Prevalence and risk factors for development of delirium in surgical and trauma intensive care unit patients.

BACKGROUND: Although known to be an independent predictor of poor outcomes in medical intensive care unit (ICU) patients, limited data exist regarding the prevalence of and risk factors for delirium among surgical (SICU) and trauma ICU (TICU) patients. The purpose of this study was to analyze the prevalence of and risk factors for delirium in surgical and trauma ICU patients. METHODS: SICU and TICU patients requiring mechanical ventilation (MV) >24 hours were prospectively evaluated for delirium using the Richmond Agitation Sedation Scale (RASS) and the Confusion Assessment Method for the ICU (CAM-ICU). Those with baseline dementia, intracranial injury, or ischemic/hemorrhagic strokes that would confound the evaluation of delirium were excluded. Markov models were used to analyze predictors for daily transition to delirium. RESULTS: One hundred patients (46 SICU and 54 TICU) were enrolled. Prevalence of delirium was 73% in the SICU and 67% in the TICU. Multivariable analyses identified midazolam [OR 2.75 (CI 1.43-5.26, p = 0.002)] exposure as the strongest independent risk factor for transitioning to delirium. Opiate exposure showed an inconsistent message such that fentanyl was a risk factor for delirium in the SICU (p = 0.007) but not in the TICU (p = 0.936), whereas morphine exposure was associated with a lower risk of delirium (SICU, p = 0.069; TICU p = 0.024). CONCLUSION: Approximately 7 of 10 SICU and TICU patients experience delirium. In keeping with other recent data on benzodiazepines, exposure to midazolam is an independent and potentially modifiable risk factor for the transitioning to delirium.

Lorazepam is an independent risk factor for transitioning to delirium in intensive care unit patients.

BACKGROUND: Delirium has recently been shown as a predictor of death, increased cost, and longer duration of stay in ventilated patients. Sedative and analgesic medications relieve anxiety and pain but may contribute to patients' transitioning into delirium. METHODS: In this cohort study, the authors designed a priori an investigation to determine whether sedative and analgesic medications independently increased the probability of daily transition to delirium. Markov regression modeling (adjusting for 11 covariates) was used in the evaluation of 198 mechanically ventilated patients to determine the probability of daily transition to delirium as a function of sedative and analgesic dose administration during the previous 24 h. RESULTS: Lorazepam was an independent risk factor for daily transition to delirium (odds ratio, 1.2 [95% confidence interval, 1.1-1.4]; P = 0.003), whereas fentanyl, morphine, and propofol were associated with higher but not statistically significant odds ratios. Increasing age and Acute Physiology and Chronic Health Evaluation II scores were also independent predictors of transitioning to delirium (multivariable P values < 0.05). CONCLUSIONS: Lorazepam administration is an important and potentially modifiable risk factor for transitioning into delirium even after adjusting for relevant covariates.

Large-scale implementation of sedation and delirium monitoring in the intensive care unit: a report from two medical centers.

OBJECTIVE: To implement sedation and delirium monitoring via a process-improvement project in accordance with Society of Critical Care Medicine guidelines and to evaluate the challenges of modifying intensive care unit (ICU) organizational practice styles. DESIGN: Prospective observational cohort study. SETTING: The medical ICUs at two institutions: the Vanderbilt University Medical Center (VUMC) and a community Veterans Affairs hospital (York-VA). SUBJECTS: Seven hundred eleven patients admitted to the medical ICUs for >24 hrs and followed over 4,163 days during a 21-month study period. INTERVENTIONS: Unit-wide nursing documentation was changed to accommodate a sedation scale (Richmond Agitation-Sedation Scale) and delirium instrument (Confusion Assessment Method for the ICU). A 20-min introductory in-service was performed for all ICU nurses, followed by graded, staged educational interventions at regular intervals. Data were collected daily for compliance, and randomly 40% of nurses each day were chosen for accuracy spot-checks by reference raters. An implementation survey questionnaire was distributed at 6 months. MEASUREMENTS AND MAIN RESULTS: The implementation project involved 64 nurses (40 at VUMC and 24 at York-VA). Sedation and delirium monitoring data were recorded for 711 patients (614 at VUMC and 97 at York-VA). Compliance with the Richmond Agitation-Sedation Scale was 94.4% (21,931 of 23,220) at VUMC and 99.7% (5,387 of 5,403) at York-VA. Compliance with the Confusion Assessment Method for the ICU was 90% (7,323 of 8,166) at VUMC and 84% (1,571 of 1,871) at York-VA. The Confusion Assessment Method for the ICU was performed more often than requested on 63% of shifts (5,146 of 8,166) at VUMC and on 8% (151 of 1871) of shifts at York-VA. Overall weighted-kappa between bedside nurses and references raters for the Richmond Agitation-Sedation Scale were 0.89 (95% confidence interval, 0.88 to 0.92) at VUMC and 0.77 (95% confidence interval, 0.72 to 0.83) at York-VA. Overall agreement (kappa) between bedside nurses and reference raters using the Confusion Assessment Method for the ICU was 0.92 (95% confidence interval, 0.90-0.94) at VUMC and 0.75 (95% confidence interval, 0.68-0.81) at York-VA. The two most-often-cited barriers to implementation were physician buy-in and time. CONCLUSIONS: With minimal training, the compliance of bedside nurses using sedation and delirium instruments was excellent. Agreement of data from bedside nurses and a reference-standard rater was very high for both the sedation scale and the delirium assessment over the duration of this process-improvement project.