MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY ppt

423 CARDIOVASCULAR DISEASES CARDIAC ARREST Cardiac arrest is cessation of heart action. Ventricular standstill (asystole) and ventricular fibrillation are the immediate causes, but the underlying etiologies are most frequently acute myocardial hypoxia or alteration in conduction or both. In obstetrics and gynecology, cardiac arrest occurs during induction of anesthesia and during operative surgery or instrumented delivery. Cardiovascular disease increases the risk of cardiac arrest, and hypoxia and hyper- tension are contributory causes. Cardiac arrest may follow shock, hypoventilation, airway obstruction, excessive anesthesia, drug administration or drug sensitivity, vasovagal reflex activity, myocardial infarction, air and amniotic fluid embolism, and heart block. Cardiac arrest occurs in ϳ1:800 to 1:1000 operations and is apt to occur during minor surgical procedures as well as during major surgery. It occurs in ϳ1:10,000 obstetric deliveries, usually operative, complicated cases. Fortunately, it is possible to save at least 75% of patients when cardiac arrest occurs in the well-managed and well-equipped operating or delivery room. CARDIOPULMONARY RESUSCITATION (CPR) CPR is used for treatment of asphyxia or cardiac arrest (Fig. 15-1). Phase I: First Aid (Emergency Oxygenation of the Brain) Basic life support must be instituted within 3–4 min for optimal ef- fectiveness and to minimize permanent brain damage. Do not wait 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY CHAPTER Copyright 2001 The McGraw-Hill Companies. Click Here for Terms of Use. BENSON & PERNOLL’S 424 HANDBOOK OF OBSTETRICS AND GYNECOLOGY FIGURE 15-1. Technique of mouth-to-mouth insufflation. for confirmation of suspected cardiac arrest. Call for help, but do not stop preparations for immediate resuscitation. Step 1: Place patient supine on a firm surface (not a bed). Step 2: Determine whether the patient is breathing. If the patient is not breathing, take immediate steps to open the airway. In unconscious patients, the lax tongue may fall backward, blocking the airway. Tilt the head backward and maintain it in this hyperextended position. Keep the mandible displaced forward by pulling strongly at the angle of the jaw. If victim is not breathing continue with the following. Step 3: Clear mouth and pharynx of mucus, blood, vomitus, or for- eign material. Step 4: Separate lips and teeth to open oral airway. Step 5: If steps 2–4 fail to open airway, forcibly blow air through mouth (keeping nose closed) or nose (keeping mouth closed) and inflate the lungs 3–5 times. Watch for chest movement. If chest movement does not occur immediately and if pharyngeal or tracheal tubes are available, use them without delay. Tracheostomy may be necessary. Step 6: Feel the carotid artery for pulsations. a. If carotid pulsations are present Give lung inflation by mouth-to-mouth breathing (keeping patient’s nostrils closed) or mouth-to-nose breathing (keeping patient’s mouth closed) 12–15 times per min— allowing about 2 sec for inspiration and 3 sec for expi- ration—until spontaneous respirations return. Continue as long as the pulses remain palpable and previously di- lated pupils remain constricted. If pulsations cease, follow directions in step 6b. b. If carotid pulsations are absent Alternate cardiac compression (closed chest cardiac massage, Fig. 15-2) and pulmonary ventilation as in step 6a. Place the heel of one hand on the sternum just above the level of the xiphoid. With the heel of the other hand on top of it, apply firm vertical pressure sufficient to force the sternum about 4–5 cm (2 inches) downward (less in children) about 80–100 times/min. After 5 ster- nal compressions, alternate with 1 quick, deep lung inflation. Repeat and continue this alternating procedure until it is possible to obtain additional assistance and more definitive care. Resuscitation must be continuous. Open heart massage should be attempted only in a hospital. When possible, obtain an ECG, but do not inter- rupt resuscitation to do so. CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 425 BENSON & PERNOLL’S 426 HANDBOOK OF OBSTETRICS AND GYNECOLOGY Phase II: Restoration of Spontaneous Circulation Until spontaneous respiration and circulation are restored, there must be no interruption of artificial ventilation and cardiac massage while steps 7–13 are being carried out. The physician must make plans for the assistance of trained hospital personnel, cardiac monitoring and assisted ventilation equipment, a defibrillator, emergency drugs, and adequate laboratory facilities. Three basic ques- tions must now be considered. What is the underlying cause, and is it correctable? What