Presented by Dr LAM Sin Man Grace at the Daily Journal Club of ICU, PYNEH, Hong Kong, on 26 May 2009
In the article "Pisani, Margaret A. MD, MPH; Murphy, Terrence E. PhD; Araujo, Katy L. B. MPH; Slattum, Patricia PharmD, PhD; Van Ness, Peter H. PhD, MPH; Inouye, Sharon K. MD, Mph. Benzodiazepine and opioid use and the duration of intensive care unit delirium in an older population. Critical Care Medicine. 37(1):177-183, January 2009", 304 consecutive admissions of age 60 or older to a 14-bed medical ICU in an urban uniersity teaching hospital were studied. Which of the following is not correct about this study?
A. Delirim occurred in 239 of 304 patients (79%).
B. Increased delirium duration was independently associated with pre-existing dementia.
C. Increased delirium duration was also independently associated with receipt of a benzodiapine or opiod, receipt of haloperidol and the severity of illness.
D. In this prospective cohort study, direct causal relationship was found between the use of bezondiazepine and delirium, especially in male subjects.
Answer: D
Direct causal relationship was not found between medication use and duration of delirium. It was only an association.
Reference
Abstract:
Objective: There is a high prevalence of delirium in older medical intensive care unit (ICU) patients and delirium is associated with adverse outcomes. We need to identify modifiable risk factors for delirium, such as medication use, in the ICU. The objective of this study was to examine the impact of benzodiazepine or opioid use on the duration of ICU delirium in an older medical population.
Design: Prospective cohort study.
Setting: Fourteen-bed medical intensive care unit in an urban university teaching hospital.
Patients: 304 consecutive admissions age 60 and older.
Interventions: None.
Main Outcome Measurements: The main outcome measure was duration of ICU delirium, specifically the first episode of ICU delirium. Patients were assessed daily for delirium with the Confusion Assessment Method for the ICU and a validated chart review method. Our main predictor was receiving benzodiazepines or opioids during ICU stay. A multivariable model was developed using Poisson rate regression.
Results: Delirium occurred in 239 of 304 patients (79%). The median duration of ICU delirium was 3 days with a range of 1-33 days. In a multivariable regression model, receipt of a benzodiazepine or opioid (rate ratio [RR] 1.64, 95% confidence interval [CI] 1.27-2.10) was associated with increased delirium duration. Other variables associated with delirium duration in this analysis include preexisting dementia (RR 1.19, 95% CI 1.07-1.33), receipt of haloperidol (RR 1.35, 95% CI 1.21-1.50), and severity of illness (RR 1.01, 95% CI 1.00-1.02).
Conclusions: The use of benzodiazepines or opioids in the ICU is associated with longer duration of a first episode of delirium. Receipt of these medications may represent modifiable risk factors for delirium. Clinicians caring for ICU patients should carefully evaluate the need for benzodiazepines, opioids, and haloperidol.