Feature Articles Pediatric Critical Care Medicine Pediatric Delirium and Associated Risk Factors: A Single-Center Prospective Observational Study*

Objective: To describe a single-institution pilot study regarding prevalence and risk factors for delirium in critically ill children. Design: A prospective observational study, with secondary analysis of data collected during the validation of a pediatric delirium screening tool, the Cornell Assessment of Pediatric Delirium. Setting: This study took place in the PICU at an urban academic medical center. Patients: Ninety-nine consecutive patients, ages newborn to 21 years. Intervention: Subjects underwent a psychiatric evaluation for delirium based on the Diagnostic and Statistical Manual IV criteria. Measurements and Main Results: Prevalence of delirium in this sample was 21%. In multivariate analysis, risk factors associated with the diagnosis of delirium were presence of developmental delay, need for mechanical ventilation, and age 2-5 years. Conclusions: In our institution, pediatric delirium is a prevalent problem, with identifiable risk factors. Further large-scale prospective studies are required to explore multi-institutional prevalence, modifiable risk factors, therapeutic interventions, and effect on long-term outcomes. (Pediatr Crit Care Med 2015; 16:303-309) Key Words: critical care; delirium; pediatric critical care; pediatrics; prevalence; risk factor D elirium is the behavioral manifestation of acute cerebral dysfunction associated with serious underlying medical illness. It presents as an acute and fluctuating change in mental status, with disordered attention and cognition (1). It is a well-known and prevalent problem in adult intensive care, linked to short-and long-term morbidity (2), increased mortality (3), and astronomical healthcare costs (4). The pathophysiology of ICU delirium is complex and multifactorial. It is the end result of diffuse cerebral metabolic abnormality. Broadly, alterations in neurotransmission, cerebral blood flow, energy metabolism, and disordered cellular homeostasis all play a role (5-7). Although it can occasionally be traced to a single etiology (e.g., alcohol toxicity or delirium tremens), in the ICU, it is frequently a result of three synergistic events: the underlying disease process, side-effects of treatment, and the highly abnormal critical care unit environment (8, 9). As an example, let us consider the patient admitted to the ICU with pneumonia and associated acute hypoxemic respiratory failure. The inflammatory process associated with the infection and hypoxia predisposes the patient to delirium. The benzodiazepine prescribed to facilitate patient-ventilator synchrony is itself deliriogenic. The prolonged period of immobilization in the ICU bed, the presence of invasive catheters and monitors, and the disruption of the patient's sleep-wake cycle all contribute to the evolving delirium (9, 10). It is important to recognize that delirium is a medical diagnosis and not simply a constellation of symptoms. Delirium is not untreated pain, oversedation, sleep deprivation, or withdrawal (although any of these may contribute to the development of delirium) Epidemiology and risk factors for pediatric delirium are not yet well described, due in part to the absence of widespread screening, underrecognition, and lack of evidence-based dat