Anesthetic Complications: Obstetric Anesthesia

OBSTETRIC ANESTHESIA

Both critical incident and closed claims analyses have been reported regarding complications and mortality related to obstetrical anesthesia.

In a study reviewing anesthesia-related maternal mortality in the United States using the Pregnancy Mortality Surveillance System, which collects data on all reported deaths causally related to pregnancy, 86 of the 5946 pregnancy-related deaths reported to the Centers for Disease Control were thought to be anesthesia related or approxi-mately 1.6% of total pregnancy related-deaths in the period 1991–2002. The anesthesia mortality rate in this period was 1.2 per million live births, compared with 2.9 per million live births in the period 1979–1990. The decline in anesthesia-related maternal mortality may be secondary to the decreased use of general anesthesia in parturients, reduced concentrations of bupivacaine in epidur-als, improved airway management protocols and devices, and greater use of incremental (rather than bolus) dosing of epidural catheters.

In a 2009 study examining the epidemiology of anesthesia-related complications in labor and deliv-ery in New York state in the period 2002–2005, an anesthesia-related complication was reported in 4438 of 957,471 deliveries (0.46%). The incidence of complications was increased in patients under-going cesarean section, those living in rural areas, and those with other medical conditions. Complica-tions of neuraxial anesthesia (eg, postdural puncture headache) were most common, followed by sys-temic complications, including aspiration or cardiac events. Other reported problems related to anes-thetic dose administration and unintended over-dosages. African American women and those aged 40–55 years were more likely to experience systemic complications, whereas Caucasian women and those aged 30–39 were more likely to experience compli-cations related to neuraxial anesthesia.

ASA Closed Claims Project analyses were reported in 2009 for the period 1990–2003. Four hundred twenty-six claims from this period were compared with 190 claims in the database prior to 1990. After 1990, the proportion of claims for mater-nal or fetal demise was lower than that recorded prior to 1990. After 1990, the number of claims for maternal nerve injury increased. In the review of claims in which anesthesia was thought to have con-tributed to the adverse outcome, anesthesia delay, poor communication, and substandard care were thought to have resulted in poor newborn outcomes. Prolonged attempts to secure neuraxial blockade in the setting of emergent cesarean section can contrib-ute to adverse fetal outcome. Additionally, the closed claims review indicated that poor communication between the obstetrician and the anesthesiologist regarding the urgency of newborn delivery was likewise thought to have contributed to newborn demise and neonatal brain injury.

Maternal death claims were secondary to airway difficulty, maternal hemorrhage, and high neuraxial blockade. The most common claim associated with obstetrical anesthesia was related to nerve injury following regional anesthesia. Nerve injury can be secondary to neuraxial anesthesia and analgesia, but also due to obstetrical causes. Early neurological consultation to identify the source of nerve injury is suggested to discern if injury could be secondary to obstetrical rather than anesthesia interventions.