Fast-track cardiac anaesthesia in the elderly: effect of two different anaesthetic techniques on mental recovery

Elderly patients may be considered for 'fast-track' cardiac anaesthesia, but can suffer psychological complications and slow recovery of mental function after surgery, which can interfere with recovery. Reduced metabolism and changed distribution of anaesthetic and sedative agents can cause poor recovery. We made a prospective randomized comparison of mental function, haemodynamic stability and extubation and discharge times in elderly patients (65-79 yr) receiving two premedication, anaesthetic and sedative techniques. Patients received either propofol (n=39) (fentanyl 10-15 microg kg(-1) and propofol 2-6 mg kg(-1) intraoperatively and a propofol infusion for 3 h postoperatively) or premedication with lorazepam followed by midazolam for anaesthesia (n=39) (fentanyl 10-15 microg kg(-1) and midazolam 0.05-0.075 mg kg(-1) intraoperatively and a midazolam infusion for 3 h postoperatively). Impairment of mental function was noted in 41% of patients in the propofol group and 83% in the lorazepam and midazolam group (P=0.001) 18 h after extubation. Patients in the propofol group were extubated earlier [1.4 (SD 0.6) vs 1.9 (0.8) h, P=0.02]; and reached standard intensive care unit discharge criteria [7.6 (4.6) vs 14.2 (13) h, P=0.02] and hospital discharge criteria [4.3 (1.0) vs 4.9 (1.1) days, P=0.04) sooner than patients in the lorazepam and midazolam group, but actual discharge times did not differ between the groups. Haemodynamic values were stable in both groups.