Background Blood pressure fluctuation is very common during non-cardiac surgery in elderly. This retrospective study was to analyse whether intraoperative hypotension in elderly and other risk factors relate to the postoperative mortality. Methods A total of 118 cases (Observational group), who underwent noncardiac surgery in three medical centers between September 2014 and March 2017, and died in the hospital after the noncardiac surgery. With 1:2 ratio of propensity matching, 236 survival cases (Control group) were selected for comparison analyses with the death cases. Intraoperative blood pressure and perioperative parameters from both groups were collected from electronic anaesthesia charts. Data were analysed with univariate logistic regression analysis where variables with p values less than 0.05 were analysed with multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve was constructed. Results There are five risk factors related to postoperative death in elderly patients: ASA grade, COPD, emergency surgery, general anesthesia, 60 < MAP ≤ 65mmHg (OR > 1), and one factor may reduce the risk of postoperative mortality, which is PACU therapy (OR < 1). Compared with the Control group, the Observational group had a higher proportion of cerebral hernia, kidney injury and trauma ( p < 0.001). The intraoperative blood transfusion volume and intraoperative blood loss volume were higher in the Observational group than the Control group ( p < 0.001). The proportion of using vasoactive drugs was higher in the Observational group ( p < 0.001), and there was more urine output during the operation in the Observational group ( p = 0.005). Conclusion The intraoperative MAP of geriatric patients lower than 65mmHg is highly related to the postoperative mortality. Elderly patients with emergency surgery, high ASA grade and a history of COPD have an increased risk of postoperative mortality. General anesthesia is a risk factor for postoperative death in elderly patients, and the PACU therapy is a protective factor to avoid postoperative death. Trial Registration This study has been retrospectively registered in the Chinese Clinical Trials Registry (ChiCTR2000038912, 10/10/2020).

This study aims to evaluate the effects of dexmedetomidine on organ function, inflammation response, and oxidative stress in elderly patients following iatrogenic lower limb ischaemia-reperfusion (IR) during unilateral total knee arthroplasty.Methods: Following unilateral total knee arthroplasty, 54 elderly patients were randomized to receive either intraoperative intravenous injection of dexmedetomidine (n = 27) or equivalent volume of 0.9% saline (n = 27). Blood samples were harvested at 5 minutes before lower limb tourniquet release (baseline); and 1, 6 and 24 hours after tourniquet release. Surrogate markers of cardiac, pulmonary, hepatic and renal function, oxidative stress, inflammatory response, along with parasympathetic and sympathetic activity were recorded and analysed.Results: The levels of blood xanthine oxidase, creatine kinase, lactic acid and respiratory index increased in patients following tourniquet-induced lower limb IR injury.