepted method of delivery in all cases of placenta previa. In most cases a transverse uterine incision is made. Occasionally a vertical incision is recommended in some circumstances. -When placenta previa is complicated by degrees of placenta accreta, control bleeding from the placental bed by: 1 -Oversewing the implantation site with 0 chromic sutures. -Cho and colleagues (1991) described placing circular interrupted 0 chromic sutures around the lower segment, above and below the transverse incision. -Druzin (1989) described four cases in which the lower uterine segment was tightly packed with gauze that successfully arrested hemorrhage. The pack was removed transvaginally 12 hours later. 2 -In some cases, bilateral uterine artery ligation is helpful, 3 -In others, internal iliac artery ligation. 4- If these methods fail, hysterectomy is necessary. Prognosis -In 1927 Bill advocated adequate transfusion and cesarean section, this results in a marked reduction in maternal mortality from placenta previa -In1945, Macafee and Johnson independently suggested expectant therapy for patients remote from term, -Preterm delivery is a major cause of perinatal death. -The fetal growth retardation is increased with placenta previa.

Physiology of Reproduction

1-Hypothalamus -It lies at the base of the brain just above the junction of optic nerves -It contains many nuclei including (Supraoptic, paraventricular & arcuate nuclei) -It secrets both releasing & inhibiting hormones *Hypothalamic releasing factors 1-Gonadotrophin releasing hormone (LHRH or Gn RH), it consists of 10 amino acids 2-Thyrotophin releasing hormone (TRH), it consists of 3 amino acids 3-Corticotrophin releasing hormone (CRH), it consists of 41 amino acids 4-Growth hormone releasing hormone, it consists of 40 amino acids *Hypothalamic inhibiting factors 1-Growth hormone inhibiting hormone, it consists of 14 amino acids 2-Prolactin inhibiting factor (Dopamine) Functions of the hypothalamus 1-Regulation of the primitive functions needed for survival as (Appetite control, temperature control, salt & water retention, metabolism & growth) 2-Control of reproduction, it acts as a transducer to convert neuronal pulses into release of GnRH Gonadotrophin releasing hormone -It is a decapeptide (10 amino acids) -Secreted by the preoptic & arcuate nuclei in pulses every 60-90 minutes -Passes in the hypophyseal portal circulation to reach the anterior pituitary ----- secretion of FSH & LH -Half life ---- 2-4 minutes -Decreased GnRH pulse frequency is associated with oligomenorrhea or amenorrhea -Increased GnRH pulse frequency is associated with PCOD Control of GnRH Pulses 1-Dopamine ---- decrease the pulse frequency 2-Endogenous opioid ---- inhibit the pulse frequency 3-Neuropeptide Y ----- stimulate the pulse frequency 4-Noreoinephrine ------ stimulate the pulse frequency II-Pitutary gland -It consists of anterior lobe (adenohypophysis) & the posterior lobe (neurohypothesis) -The adult pituitary measure 13 x 10 x 6 mm & weighs 0.5 gm -The anterior pituitary secretes: gonadotronhins (FSH & LH), & prolactin 1-Follicle stimulating hormone (FSH) -It is a water soluble glycoproteins, consists of α-subunit (92 amino acids) & β- subunit (118 amino acids) -Secreted by the basophilic cells -Begins to be secreted at the end of the previous cycle, reaching a peak at day 3 o the new cycle, then the level falls & again it rises to reach a second peak at the 13th day just before ovulation -Half life --- 3-4 hours -Actions of FSH 1-Stimulate growth, ripening & maturation of the ovarian follicles 2-Stimulate aromatase activity in the granulosa cells 3-In combination with LH, it results in ovulation 4-Stimulate the formation of LH receptors 2-Luteinizing hormone (LH) -It is a water soluble glycoprotein, consists of α- subunit (92 amino acids) & β- subunit (121 amino acids) -Secreted by the basophilic cells -LH level: It is fairly constant throughout the cycle & reaches a peak about the 13th day -Half life --- 20 minutes Actions of LH -In combination with FSH it promotes ripening of the follicles -The LH surge ----- rupture of the mature follicle & ovulation -Stimulate corpus luteum to secrete estrogen & progesterone 3-Prolactin -Polypeptide hormone (191 amino acids) -Secreted by the lactotrophs (acidophilic cells) -It is the only anterior anterior pitutary hormone controlled by hypothalamic inhibiting factor (Dopamine) Actions of prolactin 1-Lactation 2-High levels inhibit estrogen secretion by the ovary 3-Essential for corpus luteum function 4-Control of ovulation by preventing further ovulation after fertilization Hypothalamic-Pituitary-Ovarian Axis -Hypothalamus releases GnRH to & passes via the hypophyseal portal circulation & act on gonadotrophin receptors in the anterior pituitary cells resulting in cyclic release of FSH & LH -Secretions of the hypothalamic GnRH is influenced by negative feed- back effect of estrogen & progesterone -FSH stimulate the growth of primary follicles & only one predominate to form mature follicle & secrete increasing amounts of estrogen ----- estrogen peak----- stimulate the anterior pituitary to secrete LH (positive feed back) -LH surge will lead to ovulation & formation of corpus luteum that secretes estrogen & progesterone -This high estrogen level will lead to suppression of Gn.RH (negative feed back) ----- low LH levels & degeneration of corpus luteum resulting in menstruation Types of feed back mechanisms 1-Long loop feed back (may be positive or negative) -The effect of the target organ hormones (estrogens & progesterone) on the hypothalamus & pituitary 2-Short loop feed back -The pituitary trophic hormones ---- suppression of the hypothalamic releasing factors 3-Ultra short loop feed back -Autocrine & paracrine effects of GnRH on the gonadotropin secreting cells in the hypothalamic nuclei Ovaries The ovaries has two functions: 1-Production of ova (ovarian cycle) 2-Endocrine function ----- production of estrogens & progesterone -The length of the ovarian cycle range from 21-35 days -The ovarian cycle is composed of (follicular & luteal) separated by ovulation 1- Follicular phase -The phase of ripening of the ovum -Begins on the first day of menstruation & occupies the first 14 days -Under the effect of FSH, 50 or more follicles start to ripen, one of these ova outstrips the rest and matures, dominant follicle), while the others undergo atresia -During the process of ripening, the mature Graffian follicle makes its way towards the ovarian surface to bring the discus proligerus with the ovum under the peritoneum The mature Graffian follicle -Size ---- 12-24 mm -Structure ---- composed of: 1-Ovum 2-Perivitelline space surrounds the ovum 3-Zona pellucida surrounds the perivitelline space. 4-Corona radiata: granulosa cells arranged in rows surrounding the ovum and attached to the zona by fine cytoplasmic processes 5-Cumulus oophorus (discus proligerus): Group of granulosa cells that attach the corona radiata to the wall of the follicle 6-Granulosa cells that lines the inner wall of the follicle & surround the follicular space that is filled with liquor folliculi 7-Theca interna cells spindle shaped cells 8-Theca externa cells --- Stroma cells that are compressed & modified to from a false capsule Ovulation Definition ----- rupture of the mature Graffian follicle with escape of the ovum surrounded by corona radiata through a stigma in the follicular wall into the peritoneal cavity & is picked up by the fimbrae of the fallopian tube Mechanism of ovulation *Central mechanism due to LH surge *Peripheral mechanisms 1-Thinning & degeneration of the cyst wall due to the action of proteases 2-Contraction of micromuscle cells in the theca externa & the stroma (due to PG in the follicular fluid) 3-Increased intrafollicular tension due to increase in the fluid content 2- Luteal phase -The phase of formation, function & early degeneration of the corpus luteum -Duration of the luteal phase is more constant than the follicular phase -Duration is said to be 14 + 2 day *Stages of corpus luteum formation 1- Stage of Proliferation 2-Vascularization: new blood vessels invade the follicle through the site of rupture 3-Maturity: the corpus luteum is functioning with maximum activity after 5 days for 3-4 days 4-Degeneration: occur 4-6 days before the next menstrual period ---- corpus albicans & results in low estrogen and progesterone levels & menstruation Corpus luteum of pregnancy The troplablast secrete human chorionic gonadotrophins within 7 days that prevents degeneration of corpus luteum & continues to produce estrogen & progesterone ---- suppression of anterior pituitary gland & the ovarian cycle Corpus fibrosum or atreticum The primary oocytes that do not mature will disappear at menopause or soon after 1-If the oocyte is blighted at an early stage the primordial follicle is obliterated & replaced by connective tissue 2-If there is some ripening -The oocyte will disintegrate by pyknosis & chromatolysis -A small cyst is formed lined with granulosa cells surrounded by theca lutein cells Causes of follicular atresia 1-Secretion of inhibitory peptide that impairs the binding of LH receptors 2-Inhibition of FSH by negative feed back from: (Estrogen & inhibin hormone) Ovarian Hormones I- Estrogens Sources --- produced by: 1-Ovary from (Graffian follicle & Corpus luteum) 2-Adrenal cortex (small amounts) 3-Placenta Metabolism: in the liver by conjugation with glucouronide or sulphate group, excreted in feces & urine Synthesis of estrogen (Two cell theory) 1-LH acts on the theca cells to produce androgens (androstendione & testosterone ) 2-Androgens diffuses from the theca cells to the granulosa cells 3-FSH stimulates aromatase enzyme to estrogens (estradiol E2 & estriol E3) Levels (2 peaks) -First peak before ovulation (about 300 pg/ml), then it falls -Second peak in the midluteal phase (about 200 pg/ml). then decrease when corpus luteum degenerates Biological actions of estrogen 1-General effects -Appearance of secondary sex characters at puberty -On the breast: it increase the duct system & vascularity -On bones stimulates osteoblastic activity & union of epiphysis -Salt & water retention 2-Central effects (On hypothalamus & pituitary), large dose inhibits FSH release 3-Actions on the genital tract @-On the uterus -Increased vascularity -Endometrium undergo proliferation & hyperplasia -Myometrium undergo hypertrophy & increased sensitivity to oxytocin @-On the cervix -Increase the volume of