Why Bolus Epidurals with Bupivacaine?
Abstract Number: 82
Abstract Type: Original Research
Introduction: Local anesthetic boluses are frequently administrated to facilitate anesthesia after epidural catheter placement to parturients. Fear of refractory cardiovascular collapse after inadvertent intravenous bolus injection of bupivacaine (1) leads some practitioners to choose lidocaine as an alternative. The purpose of this study is to address whether bolus lidocaine is associated with quicker pain relief, hypotension, use of rescue vasopressors, or urgent Cesarean section compared with bupivacaine bolus.
Methods: After approval of the IRB at our institution, we analyzed demographic, pre-anesthetic, and outcome data collected for quality improvement purposes on all labor epidurals placed from September, 2007 to January, 2009. Outcomes were time to achieve pain-free labor, assessed every minute, and incidence of complications including non-reassured fetal heart rate, decrease of blood pressure, ephedrine administration and emergent cesarean section in 30 minutes after epidural bolus administration.
Results: 623 patients in labor with epidurals were analyzed. We excluded 23 that also used intrathecal dosing of bupivacaine. Of the remaining 600 patients, 159 received bupivacaine boluses and 441 lidocaine. Groups differed only in the amount of preload fluid administered (table). Choice of bolus medication was not associated with hypotension, ephedrine use, non-reassured fetal heart rate, or Cesarean section within 30 min of bolus (table). Time to pain relief was 5 min (IQR 5-30) for each group. No recorded variable predicted any complication by multivariate logistic regression of the entire cohort, or using a "greedy"-matched propensity scored cohort.
Conclusion: Neither time to relief of labor pain nor complications within 30 min depended on choice of bolus epidural local anesthetic.
Reference: (1) Shahram N., BMC Anesthesiology 2006, 6:15