Systemic Inflammatory Markers (NLR/PLR) and Climatic Factors as Predictors of Severity in Pediatric Carbon Monoxide Poisoning

Aim: Carbon monoxide (CO) poisoning remains a global health challenge, particularly in developing nations. This study evaluates the prognostic role of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and climatic parameters in pediatric CO poisoning severity. Material and Method: In this retrospective cohort study, 132 pediatric patients admitted to a tertiary emergency department were stratified by carboxyhemoglobin (COHb) levels (mild: <5%; moderate: 5–25%; severe: >25%). Associations between NLR/PLR, meteorological data (temperature, wind speed, air pressure), and clinical outcomes were analyzed. Results: Severe cases exhibited significantly elevated NLR (2.09 [IQR 1.24-3.54]; p=0.019) and PLR (106.2 [80.6-164.4]; p=0.032) compared to others, alongside higher COHb (31.45 [27.25-34.2]; p<0.001) and lactate (2.7 [1.8-3.45] mmol/L; p=0.07). Central nervous system symptoms (CNS) predominated in severe poisoning (28.6%, p=0.014). Maximum temperature was inversely correlated with severity (p=0.032). Conclusion: NLR and PLR serve as early indicators of CO poisoning severity, while higher air temperatures reduce risk. These findings support using routine hemogram indices for risk stratification and underscore the need for climate-aware public health interventions.