Introduction
Permissive hypercapnia is a mechanical ventilation strategy that
tolerates the partial pressure of arterial carbon dioxide
(PaCO2) above the normal range (35–45 mmHg). This
approach may protect the lung from volutrauma and barotrauma by
modulating small tidal volumes and low peak inspiratory pressures. In
adult patients with acute respiratory distress syndrome, mechanical
ventilation with a low tidal volume using permissive hypercapnia
decreased the mortality and duration of mechanical ventilation.1-3However, in pediatric or newborn patients, findings
from previous reports on the effectiveness of this strategy are
inconsistent and do not provide enough evidence of the safety profile.4,5 In preterm infants, this approach is reported to
cause a potential increase in the risk of intraventricular hemorrhage
(IVH) due to permissive hypercapnia, which can result in
neurodevelopmental impairment (NDI) because hypercapnia causes cerebral
vasodilation and increases cerebral blood flow 6.Owing
to controversial evidence on this topic, we conducted a systematic
review and meta-analysis with an aim to examine the efficacy and safety
of permissive hypercapnia, in comparison with the normocapnia strategy,
in premature infants on mechanical ventilation.