Pediatric in-hospital cardiac arrest: Respiratory failure characteristics and association with outcomes

Aims: To characterize respiratory failure prior to pediatric in-hospital cardiac arrest (IHCA) and to associate pre-arrest respiratory failure characteristics with survival outcomes.

Methods: This is a single-center, retrospective cohort study from a prospectively identified cohort of children <18 years in intensive care units (ICUs) who received cardiopulmonary resuscitation (CPR) for ≥1 minute between January 1, 2017 and June 30, 2021, and were receiving invasive mechanical ventilation (IMV) in the hour prior to IHCA. Patient characteristics, ventilatory support and gas exchange immediately pre-arrest were described and their association with the return of spontaneous circulation (ROSC) was measured.

Results: In the 187 events among 154 individual patients, the median age was 0.9 [0.2, 2.4] years, and CPR duration was 7.5 [3, 29] minutes. Respiratory failure was acute prior to 106/187 (56.7%) events, and the primary indication for IMV was respiratory in nature in 107/187 (57.2%) events. Immediately pre-arrest, the median positive end-expiratory pressure was 8 [5, 10] cmH₂O; mean airway pressure was 13 [10,18] cmH₂O; peak inspiratory pressure was 28 [24, 35] cmH₂O; and fraction of inhaled oxygen (FiO2) was 0.40 [0.25, 0.80]. Pre-arrest FiO2 was lower in patients with ROSC vs. without ROSC (0.30 vs. 0.99; p < 0.001). Patients without ROSC had greater severity of pre-arrest oxygenation failure (p < 0.001) as defined by oxygenation index, oxygen saturation index, P/F ratio or S/F ratio.

Conclusions: There was substantial heterogeneity in respiratory failure characteristics and ventilatory requirements pre-arrest. Higher pre-arrest oxygen requirement and greater degree of oxygenation failure were associated with worse survival outcomes.