All right, let's get started by talking about obstetric emergencies. The objectives of this presentation are to describe physiologic changes of pregnancy, outline the diagnosis and management of severe preeclampsia, eclampsia, and HELP syndrome, identify causes of shock in pregnancy, and the appropriate interventions. Let's start the presentation with a question, which of the following increases in pregnancy? Systemic vascular resistance, AST and ALT, blood pressure, or cardiac output? The answer here is four, cardiac output. This increases dramatically during pregnancy by about up to 50%, primarily as a result of stroke volume, as well as an increase in heart rate. It's really not unusual to see patients at term with a heart rate up to 100. Anything higher than that should prompt you to take a closer look at the patient and her individual clinical scenario. Systemic vascular resistance actually decreases as a result of vasodilation due to progesterone. This is dramatically different in hypertensive states, including preeclampsia. Liver function tests decrease, except in liver disease, including HELP syndrome. Blood pressure also decreases during pregnancy. So to summarize, cardiac output increases by almost 50%, blood volume increases by about up to 45%. Remember that blood pressure decreases, usually returning to normal by delivery. Systemic vascular resistance also decreases, although the filling pressures here remain relatively unchanged. Regarding some of the respiratory changes, there is an increase in minute ventilation as a result of tidal volume and respiratory rate. Pregnant women have a compensatory respiratory alkalosis with a PCO2 about 28 to 32 with a relatively normal pH. Reminder then, a pregnant patient with a PCO2 of 40 is a problem and they are an extremis. These patients have an increased risk of mucosal edema and a tendency to bleed, particularly during intubations. There is also a decrease in chest wall compliance due to the size of the abdomen, but there's no significant change in the AA gradient. These patients have an increased risk of hypoxia, which is worth noting. This is due to the decrease in functional residual capacity, as well as an increase in oxygen delivery and consumption. Continuing with the physiologic changes in pregnant patients, these patients have an increased risk of aspiration due to decreased esophageal sphincter pressure and increased intra-abdominal pressure. Bilirubin and transaminases typically decrease. Because of the increase in blood volume and cardiac output, there is a large increase in GFR. As a result, BUN and serum creatinine are quite low. Again, because of the increase in blood volume and plasma volume, there can be a dilutional anemia. The white blood cell count is typically a little bit elevated and that can sometimes be troublesome when coming up with differential diagnoses. The hematologic system is very convoluted in pregnancy with both an increase and a decrease in clotting factors, and these patients have a tendency to both clot and bleed. Moving on to the hypertensive disorders of pregnancy, these include pregnancy-induced hypertension, formerly called gestational hypertension, essential hypertension, which we're seeing more as average maternal age is increasing, preeclampsia, one of the common entities in pregnancy. This is secondary to placental dysfunction. It's related to pro-inflammatory angiogenic factors, and we see a decrease in both VEGF and PIGF, as well as a decrease in nitric oxide. This is considered a generalized vasospastic disease with endothelial dysfunction. There is a predilection here for the renal and cerebral vasculature to be affected. Finally, there is eclampsia, which is severe preeclampsia with seizures. The type of preeclampsia most commonly seen in ICUs is severe rather than mild or moderate preeclampsia. These patients have hypertension and proteinuria, or hypertension and significant end-organ dysfunction. Preeclampsia includes patients who are beyond 20 weeks gestation. Earlier onset is rare, but it can occur, and these patients tend to have a worse outcome in terms of end-organ damage. In severe preeclampsia, the blood pressure is significantly higher, at 160 over 110, or greater. These patients will have evidence of significant end-organ dysfunction. Eclampsia presents with generalized tonic-clonic seizures. Keep in mind that eclampsia can occur up to one to two weeks after delivery. Usually though, there are very few seizures associated with this, maybe one to three seizures. If your patient is having more frequent seizures or refractory seizures, they should have a complete neurologic workup to