cervical mucus (water & salt content) -Positive spinabarkeit -Positive Fern test @-On the vagina -Epithelial lining: proliferation & increased glycogen deposition -Increased vaginal acidity due to conversion of glycogen into lactic acid 2-Progesterone Sources 1-Ovary ( corpus luteum), 2-Placenta Metabolism in the liver & 20% is excreted in urine as pregnanediol Levels -Progesterone level starts to rise just before ovulation -Reaches a peak in the mid luteal phase (15 ng/ml) & then drops gradually before menstruation Biological effects of progesterone 1- General actions 1-Increases the basal body temperature (thermogenic) 2-Salt & water retention 3-Relaxes smooth muscles 4-On the breast: development of alveolar system 2- Central action -Large doses inhibit LH secretion 3-On the genital tract *On the uterus 1- Endometrium: induces secretory changes in an estrogen primed endometrium 2-Myometrium -- uterine contractions become frequent but of high amplitude 3-Isthmus ----- Constriction *On the Cervix -The mucus becomes more viscid with negative sptinnbarkeit & negative fern test Menstrual Cycle 1-Menstrual phase Duration ----- 3-7 days -Scattered small areas of the endometrium are necrosed & are shed off at alternative times. then the whole endometrium is cast off except the deep compact layer -At the end of menstruation, the basal part of the glands start to grow and form new glands 2-Resting phase -Duration: 1-2 days following menstruation -Thickness of endometrium: 1-2 mm -Glands: simple tubular scattered widely in the stroma -Epithelium: cubical ciliated epithelium which dips down to from glands. -Stroma: small spindle shaped connective times cells with little cytoplasm 3-Proliferative phase -Duration: 9-10 days -Glands: tubular, increase in length & dilatation more numerous -Epithelium: more columnar with central nuclei. -Stroma cells are more globular & increase in size & vascularity 4-Secretory phase (Under the effects of progesterone & estrogens) -Duration: 12-14 day (from ovulation till menstruation) -Thickness: 5-7 mm -Glands: more tortous corkscrew, distended with secretions -Stroma: shows dense leucocytic infiltration 2-3 day before menstruation. The stroma cells become more polygonal & increase in size -Differentiated into 3 layers: (superficial compact zone, Middle spongy layer & Deep compact layer)

Role of Caudal, Pudendal and Paracervical blocks : DR. Alaa Mosbah M.D OBS&GYN ,Egypt ,Mansoura

CAUDAL BLOCK Caudal epidurals in labour have become less popular because better perineal analgesia can be achieved by the use of epidural infusions and primigravidae are more likely to receive an epidural block. Also, there have been recent concerns about the risks of inadvertent intravenous and fetal injection. A modified caudal epidural technique can provide rapid onset perineal anaesthesia without cardiovascular disturbance and with relatively little loss of expulsive power. If used for perineal anaesthesia only, caudal block is a useful, safe technique for experienced anaesthetists provided that the volume of local anaesthetic is limited to a maximum of 10 mls, injected slowly (with multiple aspirations). It should be noted that this dose is less than half that which is required to achieve full labour analgesia. The block should be inserted before the head is on the perineum . Since it has been shown that pencil point spinal needles have a low incidence of headache (0 to 0.66% with 27G and 25G Whitacre needles) spinal anaesthesia is often more appropriate than lumbar or caudal epidural anaesthesia for rotational forceps, manual removal of placenta and, at times, low forceps delivery. INDICATIONS1. Unrelieved perineal pain.2. Premature urge to push.3. Low forceps delivery.4. When lumbar epidural analgesia is contraindicated. INCIDENCEIn most Australian hospitals, caudal blocks are being used less frequently in labour as the number of spinals has increased. The major indications for caudals are perineal pain, labour pain, forceps delivery, and manual removal of placenta. Less commonly, caudals can provide anaesthesia for artificial rupture of the membranes, suturing of episiotomies and repair of vaginal lacerations. CAUDAL ANALGESIA IN COMBINATION WITH OTHER MAJOR REGIONAL BLOCKS At the Royal Women's Hospital, of those women who had a caudal, at least 62% also had a lumbar epidural. The lumbar epidural was either already in situ or was inserted at the same time as the caudal. It has been shown that for the lumbar epidural route, increasing the volume of anaesthetic is more likely to secure good sacral blockade than injection in the sitting position. However, in our experience sacral blockade can occasionally only be achieved with a caudal or spinal block. COMPLICATIONSl. Vascular tap and intravascular injection of local anaesthetic .2. Failed block (8%) - the sacral hiatus is absent in 5% of adults. 