Effect of preoperative hospitalisation period on postoperative cognitive dysfunction in patients undergoing hip surgery under regional anaesthesia.

Abstract

The main objective of this prospective and observational study was to investigate the effect of the preoperative hospitalisation period on early postoperative cognitive dysfunction (POCD) development in patients undergoing total hip replacement surgery under regional anaesthesia. Between November 2013 and September 2014, 64 patients were enrolled in the study. Mini Mental Test (MMT) scores were obtained on the initial admission day (MMT1), 24hours prior to the surgery (MMT2) and 24hours after the surgery (MMT3). The patients were divided into two groups according to the MMT scores: 'no cognitive dysfunction' (group 1) and 'cognitive dysfunction' (group 2). Differences between the groups were evaluated statistically. The statistical significance level was set as P<.05 in a 95% confidence interval. The POCD incidence rate was calculated as 43.8% in all patients. The preoperative hospitalisation duration was significantly longer in patients with POCD than in patients without POCD (P<.001). The factors that affected POCD development were found to be advanced age (P<.001), high American Society of Anesthesiologists scores (P=.004), the presence of comorbid disease (P=.025), durations of surgery (P=.018) and decreased postoperative haematocrit levels (P=.014). In this study, we observed that patients with early POCD had relatively longer preoperative hospitalisation periods than those in patients without POCD. We consider that prolonged preoperative hospitalisation may contribute to increased POCD incidence rates in patients with risk factors.