Incidence of Hypotension between Epidural Administered Lidocaine and Chloroprocaine for Cesarean Section
Abstract Number: S 36
Abstract Type: Original Research
Background: Hypotension is a known side effect in neuraxial administration of local anesthetics. The resultant hypotension is a result of various hemodynamic effects including decreased venous return and decreased systemic vascular resistance. Systemic hypotension is important as it is directly related to uterine blood flow and a cause of maternal nausea and emesis. While numerous studies have compared local anesthetic effects and complications during epidural administration for cesarean section, there are few studies comparing the hemodynamic effects of chloroprocaine to lidocaine.
Methods: 151 parturients who underwent epidural anesthesia for cesarean section with lidocaine or chloroprocaine were identified during retrospective data collection. The number of episodes of hypotension were recorded with a hypotensive episode defined as a systolic blood pressure <90 mmHg or a ≥20% decrease from pre-operative baseline. Variables collected included age, pre-operative blood pressure, prior hypertensive disease (gestational or systemic), estimated blood loss, ephedrine use (mg), phenylephrine use (mg), and total intravenous fluid administration (mL).
Results: Patients receiving chloroprocaine were 4.32 times (OR 4.32, 95% Confidence Interval [CI] 1.22-15.29) more likely to experience an episode of hypotension compared to those receiving lidocaine. The mean number of hypotensive episodes in chloroprocaine patients versus lidocaine patients was 10.38 to 6.44. Only 3 of 31 (9.7%) chloroprocaine patients did not experience an episode of hypotension compared to 31 of 98 (31.6%) lidocaine patients. No significant differences existed between age, estimated blood loss, ephedrine use, phenylephrine use, pre-operative blood pressure, or total intravenous fluids.
Conclusions: The results show that patients receiving chloroprocaine during a cesarean section under epidural anesthesia were more likely to have a hypotensive episode. Despite increased episodes of hypotension chloroprocaine patients did not receive significantly more vasopressors, receive less intravenous fluids, or experience greater blood loss. The effects on fetal outcome and maternal nausea/emesis were not fully determined in this study but remain of interest in future analysis. The major limitation to this study is the small chloroprocaine patient population and additional patient recruitment is currently ongoing.
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