Effect of Intermittent Hypoxemia and Hyperoxemia during the Neonatal Period on Control of Breathing Function among Infants Born Extremely Preterm.

Abstract

Objective: To evaluate the association between intermittent hypoxemia (IH) and hyperoxemia (HOX) during the first 28 days with peripheral and central chemoreception at 36 weeks postmenstrual age among infants born extremely preterm.

Study design: For this observational study 52 infants born at 23 to 28 weeks of gestational age were enrolled. Mean daily IH frequency (SpO₂<80% for ≥10s) and percent of time in HOX (SpO₂≥98% while FiO₂>.21) were calculated for the first 28 days of life. At 36 weeks postmenstrual age (PMA), respiratory control tests assessed peripheral chemoreception by ventilatory response to 100% O₂ for 30 seconds in which decreased ventilation caused by inhibition of peripheral chemoreceptors reflects their contribution to respiratory drive. Central chemoreception was evaluated by ventilatory response to 4% inspired CO₂ for 10 minutes.

Results: Multivariable generalized linear models showed increasing IH and HOX were independently associated with an attenuated ventilatory response to 100% O₂ at 36 weeks PMA. IH and HOX were not significantly associated with an attenuated ventilatory response to CO₂.

Conclusions: In these infants born extremely preterm, neonatal intermittent hypoxemia and hyperoxemia were independently associated with attenuated peripheral chemoreception at near term corrected age. This may reflect reduced peripheral chemoreceptor oxygen sensitivity and may be in part responsible for persistence of respiratory instability in infants born preterm. Neonatal intermittent hypoxemia or hyperoxemia were not associated with reduced central chemoreception.