Delirium is a serious problem affecting patients in the intensive care unit (ICU). The number of general medical patients who experience delirium is reported to range from 10% to 30%. When the number of ICU patients is specifically looked at then that number can go as high as 80%.1 Many risk factors associated with the development of delirium have been identified, including advanced age, dementia, severity of illness, hypertension, smoking, metabolic disturbances and the use of some medications such as benzodiazepines and opioid therapy.2,3 Haloperidol is commonly used in the management of delirium despite the lack of randomized controlled trials to support its use.
To assess whether there is an association between cumulative dose haloperidol and the diagnosis of delirium the next day in medical ICU patients, the authors of this study performed a longitudinal observational study along with a marginal structural model to adjust for time-dependent confounding variables.5,6 All patients ≥ 60 years old were included once they met the inclusion and exclusion criteria. Out of the 318 patients that were initially eligible, only 309 were enrolled and 93 patients received at least one dose of haloperidol during their stay in the MICU. A total of 72 patients were intubated during the ICU stay and 21 patients were never intubated. All patients were assessed for the presence of delirium on a daily basis by a trained research nurse using the confusion assessment method for the ICU (CAM-ICU). A daily validated chart review was also used to supplement the CAM-ICU.7 The majority of patients received fentanyl for pain control and lorazepam for sedation, with a very small minority of patients receiving midazolam or propofol. Haloperidol was the only antipsychotic used and there was no sedation awakening protocol used at the time of the study. Approximately 40% of haloperidol daily dose was 6mg or less and 93% were 30mg or less.
Compared to the overall cohort (n=309), the analytical group (n=93) had higher rates of baseline depressive symptoms (38% vs 28%), pre-existing cognitive impairment (41% vs 31%), and impairment in activities of daily living (42% vs 36%). In addition, more patients receiving haloperidol experienced delirium (100% vs 79%) on at least 1 day. Among non-intubated patients only (n=21), each additional cumulative milligram of haloperidol was associated with 5% higher odds of next-day delirium (OR= 1.05 [CI, 1.02–1.09]). The median time on ventilation and the mean length of stay was longer among patients taking haloperidol compared to the overall cohort.
The authors concluded that haloperidol use in non-intubated older adults is associated with a small increase in the development of next-day delirium. Limitation of the study include the fact that this is a single observational study which makes it susceptible to imbalances of covariates. Furthermore, the indication of haloperidol was not recorded and side effects of haloperidol such as extrapyramidal symptoms was not assessed. ...