look for other causes. In eclampsia, seizures are very well controlled with magnesium, which can be used prophylactically as well. As noted, severe preeclampsia can entail significant proteinuria aligned with significant elevations in blood pressure. Because the renal vasculature is affected, oliguria often occurs, and patients can be hyperuricemic. End-organ dysfunction can present in various ways, including pulmonary edema, cerebral or visual disturbances, hepatic dysfunction, including HELP syndrome, thrombocytopenia, and cardiac insufficiency. For treatment, delivery should occur if the patient is 34 weeks gestation or beyond. Corticosteroids can also be considered if the fetus is below 34 weeks. Otherwise, initiate maternal and fetal monitoring for gestational age greater than 20 to 24 weeks. Blood pressure control should be undertaken slowly and judiciously, aiming to decrease the mean arterial pressure by about 25% during the first hour or two. As noted earlier, magnesium can be used as therapy and prophylaxis in these patients. Magnesium therapy can be continued for up to 24 hours postpartum. Patients should receive fluids for oliguria. Doctors need to remember to use caution here. Aggressive fluid resuscitation can lead to pulmonary edema due to the dramatic decrease in colloid oncotic pressure in these patients. Looking more closely at blood pressure control, again, go slowly and aim for a diastolic blood pressure of 90 to 100 over time. As far as medications, labetalol is used as a first-line therapy because it does not cause precipitous changes in blood pressure. Hydralazine has been the standard of care, and it's still widely used, especially in countries where labetalol is not available. The caution here is that hydralazine works very well as a vasodilator, and it does carry the risk of a large drop in blood pressure, especially in patients who are volume depleted. Oral nifedipine or IV nicartipine are other options. ACE inhibitors, ARBs, nitroprusside, and diuretics should absolutely be avoided in pregnant patients. You can consider some of these in the postpartum state. As mentioned earlier, magnesium is used for both prophylaxis and treatment of seizures, found to be superior to phenytoin and benzodiazepines. For administration, an IV route is preferred with the dosing shown here. If there is any risk for magnesium toxicity, for example, in patients with very low urine output, this can be treated with one gram of calcium gluconate or 500 milligrams of calcium chloride. HELP syndrome is a variant of severe preeclampsia involving hemolysis, elevated liver enzymes, and low platelet count. Most of these events incur intrapartum, but about a third happen postpartum. A fairly high number of these patients develop acute kidney injury. HELP occurs a little later than severe preeclampsia, about 27 to 36 weeks. About a third of cases occur up to seven days after delivery. Hypertension may or may not be present. The treatment of choice is urgent delivery. These patients should be also treated with magnesium and antihypertensive therapy. Plasmapheresis has been recommended, especially if TTP is likely and persists for more than 72 hours postpartum. High-dose dexamethasone has also been studied, but trials have not shown any clinical benefit. Be prepared for the complications associated with HELP. Liver capsular and subcapsular hematoma is perhaps the most significant of these complications, and you can see what that looks like on this CT slice here. There may also be hepatic rupture and renal failure. TTP in pregnancy is similar to HELP, but there are some differences, as noted here. In TTP, hypertension is not typical, LDH tends to be higher, and mental status changes are more common. Treatment of choice for TTP includes steroids and plasma exchange. Today, the common theories at HELP, acute fatty liver of pregnancy, hemolytic uremic syndrome, and TTP represent a spectrum of diseases. Moving on, hemorrhagic shock is the most common cause of maternal death worldwide. This is often due to placental issues, such as placenta previa or abruption. It's also associated with ectopic pregnancy and trauma. Intrapartum hemorrhage is defined as at least 1,000 milliliters total blood loss, or loss of blood coinciding with signs and symptoms of hypovolemia within 24 hours after delivery of the fetus or intrapartum loss. The most common cause is uterine atony. Other causes include retained placenta, uterine inversion, and rarely, uterine rupture. Treatment here includes resuscitation using a massive transfusion protocol, as well as consideration of TXA therapy, placenta removal, manual compression of the