Changes of the T-wave on range of spinal blockade after low dose epinephrine administration

BACKGROUND: Epidural test solution is administered to confirm the correct positioning of an epidural catheter. Hemodynamic changes after administration of epidural test solution reportedly help confirm intravenous (IV) placement of epidural catheters. The change in T wave amplitude is important for checking intravascular placement of epidural catheters. We examined changes in T wave amplitude according to the level of spinal anesthesia after IV epinephrine administration. METHODS: Eighty-one healthy patients undergoing spinal anesthesia were randomized into three groups: group C (control), group L (low spinal block), and group H (high spinal block). All patients received an IV administration of test solution, 3 ml of 1% lidocaine and epinephrine 10 µg. Systolic blood pressure (SBP), heart rate (HR), and T wave amplitude were measured up to 5 min after test solution administration. Adverse reactions post administration of test solution were also recorded. RESULTS: In all groups, after administration of IV test solution, SBP and HR increased, and the T wave amplitude decreased. There were no significant differences in HR, SBP, and T wave amplitude changes between the groups after administrating test solution. Fifteen out of 25 patients (60.0%), 10 out of 24 (41.6%), and 11 out of 23 (47.8%) complained of adverse symptoms in groups C, L, and H, respectively. CONCLUSIONS: This study suggests that change in T wave amplitude after administration of a low dose of epinephrine is not affected by the spinal block range.

Comparison of prophylactic anti-emetic effects of ramosetron between single bolus administration and continuous infusion following bolus administration

BACKGROUND: The authors hypothesized that the continuous infusion of ramosetron 0.15 mg following a 0.15 mg bolus administration would maintain higher 5-hydroxytryptamine type 3 receptor occupancy levels and be more effective in preventing postoperative nausea and vomiting (PONV) than a 0.3 mg single bolus administration. We conducted a study to compare the efficacy of single bolus ramosetron administration with the combination of continuous infusion following intravenous bolus administration for PONV prophylaxis. METHODS: One hundred and fifty female patients undergoing thyroidectomy were allocated randomly to one of three groups to receive a placebo (Group 1, n = 49), 0.3 mg of IV ramosetron (Group 2, n = 53), or the continuous infusion of 0.15 mg ramosetron following a bolus administration of 0.15 mg of ramosetron (Group 3, n = 48). Anesthesia was maintained with sevoflurane and N2O. The incidence of PONV, nausea severity, and use of rescue antiemetics during the postoperative 24 hours were recorded. RESULTS: Group 1 showed higher incidences of PONV during the postoperative 24 hour than Group 2 (81% vs. 58%, P = 0.02) and Group 3 (81% vs. 48%, P < 0.01), but there was no difference between Groups 2 and 3 (P = 0.39). The use of rescue antiemetics was significantly lower in Groups 2 and 3 than Group 1 during the postoperative 6 to 24 hours. CONCLUSIONS: There were no significant differences of incidence and severity of PONV between ramosetron 0.3 mg single bolus administration and the combination of ramosetron infusion after 0.15 mg bolus administration.