Sun Chong Kim

Comparison of ramosetron with ondansetron for prevention of postoperative nausea and vomiting in patients undergoing gynaecological surgery

BACKGROUNDnRamosetron is a new selective 5-hydroxytryptamine type 3 (5-HT(3)) receptor antagonist that reportedly has more potent antiemetic effects compared with other 5-HT(3) receptor antagonists. The purpose of this study was to evaluate the efficacy of ramosetron for the prevention of postoperative nausea and vomiting (PONV) with that of ondansetron or placebo in high-risk patients undergoing gynaecological surgery.nnnMETHODSnIn this prospective, randomized, double-blinded, placebo-controlled study, 162 healthy patients who were undergoing gynaecological operation under general anaesthesia using sevoflurane were enrolled. Patients were divided into three groups: the ramosetron group (0.3 mg i.v.; n=54), the ondansetron group (8 mg i.v.; n=54), and the placebo group (normal saline i.v.; n=54). The treatments were given before the end of surgery. The incidence of PONV, severity of nausea, and the use of rescue antiemetic requirements during the first 24 h after surgery were evaluated.nnnRESULTSnThe incidence of nausea was lower in the ramosetron (50%) and ondansetron (44%) groups compared with the placebo group (69%) (P<0.05). In addition, the incidence of vomiting was lower in both the ramosetron (17%) and the ondansetron (20%) groups than in the placebo group (44%) during the first 24 h after surgery (P<0.05). The visual analogue scale score for nausea was also lower in the ramosetron and ondansetron groups compared with the placebo group (P<0.05). The proportion of patients requiring rescue antiemetics was significantly lower with ramosetron (15%) when compared with the placebo group (41%) during the 24 h after surgery (P<0.05). However, there were no significant differences in the incidence of nausea and vomiting, severity of nausea, and required rescue PONV between the ramosetron and the ondansetron groups.nnnCONCLUSIONSnRamosetron 0.3 mg i.v. was as effective as ondansetron 8 mg i.v. in decreasing the incidence of PONV and reducing nausea severity in female patients during the first 24 h after gynaecological surgery.

The hemodynamic changes by different end-tidal CO2 under anesthesia using sevoflurane-N2O

BACKGROUNDnHypercapnia augments cardiac output and can initiate a sympathetically mediated release of catecholamines to increase cardiac output. Many studies of hemodynamic changes by hypercapnia under general anesthesia with inhalation anesthetics besides sevoflurane. This study examined the hemodynamic changes by increasing end-tidal carbon dioxide (EtCO2) under sevoflurane-N2O anesthesia.nnnMETHODSnTwenty patients were enrolled in the study. We studied stable, mechanically ventilated patients under general anesthesia maintained with O2 2 L/min - N2O 2 L/min - sevoflurane (1.5-2.5 vol%). Hypercapnia were obtained by reducing tidal volume and respiratory rate. EtCO2 was adjusted to 30, 40, 50 mmHg with each concentration maintained for 15 min. Global hemodynamic variables were monitored with a pulmonary artery catheter.nnnRESULTSnThere were no changes in mean arterial pressure or heart rate by hypercapnia. Acute moderate hypercapnia increased cardiac output (4.9 +/- 1.7, 5.5 +/- 1.7, 6.2 +/- 2.1 L/min; P < 0.05), cardiac index (3.0 +/- 0.9, 3.4 +/- 0.9, 3.8 +/- 1.1 L/min/m2; P < 0.05), pulmonary artery pressure (16.9 +/- 3.7, 19.6 +/- 4.2, 23.0 +/- 4.7 mmHg), but did not decrease systemic vascular resistance (1,558.3 +/- 500.4, 1,423.5 +/- 678.6, 1,156.8 +/- 374.0 dynes.sec/cm5; P > 0.05).nnnCONCLUSIONSnWhen we changed patient EtCO2 to 30, 40, and 50 mmHg, there were no changes in mean arterial blood pressure and heart rate, but systemic vascular resistance decreased, and cardiac output, cardiac index and mean pulmonary arterial pressure increased significantly.