3. Subarachnoid injection - the dural sac reaches S2 .4. Infection.5. Fetal injection . Modified caudal block is a safe technique with a limited specific place in modern obstetric anaesthesia. PARACERVICAL BLOCK The risk of complications, particularly fetal bradycardia, generally make this technique an unsuitable form of anaesthesia for obstetric patients. However, if used, it should be avoided in the presence of fetal distress or uteroplacental insufficiency and the fetal heart rate should be monitored continuously during and after insertion of the paracervical block . COMPLICATIONS1. Vaginal trauma.2. Systemic local anaesthetic toxicity due to excessive dosage or intravenous injection .3. Parametrial haematoma.4. Sacral plexus trauma.5. Infection and deep abscess formation.6. Fetal scalp injection of local anaesthetic.7. Fetal bradycardia probably caused by decreased uteroplacental perfusion.8. Needle stick injury. PUDENDAL NERVE BLOCK Pudendal nerve block provides anaesthesia for spontaneous vaginal delivery or low forceps delivery. The pudendal nerve (S2 - S4) is the major sensory innervation of the lower vagina, vulva and perineum and provides motor fibres to the external anal sphincter and the perineal muscles. Pudendal nerve block was first reported for vaginal delivery in 1916 . It is inadequate for rotational forceps delivery and manual removal of the placenta. Either a transvaginal or transperineal approach can be used. The bilateral success rate has been reported as 50% after the transvaginal approach and 25% after the transperineal approach. INDICATIONS.1. Low forceps delivery.2. Vaginal and perineal pain when lumbar or caudal epidural or spinal analgesia is unavailable, contraindicated or declined. COMPLICATIONS 1. Vaginal trauma.2. Systemic local anaesthetic toxicity due to excessive dosage or intravenous injection.3. Vaginal or ischio-rectal haematoma. 4. Infection and deep abscess formation.5. Fetal trauma or direct local anaesthetic injection.6. Needle stick injury. Caudal Analgesia Although the caudal route was the first widely used approach to the epidural space for continuous block in labour (Hingson and Edwards, 1942), and remained in frequent use in a few centres until the late 1970's (McCaul), its present role is very limited. Apart from providing good analgesia for low instrumental deliveries and perineal repair, the use of caudal block is usually restricted to a very few enthusiasts and to those cases in which a lumbar epidural is anatomically impossible or contraindicated by local infection . (However, local sepsis may also preclude the use of caudal block) . The patient should be prepared according to the guidelines shown in . Following the provision of secure venous access and preloading with crystalloid, the patient is either turned into the left lateral position with both knees flexed and forward tilt of the upper hip, or (occasionally) the knee-elbow position according to patient or operator preference. The skin of the lumbosacral area is prepared with a bactericidal solution and sterile drapes are applied. A bleb of local anaesthetic is raised in the skin overlying the sacral hiatus, between the sacral cornua, at a site deep to the proximal extremity of the natal cleft. A 21- gauge needle may then used to infiltrate the deeper tissues, but this is not essential. A variety of needles and cannulae may be used for the block itself, including a:1. 7.6 cm 19-gauge caudal needle,2. disposable 3.8 cm 19-23g hypodermic needle,3. 20-24-g intravenous catheter for a "single-shot" technique, or4. Tuohy needle (17 or 18g) and catheter for a continuous technique. Whichever needle is used, it is gently inserted at an angle of 70-80degrees to the skin and slowly advanced until the bony resistance of the sacrum is detected . The needle is withdrawn slightly, the entry angle reduced by about half, and then reinserted until the resistance of the sacrococcygeal ligament is felt at a depth of 1.5-3.8 cm. The ligament is then penetrated and the needle or catheter inserted to a depth of 2-3 cm, bearing in mind that the dural sac terminates at the S2 level, and that dural puncture should be avoided . Test aspiration for blood or CSF is performed. If the test is negative, this is followed by the injection of a 3ml test dose of local anaesthetic, with a hand positioned over the sacrum to detect any tissue swelling, resulting from malposition of the needle or catheter either subperiosteally or along the dorsal surface of the sacrum. Following a negative test dose and in the absence of pain on injection, the definitive dose may be injected slowly in small, repeated increments . If CSF is aspirated or if blood continues to be aspirated after repositioning of the needle or catheter the block should be abandoned. Single-shot needles or cannulae are withdrawn following injection. Catheters are affixed to their connectors and filters and strapped in position. Lignocaine is preferred to bupivacaine in view of the potential for large doses of bupivacaine to produce cardiovascular collapse and intractable ventricular dysrhythmias . should intravascular injection occur into one of the abundant epidural veins . The dose and concentration of lignocaine depends on the indication for the block. A recommended dose for outlet forceps delivery would be 15 to 20mls of 1.5% lignocaine with adrenaline. For perineal analgesia, a dose of 10 to 15mls of 1.0% lignocaine with adrenaline would suffice . Pudendal Nerve Block During the second stage of labour, pain largely results from distension of the lower vagina, vulva and perineum. In addition, the