RESUMO
This study explores the association between postadmission and intraoperative cerebral oxygenation (ScO2), reflecting systemic perfusion, and postoperative mortality and delirium. Forty elderly (age > 65 years) patients with hip fractures were included in this prospective observational study. The ScO2 was determined using near-infrared spectroscopy at initial resuscitation after patients were admitted to the hospital and during surgery. Postoperative delirium was assessed up to seven days after surgery using the memorial delirium assessment scale and the confusion assessment method. Ten patients (25%) developed postoperative delirium within the first seven postoperative days. At initial resuscitation ScO2 was lower in patients that later developed delirium, but the difference was not significant (p = 0.331). Intraoperative ScO2 values remained similar in the two groups. Mortality regardless of cause was 10% (4 out of 40 patients) after 30 days. At initial resuscitation ScO2 was significant lower in the mortality group than in the surviving group (p = 0.042), and the ScO2 nadir values were also significant lower (p = 0.047). Low ScO2 during initial resuscitation (defined as ScO2 < 55 for a minimum of two consecutive minutes) was also significantly associated with 30-day mortality (p = 0.015). There were no associations between low blood pressure and postoperative delirium or 30-day mortality. We found that low preoperative ScO2 was better associated with 30-day all-cause mortality in elderly patients undergoing surgery for hip fracture than blood pressure measurements. Future studies in preoperative resuscitation of hip fracture patients should focus on perfusion measures as opposed to conventional haemodynamic.
