Reactivation of Labor Epidurals for Postpartum Tubal Ligation: A Randomized Trial of Saline-infusion vs "Dry" Catheters
Abstract Number: 46
Abstract Type: Original Research
Introduction: When a women desires sterilization after delivery, the epidural catheter may be left in place and re-injected to provide anesthesia for postpartum tubal ligation. Unfortunately, it has been observed that epidural anesthesia is frequently unsuccessful when these in-situ catheters are re-injected for surgery (1). Our previous chart review observed that 69 out of 70 epidural catheters utilizing continuous saline infusion were successful. Therefore, we hypothesized that continuous infusion of normal saline at 3ml/hr, through the epidural catheter before reactivation, is associated with a greater frequency of successful epidural anesthesia compared to a "dry"catheter. Methods: Following IRB approval, written informed consent was obtained from all participants. Nineteen-gauge, single-hole, open-end epidural catheters (Arrow) were placed during labor in patients who request labor analgesia and were scheduled to undergo postpartum tubal ligation. Immediately after delivery, the patients were randomized into a prospective, double-blind trial of either saline-infused or dry catheters. Patients in the saline group were connected to an infusion of saline at a rate of 3ml/hr. Patients in the dry catheter group were connected to a stopped pump. In both cases the pump was covered with a black plastic bag to double-blind participants. After an epidural test dose was given (3-ml 1.5% lidocaine with 5 micrograms/ml of epinephrine), the epidural catheter was incrementally re-injected with 3% 2-chloroprocaine by an anesthesiologist blinded to the patient's group assignment. The primary endpoint was epidural anesthesia success (excellent, supplement required, or conversion.)
Results: Patient recruitment is ongoing. See Table.
Discussion: In a previous study (1), re-injecting the catheters within 4 hours of delivery was associated with greater frequency of successful epidural anesthesia for tubal ligation. It is too early to draw conclusions from our ongoing trial, but to-date we have had good success with the saline-infused catheters. It remains to be determined if this is a superior approach to the conventional "dry" catheters.
References: (1) Vincent et al, J. Clin. Anesth., vol. 5, July/August pp 289 (1993.)