A retrospective cohort study of the anesthetic management of postpartum tubal ligation.

Background: Neuraxial anesthesia with reactivation of a labor epidural catheter is commonly utilized for postpartum tubal ligations (PPTL), although the optimal anesthetic approach is unknown. We assessed institutional anesthesia practices for PPTL, and evaluated the failure rates of reactivation of labor epidural catheters, de novo spinal anesthesia, and spinal anesthesia after failed blocks.

Methods: We conducted a single-center retrospective cohort analysis of 300 consecutive patients who underwent a PPTL and 100 having spinal anesthesia for cesarean delivery. Anesthetic management data (existing labor epidural catheter reactivation, de novo spinal anesthesia or general anesthesia) were collected from electronic medical records. Anesthetic block failure rates were determined for each anesthetic technique.

Results: The failure rate was 15% for de novo spinal anesthesia and 23% after failed reactivation of a labor epidural catheter or spinal anesthesia. The epidural catheter reactivation failure rate was 35%. The failure rate of spinal anesthesia for cesarean delivery was 4%. Drug dosage, epidural catheter use in labor, time since epidural catheter placement or delivery, labor neuraxial technique (combined spinal-epidural, epidural), supplemental top-up doses during labor, and anesthesiologist experience did not predict neuraxial anesthesia failures.

Conclusions: Our analysis revealed an unexpectedly high neuraxial anesthesia failure rate even when de novo spinal anesthesia was used for PPTL. The results are consistent with other institutions' recent findings, and are higher than spinal anesthesia failure rates associated with cesarean delivery. Further studies are required to determine optimal anesthesia dosing strategies, and to understand the mechanisms behind high neuraxial anesthesia failures for PPTL.