The Incidence and Severity of Hypocarbia in Neonates Undergoing General Anesthesia

Extended periods of hypocarbia in preterm infants may be associated with intraventricular hemorrhage, periventricular leukomalacia, and bronchopulmonary dysplasia. To evaluate the current anesthetic practice in preterm neonates, we retrospectively reviewed the intraoperative course with regard to [Formula: see text] and ventilation during non-cardiac surgical procedures in infants <60 weeks postmenstrual age.

This was a single-center, retrospective study during non-cardiac surgical procedures in neonates. Hyperventilation was defined as a [Formula: see text] ≤ 35  mm  Hg, significant hyperventilation as a [Formula: see text] ≤ 30 mm Hg, and extreme hyperventilation as a [Formula: see text] ≤ 25  mm  Hg.

The study cohort included 112 neonates, with a median postnatal age of 40 weeks, median gestational age of 38 weeks, and median weight of 5 kg. Thirty-seven subjects (33%) had at least one arterial blood gas value that demonstrated hyperventilation. Thirteen (12%) were noted to have significant hyperventilation ([Formula: see text] ≤ 30  mm  Hg) and 2 had extreme hyperventilation ([Formula: see text] ≤ 25  mm  Hg).

The incidence of at least one arterial blood gas that demonstrated inadvertent hyperventilation in neonates was high during intraoperative care. These data may provide the baseline for future studies that address more rigorous monitoring and control of [Formula: see text] during intraoperative care. Although the duration of the anesthetic care and surgical procedure is brief compared with the neonatal ICU length of stay because there is no demonstrated benefit of hypocapnia and, in fact, well-documented harm associated with hyperventilation in neonates, care should be directed at limiting inadvertent hyperventilation. (ClinicalTrials.gov registration NCT03823716.).