Need of pharmacotherapy to prevent hemodynamic effects after subarachnoid block: A prospective randomized double blind placebo controlled study

The neuraxial anesthesia presents several advantages over general anesthesia, however hypotension and bradycardia are the inevitable consequences of spinal anesthesia (SA). In fear of fall in perfusion of vital organs like kidney, it is a common practice to administer drugs to prevent the hemodynamic changes after SA. Herewith, we have tried to evaluate the need of pharmacotherapy to prevent hemodynamic effects after subarachnoid block.

Total 120 adult patients of ASA physical status I/II admitted in a tertiary care center for elective surgeries on lower abdomen and lower limb were selected for the study. They were randomly divided into 2 equal groups. Group I (control group) received 1 cc of water for injection while Group II (study group) received 1cc (inj. Atropine 0.3 mg + inj. Ephedrine hydrochloride 5 mg) intravenously 10 min after giving spinal anesthesia. Confounding variables like volume of fluid administered, positioning and sensory level were reduced to minimum. Hemodynamic variables like heart rate, systolic, diastolic, mean blood pressure, spO2 were recorded at 5 minute intervals up to 2 hrs after commencement of spinal anaesthesia. Urine output was recorded by urometer and the values were noted every 30 min, adverse reactions were noted by a blinded observer.

The demography and types of surgeries for both the groups were comparable. Heart rates and blood pressures dropped down after giving SA. Though variation between two groups was statistically significant, at the end of 2 hours they resumed baseline levels. There was no adverse effect on urine output and incidence of adverse effects in both the groups was comparable.

It is not necessary to use preventive pharmacotherapy to counterbalance hemodynamic changes occurring after subarachnoid block.