Incidence and Characteristics of Failures in Obstetric Neuraxial Analgesia and Anesthesia: A Retrospective Analysis of 19,259 Deliveries
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P.H. Pan, T.D. Bogard and M.D. Owen. Department of Anesthesiology, Division of Obstetric Anesthesia, Wake Forest University School of Medicine, Winston-Salem, North Carolina. International Journal of Obstetric Anesthesia 2004;13:227-33PH. Pan, T.D. Bogard and M.D. Owen. Department of Anesthesiology, Division of Obstetric Anesthesia, Wake Forest University School of Medicine, Winston-Salem, North Carolina.International Journal of Obstetric Anesthesia200413227-33Although lumbar and combined spinal-epidural (CSE) analgesia are used often, the incidence and reasons for failure are not well characterized and vary. Identifying and understanding these failures will improve patient care and outcomes. This retrospective analysis was performed on a 3-yr database to evaluate the incidences and characteristics of failures in obstetric neuraxial analgesia and anesthesia.The analysis was conducted on data collected prospectively from January 2000 to December 2002 as part of an ongoing quality assurance (QA) program that consisted of five processes. (1) QA forms completed by the residents or faculty at the conclusion of patient care listing complications, failures, and comments; (2) visit by an anesthesiology faculty member to identify problems and patient complaints not already documented; (3) a QA anesthesiologist reviewed all the anesthetic records; (4) QA data summarized for presentation at monthly meetings; and (5) the 3-yr data were entered in a spreadsheet for analysis. Epidural and CSE procedures were standardized and followed normal protocols. Overall failure was defined as epidural or CSE procedures that did not provide adequate analgesia or had no sensory block after adequate dosing at any time after initial placement, inadvertent dural puncture, intravenous (IV) epidural catheter, or any technique that required replacement or alternative management.The database included 19,259 deliveries, of which 15,069 (78%) were vaginal and 4190 (22%) cesarean. The neuraxial labor analgesia rate increased yearly from 69% to 83%; the rate for cesarean section remained at 13% to 14%. The overall failure rate was 12% in patients receiving either epidural or CSE. After initial adequate analgesia, 6.8% of patients had inadequate analgesia despite adequate dosing. However, 98.8% ultimately received adequate pain relief. Six percent of epidural catheters were initially placed intravenously, but 46% of them were cleared with simple manipulation and functioned well. The incidence of overall failure, IV catheter, wet tap, inadequate analgesia, and catheter replacement was significantly lower with CSE than with epidural technique. Labor epidural catheters failed in 7.1% of patients at or during cesarean section; 4.3% required conversion to general anesthesia. For planned spinal anesthesia for cesarean section, the respective rates were 2.7% and 1.2%. Epidural and CSE failures occurred in both urgent and nonurgent cesarean sections. The overall use of general anesthesia for cesarean deliveries decreased yearly from 8%to 4.3%. Regional anesthesia was used in 93.5% of cesarean deliveries with no anesthetic-related deaths. In five cesarean patients and one labor analgesia patient, an unexpectedly high block or total spinal necessitated intubation and resuscitation. All patients were successfully resuscitated without adverse sequelae.Future studies should establish acceptable international standards for comparison, identify risk factors for neuraxial block failure, and improve techniques and equipment to reduce failures in regional analgesia and anesthesia.