Late Permissive Hypercapnia for Mechanically Ventilated Preterm Infants: A Randomized Trial

Area of Science:

• Neonatalogy
• Pediatric critical care
• Respiratory physiology

Background:

• Permissive hypercapnia is used in mechanical ventilation for preterm infants with respiratory distress syndrome.
• Optimal target levels for permissive hypercapnia beyond the initial postnatal period are not well-established.
• This study investigated higher vs. lower pH-controlled permissive hypercapnia targets.

Purpose of the Study:

• To determine if targeting higher levels of pH-controlled permissive hypercapnia beyond postnatal day 7-14 reduces mechanical ventilation duration in preterm infants.
• To assess the impact of higher permissive hypercapnia levels on ventilator-free days and bronchopulmonary dysplasia.
• To evaluate the potential lung-protective effects of higher permissive hypercapnia targets.

Main Methods:

• Single-center randomized clinical trial (NCT02799875) with 130 preterm infants (22-36 weeks' gestation).
• Infants received either higher (PaCO2 60-75 mmHg, pH ≥ 7.20) or lower (PaCO2 40-55 mmHg, pH ≥ 7.25) pH-controlled permissive hypercapnia for 28 days.
• Primary outcome: days alive and ventilator-free within 28 days post-randomization.

Main Results:

• Infants in the higher permissive hypercapnia group had significantly more alive ventilator-free days (11 ± 10 vs. 6 ± 8; P = 0.009).
• No significant difference in grade 2-3 bronchopulmonary dysplasia or death before discharge between groups (44% vs. 59%; aOR 0.54).
• Grade 2-3 bronchopulmonary dysplasia among survivors at 36 weeks' postmenstrual age did not differ significantly between groups (35% vs. 50%; aOR 0.56).

Conclusions:

• Targeting higher levels of permissive hypercapnia from postnatal day 7-14 increased ventilator-free days in preterm infants.
• This strategy may offer lung protection compared to lower permissive hypercapnia levels.
• Further research is needed to fully elucidate the long-term effects and optimal management strategies.