Effect of intraoperative dexmedetomidine on long-term survival in older patients after major noncardiac surgery: 3-year follow-up of a randomized trial.

STUDY OBJECTIVE: To assess the impact of intraoperative dexmedetomidine on long-term outcomes of older patients following major noncardiac surgery mainly for cancer. DESIGN: A long-term follow-up of patients enrolled in a randomized trial. SETTING: The initial trial was performed in a tertiary care hospital in Beijing, China. PARTICIPANTS: Patients aged 60 years or older who were scheduled for major noncardiac surgery. INTERVENTION: Participants were randomized to receive either dexmedetomidine (a loading dose of 0.6 µg/kg over 10 min, followed by a continuous infusion of 0.5 µg/kg/h until 1 h before end of surgery) or placebo during anesthesia. MEASUREMENTS: The primary endpoint was overall survival. Secondary endpoints included recurrence-free survival and event-free survival. Cox proportional hazard models were used to adjust for predefined confounding factors. Propensity score matching was employed for sensitive analysis. RESULTS: Among 620 patients who were randomized in the initial trial, 619 were included in the long-term analysis (mean age 69 years, 40% female, 77% oncological surgery). The median follow-up duration was 42 months (interquartile range 41 to 45). Overall survival did not differ between the two groups: there were 49/309 (15.9%) deaths with dexmedetomidine versus 63/310 (20.3%) with placebo (adjusted hazard ratio [HR] 0.78, 95% CI 0.53-1.13, P = 0.187). Recurrence-free survival was improved with dexmedetomidine (68/309 [22.0%] events with dexmedetomidine versus 98/310 [31.6%] with placebo; adjusted HR 0.67, 95% CI 0.49-0.92, P = 0.012). Event-free survival was also improved with dexmedetomidine (120/309 [38.8%] events with dexmedetomidine versus 145/310 [46.8%] with placebo; adjusted HR 0.78, 95% CI 0.61-1.00, P = 0.047). Results were similar after propensity-score matching and in the subgroup of cancer patients. CONCLUSIONS: In older patients having major noncardiac surgery mainly for cancer, intraoperative dexmedetomidine did not improve overall survival but was associated with improved recurrence-free and event-free survivals.

Acute Kidney Injury and 3-Year Mortality in Elderly Patients After Non-cardiac Surgery.

Objective: The present study aimed to investigate whether acute kidney injury (AKI) was associated with 3-year mortality in elderly patients after non-cardiac surgery. Methods: The present study was a 3-year follow-up study of two randomized controlled trials. A total of 1,319 elderly patients who received non-cardiac surgery under general anesthesia were screened. AKI was diagnosed by the elevation of serum creatinine within a 7-day postoperative period according to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. A long-term telephonic follow-up was undertaken by investigators who were not involved in the previous two trials and had no access to the study group assignment. The date of death was taken from the official medical death certificate. The primary outcome was to investigate the association between AKI and postoperative 3-year mortality using the multivariable Cox regression risk model. Results: Of the 1,297 elderly patients (mean age 71.8 ± 7.2 years old) who were included in the study, the incidence of AKI was 15.5% (201/1297). Of the patients with AKI, 85% (170/201) were at stage 1, 10% (20/201) at stage 2, and 5% (11/201) at stage 3. The 3-year all-cause mortality was 28.9% (58/201) in patients with AKI and 24.0% (263/1,096) in patients without AKI (hazard ratio 1.247, 95% confidence interval 0.939-1.657, P = 0.128). The multivariable Cox regression showed that AKI was not associated with 3-year mortality after adjustment of confounding factors (adjusted hazard ratio 1.045, 95% confidence interval 0.780-1.401, P = 0.766). Conclusions: AKI was a common postoperative complication, but it was not associated with 3-year mortality in elderly patients who underwent non-cardiac surgery. The low incidence of severe AKI might underestimate its underlying association with long-term mortality.