musculature of the anterior compartment of the pelvis must be negotiated by the descending presenting part. These structures obtain most of their sensory and motor innervation from the second to fourth sacral nerve roots via the pudendal nerve. Pudendal nerve blocks are of value in providing analgesia for the second stage when contraindications to neuraxial blockade exist and for the provision of pelvic floor relaxation when forceps delivery is required. They may also be used to provide anaesthesia of the perineum in order to create or repair an episiotomy. Pudendal nerve blocks have been utilized in the past as an alternative to epidurals in assisted twin and breech deliveries . Increasing evidence supporting the safety of epidurals in these situations has contributed to a diminished use of pudendal nerve blocks . The anatomy of the pudendal nerve should be considered when performing the block. The block is performed with the patient in the lithotomy position. Two approaches have been described: transvaginal and transcutaneous or perineal. The basis of both approaches is to block the nerve before it gives off its terminal branches. Its most reliable landmarks are exploited - the ischial spine in the transvaginal, and the ischial tuberosity, in the perineal approach. Transvaginal approach:In the transvaginal approach, the ischial spine can be palpated either transvaginally or per rectum. It is important to use a needle with a guide in order to limit the depth of submucosal penetration ("Huber" security point ). When a left sided block is performed, the ischial spine is palpated with the index finger of the left hand, the syringe is held in the right hand and the needle is guided between the index and middle fingers of the left hand towards the ischial spine. The sacrospinous ligament lies 1 cm medial and posterior to the spine. The needle is passed through the ligament for a distance of 1 cm until a loss of resistance is appreciated. The tip now lies in the area of the pudendal nerve. The pudendal vessels are closely associated. After aspiration, 10 mls of local anaesthetic solution are injected. The block is repeated on the other side. Perineal approach:The perineal approach is considered valuable when the engaged head makes vaginal palpation difficult. The ischial tuberosity is located by palpation . The needle is introduced slightly medial to this point, for a distance of 2.5 cm. The nerve is usually encountered without eliciting paraesthesia. Up to 8 mls of solution is infiltrated at this point. The needle is then withdrawn and directed into the deep and superficial tissue of the vulva along its anterior margin in order to block the the ilioinguinal and genitofemoral component . The block is repeated on the other side. The limitations of this block include:- Failure to provide adequate analgesia. It has been reported that up to half of all bilateral pudendal blocks are ineffective on one or both sides . A pudendal nerve block will not abolish sensation to the anterior part of the perineum because this region is supplied by branches of the ilioinguinal and genitofemoral nerves. Subcutaneous infiltration anteriorly along the vulva is therefore described as a component of this technique. Failure to wait sufficient time is a commonly cited reason for failure of a pudendal block. Pudendal nerve blocks do not abolish the pain of uterine contraction and cervical dilation which is transmitted via sympathetic nerve fibres derived from spinal levels T10 - L2 . It does not cause relaxation of the uterus. - Intravascular injection with subsequent local anaesthetic toxicity is a risk imposed by the close proximity of the pudendal vessels . - Fetal complications are uncommon. Exposure of the fetus to a high plasma level of local anaesthetic is a possibility that should be considered. Delivery usually occurs within a short period of time which may not allow for clearance of local anaesthetic from fetus via the placenta. 1% lignocaine is the most commonly used agent. Peak concentrations occur within 10 - 20 minutes. The maternal plasma concentrations which occur after this block are much lower than after either epidural or paracervical blocks. This block has been reported to prolong the second stage of labour as a result of loss of the bearing-down reflex. The addition of adrenaline may further prolong the second stage of labour . Paracervical Block Paracervical blockade may be used as a means of reducing pain during the first stage of labour. Pain associated with uterine contraction and cervical stretching and dilatation is transmitted from these structures on visceral afferents which accompany sympathetic fibres. These pass sequentially through the uterine, cervical, inferior hypogastric and superior hypogastric plexuses to the lumbar and lower thoracic sympathetic chains. During early labour, the bulk of these enter the spinal cord at the T11 - T12 segments. As pain becomes more severe, the two adjacent segments, T10 and L1 become involved . The block is performed bilaterally with the patient in the lithotomy position. The proximity of the broad ligaments just deep to the lateral fornices of the vagina is exploited with the aim of interrupting pain transmission at the level of