is the nature of the cardiac arrest? What further measures will be necessary? Step 7: Provide for intubation, administration of 100% oxygen, and mechanically assisted ventilation. A cutdown for FIGURE 15-2. Technique of external cardiac massage. Heavy circle in heart drawing shows area of application of force. Circles on supine figure show points of application of electrodes for defibrillation. long-term IV therapy and monitoring should be esta- blished as soon as possible. Attach ECG leads and take the first of serial specimens for arterial blood gases and pH. Promote venous return and combat shock by elevat- ing legs, and give IV fluids as available and indicated. The use of firmly applied tourniquets or military anti- shock trousers (MAST suit) on the extremities may be of value to occlude arteries to reduce the size of the vascular bed. Step 8: If a spontaneous effective heartbeat is not restored after 1–2 min of cardiac compression, have an assistant give epinephrine, 0.5–1 mg (0.5–1 mL of 1:10,000 aqueous solution) IV every 5 min as indicated. Epinephrine may stim- ulate cardiac contractions and induce ventricular fibrillation that can then be treated by DC countershock (see step 11). Step 9: If the victim is pulseless for more than 10 min, give sodium bicarbonate solution, 1 mEq/kg IV, to combat im- pending metabolic acidosis. Repeat no more than one-half the initial dose every 10 min during cardiopulmonary resuscitation until spontaneous circulation is restored. Mon- itoring of arterial blood gases and pH is required during bicarbonate treatment to prevent alkalosis and severe hy- perosmolar states. Step 10: If asystole and electromechanical dissociation persist, continue artificial respiration and external cardiac compression, epinephrine, and sodium bicarbonate. Monitor blood pH, gases, and electrolytes. Step 11: If ECG demonstrates ventricular fibrillation, maintain cardiac massage until just before giving an external defib- rillating DC shock of 200–300 J for 0.25 sec, with one pad- dle electrode firmly applied to the skin over the apex of the heart and the other just to the right of the upper sternum. Monitor with ECG. If cardiac function is not restored, re- sume massage and repeat shock at intervals of 1–3 min. Step 12: Thoracotomy and open heart massage may be considered (but only in a hospital) if cardiac function fails to return after all of the above measures have been used. Step 13: If cardiac, pulmonary, and central nervous system func- tions are restored, the patient should be observed carefully for shock and complications of the precipitating cause. HEART DISEASE Congenital heart disease is the principal cardiovascular problem complicating pregnancy in the United States. Rheumatic heart CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 427 BENSON & PERNOLL’S 428 HANDBOOK OF OBSTETRICS AND GYNECOLOGY disease is less a problem today than 40 years ago because of better rheumatic fever prophylaxis, improved health care, and advances in cardiovascular surgery. Syphilitic carditis has all but disappeared in pregnancy. Women with collagen disorders (e.g., Marfan’s syn- drome) or those with prosthetic heart valves are prone to cardiac problems during pregnancy. Reported incidences of heart disease vary from 0.5% to 2% of obstetric patients but probably are lower in the general population because only referral centers are likely to report their experience. Manifestations of coronary heart disease are rare during pregnancy. Similarly, pericardial disorders are very in- frequently seen. Hypertrophic obstructive or nonobstructive cardiomyopathy in pregnancy is rarely complicated by pregnancy and delivery. Heart disease is a major cause of maternal death, but maternal and perinatal mortality rates are only slightly increased if the disability is minimal. FUNCTIONAL CLASSIFICATION OF HEART DISEASE For practical purposes, the functional capacity of the heart is the best single measurement of cardiopulmonary status. Class I: Ordinary physical activity causes no discomfort. Class II: Ordinary activity causes discomfort and slight disability. Class III: Less than ordinary activity causes discomfort or disability; patient is barely compensated. Class IV: Patient decompensated; any physical activity causes acute distress. Eighty percent of obstetric patients with heart disease have lesions that do not interfere seriously with their activities (classes I and II) and usually do well. About 85% of deaths ascribed to heart disease complicating pregnancy occur in patients with class III or IV lesions (20% of all pregnant patients with heart disease). Nev- ertheless, much can still be done to improve the prognosis for the mother and infant in these unfavorable