Haemodynamic effects of induction of epidural analgesia in labour

Abstract

The effect of induction of epidural analgesia with 0.5 per cent bupivicaine on maternal haemodynamics was investigated in 21 patients with uncomplicated full-term pregnancies in early labour. Stroke volume, heart rate, and cardiac output (SV, HR, and CO) were measured by transcutaneous aortovelography (TAV). Systolic, diastolic, and mean arterial blood pressures (SBP, DNP, and MAP) were measured by indirect automatic oscillometry. Measurements were made with the patient in the left lateral decubitus position before and after an intravenous bolus of 500 ml of lactated Ringer's solution preceding induction of epidural analgesia, and again 30 and 45 minutes after induction. The 500 ml bolus of lactated Ringer's solution did not prevent fall of CO and BP measured 30 minutes after induction, when there were statistically significant decreases in CO and cardiac index ( -10.2 and -10.6 per cent, p < 0.05), andinSBP,DBP, and MAP (-9.7, -12.5, and -11.9 percent, p > 0.005, p > 0.005 andp > 0.01 respectively). At45 minutes after induction, CO and cardiac index had returned to baseline values. Although the decreases in SDP and DBP persisted, the change in MAP was not statistically significant. © 1988 Canadian Anesthesiologists.