Relationship between delirium incidence and different operation timings of hip arthroplasty in elderly patients

Abstract

Objective To study the effect of different timing of surgery on the incidence of postoperative delirium in elderly patients undergoing hip replacement. Method According to the criteria of admission, a total of 83 patients undergoing hip replacement over 65 years old were selected in Shunde Second People’s Hospital from February 2013 to February 2017. The total hip replacement group (THR, 39 cases) and the femoral head replacement group (FHR, 44 cases) were divided into the total hip replacement group. The patients of different operation method were divided into the control group (C) and the experimental group (T) according to the operation time (later than 48 h or earlier than 48 h after injury). Finally, four groups of THR-C(25 cases)、THR-T(14 cases)、FHR-C(21 cases)、FHR-T(23 cases) were obtained. Anesthesia and operation were performed by intraspinal anesthesia. Heart rate (HR), mean arterial pressure (MAP), and surplus pulse O2(SpO2) were maintained before the operation (Tp), during the operation (T0) and three days after theoperation(T1~T3), and pain score (VAS) at each time point was recorded. The confusion assessment method- Chinese reversion (CAM-CR) for delirium was used to assess the delirium at each time point and record the number of delirium at each time point. Chi-square test or rank sum test were used to analyse the data. Results Before operation, all the patients were in moderate and severe pain (VAS: 6-8), high blood pressure (MAP: 110-99mmHg), and intraoperative and postoperative indexes improved significantly (VAS: H=201.22; MAP: F=576.348, P<0.05). The incidence of delirium on the 3rd day after operation: the delirium incidence of surgical treatment within 48 h was less than that late than 48 h (THR-C vs THR-T: χ2=4.92; FHR-C vs FHR-T: χ2=7.58, both P<0.05); and the delirium incidence of FHR was lower than that of THR (THR-C vs THR-T: χ2=4.27, P<0.05); among them, THR-C group had the highest incidence of 56.0%, while FHR-T group had the lowest incidence of 13.0% (χ2=7.877, P<0.05). The duration of hospitalization the patients operated within 48 h was significantly shorter than the patients operated late than 48 h(THR-C vs THR-T: F=6.892; FHR-C vs FHR-T: F=127.489, P<0.05); the FHR-T group had the shortest length of hospital stay(14.8±7.6)d(F=214.086, P<0.05). The length of hospital stay in the patients operated within 48 h was significantly shorter than the patients operated late than 48 h (THR: F=6.892; FHR: F=127.489, both P<0.05). Conclusion The incidence of postoperative delirium in the elderly patients with hip replacement is affected by the surgical timing, and surgical treatment within 48 h can significantly reduce the incidence of postoperative delirium and shorten the time of hospitalization. Key words: Aged; Hip; Arthroplasty; Delirium; Incidence