Comparison of esmolol and nitroglycerine on hemodynamic parameters during extubation in obese patients following laparoscopic cholecystectomy: a prospective randomized study

Introduction: One of the main concerns for the anesthesiologist in obese hypertensive patients is to prevent hypertension, tachycardia and arrhythmias during extubation, and to ensure an awake patient with full airway control and stable hemodynamics. Our aim was to compare the effects of single bolus of intravenous nitroglycerine and intravenous esmolol on hemodynamic response and quality of extubation following tracheal extubation in obese patients posted for elective laparoscopic surgery. Methodology: 60 ASA PS II and III patients with BMI > 25, undergoing elective laparoscopic cholecystectomy under general anesthesia were randomly divided into two groups: Group E (n=30) received esmolol 2 mg/kg intravenously; Group N (n=30) received nitroglycerine 2 mu g/kg before extubation. Heart rate (HR), systolic, diastolic and mean arterial pressures were recorded at time of discontinuation of isoflurane (T0), at time of reversal (T1), before (T2) and after (T3) extubation, 3 min (T4) and 5 min (T5) postextubation. Statistical analysis was done using Stata 11 software. For continuous variables, mean and standard deviations were compared using unpaired t-test. For categorical data chi-square test was applied. For comparison of scores two-sample Wilcoxon rank-sum (Mann-Whitney) test was used. P-value < 0.05 was considered significant. Rate pressure product was calculated and was the primary outcome measure. Results: HR rate was significantly lower in Group E as compared to Group N at T2 (82.06 +/- 13.7 vs 100.31 +/- 12.04, p < 0.05), T3 (80.8 +/- 8.7 vs 99.06 +/- 16.17, p > 0.05) and T4 (67.23 +/- 8.68 vs 90.03 +/- 8.27, p < 0.01). Maximum percentage decline in HR (19.22%) in Group E was seen at T4 compared to T0. Systolic blood pressure was significantly low compared to Group N at T2 (148.9 +/- 8.66 vs 155.7 +/- 14.81, p < 0.05), T3 (131.9 +/- 8.91 vs 137.9 +/- 8.86, p < 0.01 and T4 (127.56 +/- 9.01 vs 135.63 +/- 9.71, p < 0.01). Rate pressure product was significantly lower in Group E at T2, T3 and T4 as compared to Group N. Maximum percentage decline in rate pressure product (23.38%) in Group E was seen at T4 when compared to T0. No significant difference was observed in sedation score, time to extubation or quality of extubation. Conclusion: Administration of nitroglycerine and esmolol intravenously prior to extubation in obese hypertensive patients is a practical and safe method to ensure stable hemodynamics with good patient awakening and airway control during extubation. Esmolol has a significantly better effect in controlling rate pressure product.