Positive end-expiratory pressure impact on cardiac output and cerebral hemodynamics in newborns

This study aimed to clarify the extrapulmonary effects of positive end-expiratory pressure (PEEP) in neonates using noninvasive monitoring techniques to monitor cardiac output (CO) and cerebral hemodynamics. This was a prospective, nonrandomized, consecutive enrollment, single-centre study. Newborns weighing ≥ 1,000 g admitted to the neonatal intensive care unit for invasive mechanical ventilation from April 2023 to December 2024 were included. PEEP levels increased sequentially to 5 cm H₂O, 7 cmH₂O, and 10 cm H₂O or peak inspiratory pressure not exceeding 25 cmH₂O (incremental phase) and then decreased to 5 cm H₂O by employing the reverse of the aforementioned procedure (decremental phase) while monitoring stroke volume (SV), CO, and cerebral hemodynamic indexes, including tissue haemoglobin oxygen saturation and total haemoglobin on term and preterm infants using the electrical cardiometry and near-infrared time-resolved spectroscopy. Throughout the procedure, fraction of inspired oxygen, inspiratory time, and tidal volume were maintained at baseline values determined before initiation. This study included 16 term infants (median gestational age: 38 [IQR, 38-39] weeks; median birth weight: 2,778 [IQR, 2,296-3,046] g) and 20 preterm infants (median gestational age: 31 [IQR, 30-33] weeks; median birth weight: 1,459 [IQR, 1,264-2,044] g). High PEEP significantly reduced SV and CO compared to mild PEEP in both term and preterm neonates. tNIRS-1 measurements remained stable throughout the procedure.

PEEP levels used in this study reduced CO without affecting cerebral perfusion. Although clinically used PEEP levels have minimal impact on cerebral perfusion in newborns, high PEEP may decrease blood circulation to organs outside the brain.

•Setting an appropriate positive end-expiratory pressure (PEEP) is a key component of ventilator management in newborns. PEEP influence extrapulmonary functions, including cardiac output (CO) and cerebral hemodynamics. However, limited research has explored these extrapulmonary effects of PEEP in neonates.

• The PEEP levels used in this study reduced CO without affecting cerebral perfusion in newborns. Clinically used PEEP levels have minimal impact on cerebral perfusion in newborns. However, high PEEP may decrease blood circulation to organs outside the brain.