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The Local and Systemic Exposure to Oxygen in Children With Severe Bronchiolitis on Invasive Mechanical Ventilation: A
Thijs A Lilien1, Eleonore S V de Sonnaville, Job B M van Woensel
1Department of Pediatric Intensive Care Medicine, Emma Children's Hospital, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.
Insights
Oxygen overuse is common in critically ill children with bronchiolitis on mechanical ventilation. While systemic oxygen levels were not dangerously high, pulmonary oxygen exposure often exceeded recommended levels, indicating a need for revised oxygenation targets.
Area of Science:
- Pediatric Critical Care Medicine
- Respiratory Physiology
- Neonatology
Background:
- Oxygen supplementation is vital for critically ill children with bronchiolitis in the Pediatric Intensive Care Unit (PICU).
- High-dose oxygen carries known risks, necessitating careful management.
- Understanding oxygen exposure in mechanically ventilated children with severe bronchiolitis is crucial.
Purpose of the Study:
- To describe pulmonary and systemic oxygen exposure during invasive mechanical ventilation (IMV) in children with severe bronchiolitis.
- To estimate potentially avoidable high-dose oxygen exposure in this patient population.
Main Methods:
- A retrospective cohort study was conducted at a single-center, tertiary-care PICU.
- Data from 176 children younger than 2 years receiving IMV for severe bronchiolitis were analyzed.
- Hourly fraction of inspired oxygen (Fio2) and peripheral oxygen saturation (Spo2) were measured up to day 10 of IMV, alongside arterial blood gas data.
Main Results:
- Pulmonary oxygen exposure, measured by time-weighted average Fio2, was highest on day 1 of IMV (median 0.46) and decreased thereafter.
- Systemic oxygen exposure was generally low, with no severe hyperoxemia observed (TWA-Pao2 > 248 Torr).
- Oxygen overuse was frequent: 52.3% of patients experienced at least one day of potential overuse, and 14.8% had severe overuse. Higher oxygen doses correlated with increased overuse (r=0.59). Caregivers often maintained high Fio2 (≥0.50) even with high Spo2 (≥97%).
Conclusions:
- Moderate to high pulmonary oxygen exposure and frequent oxygen overuse are common in mechanically ventilated children with severe bronchiolitis.
- This overuse did not lead to a high systemic oxygen burden in this cohort.
- Further research is needed to establish optimal oxygenation targets to prevent excessive oxygen use in this vulnerable population.
Objectives:
Oxygen supplementation is a cornerstone treatment in critically ill children with bronchiolitis in the PICU. However, potential deleterious effects of high-dose oxygen are well-known. In this study, we aim to describe the pulmonary (local) and arterial (systemic) oxygen exposure over the duration of invasive mechanical ventilation (IMV) in children with severe bronchiolitis. Our secondary aim was to estimate potentially avoidable exposure to high-dose oxygen in these patients.
Design:
Retrospective cohort study.
Setting:
Single-center, tertiary-care PICU.
Patients:
Children younger than 2 years old admitted to the PICU for severe bronchiolitis receiving IMV.
Interventions:
None.
Measurements And Main Results:
Hourly measurements of Fio2 and peripheral oxygen saturation (Spo2), and arterial blood gas data were collected up to day 10 of IMV. A total of 24,451 hours of IMV were observed in 176 patients (median age of 1.0 mo [interquartile range (IQR), 1.0-2.3 mo]). The pulmonary exposure to oxygen was highest during the first day of IMV (median time-weighted average [TWA]-Fio2 0.46 [IQR, 0.39-0.53]), which significantly decreased over subsequent days. The systemic exposure to oxygen was relatively low, as severe hyperoxemia (TWA-Pao2 > 248 Torr [> 33 kPa]) was not observed. However, overuse of oxygen was common with 52.3% of patients (n = 92) having at least 1 day of possible excessive oxygen exposure and 14.8% (n = 26) with severe exposure. Furthermore, higher oxygen dosages correlated with increasing overuse of oxygen (rrepeated measures, 0.59; 95% CI, 0.54-0.63). Additionally, caregivers were likely to keep Fio2 greater than or equal to 0.50 when Spo2 greater than or equal to 97%.
Conclusions:
Moderate to high-dose pulmonary oxygen exposure and potential overuse of oxygen were common in this cohort of severe bronchiolitis patients requiring IMV; however, this was not accompanied by a high systemic oxygen burden. Further studies are needed to determine optimal oxygenation targets to prevent overzealous use of oxygen in this vulnerable population.
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