Fri., 10/9/09 Hip & Geriatric, Paper #41, 10:37 am OTA-2009
Depth of Sedation and Postoperative Delirium during Spinal Anesthesia for Hip
Fracture Repair in Elderly Patients: A Randomized Controlled Study
Frederick Sieber, MD (n); Khwaja Zakriya, MD(n); Hochang Lee, MD (n);
Paul Rosenberg, MD (n); Simon C. Mears, MD (7-Zimmer);
Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA
Purpose: Delirium is a common and often catastrophic postoperative complication of hip fracture repair in the elderly. While anesthesia is hypothesized to have a causal role in the pathophysiology of delirium, several studies have reported no difference in rate of postoperative delirium among patients with general anesthesia compared to patients with spinal anesthesia. However, no previous study has controlled for the depth of sedation despite the substantial individual variability in dosage of anesthetic agents to induce adequate sedation among elderly patients. We hypothesized that minimizing sedation depth during spinal anesthesia for hip fracture repair in elderly patients would decrease the incidence of postoperative delirium.
Methods: We conducted a double-blind, randomized controlled trial with 114 elderly patients (mean age, 81.5 ± 7.1 years; 73% female) who underwent hip fracture repair at the Johns Hopkins Bayview Medical Center. Subjects were randomized to either light sedation (bispectral index >80) or deep sedation (bispectral index <50), with propofol as the sedative anesthetic agent. Postoperative delirium was assessed daily by a trained research nurse based on the Confusion Assessment Method beginning on the second postoperative day.
Results: The 2 groups were comparable in age, preoperative mini-mental status examination score, dementia diagnosis, American Society of Anesthesiologists score, type of procedure, or intra- and postoperative opioid usage. Significantly more patients in the deep sedation group developed postoperative delirium than in the light sedation group (40.4% [23/57] vs 19.3% [11/57]; P = 0.014). The average number of days of delirium during the hospitalization were greater in the deep sedation group than in the light sedation group (1.35 days vs 0.54; P = 0.014). Patients with dementia were more likely to develop postoperative delirium than patients without dementia (16/29 vs 18/85; P <0.0001).
Conclusions: These data supports our hypothesis that minimizing level of sedation during spinal anesthesia could prevent postoperative delirium after surgery. Dementia is also a key risk factor for postoperative delirium. Further study is needed to determine the long-term outcomes (eg, mortality and function) of patients undergoing varying depths of sedation during hip fracture repair.
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant