Major complications, delirium associated with adverse events after elective surgery in older adults

Major postoperative complications and delirium contribute independently to adverse outcomes and high resource use in patients who undergo major surgery; however, their interrelationship has not been well examined. Understanding the risks of adverse outcomes in an aging surgical population is essential to implementing programs with the potential to decrease complications, mortality, and costs and to increase safety, according to background information in the article.

Sharon K. Inouye, M.D., M.P.H., of Beth Israel Deaconess Medical Center, Boston, and colleagues evaluated the association of major postoperative complications and delirium, alone and combined, with adverse outcomes after surgery. The study included 566 patients (70 years or older) who underwent elective major orthopedic, vascular, or abdominal surgical procedures with a minimum 3-day hospitalization at two large academic medical centers.

Major postoperative complications were defined as life-altering or life-threatening events. Delirium was measured daily. Four subgroups were analyzed: (1) no complications or delirium; (2) complications only; (3) delirium only; and (4) complications and delirium. Adverse outcomes included a length of stay (LOS) of more than 5 days, institutional discharge, and rehospitalization within 30 days of discharge.

Of the 566 participants, 47 (8 percent) developed major complications and 135 (24 percent) developed delirium. The researchers found that major complications alone contributed significantly to prolonged LOS only while delirium alone contributed significantly to all adverse outcomes (LOS, institutional discharge, and hospital readmission). When delirium and other major complications occurred together, the effect on adverse outcomes was the greatest, but this effect occurred relatively infrequently (20 of 566 participants [3.5 percent]). Delirium exerted the highest attributable risk compared with all other adverse events.

"Delirium is not consistently considered a major postoperative complication. However, given its prevalence and clinical effect, delirium should be considered a leading postoperative complication for predicting adverse hospital outcomes," the authors write.

"These results suggest that it is important to manage delirium and major postoperative complications simultaneously to reduce the risks posed by both conditions. Efforts should be implemented in those at high risk of delirium or complications following elective noncardiac surgery. Preventive strategies, such as the Hospital Elder Life Program, proactive geriatric consultation, and co-management services, have been shown to be effective to reduce delirium, ideally when implemented before and continued after surgery."