An Inhalation Bolus of Sevoflurane Versus an Intravenous Bolus of Remifentanil for Controlling Hemodynamic Responses to Surgical Stress During Major Surgery: A Prospective Randomized Trial

UNLABELLED: We studied 120 patients scheduled for elective major thoracic or abdominal surgery, randomized into 2 groups: a Sevoflurane group (n = 63) and a Remifentanil group (n = 57). Heart rate (HR) and mean arterial pressure (MAP) are indicative of sympathetic response to surgical stress. A positive response was defined as a 15% increase in the HR and MAP above baseline measurements. When a positive response occurred, in the Sevoflurane group we administered a bolus dose of 8% sevoflurane (fresh gas flow 6 L/min) and in the Remifentanil group, an IV bolus dose of remifentanil 1 microg x kg(-1) x min(-1), which was maintained until MAP and HR returned to baseline measurements (effective bolus). If, after a bolus dose, a decrease in MAP and/or HR of >15% occurred with respect to baseline values, the response was considered to be excessive. The bolus dose was ineffective in 4.8% of the responses in the Sevoflurane group and in 17.8% of the responses in the Remifentanil group (P < 0.05). In the Sevoflurane group, an excessive effect occurred in 12% of responses, and in 26.7% in the Remifentanil group (P < 0.05). An inhalation bolus of sevoflurane seems to be more effective than an IV remifentanil bolus during maintenance, with more effective control of hemodynamic responses to surgical stress. IMPLICATIONS: We compared an inhalation bolus of sevoflurane with remifentanil for managing hemodynamic responses to major abdominal or thoracic surgery. This prospective, randomized trial demonstrated better results with sevoflurane.