Sevoflurane was more effective than remifentanil controlling hemodynamic function in patients undergoing laparoscopy

MV Bellido3, I Bellido1, T Fernandez-Vilchez T2, MJ Fernandez-Baena3, A Gomez-Luque2. 1University of Malaga, Pharmacology and Clinical Therapeutics, Spain, 2Virgen de la Victoria University Hospital, Anaesthesia Service, Spain, 3Carlos Haya University Hospital, Anaesthesia Service, Spain

Background: Significant hemodynamic effects (increases of QT dispersion, heart rate (HR) variability, reduced mean arterial pressure (MAP)) have been described during pneumoperitoneum associated with head-up position in patients undergoing laparoscopy surgery regardless to the anesthetic techniques used (1). Sevoflurane provides a better myocardial protection than isoflurane. Remifentanil rapid onset of action, short half-life, and lack of hemodynamic effects make it a versatile drug for hemodynamic control during surgery. Controlled studies are needed to determine the best anesthetic able to control the hemodynamic response during surgery without causing significant cardiovascular depression.

Aims: To quantify the efficacy and safety of sevoflurane repeated inhalatory bolus vs. one inhalatory bolus of sevoflurane followed by repeated remifentanil IV bolus in the hemodynamic function control during anesthesia in patients undergoing laparoscopy surgery.

Methods: After obtaining approval by Malaga University Ethics Review Board and informed consent prior to the study, a prospective, randomized and controlled study in ASA class I-III patients scheduled for elective abdominal laparoscopic major surgery undergoing general anesthesia was done. All patients received midazolam 0.03 mg/kg IV premedication and an inhaled induction with sevoflurane 8% (fresh gas flow 6 L/min, and FiO2 100%) one bolus, and cisatracurium 0.1 mg/kg bolus dose (after loss eyelash reflex). After that patients were randomized to sevoflurane 8%/3 min bolus dose group and remifentanil 2 µg/kg/2 min bolus dose + sevoflurane 1% continuous inhalation group. After then maintenance of anesthesia in both groups was the same (sevoflurane 1%, fresh gas flow 2 L/min, semi-closed circuit, and remifentanil 0.1 µg/kg/min, and cisatracurium 0.1 mg/kg/min. Clinical and surgical parameters, bispectral index, MAP, HR, pulse oxymetry and capnography were monitored. An excessive hemodynamic response was defined as a MAP or HR decrease of ≥15% below baseline values. Results were analyzed by Student t test, ANOVA test followed by Bonferroni post-test, and Chi-square test.

Results: 106 patients (80% male, aged 65.5±12.4 years old, ASA class II-III) undergoing general (35%) and urology (65%) surgery were treated with sevoflurane (n=54) and remifentanil (n=52) were included. Sevoflurane was significantly more effective than remifentanil in preventing a hemodynamic response to a surgical stimulus thus there was an excessive hemodynamic response (mainly namely decrease in MAP) in remifentanil group compared with Sevoflurane group (71.4% vs. 28.6%, respectively (P<0.05). No significant differences were found for both groups in the duration of the effective bolus doses for the control of hemodynamic response to surgical stress, extubation time, and postoperative pain and sedation scores at 1 and 5 min after extubation.

Conclusion: Sevoflurane was more effective than remifentanil in control the hemodynamic response to surgical stress in patients undergoing laparoscopy surgery under general anesthesia.

Reference: (1) Di Iorio C et al (2010). Minerva Anestesiol 76 (11): 882.