Diagnostic accuracy of delirium diagnosis in pediatric intensive care: a systematic review

INTRODUCTION: Delirium is common in adult intensive care, with validated tools for measurement, known risk factors and adverse neurocognitive outcomes. We aimed to determine what is known about pediatric delirium in the pediatric intensive care unit (PICU). METHODS: We conducted a systematic search for and review of studies of the accuracy of delirium diagnosis in children in the PICU. Secondary aims were to determine the prevalence, risk factors and outcomes associated with pediatric delirium. We created screening and data collection tools based on published recommendations. RESULTS: After screening 145 titles and abstracts, followed by 35 full-text publications and reference lists of included publications, 9 reports of 5 studies were included. Each of the five included studies was on a single index test: (1) the Pediatric Anesthesia Emergence Delirium Scale (PAED; for ages 1 to 17 years), (2) the Pediatric Confusion Assessment Method for the Intensive Care Unit (p-CAM-ICU; for ages ≥5 years), (3) the Cornell Assessment of Pediatric Delirium (CAP-D; a modification of the PAED designed to detect hypoactive delirium), (4) the revised Cornell Assessment of Pediatric Delirium (CAP-D(R)) and (5) clinical suspicion. We found that all five studies had a high risk of bias on at least one domain in the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Sample size, sensitivity, specificity, and effectiveness (correct classification divided by total tests done) were: PAED 144, 91%, 98%, <91% (>16% of scores required imputation for missing data); p-CAM 68, 78%, 98%, 96%; CAP-D 50, 91%, 100%, 89%; CAP-D (R) 111, and of assessments 94%, 79%, <82% (it is not clear if any assessments were not included); and clinical suspicion 877, N/A (only positive predictive value calculable, 66%). Prevalence of delirium was 17%, 13%, 28%, 21%, and 5% respectively. Only the clinical suspicion study researchers statistically determined any risk factors for delirium (pediatric risk of mortality, pediatric index of mortality, ventilation, age) or outcomes of delirium (length of stay and mortality). CONCLUSION: High-quality research to determine the accuracy of delirium screening tools in the PICU are required before prevalence, risk factors and outcomes can be determined and before a routine screening tool can be recommended. Direct comparisons of the p-CAM-ICU and CAP-D(R) should be performed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-014-0489-x) contains supplementary material, which is available to authorized users.