Does Prophylactic Use of Ondansetron and Phenylephrine Prevent Spinal Anesthesia Induced Hypotension in Adult Surgical Patients? A Cross-Sectional Analytical Study

Abstract

Introduction: Various drugs and techniques have been used to mitigate spinal anesthesia induced hypotension.We conducted this study to analyze whether prophylactic usage of ondansetron and phenylephrine would prevent spinal anesthesia induced hypotension.

Methods: This prospective cross-sectional analytical study was conducted in 135 adult patients who underwent orthopedic, general surgical, urological and gynecological surgery under spinal anesthesia . It was conducted after approval from institutional review board and getting written and informed consent. Convenient sampling technique was used.After spinal anesthesia; 2 mL bolus of study drug was injected. Group O received 4 mg Ondansetron, Group P received 100 µg Phenylephrine and Group N received 2ml Normal Saline. The episodes of hypotension,bradycardia, nausea/vomiting and dose of mephentermine was noted. Data was analyzed using SPSS 21.0.

Results: Hypotension was present in 34 patients (74.07) irrespective of pharmacologic prophylaxis. Hypotension was present in 14 patients (31.11%) in Group O; followed by patients in Group N; 12 (26.67%) and Group P; 8 (17.78%). This difference was not significant statistically when Group O and Group P were compared with Group N (p=0.64 and 0.34 respectively). Patients in Group P and Group O didn’t experience severe nausea whereas 1 (2.22%) patient had severe nausea in Group N. Likewise, 1 (2.94%) patient each in Group N and Group O had vomiting. Bradycardia was present in 2 (5.88%), 1 (2.22%) and 7 (20.58%) patients in Group N, O and P respectively.

Conclusion: The prophylactic use of phenylephrine and ondansetron didn’t prevent spinal anesthesia induced hypotension.