The effect of colloid preload versus prophylactic ephedrine administration on QTc intervals during cesarean delivery: A randomized controlled study

Abstract

Aim: We aimed to investigate the effect of colloid infusion immediately before the spinal anesthesia, and the prophylactic intravenous (IV) infusion of ephedrine after injection of intrathecal bupivacaine on  hemodynamic parameters, QT, The QT interval corrected for heart rate (QTc), and dispersion of QTc (QTcDisp) intervals in women undergoing the elective cesarean section.
Materials and Methods: Sixty women scheduled for elective cesarean delivery with spinal anesthesia were allocated randomly to receive either IV fluid preloading with 0.5 L of 6% w/v hydroxyethyl starch solution immediately before the spinal anesthesia (colloid group, n = 30) or prophylactic IV infusion of 15 mg ephedrine (diluted with 10 ml saline, n = 30) over 1.min period after the injection of intrathecal  bupivacaine (ephedrine group). Electrocardiography (ECG) tracings were recorded before anesthesia procedure at baseline (T₀), 5 min (T₁), 10 min (T₂), 30 min (T₃), 60 min (T₄), and 120 min (T₅) after the spinal anesthesia. Systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP), heart rate (HR), and peripheral oxygen saturation (SpO₂) values were also recorded at the same time  intervals.
Results: There were no significant differences between groups with respect to MAP, HR, SpO₂, QT, and QTc intervals at any time points (P > 0.05). When compared with the colloid group, the QTcDisp interval at T_o1 was significantly longer in the ephedrine group (P < 0.05).
Conclusion: Both methods have similar effects on the ECG and hemodynamic parameters during  cesarean section. So, both methods may be used in patients undergoing elective cesarean delivery under spinal anesthesia.

Key words: Anesthesia, cesarean section, colloid, electrocardiography, ephedrine, spinal