At least three randomized studies have been performed to compare these methods of analgesia and anesthesia. Wallace and colleagues (1995) studied 80 women at Parkland Hospital with severe preeclampsia who were to undergo cesarean delivery. They had not been given labor epidural analgesia and were randomly assigned to receive general anesthesia, epidural analgesia, or combined spinal-epidural analgesia. heir average preoperative blood pressures approximated 170/110 mm Hg, and all had proteinuria. Maternal and perinatal outcomes in each group were similar. Maternal hypotension resulting from regional analgesia was managed with judicious intravenous fluid administration. In women undergoing general anesthesia, maternal blood pressure was managed to avoid severe hypertension. here were no serious maternal or fetal complications attributable to any of the three anesthetic methods. It was concluded that all three are acceptable for use in women with pregnancies complicated by severe preeclampsia if steps are taken to ensure a careful approach to the selected method.
Another randomized study included 70 women with severe preeclampsia receiving spinal analgesia versus general anesthesia for cesarean delivery (Dyer, 2003). Their maternal and fetal outcomes were equivalent. In a third study, 116 women with severe preeclampsia received either epidural or patient-controlled intravenous meperidine analgesia during labor (Head, 2002). More women-9 percent-from the group assigned to epidural analgesia required ephedrine for hypotension. As expected, pain relief was superior in the epidural group. Maternal and neonatal complications were similar between groups, and one woman in each group developed pulmonary edema. Importantly, epidural analgesia is not considered treatment of preeclampsia (Lucas, 2001; Ray, 2017).
Judicious fluid administration is essential in severely preeclamptic women who receive regional analgesia. Vigorous crystalloid infusion with epidural blockade in women with severe preeclampsia elevates pulmonary capillary wedge pressures (Newsome, 1986). Aggressive volume replacement in preeclamptic women raises their risk for pulmonary edema, especially in the first 72 hours postpartum (Clark, 1985; Cotton, 1986a). Finally, most cases of pharyngolaryngeal edema are related to aggressive volume therapy (Heller, 1983).
Hemoconcentration or lack of norml pregnancy-induced hyper volemia is an almost predictable feature of severe preeclampsia eclampsia (see Fig. 40-7) (Zeeman, 2009). These women, who consequenty ack nomal pregnany hypervoemia, are much less toer ant of even normal blood oss than are nomotensive pregnant women.
Importantly, an appreciable fall in blood pressure soon ater delivery most oten means excessive blood loss and not sudden resolution of vasospasm and endothelial damage. When oliguria follows delivery, the hematocrit should be evaluated frequently to help detect excessive blood loss. If identiied, hemorrhage should be treated appropriately by crystalloid and blood transusion.