circumstances. PATHOLOGIC PHYSIOLOGY The effects of pregnancy on certain circulatory and respiratory func- tions are reviewed in Chapter 4. Understanding gestational cardiovascular and hemodynamic adaptations is key in preventing or man- aging cardiac complications during pregnancy. Three major burdens on the heart are associated with pregnancy: cardiac output is increased by ϳ40%, the heart rate is accelerated by 10–15 beats per minute (bpm), and the plasma volume is expanded by 45%–50%. These unavoidable stresses must be considered in ap- praising the patient’s ability to undergo pregnancy, delivery, and the puerperium. By the 12th week of pregnancy, increased physiologic factors, especially blood volume increase, may produce systolic flow mur- murs. These, together with the third heart sound often noted during pregnancy, can lead to a false diagnosis of heart disease. Cardiac arrhythmias (e.g., atrial fibrillation or flutter), common in women with mitral valve or congenital heart disease, may be a serious sign of cardiopathy. In addition to these physiologic burdens, there are avoidable or treatable medical liabilities (e.g., anemia, obesity, hyperthyroidism, thyroid disease, infection, and emotional and physical stresses). Youth, adequate functional cardiac reserve, stability of the cardiac lesion, and an optimistic, cooperative attitude are important assets that do much to improve the cardiac patient’s chances for a suc- cessful confinement. Labor, delivery, and the early puerperium impose the following specific physiologic burdens on the maternal heart. DURING LABOR AND DELIVERY The heart rate slows with each contraction and returns to the resting level between contractions. The alteration is less in the lateral recumbent as compared to the supine position. Oxygen consumption increases intermittently with uterine contractions, approaching that of moderate to severe exercise. Tachycardia during the second stage may result from distention of the right atrium and ventricle by blood from the uterus and from the effect of straining. DURING THE PUERPERIUM Cardiac output increases slightly for ϳ1 week after delivery. Elim- ination of the placenta, contraction of the uterus, and reduction of the pelvic circulation suddenly make more blood available to the heart. A decrease in plasma volume (and increase in hematocrit) occurs for about 12 h after delivery. A second marked decrease in plasma volume, with an accompanying reduction in the amount of total body water, persists for 7–9 days. These changes are due to postpartal diuresis. CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 429 BENSON & PERNOLL’S 430 HANDBOOK OF OBSTETRICS AND GYNECOLOGY TREATMENT Determine the functional cardiac status (class I–IV) before the third month if possible and again at 7–8 months. Obtain consulta- tion with a cardiologist for all class II–IV patients early in pregnancy. Restrict physical activity to necessary duties only, with fa- tigue as a limiting factor. Acertain that the patient obtains assistance with essential household duties (child care, laundry, cleaning, and marketing). Assist the patient and her family to un- derstand the medical problem and allay her fears, anxiety, and tension. Periods of maximal cardiac stress occur at 14–32 weeks, during labor, and, particularly, during the immediate postpartum period. Especially good rapport and medical control must be main- tained at these times. General Medical Measures Anemia, hyperthyroidism, and obesity are corrected as indicated. In pregnant cardiac patients, sodium restriction may be necessary after 8–12 weeks. Warfarin anticoagulant therapy is avoided during pregnancy because of teratic effects. Cardiac complications, such as congestive failure, pulmonary edema, infective endo- carditis, and arrhythmia, are treated as in the nonpregnant patient. Diuretics may be necessary, but should not be used to the point of hyponatremia. Hypokalemia is also to be avoided. Preeclampsia-eclampsia is prevented or treated. All infections must be treated specifically, promptly, and vigorously. Intercur- rent respiratory, gastrointestinal tract, or urinary tract infections can be serious. Therapy by Classification Class I-II The great majority of these patients who are asymptomatic or who have only mild distress with their usual activities can continue in pregnancy with minimal restriction or intervention other than close medical supervision. Severe activity-induced symptoms indicate cardiac decompensation, in which case, hospitalization, treatment for cardiac failure, and bedrest until delivery are necessary. Class III In selected cases, pregnant patients with mitral stenosis who develop marked cardiac symptoms with average activity may be can- didates for