Serum Procalcitonin and Outcomes in Severe Pediatric Pneumonia: A Secondary Analysis of An Observational Multicenter Study

Abstract Background Evidence on procalcitonin’s role in the management of severe pediatric pneumonia is limited. This study aims to determine the association between procalcitonin and severity of illness in children with severe pneumonia. Methods In this secondary analysis of a multi-center study in Asia, peak serum procalcitonin (measured within 5 days) was categorized into four groups (<0.5, 0.5–2.0, 2.0–10.0, >10.0 ng/mL). The primary outcome was mortality and secondary outcomes were acute respiratory distress syndrome (ARDS), septic shock, and multiorgan dysfunction. Area under the receiver operating curve (AUROC) analysis was used to assess the association of peak procalcitonin levels with primary and secondary outcomes. Results Of 846 patients, 344 had early procalcitonin data. Mortality increased in groups with higher peak procalcitonin levels [8/162 (4.9%), 3/69 (4.4%), 8/55 (14.6%) vs. 11/58 (19.0%); p=0.002]. The proportion of patients with ARDS [23/162 (14.2%), 14/69 (20.3%), 10/55 (18.2%) vs. 25/58 (43.1%); p<0.001], septic shock [8/162 (4.9%), 10/69 (14.5%), 13/55 (23.2%) vs. 32/58 (55.2%); p<0.001], multiorgan failure [19/162 (11.7%), 13/69 (18.8%), 12/55 (21.4%) vs. 23/58 (39.7%); p<0.001] was also higher in groups with higher peak procalcitonin levels. The AUROC for procalcitonin showed moderate discrimination for mortality [0.69 (95%CI 0.58, 0.80)] and good discrimination for septic shock [0.81 (95%CI 0.76, 0.87)]. Conclusion In critically ill children with severe pneumonia, higher serum procalcitonin was associated with mortality, ARDS, septic shock and multi-organ dysfunction. Procalcitonin alone is insufficient for clinical decision-making and should be interpreted alongside clinical assessment