uterus, uterine contraction using oxytocin and prostaglandins, and correcting the coagulopathy. Other options include the use of a balloon tamponade, arterial embolization, or hysterectomy. It tends to be reserved for patients who have experienced failure of other options, or for patients with uterine rupture. Peripartum cardiomyopathy is a dilated cardiomyopathy, similar epidemiologically to idiopathic dilated cardiomyopathy in the non-pregnant population, but this happens in a young, healthy pregnant patient. It occurs in the last month of pregnancy to five months out postpartum. During the last part of pregnancy, it can be really easy to miss, because men and women at this stage of pregnancy are short of breath, have fetal edema, or they may have an extra heart sound or palpitations. It can be difficult to distinguish whether these symptoms are happening because of cardiomyopathy or as part of the classic symptoms of pregnancy. Treatment of choice here includes the use of diuretics, vasodilators, or inotropes. Remember that ACE and ARB should still be avoided in women who are still pregnant. It's important to note that these patients have a high incidence of systemic and pulmonary thrombosis. Most of these patients need to have anticoagulation for months or even years, depending on their symptoms and presentation. About a quarter of these patients will wind up on ECMO and potentially need a heart transplant. Let's move on to our second question. A pregnant woman at 34 weeks gestation was a restrained passenger in a motor vehicle accident. On arrival in the ED, she is lethargic on a backboard with a C-collar in place. Her blood pressure is 70 over 40, heart rate is 110, respiration rate is 20. Which of the following is the most appropriate initial intervention? Transfusion of RH negative blood, emergent operative delivery, intubation and mechanical ventilation, elevation of the right hip, or two liters of Ringer's lactated solution. The best answer here is four, elevate the right hip. When the patient is supine, the inferior vena cava and aorta are being compressed, meaning that cardiac output and blood pressure are immediately decreased. Elevating the right hip alleviates that pressure. As we just noted, in a pregnant trauma patient, the left lateral decubitus position is used and the hip is elevated to displace the uterus. RH negative blood is given for emergent transfusions. Because maternal vital signs can be misleading, these patients should be monitored in the ED for at least four hours, even if the accident was minor. Use an abdominal shield for radiography, but do not avoid using radiography. Finally, do not forget to administer immune globulin within the first 72 hours. For patients who need mechanical ventilation, a smaller endotracheal tube is recommended due to the elevated edema in the mucosal tissues. Aim to maintain a slightly higher arterial oxygen saturation. Higher airway pressure should be expected due to the restrictive chest wall. For instance, a plateau pressure over 30 is not unusual. Remember, the abdominal pressure is going to be high in these patients. Non-invasive ventilation should be used with caution due to the increased risk of aspiration. Finally, you need to monitor the fetus for the effects of ventilator changes, especially for women who are beyond 24 weeks of gestation. Changes in fetal vital signs are often the first indication that something is wrong with the mother. Tocholitic-associated pulmonary edema is associated with the use of beta-2 agonists, such as terbutaline, ritotrin, and albuterol, and so their use should be limited or avoided. In addition to discontinuing tocholitics, treatment usually involves diuretics. Mechanical ventilation is rarely needed. Asthma is the most common respiratory disorder in pregnancy. During pregnancy, about one-third of women improve, a third worsen, and a third have no change in their symptoms. Asthma increases the risk of maternal and fetal complications, and the second trimester tends to be the worst as there are more exacerbations during this time. Inhaled agents are preferred for asthma control, including both bronchodilators and steroids. Systemic corticosteroids are also safe. What about pregnancy and COVID? We know that the hormonal, cardiovascular physiology, and immunomodulatory changes during pregnancy increase susceptibility to respiratory infections and may predispose to severe presentations of the disease. This is true of all respiratory infections in pregnancy, including pneumonia. Moving on to advanced life support, always get the patient off the right hip. During cardiac arrest, maneuvers such as CPR can be