Comparison of Phenylephrine and Ephedrine in the Treatment of Hemodynamic Disorders After Spinal Anesthesia in the Elderly

Overview

Spinal anesthesia is often used for lower limb surgery in elderly. Hypotension is a side effect of spinal block. In this study, intravenous ephedrine and phenylephrine will be compared with each other to prevent spinal anesthesia-induced hypotension, which is defined in absolute terms as a systolic blood pressure \< 100 mmHg or in relative terms as a 20% fall of systolic blood pressure from baseline.

Randomized single centre clinical randomized study will be performed on 50 participants. The inclusion criteria are participants (age more than 65 years) with proximal femoral fracture scheduled for lower limb surgery under spinal anesthesia. The Ethics Committee approved this prospective study. Informed consent will be taken from individual subjects. Participants are randomly allocated into one of the two study groups. Group A: participants who will receive intravenous 25 mg of ephedrine added to syringe with 50 ml 0,9% sodium chloride solution during 20 minutes. Group B: Phenylephrine 5 mg will be added to syringe with 50 ml 0,9% sodium chloride solution, participants will receive intravenous 0,3 mg of phenylephrine during 20 minutes. Randomization is achieved with the help of Random.org. In order to reduce pain prior to spinal anesthesia an ultrasound-guided fascia iliaca block will be performed using a volume of 30 ml ropivacaine 0,2%. After skin infiltration with 3 ml of lidocaine, a 25G Pencan spinal needle will be inserted at the L3-L4 or L4-L5 vertebral interspaces. After aspirating cerebrospinal fluid, participants will receive hyperbaric bupivacaine 0.5% at 0,11 mg/cm according to the participant height. Ephedrine and phenylephrine will be given intravenous immediately after injection of bupivacaine. Impedance cardiography will be used to measure hemodynamic parameters: cardiac output, stroke volume, cardiac index, stroke index, systemic vascular resistance, systemic vascular resistance index. Heart rate, blood pressure and oxygen saturation will also be controlled. All these parameters will be measured and recorded every 5 minutes until 30 minutes after spinal anesthesia. The data will be statistically analyzed.