Esmolol reduces anesthetic requirements thereby facilitating early extubation; a prospective controlled study in patients undergoing intracranial surgery

Abstract

Background: Adequate cerebral perfusion pressure with quick and smooth emergence from anesthesia is a major concern of the neuroanesthesiologist. Anesthesia techniques that minimize anesthetic requirements and their effects may be beneficial. Esmolol, a short acting hyperselective β-adrenergic blocker is effective in blunting adrenergic response to several perioperative stimuli and so it might interfere in the effect of the anesthetic drugs on the brain. This study was designed to investigate the effect of esmolol on the consumption of propofol and sevoflurane in patients undergoing craniotomy.

Method: Forty-two patients that underwent craniotomy for aneurysm clipping or tumour dissection were randomly divided in two groups (four subgroups). Anesthesia was induced with propofol, fentanyl and a single dose of cis-atracurium, followed by continuous infusion of remifentanil and either propofol or sevoflurane. Patients in the esmolol group received 500 mcg/kg of esmolol bolus 10 min before induction of anesthesia, followed by additional 200 mcg/kg/min of esmolol. Monitoring of the depth of anesthesia was also performed using the Bispectral Index-BIS and cardiac output. The inspired concentration of sevoflurane and the infusion rate of propofol were adjusted in order to maintain a BIS value between 40-50. Intraoperative emergence was detected by the elevation of BIS value, HR or MAP.

Results: The initial and the intraoperative doses of propofol and sevoflurane were 18-50 mcg/kg/min and 0.2-0.5 MAC respectively in the esmolol group, whereas in the control group they where 100-150 mcg/kg/ and 0.9-2.0 MAC respectively (p = 0.000 for both groups). All procedures were anesthesiologically uneventful with no episodes of intraoperative emerge.

Conclusions: Esmolol is effective not only in attenuating intraoperative hemodynamic changes related to sympathetic overdrive but also in minimizing significant propofol and sevoflurane requirements without compromising the hemodynamic status. ClinicalTrials.gov Identifier: NCT02455440 . Registered 26 May 2015.

Fig. 1

Intraoperative fluctuations of propofol in the control (top of the picture) and the esmolol group (bottom of the picture). Each patient is indicated with a different color. Initial infusion rate of propofol is higher in the control group compared to the esmolol group. Also, infusion rate of propofol at each time point was much lower for the esmolol group than for the control group. Mean value of propofol in control group was 134 ± 12.9mcg/Kg/min, where in the esmolol group was 25.83 ± 9.32 mcg/kg/min during the procedure

Fig. 2

Intraoperative fluctuations of sevoflurane in the control (top of the picture) and the esmolol group (bottom of the picture). Each patient is indicated with a different color. Initial MAC of sevoflurane is higher in the control group compared to the esmolol group. Also MAC of sevoflurane at each time point was much lower for the esmolol group than the control group. Mean value of sevoflurane in control group was 1.49 ± 0.288 MAC MAC, where in the esmolol group was 0.31 ± 0.13MAC during the procedure

Fig. 3

Desaturation of regional cerebral oxygenation during craniotomy. The blue arrow indicates the period of desaturation

Fig. 4

Mean arterial pressure (MAP) fluctuation regarding perioperative time in the control and esmolol group

Fig. 5

Heart rate fluctuations during perioperative period in the control and esmolol group