the uterine and pelvic plexuses . An 18.5 cm needle with a security tip (Iowa trumpet, Kobak) is used to limit the injection to within 1.5 - 2 cm of the epithelium. The needle is connected to a 20 ml Luer-Lok syringe. Measures to avoid intravascular injection are vital. After careful aspiration non-adrenaline containing local anaesthetic solution is infiltrated. The specific injection sites have been variously described: 3 and 9 oclock; 4 and 8 oclock; or alternatively all sites . The distribution of radio-opaque dyes observed in X-ray studies is similar . An interval of 15 minutes should be observed between injections during which time signs of maternal and fetal toxicity should be excluded. Paracervical blockade can be used to provide analgesia during the first stage of labour when contraindications of epidural analgesia are present. The optimal time for institution of this block is the accelerated phase of the first stage when the severity of pain increases. The presenting part is typically engaged. The cervix is thin and effaced and has a tendency to be drawn up during uterine contractions . Paracervical blockade does not provide analgesia of the perineum during the second stage during which pain is transmitted primarily via the pudendal nerves to the S2 - 4 spinal cord segments . The technique has several limitations. The failure rate is reported to be as high as 18% . The proximity of uterine blood vessels in the vaginal fornices creates maternal and fetal risks. Fetal bradycardia occurs in 10-50% of cases . This is attributed to asphyxia which is believed to result from transient uterine artery vasospasm due to high concentrations of local anaesthetic in the paracervical region. The technique has a duration of action limited to 90 minutes with plain lignocaine. The use of adrenaline or bupivacaine in an attempt to increase the duration of the block should be avoided as both increase the incidence of fetal bradycardia . Preparation and Monitoring for Regional Blockade Adequate preparation of the obstetric patient is vital in order to minimise the complications of regional anaesthesia. This will be achieved by obtaining a history, performing a physical examination, and, if indicated, performing preliminary investigations. Of particular relevance in the history is the presence of cardiac disease, pre-eclampsia, coagulopathy, or any maternal condition which may present a relative contraindication to neuraxial blockade. The presence of any of these conditions may preclude the selection of the spinal and/or epidural route for analgesia or anaesthesia. Informed consent must be obtained. Fasting and acid-aspiration prophylaxis should be observed in patients undergoing caesarean section. The presence of a skilled assistant is essential. During the performance of the block and subsequently, careful attention to positioning will increase the likelihood of a succesful block. Large bore intravenous access and adequate prehydration will be required to minimise hypotension. Either reusable or disposable Tuohy needles and syringes may be used. Tuohy needles feature blunt cutting tips whose ends are curved. This assists in identification of the epidural space without dural puncture. The commonly used sizes for obstetric analgesia are 16g and 18g. These needles accept 18 and 20 gauge catheters respectively. Epidural catheters are typically made from PVC. The tip features either three helically-arranged lateral injection holes, or a single end hole . Three holed designs have been criticised for their potential to result in a malpositioned catheter such that individual holes may lie between different meningeal layers or in an epidural vein. This can result in a multi-compartment block or inadvertent intravascular injection of local anaesthetic . Single ended catheters have a higher incidence of false negative aspiration for blood and missed segments. Appropriate monitoring should be instituted. This should include monitoring of:1. The maternal circulation (pulse rate and blood pressure).Hypotension may complicate neuraxial blockade despite careful attention to prehydration and avoidance of aortocaval compression. A baseline pulse rate and blood pressure must be obtained before initiating the block. Blood pressure should be measured at intervals of not more than 5 minutes during establishment of the block and thereafter hourly whilst the block is being maintained. During caesarean section the blood pressure should be measured at 5 minute intervals. A qualified person should be responsible for hemodynamic monitoring. Appropriate management of hypotension should be instituted early. 2. The level of the block.The level of the block should be monitored 3. The fetus. Methods of monitoring fetal wellbeing include:a. Auscultation of heart rate with pinnards or doppler.b. Graphical display of the cardiotocograph .c. The use of scalp electrodes.d. Measurement of fetal scalp pH. The fetus should be monitored whenever an epidural is being utilised. In uncomplicated labours this is usually accomplished with a cardiotocograph. Scalp electrodes are used when the cardiotocograph fails to generate a reliable trace or when fetal distress is present. This requires a sufficiently dilated cervix. Scalp pH is used to gain more information on fetal wellbeing when other signs of fetal distress are present. 4. Bladder function.Painless bladder distension as the result of neural blockade may contribute to postpartum stress incontinence. This has been observed to occur in association with concentrations of bupivacaine of 0.5% .The bladder should be emptied intermittently. Prevention of local anaesthetic toxicity How do we Prevent the Development of Local Anaesthetic Toxicity? The use of local anesthetics (LA) may be accompanied by systemic and Iocalised adverse reactions, usually secondary to:1. accidental intravascular injection,2. inadvertent intrathecal injection, or3. administration of an excessive dose. Intravenous injection of 20-25 mg of bupivacaine has been reported to induce fatal cardiovascular collapse . Factors which can diminish the incidence of toxic reactions are:1. fractionation of the injected dose, 2. aspiration before injection, 3. selection of less toxic LAs . 4. reduction in the concentration of LA, and 5. test-dosing before injection of the main dose. The diagnosis of inadvertent intravascular placement of an epidural needle or catheter can be made by using either air or a sympathomimetic amine as the 'marker' agent. Unintended intrathecal placement can be diagnosed by the injection of an appropriately small dose of a rapid onset LA. Injection of 1 ml of air into an epidural catheter can be a highly specific and sensitive marker of intravascular catheter Iocalisation, but the safety of the doppler test has yet to be proven and, moreover, a precordial doppler and an extra person have to be available . Epinephrine, the catecholamine currently used in most test-doses, has several disadvantages. This mixed alpha- and beta-adrenergic agent does not consistently produce maternal tachycardia in laboring women. Cyclic maternal heart rate changes, due to painful uterine contractions, occur normally in unanesthetised parturients. The effect of epinephrine superimposed on these physiological changes in heart rate is not always discernible. Moreover, a major adverse effect of systemic epinephrine is its inhibition of uterine blood flow (UBF). This reduction of UBF has been demonstrated in gravid ewes and lasts for 2-5 minutes . Although the chronotropic response in term pregnant women is reduced, a test dose containing 5 mcg of isoproterenol (isoprenaline) might be a safer and more effective alternative .Isoproterenol produces a superior increase in maternal heart rate with minor effects on uterine blood flow in the chronic maternal fetal sheep preparation . In this animal model, incorporation of isoproterenol as a test dose does not produce neurotoxicty . These results suggest that isoproterenol may be safe for use as an epidural test dose in pregnant women. Some contradictory results exist concerning the increased sensitivity, during pregnancy, to the toxicity of local anesthetics. Santos et al. compared the systemic toxicity of ropivacaine and bupivacaine in non-pregnant and pregnant ewes and concluded that..."The systemic toxicity of ropivacaine or bupivacaine is not enhanced by gestation in sheep. This is in contrast to an earlier study in which cardiotoxicity of bupivacaine was enhanced during ovine pregnancy." A major concern in pregnancy is the trans-placental distribution of local anesthetics . Differences in the cord-to-maternal plasma drug concentration ratio essentially reflect trans-placental differences in the extent of plasma binding . When this ratio is high there should be a delay in the equilibration of drug in fetal tissues. Conversely, similar umbilical artery and umbilical vein concentration ratios observed for the various agents argue against large differences in their equilibration rates in the fetus. Thus, the impact, if any, of plasma binding on the risks of fetal toxicity is unclear . The prevention of toxicity of local anesthetics in the mother and the fetus is of utmost importance but, in this field, many questions remain to be answered. Regional techniques compared The use of subarachnoid local anaesthetic agents and narcotics for labour and delivery varies between institutions and individual anaesthetists. While practices may vary, the role of subarachnoid anaesthesia in comparison with other regional techniques can be defined in terms of the relative advantages and disadvantages of this method of anaesthesia. Efficacy and application of blockade:Local anaesthetics may be used intrathecally to accomplish sacral anaesthesia for instrumental vaginal deliveries and for other obstetric procedures. Subarachnoid blockade to a level above T7 may also be employed for cesarean section. Under these circumstances, subarachnoid blockade provides reliable, dense surgical anaesthesia. Epidural anaesthesia is also suitable for both labour and delivery but, sometimes, sacral segments may be difficult to block (with a lumbar epidural) and the blocks may occasionally be patchy or asymmetrical . In comparison to subarachnoid blockade, caudal blockade is only suitable for sacral anaesthesia . Opiates may also be administered by the subarachnoid route and provide good analgesia for labour but not for delivery . Furthermore, intrathecal opiates provide