mitral valvulotomy up to the eighth month. Generally, in the absence of an operable lesion, severe activity limitation or bedrest until term is recommended. Class IV All gravidas up to about the 14th week of pregnancy with severe functional incapacity at rest, who do not have an operable cardiac abnormality, should consider abortion. If the lesion is not correctable, sterilization should also be considered. In some cases, cardiac surgery during pregnancy may be necessary. If the incapacity takes place in late pregnancy, it may be possible to prolong the pregnancy by maximal medical intervention to a premature but viable delivery. Specific Delivery Measures Vaginal delivery is preferred for patients with heart disease, except where there are obstetric indications for cesarean section. However, coarctation or aneurysm of the aorta contraindicates vaginal delivery, and numerous other patients will also require cesarean section on an individualized basis. The third stage of labor is managed carefully to limit postpartum bleeding. Ergot preparations, which have a pressor effect, should not be used, but oxytocin may be uti- lized by slow intravenous infusion. Some recommend using it after delivery as prophylaxis for uterine atony. Lowering the patient’s legs promptly after delivery (or deliver with the legs down) reduces drainage of peripherally pooled blood into the systemic circulation. Some patients who have experienced no cardiac symptoms during pregnancy or labor may go into shock or acute cardiac failure immediately after delivery because of sudden engorgement of the splanchnic vessels. These patients require treatment for hypo- volemic shock and acute cardiac failure. Class I or II patients may breastfeed. Cautious, brief, early am- bulation of class I–III patients may be useful, provided the medical course is otherwise uncomplicated. Class II–IV patients must remain in the hospital after delivery until cardiovascular function is stable. Before discharge, it is prudent to ascertain that the patient is returning to a controlled home situation where adequate rest in a nonstressful milieu will be possible. Contraception and sterilization should be discussed, particularly for class II–IV patients with con- tinuing disease or life-threatening conditions. Surgical Measures Therapeutic abortion may be indicated in 5%–8% of cases of heart disease complicating pregnancy. Patients who have had cardiac failure in a previous pregnancy will usually have failure again with another pregnancy, and should consider abortion or sterilization or both. Abortion is seldom beneficial after the fourth month but may be considered. If the cardiac lesion is severe enough to warrant abortion and if surgical treatment is not feasible, sterilization probably CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 431 BENSON & PERNOLL’S 432 HANDBOOK OF OBSTETRICS AND GYNECOLOGY is indicated. If the patient is not sterilized, strict pregnancy pre- vention must be employed. Mitral valvotomy is indicated in patients with severe stenosis of the mitral valve who have insufficient cardiac reserve, even with ideal supportive therapy, to withstand the stress of pregnancy. In general, such patients will have had cardiac decompensation in a previous pregnancy despite the best care. Surgical and other interventional therapies have materially al- tered the prognosis of pregnant women with valvular heart disease. Although heart valve replacement of young women remains con- troversial, it is uncontrovertibly safer in some circumstances than not having the procedure. Generally, because of maternal and fetal risks, open heart surgery is undertaken only when other possibili- ties have more morbidity and mortality. PROGNOSIS Maternal Death Cardiovascular disease is the sixth leading cause of maternal death (after infection, preeclampsia-eclampsia, hemorrhage, trauma, and complications of anesthesia). The maternal mortality rate for all types of heart disease is 0.5%–2% in large medical centers in the United States, and heart disease accounts for 5%–8% of all maternal deaths. Perinatal Mortality The perinatal mortality rate (including fetal deaths due to therapeutic abortion) largely depends on the functional severity of the mother’s heart disease. Approximate rates are shown. Mother’s Functional Disability Perinatal Mortality Rate Class I ϳ5% Class II 10%–15% Class III ϳ35% Class IV Ͼ50% Perinatal Morbidity The incidence of congenital defects is greater among infants delivered of women with congenital and syphilitic heart disease than among those delivered of women with normal hearts, but rheumatic and other types of heart disease do not (without other factors) increase the incidence of fetal anomalies. Other forms of perinatal morbidity depend on the circumstances of the pregnancy and delivery and may include the sequelae of hypoxia and acidosis. [...]