Cardiac troponin I as a predictor of respiratory failure in children hospitalized with respiratory syncytial virus (RSV) infections: a pilot study.

This pilot study was performed to assess the use of cardiac troponin I to predict respiratory failure in children admitted to the hospital with respiratory syncytial virus (RSV) infections. We enrolled a prospective convenience sample of children under 5 years of age who were admitted to our university-based, tertiary care children's hospital from December 1, 2000, to February 1, 2002, with RSV infections. A cardiac troponin I was drawn at admission. We assessed the test characteristics for positive cardiac troponin I (defined as >0.3 ng/mL, the manufacturer's upper limit of normal) in correctly identifying children who had respiratory failure as evidenced by the need for endotracheal intubation. Twenty-five children from 9 days to 38 months of age were included. Ten children had a positive cardiac troponin I and 3 of these children had respiratory failure. A positive cardiac troponin I demonstrated a sensitivity of 100%, specificity 68%, positive predictive value of 30%, negative predictive value of 100%, and accuracy of 72%. The area under the receiver operating characteristic curve was 0.939 (95% confidence interval, 0.820-1.0), suggesting a high degree of discriminatory power in selecting children with respiratory failure. A sample size calculation revealed that a follow-up study of 359 patients is needed before the clinical use of cardiac troponin I for this purpose.