Effects of Preoperative Serotonin-Receptor-Antagonist Administration in Spinal Anesthesia-Induced Hypotension: A Randomized, Double-blind Comparison Study of Ramosetron and Ondansetron.
OBJECTIVE
The adverse effects of spinal anesthesia (SA) include arterial hypotension and bradycardia. The aim of this study was to compare the effects of 2 type 3 serotonin receptor antagonists in SA-induced adverse effects. Specifically, we assessed whether ramosetron was more effective than ondansetron in reducing SA-induced decreases in blood pressure (BP) and heart rate (HR).


METHODS
A total of 117 patients undergoing orthopedic surgery and receiving SA were intravenously administered 0.3 mg of ramosetron (n = 39, group R), 4 mg of ondansetron (n = 39, group O4), or 8 mg of ondansetron (n = 39, group O8). Systolic BP (SBP), diastolic BP (DBP), mean BP (MBP), HR, and the lowest SBP, DBP, MBP, and HR values were measured preoperatively (baseline) and intraoperatively. The incidence of postoperative nausea and vomiting, the need for rescue antiemetics, the amount of patient-controlled analgesia consumption, and pain score in the first 48 hours after surgery were determined.


RESULTS
Baseline values did not significantly differ among the 3 groups. After SA, SBP, DBP, MBP, and HR were lower than their baseline values in all 3 groups. The differences between the baseline and the lowest values were significantly less in group R than in groups O4 and O8 with respect to SBP (P < 0.001), DBP (P = 0.001), and MBP (P < 0.001) less in group R than in group O4 with respect to HR (P = 0.032). Intergroup differences were not significant for postoperative nausea and vomiting, the need for rescue antiemetics, patient-controlled analgesia consumption, or pain score.


CONCLUSIONS
The administration of ramosetron (0.3 mg) significantly attenuated the SA-induced decrease in BP compared with 4 or 8 mg of ondansetron and HR compared with 4 mg of ondansetron.
From the *Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi; and † Department of Anesthesiology and Pain Medicine, Dankook University Hospital, Cheonan, Chungcheongnam, South Korea.
Hyun-Jung
HJ
Shin
Eun-Su
ES
Choi
Gwan-Woo
GW
Lee
Sang-Hwan
SH
Do
D000328:Adult; D000368:Aged; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D001562:Benzimidazoles / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007022:Hypotension / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D017294:Ondansetron / Q000008:administration & dosage*; D020250:Postoperative Nausea and Vomiting / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control; D011300:Preoperative Care / Q000379:methods*; D012702:Serotonin Antagonists / Q000008:administration & dosage*; D016896:Treatment Outcome
D001562:Benzimidazoles; D012702:Serotonin Antagonists; D017294:Ondansetron; C071315:ramosetron