Frequency and outcomes of cumulative excess oxygen exposure in ventilated pediatric ICU patients.

Abstract

Objective: To determine the frequency of cumulative excess oxygen exposure (CEOE) and its association with mortality in ventilated children. Study Design: Retrospective Cohort study. Setting: Pediatric ICU of Sindh Institute of Child Health and Neonatology, Karachi. Period: January 2023 to June 2023. Methods: The study sample size of 200 was determined using the OpenEpi sample size calculator employing a non-probability consecutive sampling method, and included children (1 month–15 years) admitted who required invasive ventilation ≥24 hours. CEOE was defined as mean hourly FiO₂ >0.21 with SpO₂ ≥95% in the first 24 hours of ventilation. Patients were stratified into quartiles: hypoxemia (SpO₂ <94%), no CEOE, and CEOE quartiles (Q1: >21–30%, Q2: 30–45%, Q3: 45–60%, Q4: ≥60%). Variables included hourly FiO₂ >21% with SpO₂ >95%, clinical parameters, admitting diagnosis, length of stay, comorbidities, and outcome (survival or exitus). Statistical analysis was performed using Chi-Square and Mann-Whitney U tests, with p <0.05 considered significant. Results: Among 115 patients, mean CEOE was 37.3 ± 11.9%, with overall mortality of 26.1%. Non-survivors had higher mean CEOE than survivors (41.2 ± 10.9% vs. 36.2 ± 12.0%; p<0.009). Mortality, multi-organ dysfunction, and PICU stay increased stepwise across CEOE quartiles. Logistic regression showed higher odds of mortality in Q2 and Q3 versus Q1, though not statistically significant after adjusting for age and gender. Conclusion: In ventilated children, excessive oxygen exposure was common and associated with increased mortality, organ dysfunction, and longer PICU stay. These findings highlight the need for vigilant oxygen titration and careful avoidance of hyperoxia to improve outcomes in pediatric critical care