In some women, epidural analgesia is insuicient for cesarean delivery. For example, in a Maternal Fetal Medicine Units (MFMU) Network study, 4 percent of women initially given epidural analgesia required a general anesthetic for cesarean delivery (Bloom, 2005). Also at times, perineal analgesia for delivery is diicult to obtain, especially with the lumbar epidural technique. When this situation is encountered, pudendal block or systemic analgesia or rarely general anesthesia may be added.
Hypotension. Sympathetic blockade from epidurally injected analgesic agents can cause hypotension and decreased cardiac output. Despite precautions, hypotension is the most frequent side efect and is severe enough to require treatment in a third of women (Sharma, 1997). According to Miller and coworkers (2013), hypotension is more common-20 percent-in women with an admission pulse pressure <45 mm Hg, compared with 6 percent in those whose pulse pressure is >45 mm Hg. In normal gravidas, hypotension induced by epidural analgesia usually can be prevented by rapid infusion of 500 to 1000 mL of crystalloid solution as described for spinal analgesia. Maintaining a lateral position also minimizes hypotension.
Maternal Fever. Fusi and colleagues (1989) observed that the mean temperature rose in laboring women given epidural analgesia. Subsequently, several randomized and retrospective cohort studies have confirmed that some women develop intrapartum fever following this procedure. Many studies are limited by inabiliry to control for other risk factors such as labor length, duration of ruptured membranes, and number of vaginal examinations. With this in mind, the frequency of intrapartum fever associated with epidural analgesia was found by Lieberman and O'Donoghue (2002) to be 10 to 15 percent above the baseline rate.
The two general theories concerning the etiology of maternal hyperthermia are maternaletal inection or dysregulation of body temperature. Dashe and coworkers (1999) studied placental histopathology in laboring women given epidural analgesia and identified intrapartum fever only when there was placental inflammation. This suggests that fever is due to infection. he other proposed mechanisms include alteration of the hypothalamic thermoregulatory set point; impairment of peripheral thermoreceptor input to the central nervous system, with selective blockage of warm stimuli; or imbalance between heat production and heat loss. Sharma (2014) randomized 400 nulliparas with labor epidural analgesia to receive cefoxitin 2 g prophylactically versus placebo. It was hypothesized that epidural-related fever was due to infection and that prophylactic antimicrobial use should significantly reduce the rate of fever. Approximately equal proportions-about 40 percentof women developed fever > 38°C during labor. This suggests that infection is unlikely to be the cause of fever.
Back Pain. An association between epidural analgesia and subsequent back pain has been reported by some but not all. In a prospective cohort study, Butler and Fuller (1998) reported that back pain after delivery was common with epidural analgesia, however, persistent pain was uncommon. Based on their systematic review, Lieberman and O'Donoghue (2002) concluded that available data do not support an association between epidural analgesia and development of de novo, long-term backache.
Miscellaneous Complications. A spinal or epidural hematoma is a rare complication of an epidural catheter (Grant, 2007). Epidural abscesses are equally infrequent (Darouiche, 2006). And uncommonly, the plastic epidural catheter can be sheared of (Noblett, 2007).