Maximum Pao(2) in the First 72 Hours of Intensive Care Is Associated With Risk-Adjusted Mortality in Pediatric Patients Undergoing Mechanical Ventilation

A relationship between Pao(2) and mortality has previously been observed in single-center studies. We performed a retrospective cohort study of the Pediatric Health Information System plus database including patients less than or equal to 21 years old admitted to a medical or cardiac ICU who received invasive ventilation within 72 hours of admission. We trained and validated a multivariable logistic regression mortality prediction model with very good discrimination (C-statistic, 0.86; 95% CI, 0.79–0.92; area under the precision-recall curve, 0.39) and acceptable calibration (standardized mortality ratio, 0.96; 95% CI, 0.75–1.23; calibration belt p = 0.07). Maximum Pao(2) measurements demonstrated a parabolic (“U-shaped”) relationship with PICU mortality (Box-Tidwell p < 0.01). Maximum Pao(2) was a statistically significant predictor of risk-adjusted mortality (standardized odds ratio, 1.27; 95% CI, 1.23–1.32; p < 0.001). This analysis is the first multicenter pediatric study to identify a relationship between the extremes in Pao(2) values and PICU mortality. Clinicians should remain judicious in the use of oxygen when caring for children.