Delirium and Mortality in Critically Ill Children: Epidemiology and Outcomes of Pediatric Delirium

Objectives: Delirium occurs frequently in adults and is an independent predictor of mortality. However, the epidemiology and outcomes of pediatric delirium are not well-characterized. The primary objectives of this study were to describe the frequency of delirium in critically ill children, its duration, associated risk factors, and effect on in-hospital outcomes, including mortality. Secondary objectives included determination of delirium subtype, and effect of delirium on duration of mechanical ventilation, and length of hospital stay. Design: Prospective, longitudinal cohort study. Setting: Urban academic tertiary care PICU. Patients: All consecutive admissions from September 2014 through August 2015. Interventions: Children were screened for delirium twice daily throughout their ICU stay. Measurements and Main Results: Of 1,547 consecutive patients, delirium was diagnosed in 267 (17%) and lasted a median of 2 days (interquartile range, 1-5). Seventy-eight percent of children with delirium developed it within the first 3 PICU days. Most cases of delirium were of the hypoactive (46%) and mixed (45%) subtypes; only 8% of delirium episodes were characterized as hyperactive delirium. In multivariable analysis, independent predictors of delirium included age less than or equal to 2 years old, developmental delay, severity of illness, prior coma, mechanical ventilation, and receipt of benzodiazepines and anticholinergics. PICU length of stay was increased in children with delirium (adjusted relative length of stay, 2.3; CI = 2.12.5; p<0.001), as was duration of mechanical ventilation (median, 4 vs 1 d; p<0.001). Delirium was a strong and independent predictor of mortality (adjusted odds ratio, 4.39; CI = 1.96-9.99; p<0.001). Conclusions: Delirium occurs frequently in critically ill children and is independently associated with mortality. Some in-hospital risk factors for delirium development are modifiable. Interventional studies are needed to determine best practices to limit delirium exposure in at-risk children.