Anticholinergic drug exposure at intensive care unit admission affects the occurrence of delirium. A prospective cohort study

Background: Anticholinergic drugs may increase the risk of delirium in non-critically ill patients, but it is unclear whether exposure to these drugs is also a risk factor for Intensive Care Unit (ICU) delirium. In this study the hypothesis was tested that anticholinergic drug exposure at ICU admission increases the risk to develop delirium during ICU stay, particularly in patients with advanced age and severe sepsis. Methods: A prospective cohort study was performed in the mixed 32-bed medical-surgical ICU of the University Medical Center Utrecht, the Netherlands in the period from January 2011 till June 2013. Included were nonneurological patients that were consecutively admitted for more than 24 hours. The presence of delirium was evaluated each day using a validated algorithm based on the Confusion Assessment Method for the ICU (CAM-ICU), the initiation of delirium treatment as well as chart review by researchers. Anticholinergic drug exposure at ICU admission was assessed using the Anticholinergic Drug Scale (ADS). To evaluate the association between anticholinergic drug exposure at ICU admission and the risk of developing delirium, we performed multivariable competing risk Cox proportional hazard analysis corrected for confounding factors. Results: Approximately half (47%, n=513) of the 1090 included patients developed delirium during ICU admission. The absolute risk for delirium development increased with more anticholinergic drug exposure: 42% in patients with ADS score=0, 49% in patients with ADS score=1, and 53% in patients with ADS higher than 1. Taking competing events (death and discharge) and potential confounding factors into account, the subdistribution hazard ratio (SHR) was 1.13 (95% CI: 0.91-1.40) for ADS score=1 point and 1.35 (95% CI: 1.09-1.68) for ADS ≥2 compared with an ADS score=0 (no anticholinergic drug exposure). The effect was strongest during the first days of ICU admittance and was strongest in patients above 65 year without severe sepsis and/or septic shock (SHR 2.15, 95% CI 1.43-3.25). Conclusions: Anticholinergic drug exposure at ICU admission increases the risk of delirium in critically ill patients. This effect was most pronounced in patients older than 65 years without severe sepsis and/or septic shock, and declining over time

Anticholinergic drug exposure at intensive care unit admission affects the occurrence of delirium. A prospective cohort study

Background: Anticholinergic drugs may increase the risk of delirium in non-critically ill patients, but it is unclear whether exposure to these drugs is also a risk factor for Intensive Care Unit (ICU) delirium. In this study the hypothesis was tested that anticholinergic drug exposure at ICU admission increases the risk to develop delirium during ICU stay, particularly in patients with advanced age and severe sepsis. Methods: A prospective cohort study was performed in the mixed 32-bed medical-surgical ICU of the University Medical Center Utrecht, the Netherlands in the period from January 2011 till June 2013. Included were nonneurological patients that were consecutively admitted for more than 24 hours. The presence of delirium was evaluated each day using a validated algorithm based on the Confusion Assessment Method for the ICU (CAM-ICU), the initiation of delirium treatment as well as chart review by researchers. Anticholinergic drug exposure at ICU admission was assessed using the Anticholinergic Drug Scale (ADS). To evaluate the association between anticholinergic drug exposure at ICU admission and the risk of developing delirium, we performed multivariable competing risk Cox proportional hazard analysis corrected for confounding factors. Results: Approximately half (47%, n=513) of the 1090 included patients developed delirium during ICU admission. The absolute risk for delirium development increased with more anticholinergic drug exposure: 42% in patients with ADS score=0, 49% in patients with ADS score=1, and 53% in patients with ADS higher than 1. Taking competing events (death and discharge) and potential confounding factors into account, the subdistribution hazard ratio (SHR) was 1.13 (95% CI: 0.91-1.40) for ADS score=1 point and 1.35 (95% CI: 1.09-1.68) for ADS ≥2 compared with an ADS score=0 (no anticholinergic drug exposure). The effect was strongest during the first days of ICU admittance and was strongest in patients above 65 year without severe sepsis and/or septic shock (SHR 2.15, 95% CI 1.43-3.25). Conclusions: Anticholinergic drug exposure at ICU admission increases the risk of delirium in critically ill patients. This effect was most pronounced in patients older than 65 years without severe sepsis and/or septic shock, and declining over time

Delirium detection using relative delta power based on 1 minute single-channel EEG : a multicentre study

Background: Delirium is frequently unrecognised. EEG shows slower frequencies (i.e. below 4 Hz) during delirium, which might be useful in improving delirium recognition. We studied the discriminative performance of a brief single-channel EEG recording for delirium detection in an independent cohort of patients. Methods: In this prospective, multicentre study, postoperative patients aged ≥60 yr were included (n=159). Before operation and during the first 3 postoperative days, patients underwent a 5-min EEG recording, followed by a video-recorded standardised cognitive assessment. Two or, in case of disagreement, three delirium experts classified each postoperative day based on the video and chart review. Relative delta power (1–4 Hz) was based on 1-min artifact-free EEG. The diagnostic value of the relative delta power was evaluated by the area under the receiver operating characteristic curve (AUROC), using the expert classification as the gold standard. Results: Experts classified 84 (23.3%) postoperative days as either delirium or possible delirium, and 276 (76.7%) non-delirium days. The AUROC of the relative EEG delta power was 0.75 [95% confidence interval (CI) 0.69–0.82]. Exploratory analysis showed that relative power from 1 to 6 Hz had significantly higher AUROC (0.78, 95% CI 0.72–0.84, P=0.014). Conclusions: Delirium/possible delirium can be detected in older postoperative patients based on a single-channel EEG recording that can be automatically analysed. This objective detection method with a continuous scale instead of a dichotomised outcome is a promising approach for routine detection of delirium. Clinical trial registration: NCT02404181

Delirium detection using relative delta power based on 1 minute single-channel EEG : a multicentre study

Background: Delirium is frequently unrecognised. EEG shows slower frequencies (i.e. below 4 Hz) during delirium, which might be useful in improving delirium recognition. We studied the discriminative performance of a brief single-channel EEG recording for delirium detection in an independent cohort of patients. Methods: In this prospective, multicentre study, postoperative patients aged ≥60 yr were included (n=159). Before operation and during the first 3 postoperative days, patients underwent a 5-min EEG recording, followed by a video-recorded standardised cognitive assessment. Two or, in case of disagreement, three delirium experts classified each postoperative day based on the video and chart review. Relative delta power (1–4 Hz) was based on 1-min artifact-free EEG. The diagnostic value of the relative delta power was evaluated by the area under the receiver operating characteristic curve (AUROC), using the expert classification as the gold standard. Results: Experts classified 84 (23.3%) postoperative days as either delirium or possible delirium, and 276 (76.7%) non-delirium days. The AUROC of the relative EEG delta power was 0.75 [95% confidence interval (CI) 0.69–0.82]. Exploratory analysis showed that relative power from 1 to 6 Hz had significantly higher AUROC (0.78, 95% CI 0.72–0.84, P=0.014). Conclusions: Delirium/possible delirium can be detected in older postoperative patients based on a single-channel EEG recording that can be automatically analysed. This objective detection method with a continuous scale instead of a dichotomised outcome is a promising approach for routine detection of delirium. Clinical trial registration: NCT02404181