On the utility of diagnostic instruments for pediatric delirium in critical illness: an evaluation of the Pediatric Anesthesia Emergence Delirium Scale, the Delirium Rating Scale 88, and the Delirium Rating Scale-Revised R-98

PURPOSE: Delirium is a poor-prognosis neuropsychiatric disorder. Pediatric delirium (PD) remains understudied, particularly at pediatric intensive care units (PICU). Although the Pediatric Anesthesia Emergence Delirium (PAED) scale, the Delirium Rating Scale (DRS-88), and the Delirium Rating Scale-Revised (DRS-R-98) are available, none have been validated for use in PICU settings. The aim of the present study was to investigate the use of the DRS/PAED instruments as diagnostic tools for PD in the PICU. METHODS: A prospective panel study was conducted, under circumstances of routine clinical care, investigating the diagnostic properties of the PAED, DRS-88, and DRS-R-98 in PICU patients at a tertiary university medical center. A total of 182 non-electively admitted, critically ill pediatric patients, aged 1–17 years, were included between November 2006 and February 2010. Sensitivity, specificity, and receiver operating characteristic (ROC) curves were calculated. Three psychometric properties were analyzed: (1) internal consistency (2) proportion of items not rateable, and (3) discriminative ability. RESULTS: The PAED could be completed in 144 (93.5%) patients, much more frequently than either the DRS-88 (66.9%) or the DRS-R-98 (46.8%). Compared with the clinical gold standard diagnosis of delirium, the PAED had a sensitivity of 91% and a specificity of 98% (AUC 0.99). The optimal PAED cutoff score as a screening instrument in this PICU setting was 8. Cronbach’s alpha was 0.89; discriminative ability was high. CONCLUSIONS: The PAED is a valid instrument for PD in critically ill children, given its reliance on routinely rateable observational signs and symptoms.