difficult in the left lateral decubitus position, so most of the time, the uterus is displaced manually to the left. There are no changes in standard compressions, ACLS dosing, or defibrillation in these patients. Ideally, IV access is above the diaphragm. Peripornam-Caesarean delivery can be necessary. It should be performed within five minutes of cardiac arrest if the fetal age is 24 weeks or more. The goal here is that delivery of the fetus leads to improved quality of CPR and resuscitation for the mother. Fetal survivability is also typically improved. Moving on to our third question, which of the following suggests the diagnosis of amniotic fluid embolism rather than venous air embolism? Sudden cardiovascular collapse, occurrence during labor, diffuse bilateral pulmonary infiltrates, or disseminated intravascular coagulation? The answer here is four, disseminated intravascular coagulation. Touching briefly on emboli, this is a quick comparison of amniotic fluid embolism and venous air embolism. With amniotic fluid embolism, there is cardiovascular collapse, DIC, hemorrhage, and respiratory failure. There is no specific treatment for amniotic fluid embolism. Instead, the goal is to treat everything that's occurred and support the mom through, whether it's DIC, respiratory failure, or cardiovascular collapse. You need to evacuate the uterus and provide supportive care using ECMO when needed. Venous air embolism is also associated with precordial millwheel murmur. Treatment here involves putting the patient in the left lateral decubitus position and administering 100% oxygen using hyperbaric therapy if neurologic changes and cardiovascular instability are present. Question four. A woman at 32 weeks gestation is suspected of having a pulmonary embolism. She has no leg symptoms and chest radiograph is normal. Which of the following tests is recommended initially for diagnosis? D-dimer, ventilation perfusion scan, CT angiography, or MRI? The best answer here is three, CT angiography. With thromboembolic disease, bear in mind that pregnancy is a hypercoagulable state with increased thrombin activity and fibrinolysis. The incidence of both deep venous thrombosis and pulmonary embolism is also higher. D-dimer levels are increased during pregnancy, especially after 16 weeks. VQ scanning can be used, but the best diagnostic modality is CT angiography. Deep venous thrombosis occurs primarily in the left leg or pelvic region. Pelvic and iliofemoral clots are most common. Venography or serial Doppler studies are used for diagnosis. Management here includes heparin, preferably adjusted dose, low molecular weight heparin. Adjusted dose, unfractionated heparin can be used if necessary. Warfarin is contraindicated, especially during the first trimester. Oral thrombin, 10A inhibitors should be avoided. If the patient is unstable, consider thrombolytics and treat until 6 weeks postpartum for a minimum of 3 or 6 months total treatment, including both prepartum and postpartum treatment. Maternal sepsis is a life-threatening condition defined as organ dysfunction resulting from infection during pregnancy, childbirth, post-abortion, or postpartum period. It is the third most common cause of maternal mortality globally after postpartum hemorrhage and preeclampsia. Maternal sepsis is associated with poor maternal and fetal outcomes, as well as an increased incidence of neonatal sepsis. Maternal sepsis is often polymicrobial. Common organisms include E. coli and group A and B strep. Most respiratory infections tend to be typical, such as pneumococcal infections. Lassa and varicella can be deadly in a pregnant woman. In fact, pregnant women tend to have higher rates of morbidity and mortality from the infections on this list. As far as imaging, it's important to assess the risks and benefits. Do not delay an important diagnosis by avoiding imaging. CT of the abdomen and pelvis should not cause harm with appropriate shielding and dose reduction methods. For MRI, the safety has not been established, and gadolinium should be avoided. Finally, when prescribing drugs in pregnant patients, consider the adverse effect on the fetus. Work closely with the pharmacist. Because blood volume is significantly increased, many antibiotics and other drugs have to be increased as well, which is why it is essential to consult with the pharmacist. As mentioned earlier, avoid ACE inhibitors, ARBs, barbiturates, warfarin, and quinolones. Avoid drugs that decrease placental blood flow, for instance, vasoconstrictors. Thank you for your time.

obstetric emergencies

preeclampsia

eclampsia

hemorrhagic shock

maternal health

seizure prevention