The effect of anesthesiologic technique on the mental state of elderly patients submitted for orthopedic surgery of the lower limbs

UNLABELLED: Influence of anesthetic technique on mental status in elderly patients submitted to major orthopedic procedures of lower limbs. Mental impairment is a common occurrence in elderly patients after major orthopedic surgery. Few studies have been published so far on this topic in spite of its relevant clinical and economic implications. OBJECTIVE: 1) To verify whether anesthesia has a causative role in postoperative mental confusion in elderly patients; 2) to compare the effects of General Anesthesia (GA) and Spinal Anesthesia (SA) on mental status. DESIGN: Controlled, comparative study. PATIENTS: Sixty patients aged > or = 70, ASA I-II, submitted to femoral neck repair. SETTING: Anesthesia Dept. and Orthopedic Dept. of a District Hospital in Italy. METHOD: The day before surgery the mental status of elected patients was evaluated employing a modified Organic Brain Syndrome (OBS) scale (Gustafsson). The better the mental status, the lesser the OBS score. It was possible therefore to distinguish "oriented" from "confuse" patients (38 vs 22) if they scored 6 respectively. Patients from each group were than randomly assigned to receive either GA or selective SA. Neither group was premedicated. GA was induced with propofol 1 mg/kg and maintained with O2/N2O 40/60% and isoflurane; atracurium was employed to facilitate mioresolution. Spinal anesthesia was performed with hyperbaric 1% bupivacaine. All patients were monitored in the Recovery Room (RR) for at least one hour. Occurrence of hypotension and/or hypoxia in the Operating Room (OR) or the RR was immediately treated. Mental status was reassessed on the 1st and 2nd postoperative day and results were compared with the corresponding preoperative OBS scores both in GA patients and in SA patients. RESULTS: No statistically significant differences were found between pre- and postoperative OBS scores in both GA and SA group, whether "oriented" or "confuse". CONCLUSIONS: Mental status of elderly patients submitted to femoral neck repair doesn't seem to be influenced by the anesthetic technique chosen, independent of preoperative psychic conditions.