A recent study, published in the January issue of Mayo Clinic Proceedings, demonstrates that in elderly patients undergoing hip fracture repair under spinal anesthesia with propofol sedation, the prevalence of delirium can be decreased by 50 percent with light sedation, compared to deep sedation.
"These data show that, for every 3.5 to 4.7 patients treated in this manner, one incident of delirium will be prevented," says Frederick Sieber, M.D., primary investigator of the study from the Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medicine in Baltimore. "Therefore, interventions capable of reducing the occurrence of postoperative delirium would be important from a public health perspective."
Several demographic and perioperative variables are associated with postoperative delirium in elderly patients after hip fracture repair. The most important is preoperative dementia. Other risk factors for postoperative delirium include age, systemic disease and functionality. Inhalational and intravenous anesthetics, opioids, benzodiazepines and anticholinergic drugs are all known or suspected risk factors for postoperative delirium.
Although postoperative delirium usually resolves within 48 hours of onset, delirium can persist and is associated with poor functional recovery, increased length of stay in hospitals, higher costs, and greater likelihood of placement in an assisted-living facility after surgery.
In addition to decreasing the prevalence of delirium, lighter sedation in this group of elderly surgical patients was associated with a reduction in delirium that averaged almost one day for each patient in the light sedation group. The effects of lighter sedation were observed in patients with or without preoperative cognitive dysfunction.
Limiting depth of sedation during spinal anesthesia is a simple, safe and cost-effective intervention for preventing postoperative delirium in elderly patients that could be widely and readily adopted, say Dr. Sieber.