Randomized trial of bolus phenylephrine or ephedrine for maintenance of arterial pressure during spinal anaesthesia for Caesarean section

Abstract

Thirty-eight healthy women undergoing elective Caesarean section under spinal anaesthesia at term were allocated randomly to receive boluses of either phenylephrine 100 micrograms or ephedrine 5 mg for maintenance of maternal arterial pressure. The indication for administration of vasopressor was a reduction in systolic pressure to < or = 90% of baseline values. Maternal arterial pressure (BP) and heart rate (HR) were measured every minute by automated oscillometry. Cardiac output (CO) was measured by cross-sectional and Doppler echocardiography before and after preloading with 1500 ml Ringer lactate solution and then every 2 min after administration of bupivacaine. Umbilical artery pulsatility index (PI) was measured using Doppler before and after spinal anaesthesia. The median (range) number of boluses of phenylephrine and ephedrine was similar; 6 (1-10) vs 4 (1-8) respectively. Maternal systolic BP and CO changes were similar in both groups, but the mean [95% CI] maximum percentage change in maternal HR was larger in the phenylephrine group (-28.5 [-24.2, -32.9]%) than in the ephedrine group (-14.4 [-10.6, -18.2]%). As a consequence atropine was required in 11/19 women in the phenylephrine group compared with 2/19 in the ephedrine group (P < 0.01). Mean umbilical artery pH [95% CI] was higher in the phenylephrine group (7.29 [7.28-7.30]) than in the ephedrine group (7.27 [7.25-7.28]). The results of the present study support the use of phenylephrine for maintenance of maternal arterial pressure during spinal anaesthesia for elective Caesarean section.

Randomised trial of intravenous infusion of ephedrine or mephentermine for management of hypotension during spinal anaesthesia for Caesarean section

“…Commonly used methods to prevent or treat such hypotension include preloading with fluids [5], avoidance of aortocaval compression [6] and the administration of vasopressor drugs [7][8][9][10]. Various vasopressor drugs have been studied for this purpose, e.g.…”

Monitoramento não invasivo baseado na biorreatância revela instabilidade hemodinâmica significativa durante cesárea eletiva sob raquianestesia

“…However, hemodynamic changes during cesarean delivery have been assessed through a variety of different methods, including thoracic 15 and whole body impedance 8 , echocardiography and Doppler ultrasound 19 , all minimally invasive techniques 9 , as well as pulmonary artery catheterization and thermodilution. All of these methods have limitations, and are unlikely to become routine clinical practice especially as bedside monitoring techniques.…”

Anaesthesia for insertion of bone‐anchored hearing aids in children: a 7‐year audit

“…There are limited data looking at the incidence and prophylaxis of venous thromboembolism in neurotrauma [20]. The benefits of prophylactic measures have therefore been imperfect and remain controversial.…”

“…Other vasoconstrictors are available but ephedrine may be the most suitable choice because of its b 2 -agonism and theoretical maintenance of uterine blood flow. The a-agonist phenylephrine has been compared with ephedrine in terms of maintenance of blood pressure and cord blood gases but results are inconsistent [19,20]. However, significantly more episodes of maternal bradycardia occur with phenylephrine.…”

“…Furthermore, it is less expensive to prevent than to treat venous thromboembolic complications. Knowledge of available prophylactic methods is critical to the management of these patients.There are limited data looking at the incidence and prophylaxis of venous thromboembolism in neurotrauma [20]. The benefits of prophylactic measures have therefore been imperfect and remain controversial.…”