Sensitivity and specificity of the animal fluency test for predicting postoperative delirium.

BACKGROUND: Preoperative cognitive impairment is a major risk factor for postoperative delirium. We therefore investigated the prognostic significance and feasibility of administering a brief cognitive screen before surgery. METHODS: Patients > 65 yr of age undergoing hip, knee, or spine surgery were enrolled. A 60-sec cognitive screen, the animal fluency test (AFT), was administered preoperatively. Postoperative delirium was measured using a chart-based tool previously validated using criteria from the Confusion Assessment Method. RESULTS: Of the 362 patients satisfying the inclusion/exclusion criteria, 199 (55%) underwent the AFT. Among them, 57 patients (29%) had an AFT score < 15, and 38 patients (19%, 95% confidence interval [CI]: 14 to 25%) developed postoperative delirium as measured by chart review. Patients with scores of < 15 were more likely to develop postoperative delirium than those who scored ≥ 15 (54% vs 5%, P < 0.01). A multiple logistic regression, with postoperative delirium as the dependent variable, identified an AFT score of < 15 (odds ratio 20.1, 95% CI: 7.9 to 51.4) and high American Society of Anesthesiologists classification (odds ratio 3.5, 95% CI: 1.3 to 9.2) as independent predictors. CONCLUSIONS: The AFT is a potentially useful brief cognitive screen for identifying patients at risk of developing postoperative delirium. Limited participation by eligible participants in this study, however, raises questions about how useful and feasible systematic administration of the test is. Large studies using prospective measurement of postoperative delirium are indicated to validate our results.

Intraoperative opioid dosing in children with and without cerebral palsy.

OBJECTIVE: To describe the differences in intraoperative opioid dosing and associated outcomes in children with and without cerebral palsy (CP). BACKGROUND: Previous work on children with cognitive impairment has suggested that they receive less intraoperative opioid than children without cognitive impairment. This finding may be due to a common concern that impaired children are hypersensitive to the adverse effects of opioids. Patterns in intraoperative opioid dosing have yet to be studied in children with motor impairment (e.g. CP). METHODS: We examined the medical records of pediatric patients with CP who underwent orthopedic surgery over the last decade at our institution, as well as the records of a randomly selected group of pediatric orthopedic patients without CP (non-CP). Outcome variables were intraoperative opioid dosing, postoperative intensive care unit (ICU) admission, and postoperative oxygen desaturation. We collected demographic, surgical, and medical data for covariate analysis. A stepwise multivariate regression was used for each outcome. RESULTS: Seventy-one (71) CP and 77 non-CP charts were included in the study. CP children received significantly less intraoperative opioid (3.26 +/- 3.01 microg.kg(-1) fentanyl dose equivalents) than non-CP children (4.58 +/- 3.79 microg.kg(-1)) (P = 0.02), and this difference was corroborated by the regression analysis, which significantly associated CP with decreased opioid dosing (P < 0.001). In addition, intraoperative opioid dosing, but not CP, predicted ICU admission (odds ratio: 1.463, 95% CI: 1.042-2.054, P = 0.03) and postoperative oxygen desaturation (odds ratio: 1.174, 95% CI: 1.031-1.338, P = 0.02). CONCLUSIONS: Similar to prior research on children with cognitive impairment, a reduction in intraoperative opioid dosing was found in children with CP. Given the discrepant doses of intraoperative opioid between groups, it is unclear whether children with CP are at any greater risk for untoward opioid-related events.