superior analgesia when compared to opiates administered via the epidural route . Side effects such as pruritus may be higher in patients receiving intrathecal opiates. Speed of onset:When compared to epidural or caudal anaesthesia, subarachnoid anaesthesia offers a rapid onset of action which is often of benefit to the patient, anaesthetist and surgeon. Unfortunately, an increased speed of onset of anaesthesia is only purchased at the price of a greater degree of hypotension . Postdural puncture headache:Postdural puncture headache may occur in up to 20% of patients when a 25-gauge spinal needle is used . This miserable complication occurs more frequently in young females and is responsible for the reluctance of many anaesthetists to use this technique in the parturient. Except in cases of inadvertent dural puncture with the needle, this problem is not seen with epidural or caudal anaesthesia. The use of 26-gauge spinal needles has been shown to lower the incidence of postdural puncture headache . The use of 29-gauge needles has been associated with little risk of postdural puncture headache, even in young patients . The low incidence of headache with these small needles increases the acceptability of subarachnoid blockade in obstetric anaesthesia . Titratable level of blockade and continuous infusions:The use of epidural catheters to provide a means by which the level of anaesthesia can titrated, topped up, or continuously infused for labour and delivery has been well established. The routine use of subarachnoid catheters for uncomplicated vaginal delivery has not gained wide acceptance in obstetric anaesthesia for several reasons. It has been stated that the large bore needles usually employed to introduce catheters would be associated with a high incidence of postdural puncture headache but this does not appear to occur in clinical practice . These catheters may increase the risk of infection, although again, there is very little supporting evidence for this concern. In an attempt to address these issues, microcatheters (32-gauge) which can be passed through a standard 25 or 26-gauge spinal needle have been used. Continuous spinal anaesthesia is obtained with negligible risk of local anaesthetic toxicity to the mother and fetus. Significant problems have been reported with these microcatheters and include cauda equina syndrome, kinking, difficulty in threading and catheter fracture. The more recent use of combined spinal epidural techniques allows for continuous and titratable anaesthesia with the advantage of a rapid and dense subarachnoid block. The potential disadvantages of an intrathecal catheter are avoided and, with a small spinal needle, the risk of postdural puncture is minimal . Overall, because of its advantages spinal anaesthesia (especially with the use of smaller spinal needles) continues to challenge the pre-eminent role of epidural anaesthesia in obstetrics. CHARACTERISTICS OF LOCAL ANESTHETIC TOXICITY (I) CNS toxicity:a) Excitation Phase: tinnitus, confusion, restlesness, perioral numbness or tingling, metallic taste, lightheadness, sense of dread and impending doom.b) Convulsive Phase: grand-mal clonic-tonic seizurec) Depression Phase: CNS depression with drowsiness and unconsciousness.d) Repiratory depression and apnea. (II) CVS Toxicity:a) Excitation Phase: - hypertension, tachycardia (with convulsions) b) Depression Phase:(i) Negative inotropic effect with decreased blood pressure, cardiac output and stroke volume.(ii) Peripheral vasodilation with further hypotension. c) Cardiovascular Collapse KEY FEATURES OF BUPIVACAINE TOXICITY (i) More likely to result in cardiovascular collapse (CV collapse dose / dose for convulsions = 3.7 for bupivacaine and 7.1 for lidocaine). (ii) Ventricular arrhythmias are more likely to accompany cardiac toxicity (use bretylium). (iii) Pregnant women are more sensitive to cardiac toxicity from bupivacaine. (iv) Resuscitation is usually legthy. (v) Toxicity is enhanced by acidosis and hypercarbia. PossibleEffects of Major Regional Blockade on Cardiotocographic Patterns. Uterine Contractions Mechanism Increased Frequency and intensity Analgesia decreases catechol amine leels Decreased Frequency and intensity Decreased blood supply to uterus. ?Inhibition of motor nerve supply to uterus?Direct effect of Local Anaesthetic on smooth muscle Fetal heart rate: beat to beat variability Increase Acute fetal hypoxia due to placental hypoperfusion Decrease Direct effect of local anaesthetic agents.Chronic hypoxia and acidosis from placental hypoperfusion Fetal heart rate:Long term deceleations Early Head compression from increased uterine tone. Late Placental insufficiency worsened by placental hypoperfusion Variable/td> Cord compression aggravated by maternal hypotension and increased intensityof uterine contractions. RECOMMENDED MAXIMUM DOSES OF LOCAL ANAESTHETICS -Illustrated in the case of a 60Kg woman Drug Dose Dose/Kg AMIDES Lidocaine with epi 420 (7mg/kg) Lidocaine plain 300 (5mg/kg) Bupivacaine with epi 180 (3mg/kg) Bupivacaine plain 120 (2mg/kg) Etidocaine 240 (4mg/kg) Mepivacaine 420 (7mg/kg) Prilocaine 720 (12mg/kg) ESTERS Cocaine 180 (3mg/kg) Procaine 840 (14mg/kg) Chloroprocaine 840 (14mg/kg) Tetracaine 180 (3mg/kg)