Carbon Dioxide Levels in Extremely Preterm Neonates Ventilated With High Frequency Jet Ventilation

Area of Science:

• Neonatalogy
• Respiratory Medicine
• Critical Care

Background:

• Close monitoring of carbon dioxide (CO2) levels is vital for extremely preterm neonates.
• Optimal CO2 thresholds for these infants remain undefined.
• This study evaluates CO2 levels' impact on outcomes in neonates on high frequency jet ventilation (HFJV).

Purpose of the Study:

• To assess the association between P aCO2 levels in the first 24 hours of life and outcomes in extremely preterm neonates.
• To determine optimal P aCO2 thresholds for survival without severe intraventricular hemorrhage (IVH).
• To evaluate the impact of P aCO2 on neonates ventilated with first-intention HFJV.

Main Methods:

• Retrospective analysis of neonates (≤26 weeks gestational age) ventilated with first-intention HFJV (2022-2024).
• Comparison of P aCO2 metrics (lowest, peak, fluctuations, deviation from target) between survivors without severe IVH and those with severe IVH or death.
• Analysis of P aCO2 deviation from the target range of 40-50 mm Hg.

Main Results:

• Higher peak P aCO2, greater P aCO2 fluctuations, and larger deviation from target were significantly associated with severe IVH or death.
• Neonates surviving without severe IVH had lower peak P aCO2 (54.6 vs 66.7 mm Hg), fluctuations (16.6 vs 30.8 mm Hg), and deviation (9.7 vs 20.0 mm Hg).
• Cutoffs of peak P aCO2 <65 mm Hg, fluctuations <25 mm Hg, and deviation <15 mm Hg showed high sensitivity and specificity for favorable outcomes.

Conclusions:

• Maintaining peak P aCO2 <65 mm Hg, P aCO2 fluctuations <25 mm Hg, and deviation from target <15 mm Hg is crucial.
• These P aCO2 targets are significantly associated with survival without severe IVH in extremely preterm neonates on HFJV.
• Establishing these thresholds can guide respiratory support strategies for vulnerable infants.