Palonosetron might not attenuate spinal anesthesia-induced hypotension during orthopedic surgery

ABSTRACT

BACKGROUND: 5-Hydroxytryptamine3 (5-HT3) receptor antagonists have been reported to attenuate spinal anesthesia-induced hemodynamic changes. This study was conducted to determine whether the second generation 5-HT3, antagonist palonosetron attenuates hypotension and bradycardia during spinal anesthesia. METHODS: Sixty adult patients scheduled for lower limb surgery were enrolled in this study. Patients were randomly assigned to receive either normal saline (Control group, N = 30) or palonosetron (0.075 mg, i.v.) (Palonosetron group, N = 30) prior to spinal anesthesia. Hemodynamic variables were recorded during anesthesia. RESULTS: The mean blood pressure (MBP) were 89.2 ± 11.4 mmHg in the control group and 87.6 ± 12.1 mmHg in the palonosetron group at 10 min after intrathecal injection (P = 0.609). The median blocked levels of the control group and the palonosetron group were T10 (interquartile range, 9-10) and T10 (8-10) at 20 min after intrathecal injection (P = 0.939). Requirements for ephedrine, phenylephrine, and atropine were similar (P = 0.652, 0.533 and 0.417, respectively). The incidences of hypotension (40% vs. 41%) and bradycardia (7% vs. 17%) were comparable (P = 0.562, P = 0.198, respectively) between the control and the palonosetron group. There were no significances in the changes of systolic blood pressure, diastolic blood pressure, MBP and heart rate by the group (P = 0.632, 0.287, 0.556, 0.733, respectively). CONCLUSIONS: Intravenous palonosetron (0.075 mg) prior to spinal anesthesia might not attenuate spinal anesthesia-induced hypotension during low level of neuroaxial block for lower limb surgery.