title: Benzodiazepine and opioid use and the duration of intensive care unit delirium in an older population.
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.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Fourteen-bed medical intensive care unit in an urban university teaching hospital.
  
  
  METHODS
  304 consecutive admissions age 60 and older.
  
  
  METHODS
  None.
  
  
  METHODS
  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.
authors.affiliation: Department of Internal Medicine, Pulmonary and Critical Care Section, and the Program on Aging, Yale University School of Medicine, USA. margaret.pisani@yale.edu
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Pisani
authors.forename: Terrence E
authors.initials: TE
authors.lastname: Murphy
authors.forename: Katy L B
authors.initials: KL
authors.lastname: Araujo
authors.forename: Patricia
authors.initials: P
authors.lastname: Slattum
authors.forename: Peter H
authors.initials: PH
authors.lastname: Van Ness
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Inouye
mesh_terms: D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects*; D001569:Benzodiazepines / Q000009:adverse effects*; D003693:Delirium / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D001569:Benzodiazepines