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.
Pandharipande
Pratik
P
Department of Anesthesia/Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA. pratik.pandharipande@vanderbilt.edu
Shintani
Ayumi
A
Peterson
Josh
J
Pun
Brenda Truman
BT
Wilkinson
Grant R
GR
Dittus
Robert S
RS
Bernard
Gordon R
GR
Ely
E Wesley
EW
D018806:APACHE; D000367:Age Factors; D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects; D014150:Antipsychotic Agents / Q000009:adverse effects; D003128:Coma / Q000139:chemically induced / Q000453:epidemiology; D003422:Critical Care; D003693:Delirium / Q000139:chemically induced* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D007902:Length of Stay; D008140:Lorazepam / Q000009:adverse effects*; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D016896:Treatment Outcome
D000701:Analgesics, Opioid; D014150:Antipsychotic Agents; D006993:Hypnotics and Sedatives; D008140:Lorazepam