Conversion of epidural labour analgesia to epidural anesthesia for intrapartum Cesarean delivery

To determine the rate of successful conversion of epidural labour analgesia (ELA) to epidural surgical anesthesia (ESA) for intrapartum Cesarean delivery (CD) with identification of potential risk factors for inadequate ESA. Secondary outcomes include a comparison of the management by subspecialist obstetric anesthesiologists (OB) vs. generalist anesthesiologists (GEN), when inadequate ESA was encountered, with an intention of identifying potential interventional strategies to reduce the need for general anesthesia (GA).

Health records of all parturients who received ELA and who underwent intrapartum CD during the 3-year period from April 01, 2001 to March 31, 2004 were manually reviewed. Data were analyzed using t test, Chi-square, Fisher's exact test, and analysis of variance where appropriate. A P < 0.05 was considered significant.

Eight hundred ninety-nine cases were identified. Four were excluded, as two received continuous spinal labour analgesia and two underwent emergency CD with insufficient time for conversion to ESA. Initially, 86.6% (775/895) of the 895 cases were successfully converted to ESA leaving 120 cases of inadequate ESA, 36 of these were managed by OB and 84 by GEN. Ineffective ELA was identified as a risk factor for unsuccessful conversion. Pulling the epidural catheter back 1 cm was identified as an effective intervention that resulted in the successful conversion in >80% of the 120 cases of inadequate ESA. Spinal anesthesia proved effective in 75% of cases. Both interventions reduced the need for GA to 1.2% for OB and 5.6% for GEN.

This investigation provides anesthesiologists with strategies to manage inadequate ESA for intrapartum CD that may reduce the need for GA.