... hyperbilirubinemia, and if it is used, maternal folic acid should be administered CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 451 BILIARY AND HEPATIC DISORDERS CHOLEDOCHOLITHIASIS AND CHOLECYSTITIS Severe choledocholithiasis and cholecystitis are uncommon during pregnancy despite the fact that the smooth muscle relaxation of pregnancy (due to progesterone) is predisposing and women have... costovertebral angle and flank with radiation to the lower quadrant and vulva, urinary urgency, and hematuria without (initially) pyuria or fever are characteristic of ureteral stone Intravenous urography may demonstrate partial obstruction and the stone CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 447 Symptomatic therapy with analgesics and antispasmodics is always indicated and may be best... trauma surgeon, neonatologist, and other necessary specialists may improve outcomes CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 435 HEMATOLOGIC DISORDERS ANEMIA The physiologic alterations discussed in Chapter 3 and certain of the pathologic changes possible during pregnancy make the determination of anemia difficult Not only do blood values during pregnancy differ from those in... risk for cirrhosis and hepatocellular CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 455 carcinoma, there is controversy about the amount of risk and the time required for this progression Current best estimates are that ϳ20–30% of infected individuals will develop fibrosis and cirrhosis Of those with fibrosis and cirrhosis, ϳ20% will progress to liver decompensation and 10%–20% to hepatocellular... CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 457 of dermatitis herpetiformis It is not related to the herpesvirus, and the nomenclature is unfortunate The intensely burning, pruritic, occasionally painful urticarial papulovesicular eruption involving the buttocks, extensor surfaces of the arms and legs, back, and upper abdomen begins during or after the fifth month of pregnancy Occasionally,... suffice, and cesarean section is not indicated for delivery Elective surgery for repair of an abdominal hernia should be delayed until after pregnancy, but emergency operation for the relief and correction of an incarcerated hernia may be performed during pregnancy DERMATOLOGIC COMPLICATIONS Pregnancy has a sparing effect on most dermatoses With few exceptions, skin disorders during pregnancy and the... adequate and anaerobic and aerobic organism antibiotic coverage The pelvic examination is usually normal, but about one third of patients will have palpable veins in the vaginal fornices or parametrial or lower abdominal areas The pulse and the respiratory rate may be rapid In untreated cases, 30%–40% will have septic pulmonary embolism CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY. ..CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 433 PERIPARTUM CARDIOMYOPATHY This uncommon myocardial disorder usually presents as cardiac failure 1–5 months postpartum, but may present during pregnancy Peripartal cardiomyopathy has an unknown etiology It is potentially critical and most often affects multiparas with no evidence of prior... correction of fluid and electrolyte imbalance by means of parenteral fluids, intestinal (nasogastric) decompression, and evacuation of the rectosigmoid colon by enemas In more difficult cases, gastric suction usually will suffice If ileus is marked, a long intestinal tube (Werner, Miller-Abbott) should be inserted to decompress the small bowel CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 449... fever, fluid and electrolyte imbalance, collapse, toxicosis, and death When the disease becomes chronic, malnutrition and invalidism are associated with remissions and exacerbations of diarrhea There is no specific treatment Dietary, symptomatic, and supportive medical measures, corticosteroids, and sulfasalazine are usually employed during pregnancy Although, the last two are possible teratogens, that . abortion and if surgical treatment is not feasible, sterilization probably CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 431 BENSON & PERNOLL’S 432 HANDBOOK OF OBSTETRICS AND. problem complicating pregnancy in the United States. Rheumatic heart CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 427 BENSON & PERNOLL’S 428 HANDBOOK OF OBSTETRICS AND GYNECOLOGY disease. 40% will CHAPTER 15 MEDICAL AND SURGICAL COMPLICATIONS DURING PREGNANCY 435 BENSON & PERNOLL’S 436 HANDBOOK OF OBSTETRICS AND GYNECOLOGY have iron stores of 100–500 mg and 40% have virtually

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