New study gives insights on sedation and postoperative delirium risk in older patients

Limiting sedation levels for older adults undergoing hip fracture repair did not reduce the risk of postoperative delirium, according to results from an NIA-funded clinical trial. However, a subgroup analysis found that lighter sedation reduced the risk of postoperative delirium among older adults in better overall health. The results from the Strategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients (STRIDE) clinical trial were published on Aug. 8, 2018 in JAMA Surgery.

Delirium is an acute disturbance in attention and awareness with symptoms that can include disorganized thinking and agitation. More than 7 million hospitalized Americans per year experience delirium. It can affect patients of any age but is more common among older adults who experience major illness—especially involving an intensive care unit (ICU) stay—or have major surgery. Delirium is also associated with higher hospital costs and multiple adverse outcomes, such as longer hospital stays, long-term cognitive impairment, and death.

The STRIDE trial took place between 2011 and 2016 and included patients 65 and older who were undergoing nonelective hip-fracture repair at the Johns Hopkins Bayview Medical Center. A total of 200 patients participated, half receiving lighter sedation, the other half heavier.

Results of the trial showed that the level of sedation didn’t provide significant overall benefit in reducing delirium. However, further analysis revealed that for older patients with few or no pre-existing co-morbidities, lighter sedation compared to heavier sedation led to a decreased risk of postoperative delirium. Among older patients with multiple chronic health conditions, who represent the majority of the hip-fracture population, lighter sedation during surgery was not associated with reduced risk of postoperative delirium. Given these findings, the researchers noted that sedation levels during surgery should match a patient’s health status.

Study author Frederick Sieber, M.D., professor of anesthesiology and critical care medicine at the Johns Hopkins University School of Medicine, noted that the challenge for future research will be to identify the mechanisms and interactions between comorbidities and precipitating risk factors for postoperative delirium.

The STRIDE trail was funded by NIH grant AG033615. ClinicalTrials.gov number NCT00590707.

Reference: Sieber FE et al. Effect of depth of sedation in older patients undergoing hip fracture repair on postoperative delirium: The STRIDE randomized clinical trial. JAMA Surgery. Published online Aug. 08, 2018. doi:10.1001/jamasurg.2018.2602.