FROM ANNALS OF SURGERY
Publish date: May 25, 2018
Lead authorof the University of Chicago Medical Center and her colleagues wrote, “Postoperative delirium has been associated with mortality, morbidity, prolonged length of stay, and increased costs of care. Furthermore, postoperative delirium may be associated with long-term cognitive and functional decline. However, postoperative delirium has not been incorporated as an outcome measure into major surgical quality registries. Approximately one-third of hospitalized delirium is believed to be preventable, making postoperative delirium an ideal target for surgical quality improvement efforts,” Dr. Berian and her colleagues reported in the .
The Geriatric Surgery Pilot data abstractors were instructed to assign postoperative delirium if the medical record words indicating an acute confusional stat such a mental status change, confusion, disorientation, agitation, delirium, and inappropriate behavior. Data were collected from the period 2 hours after surgery to exclude effects of the pharmacologic agents of anesthesia. Delirium status was ascertained as a binary outcome (Yes/No).
Postoperative delirium was observed in 2,427 patients for an average, unadjusted rate of 12.0%. Investigators identified 20 risk factors markedly associated with delirium. The strongest predictors included preoperative cognitive impairment, preoperative use of mobility aid, surrogate consent form, ASA class 4 or greater, age 80 years and older, preoperative sepsis, and fall history within 1 year. Patients with delirium generally were older than patients without delirium were and accounted for a greater proportion of emergency cases. Postoperative hospital length of stay was about 4 days longer on average for patients with delirium, compared with those without delirium.
By specialty, the highest rates of postoperative delirium occurred following cardiothoracic (13.7%), orthopedic (13.0%), and general surgeries (13.0%). Study authors found varied associated risk for postoperative delirium within each surgical specialty. For example, in general surgery, the risk for postoperative delirium with partial mastectomy was low, compared with a mid-level risk in the repair of a recurrent, incarcerated, or strangulated inguinal hernia and a high-level risk in Whipple operations.
The model developed to measure delirium management success in 30 hospitals found that adjusted delirium rates ranged from 3.2% to 27.5%, with eight poor- and five excellent-performing outliers. Authors noted that their model demonstrated good calibration and discrimination. Examination of changes in the Bayesian Information Criteria indicates that as few as 10-12 variables may suffice in building a parsimonious model with “an excellent fit.”
Study authors noted that screening for postoperative delirium in older adults is likely in the best interests of patients. However, they also mentioned that such screening may identify cases of postoperative delirium that were previously unrecognized, resulting in higher rates. In addition, the inclusion of only ACS NSQIP hospitals and the voluntary participation may mean a biased dataset. No one delirium prevention intervention was implemented across the hospitals and so the study doesn’t indicate why some hospitals are more successful than are others. Chart-based identification of patients who have delirium needs further study to assess validity.
Authors concluded that one solution may be to “standardize and consistently employ delirium screening in high-risk patients across hospitals, as has been advocated by a coalition of interdisciplinary experts in geriatric care.”
This project is funded in part by a grant from the John A. Hartford Foundation. The authors declare no conflict of interests.