The preventive effect of 5-hydroxytryptamine-3 receptor antagonist on blood pressure reduction and postoperative nausea and vomiting during general anesthesia induction: A double-blinded, randomized controlled trial

Study objective: Administering a 5-hydroxytryptamine-3 receptor (5-HT3) at anesthesia induction may aid in achieving hemodynamic stability during general anesthesia induced using opioids. Therefore, we aimed to evaluate the effect of ramosetron, a 5-HT3 antagonist, administered on hypotension at the induction of total intravenous anesthesia (TIVA) with propofol and remifentanil. Additionally, we aimed to compare the impact of ramosetron administration at anesthesia induction versus that at the end of the surgery on postoperative nausea and vomiting (PONV). Design: Patients were randomly allocated to the Induction group (administration of ramosetron [0.3 mg/5 ml] at anesthesia induction and normal saline [5 ml] at the end of the surgery) or End group (administration of normal saline [5 ml] at anesthesia induction and ramosetron [0.3 mg/5 ml] at the end of the surgery). Hemodynamic status, PONV, and postoperative pain were assessed. Setting: Operating room, post-anesthetic care unit, and general ward. Patients: In total, 176 non-smoking patients without any past medical history undergoing laparoscopic gynecological surgeries under TIVA were included in the study. Measurements: Blood pressure (BP), heart rate, PONV, visual analog scale (VAS). Main results: The Induction group exhibited significantly higher BP at anesthesia induction and required significantly lower doses of phenylephrine and ephedrine during anesthesia than the End group had. However, PONV and postoperative pain were similar between the two groups. Conclusions: Administering ramosetron at anesthesia induction resulted in significantly better hemodynamic stability with significantly lesser requirement of phenylephrine and ephedrine than administering at the end of the surgery did. Therefore, we recommend ramosetron administration at anesthesia induction rather than at the end of the surgery to prevent PONV and the decrease in the mean BP during TIVA with propofol and remifentanil.