Management of AFE is aimed to support acute multisystem dysfunction. Initial diagnostic testing to consider in a patient whose differential diagnosis includes AFE is summarized in Table 14-6. With or without evidence of hemorrhage as a presenting symptom, blood products should be ordered expeditiously in anticipation of profound bleeding and DIC. Cardiac enzymes may be elevated and arterial blood gas levels will demonstrate hypoxemia. Electrocardiogram may demonstrate tachycardia with possible right ventricular strain. Chest radiography may demonstrate nonspecific increased opacities and transesophageal echocardiography can reveal severe pulmonary hypertension, acute right ventricular failure, and deviation of the interventricular septum.
TABLE 14-6.Initial Diagnostic Testing Suggested For a Woman Presenting With Signs and Symptoms of AFE ||Download (.pdf) TABLE 14-6. Initial Diagnostic Testing Suggested For a Woman Presenting With Signs and Symptoms of AFE
|Laboratory ||Other |
Complete blood count with platelets
Arterial blood gas
Blood type and antibody screen
Coagulation profile (PT, INR, PTT, and fibrinogen)
The primary management goals include rapid maternal cardiopulmonary stabilization with prevention of hypoxia and maintenance of vascular perfusion. This may require endotracheal intubation to keep oxygen saturation at 90% or greater. Treatment of hypotension should include optimization of preload with infusion of crystalloid solutions. In cases of refractory hypotension, vasopressors such as dopamine or norepinephrine may be necessary. Central monitoring of cardiovascular function may assist in these endeavors.
Eighty-seven percent of patients in the national AFE registry suffered cardiac arrest.5 Of these, 40% occurred within 5 minutes of symptom onset. The most common dysrhythmia was found to be electromechanical dissociation, followed by bradycardia and ventricular tachycardia or fibrillation. Inotropic agents may need to be administered to improve myocardial function. In these cases, administration of all conventional cardiac support measures, including medications used in resuscitation, should be used without delay. The patient should be placed in the left lateral position before chest compressions to avoid compression of the inferior vena cava by the gravid uterus. In cases in which asystole or malignant arrhythmia is present for greater than 4 minutes, perimortem cesarean delivery should be considered. In such women, it is unlikely that cesarean section would adversely affect maternal outcome. Even properly performed cardiopulmonary resuscitation, difficult at best in a pregnant woman, provides only a maximum of 30% of normal cardiac output. Under these circumstances, it is fair to assume that the proportion of blood directed to the uterus and other splanchnic beds is minimal. Thus, the fetus will be profoundly hypoxic at all times following maternal cardiac arrest. For the pregnant patient, the standard ABCs of cardiopulmonary resuscitation should be modified to include a fourth category, D for delivery.
When AFE occurs prior to delivery, there is a significant chance of perinatal death, and a substantial risk of permanent neurodevelopmental deficits among surviving infants. There is a clear relationship between neonatal outcome and event-to-delivery interval in those women suffering cardiac arrest (Table 14-7). Intact fetal survival has been shown to be highest when delivery is accomplished within 5 minutes of maternal cardiac arrest; however, the decision to deliver should not be abandoned if determined beyond the 5-minute mark.
TABLE 14-7.Cardiac Arrest-to-Delivery Interval and Neonatal Outcome ||Download (.pdf) TABLE 14-7. Cardiac Arrest-to-Delivery Interval and Neonatal Outcome
|Interval (min) ||Survival ||Intact survival |
|<5 ||3/3 ||2/3 (67%) |
|5-15 ||3/3 ||2/3 (67%) |
|16-25 ||2/5 ||2/5 (40%) |
|26-35 ||3/4 ||1/4 (25%) |
|36-54 ||0/1 ||0/1 (0%) |
In a mother who is hemodynamically unstable but has not yet undergone cardiac arrest, maternal considerations must be weighed carefully against those of the fetus. The decision to subject such an unstable mother to a major surgical procedure (cesarean section) is a difficult one, and each case must be individualized. However, it is axiomatic in these situations that where a choice must be made, maternal well-being must take precedence over that of the fetus.
Selective arterial embolization has been reported in cases of AFE, but efficacy remains unproven.35 Recombinant factor VII has been used and reported in cases of severe coagulopathy resistant to conventional blood and product replacement.36,37 Other case reports have described the use of continuous hemodiafiltration, extracorporeal membrane oxygenation, and intra-aortic balloon counterpulsation in cases of AFE.38,39, 40 In 1 report, early transesophageal echocardiogram demonstrating severe pulmonary vasoconstriction and cor pulmonale lead to successful rescue using cardiopulmonary bypass. Nitric oxide appeared to be of benefit in 1 case report.41 The roles of these interventions in managing AFE remain unknown.
Significant maternal morbidity is associated with AFE. Over 75% of patients in the UK registry required intensive care management, with an average length of stay of 5 days among survivors and an average of 34 units of blood products was required in these patients. In the US AFE registry, only 15% of patients who had cardiac arrest survived neurologically intact. Other sequelae include liver hematoma, renal and multisystem failure, and ischemic encephalopathy. Overall morbidity and mortality of AFE has improved with early recognition of the syndrome and improved resuscitative efforts involving multiple disciplines of medicine. In cases recorded within the UK registry, women who survived AFE had a shorter time frame between symptom onset and treatment (42 vs 108 minutes).42,43
There have been reported cases of successful pregnancies following AFE, and no reported recurrences to our knowledge. Although data is limited, there is no evidence to suggest that there is a recurrence risk for AFE in future pregnancies.