INTRAMUSCULAR PHENYLEPHRINE DOSE COMPARISON FOR PREVENTION OF SPINAL ANESTHESIA INDUCED HYPOTENSION DURING CESAREAN SECTION: A PROSPECTIVE RANDOMIZED DOUBLE BLIND STUDY

OBJECTIVE: To determine the more effective dose of intramuscular (IM) Phenylephrine in preventing hypotension due to spinal anesthesia (SA) administered for cesarean section. METHODS: The study was conducted from January 1, 2020 to July 31, 2020, at Rehman Medical Institute, Peshawar, Pakistan. Sixty participants of American Society of Anesthesiologists (ASA) physical status 1 and 2, scheduled for elective cesarean section (CS) under SA were enrolled in this prospective double-blind study and randomized into two equal groups, P4-group and P8-group. P4-group received IM Phenylephrine 04 mg and P8-group received IM Phenylephrine 08 mg before SA. The incidence and intensity of hypotension, rescue doses of Phenylephrine and any adverse event, were recorded. Data collected was analyzed using Epi lnfo ™ version 7.2.5. RESULTS: Mean age of patients from P4-Group and P8-Group was 28.10±4.39 years and 28.33±4.95 years respectively. There were no statistically significant differences in the two groups with respect to demographic and clinical characteristics. Hypotension occurred in 33.3% (n=20/60) of participants. The incidence of hypotension in P4-group and P8-group were 46.7% (n=14/30) and 20% (n=6/30) respectively. In P8-group, risk of hypotension was 1.5 times less common compared with P4-group with 95% confidence interval of 1.02–2.19 (p=0.02). There was also no statistically significant difference between the onset of hypotension in the two groups. Those who developed hypotension had consumed a lesser amount of rescue Phenylephrine in P8-group compared with P4-group (p-value <0.01). CONCLUSION: Phenylephrine 08 mg IM preemptively controlled SA induced hypotension in a sustained way in the fit parturients.