Effect of remifentanil on hemodynamics and spontaneous ventilation at the early induction phase in elderly patients

Twenty two patients requiring elective surgery under general anesthesia were enrolled. During the study, subjects inhaled 50% oxygen by a facemask. Heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), stroke volume (SV) and respiratory rate (RR) were recorded before (baseline) and during continuous infusion of remifentanil at rate of 0.25 μg · kg^-1 · min^-1. Arterial blood gases analysis were performed at the baseline and 5 min after initiation of remifentanil administration. HR was slightly decreased by remifentanil infusion compared to the baseline. Instead, there were slight increases in SV and CO. Although RR remained unchanged, partial pressure of arterial carbon dioxide were slightly increased. In elderly patients under spontaneous respiration, administration of remifentanil 0.25 / xg · kg^-1 · min^-1 for five minutes prior to propofol did not significantly deteriorate hemodynamics and ventilator function.