Hanamoto H, Sugimura M, Morimoto Y, Kudo C, Boku A, Niwa H. Small bolus of esmolol effectively prevents sodium nitroprusside-induced reflex tachycardia without adversely affecting blood pressure.
J Oral Maxillofac Surg 2012;
70:1045-51. [PMID:
22364858 DOI:
10.1016/j.joms.2011.12.036]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 12/27/2011] [Accepted: 12/30/2011] [Indexed: 11/30/2022]
Abstract
PURPOSE
Hypotensive anesthesia with sodium nitroprusside (SNP) often is associated with reflex tachycardia. The purpose of this study was to investigate whether a small bolus of esmolol could counteract SNP-induced reflex tachycardia and sympathetic activation without affecting blood pressure.
MATERIALS AND METHODS
Using a time-series study design, 27 healthy young patients scheduled for mandibular osteotomy were enrolled in this study. General anesthesia was maintained with 2% sevoflurane and 67% nitrous oxide in oxygen. SNP was administered to decrease the mean arterial pressure to 55 to 65 mm Hg. When heart rate (HR) increased reflexively to higher than 95 beats/min from SNP-induced hypotension, esmolol 0.5 mg/kg was given. Blood pressure and HR were measured, and the low-frequency component (0.04 to 0.15 Hz) of systolic blood pressure variability and high-frequency component (0.15 to 0.4 Hz) of HR variability were calculated to evaluate the autonomic condition. Data were analyzed using 1-way analysis of variance after multiple comparisons or t test. P < .05 was considered statistically significant.
RESULTS
Of the 27 patients analyzed, 19 patients (70%) required esmolol. In these patients, SNP caused an increase in the low-frequency component of systolic blood pressure variability and a decrease in the high-frequency component of HR variability, leading to tachycardia (HR range, 95.9 ± 7.3 to 106.7 ± 7.4 beats/min; P < .001). Esmolol suppressed the effects of SNP on the low-frequency component of systolic blood pressure variability and high-frequency component of HR variability, resulting in an immediate decrease in HR to 86.9 ± 6.2 beats/min (P < .001), whereas mean arterial pressure remained unchanged.
CONCLUSIONS
A small bolus of esmolol can suppress reflex tachycardia without significantly changing mean arterial pressure. Thus, esmolol restores the autonomic imbalance induced by SNP during hypotensive anesthesia.
Collapse