Obstetrical anesthesia presents unique challenges. Labor begins without warning, and anesthesia may be required within minutes of a full meal. Vomiting with aspiration of gastric contents is a constant threat. The usual physiological adaptations of pregnancy require special consideration, especially with disorders such as preeclampsia, placental abruption, or sepsis syndrome.
Of all anesthesia-related deaths in the United States from 1995 to 2005, 3.6 percent were in pregnant women (Li, 2009). Berg and colleagues (2010) analyzed deaths of women during or within 1 year of pregnancy in the United States from 1998 through 2005. They found that 54 of 4693—1.2 percent—such deaths were attributable to anesthesia complications. Hawkins and associates (2011) analyzed anesthesia-related maternal mortality in this country between 1979 and 2002. As shown in Table 25-1, anesthetic-related maternal mortality rates decreased nearly 60 percent during this time, and there currently is approximately one anesthetic death per million live births. About two thirds of deaths associated with general anesthesia were caused by intubation failure or induction problems during cesarean delivery. Deaths associated with regional analgesia were caused by high spinal or epidural blocks—26 percent; respiratory failure—19 percent; and drug reaction—19 percent. The improved case-fatality rate for general anesthesia was especially notable considering that such anesthesia is now used for the highest-risk patients and the most hurried emergencies, that is, decision-incision intervals < 15 minutes (Bloom, 2005).
TABLE 25-1Case-Fatality Rates and Rate Ratios of Anesthesia-Related Deaths During Cesarean Delivery by Type of Anesthesia in the United States, 1979–2002 |Favorite Table|Download (.pdf) TABLE 25-1 Case-Fatality Rates and Rate Ratios of Anesthesia-Related Deaths During Cesarean Delivery by Type of Anesthesia in the United States, 1979–2002
| ||Case-Fatality Ratesa || |
|Year of Death ||General Anesthesia ||Regional Analgesia ||Rate Ratios |
|1979–1984 ||20.0 ||8.6 ||2.3 (95% CI 1.9–2.9) |
|1985–1990 ||32.3 ||1.9 ||16.7 (95% CI 12.9–21.8) |
|1991–1996 ||16.8 ||2.5 ||6.7 (95% CI 3.0–14.9) |
|1997–2002 ||6.5 ||3.8 ||1.7 (95% CI 0–4.6) |
Several factors have contributed to improved obstetrical anesthesia safety (Hawkins, 2011). The most significant is the increased use of regional analgesia. Increased availability of in-house anesthesia coverage almost certainly is another important reason. Despite these encouraging results suggesting the safety of general anesthesia, there are now reports of increasing complications with regional analgesia techniques.
Obstetrical Anesthesia Services
The American College of Obstetricians and Gynecologists (2008) reaffirmed its joint position with the American Society of Anesthesiologists that a woman’s request for labor pain relief is sufficient medical indication for its provision. Identification of any of the risk factors shown in Table 25-2 should prompt consultation with anesthesia personnel to permit a joint management plan. This plan should include strategies to minimize the need for emergency anesthesia in ...