On pediatric delirium in critical illness : A clinical multidisciplinary study in child neuropsychiatry at the PICU

Abstract

Context: Delirium in children is a serious but understudied neuropsychiatric disorder. As a consequence, there is little to guide the clinician in terms of identifying those at risk. Objective: To study, in a pediatric intensive care unit (PICU), the predictive power of widely used generic pediatric mortality scoring systems in relation to the occurrence of pediatric delirium (PD). Design and methods: Four-year prospective observational study, 2002 – 2005. Predictors used were the Pediatric Index of Mortality (PIM) and Pediatric Risk of Mortality (PRISM II). Setting: A tertiary 8-bed PICU in the Netherlands. Patients: 877 critically ill children who were, acutely, non-electively and consecutively admitted. Main outcome measure: Pediatric delirium. Main results: Out of 877 children with mean age 4.4 years, 40 were diagnosed with PD (Cumulative incidence: 4.5 %), 85% of whom (versus 40% in the non-delirium group) were mechanically ventilated. The area under the curve of the receiver operator characteristic curve of the PIM was 0.70, and of the PRISM II 0.73, with optimal cut-off points around the median value. A PIM or PRISM II score above the median was strongly associated with later PD in terms of relative risk (PIM: OR=9.1; 95% CI: 3.2 26.0; PRISM II: OR=19.7; 95% CI: 4.7 82.2), with lower values for positive predictive value (PIM: 7.8%; PRISM II: 8.2%, rising to respectively 10.2% and 10.7% in mechanically ventilated patients) but high values for negative predictive value (PIM: 99.1%; PRISM II: 99.6%).