Association of Severe Hyperoxemia Events and Mortality Among Patients Admitted to a Pediatric Intensive Care Unit

Abstract

Key Points Question Is severe hyperoxemia (arterial oxygen tension ≥300 mm Hg) associated with mortality among critically ill children? Findings In this cohort study of 23 719 intensive care encounters from 2009 to 2018 at a children’s hospital, 6250 patients had at least 1 measured arterial oxygen tension value. After adjusting for covariates, severe hyperoxemia appeared to be independently associated with in-hospital mortality, and a stepwise increase in the adjusted odds of mortality was observed with more episodes of severe hyperoxemia. Meaning Severe hyperoxemia appeared to be associated with mortality in a large, single-center cohort of critically ill children; prospective data are needed to assess causality.

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

“…However, the highest Pa o 2 measurements in the liberal oxygen therapy group from that study were less than 150 mm Hg. In contrast, the present study and several prior pediatric studies ( 4 – 7 ) have demonstrated a significant association only with either extreme hyperoxemia and death. In the present study, the optimal maximum Pa o 2 value in the first 72 hours of mechanical ventilation appears to be between 100 and 400 mm Hg.…”

“…Previous studies have observed Pa o 2 threshold values between 300 and 550 mm Hg to be associated with increased mortality ( 4 – 7 ). Together, these results suggest that both hypoxemia and extreme hyperoxemia are associated with risk-adjusted mortality; however, the precise thresholds associated with clinical harm remain uncertain and likely vary by clinical condition ( 4 – 7 ). A recent randomized controlled trial among adults demonstrated no difference between conservative and liberal oxygen management strategies ( 3 ).…”

“…Expert opinion has suggested that extreme hyperoxemia may be an indirect measurement of patients undergoing brain death testing or being assessed for organ donation eligibility ( 4 ). However, as relatively few PICU patients undergo brain death testing within 24 hours of admission, the findings of our sensitivity analysis, combined with prior studies of the impact of early hyperoxemia, would suggest this is less likely ( 6 , 7 ).…”

“…Third, we excluded patients with cardiac arrest prior to admission. Fourth, because prior work has suggested a time-dependent effect of hyperoxemia ( 4 – 7 ), we restricted the cohort to patients with invasive mechanical ventilation and Pa o 2 measurements within 24 hours of admission. Fifth, we broadened the cohort to include patients who underwent invasive mechanical ventilation and Pa o 2 measurements at any time during admission.…”

“…Several randomized controlled trials and meta-analyses of oxygen management strategies in adults have come to differing conclusions regarding the importance of hyperoxemia ( 1 – 3 ). While fewer data exist for children, there is a growing body of literature identifying a relationship between the Pa o 2 values and mortality in PICU settings ( 4 – 7 ). Limitations of these previous studies include data from single centers, variable definitions of hyperoxemia, and absent or uncalibrated risk-adjustment strategies.…”