Predictors of cognitive dysfunction after major noncardiac surgery.

BACKGROUND: The authors designed a prospective longitudinal study to investigate the hypothesis that advancing age is a risk factor for postoperative cognitive dysfunction (POCD) after major noncardiac surgery and the impact of POCD on mortality in the first year after surgery. METHODS: One thousand sixty-four patients aged 18 yr or older completed neuropsychological tests before surgery, at hospital discharge, and 3 months after surgery. Patients were categorized as young (18-39 yr), middle-aged (40-59 yr), or elderly (60 yr or older). At 1 yr after surgery, patients were contacted to determine their survival status. RESULTS: At hospital discharge, POCD was present in 117 (36.6%) young, 112 (30.4%) middle-aged, and 138 (41.4%) elderly patients. There was a significant difference between all age groups and the age-matched control subjects (P < 0.001). At 3 months after surgery, POCD was present in 16 (5.7%) young, 19 (5.6%) middle-aged, and 39 (12.7%) elderly patients. At this time point, the prevalence of cognitive dysfunction was similar between age-matched controls and young and middle-aged patients but significantly higher in elderly patients compared to elderly control subjects (P < 0.001). The independent risk factors for POCD at 3 months after surgery were increasing age, lower educational level, a history of previous cerebral vascular accident with no residual impairment, and POCD at hospital discharge. Patients with POCD at hospital discharge were more likely to die in the first 3 months after surgery (P = 0.02). Likewise, patients who had POCD at both hospital discharge and 3 months after surgery were more likely to die in the first year after surgery (P = 0.02). CONCLUSIONS: Cognitive dysfunction is common in adult patients of all ages at hospital discharge after major noncardiac surgery, but only the elderly (aged 60 yr or older) are at significant risk for long-term cognitive problems. Patients with POCD are at an increased risk of death in the first year after surgery.

Learning about new anesthetics using a model driven, full human simulator.

OBJECTIVE: New pharmacological agents are introduced into medical practice at an ever-increasing pace. Teaching how to use new medications in the clinical setting presents educational challenges and puts patients at risk. METHODS: Patients and clinical settings in which remifentanil might provide clinical advantages over existing anesthetics were identified. A simulator curriculum was developed to demonstrate the use of remifentanil in the sample cases. The simulation was designed to highlight the clinical advantages and potential side effects of remifentanil. A screen displaying the concentrations of remifentanil in plasma and in the hypothetical effector site was developed. A simulator was modified (addition of an infusion pump and a pharmacokinetic screen display) and transported to several cities in the U.S.A. An instructor guided small groups of anesthesiologists and anesthetists through a structured program that enabled participants to observe drug effects in simulated patients. RESULTS: There were 836 participants in the remifentanil program, which was offered in 58 cities in the U.S.A. Surveys were completed by 574 anesthesiologists. There was a significant difference in comfort level for using remifentanil after the session compared to before (Chi-square, p < 0.001.) The statement: "Clinical simulation experience is a means to learn about new agents like remifentanil" was rated as "excellent" by 81% and as "good" by 19% of participants. No participant found the experience to be "not useful." CONCLUSIONS: Patient simulation is a novel method of introducing new drugs to the medical community and is perceived by anesthesia providers as a valuable addition to available teaching methods.