Comparison of early cognitive function and recovery after desflurane or sevoflurane anaesthesia in the elderly: a double-blinded randomized controlled trial.

BACKGROUND Postoperative cognitive dysfunction (POCD) is being recognized as a complication contributing to perioperative morbidity and mortality of the elderly. We hypothesized that the use of the shorter-acting volatile anaesthetic desflurane would be associated with less incidence of POCD when compared with sevoflurane. METHODS Approved by the local ethical committee, 80 patients (aged 65-75 yr) were enrolled in this randomized, double-blinded study. Patients were allocated to either the desflurane (n=40) or the sevoflurane (n=40) group. The primary outcome was the cognitive Test for Attentional Performance with its subtests Alertness, Divided Attention, Visual Scanning, Working Memory, and Reaction Change. In addition, Paper-Pencil Tests [Well-being Test BF-S, Recall of Digit Span (DST), Digit-Symbol-Substitution Test, Trail Making Tests A and B, and Spielberg State-Trait Anxiety Inventory] were measured. After baseline assessment 12-24 h before operation, patients were followed up 6-8 and 66-72 h after operation. Among other outcome parameters, emergence times from anaesthesia and modified Aldrete scores were recorded. RESULTS There was no difference in the incidence of POCD. However, according to the Paper-Pencil Tests, significant improvements for the desflurane group could be detected (Well-being Test at 6-8 h, DST at 6-8 h, and Trail Making Test at 66-72 h). Emergence was significantly faster in the desflurane group for 'time to open eyes' and 'time to extubation'. CONCLUSIONS The total incidence of POCD showed no differences between the desflurane and the sevoflurane groups. However, the tests Well-being scale, DST, and Trail Making Test, emergence times, and patients' satisfaction were in favour of desflurane.