Pediatr Res

. 2022 Mar 19. doi: 10.1038/s41390-022-02001-2. Online ahead of print. https://pubmed.ncbi.nlm.nih.gov/35306536/

Ventilation-to-perfusion relationships and right-to-left shunt during neonatal intensive care in infants with congenital diaphragmatic hernia

Theodore Dassios ^1 2, Fahad M Shareef Arattu Thodika ³, Emma Williams ³, Mark Davenport ⁴, Kypros H Nicolaides ⁵, Anne Greenough ^3 6 7Affiliations expand

• PMID: 35306536
• DOI: 10.1038/s41390-022-02001-2

Abstract

Background: We aimed to explore the postnatal evolution of ventilation/perfusion ratio (V_A/Q) and right-to-left shunt in infants with congenital diaphragmatic hernia (CDH) and whether these indices predicted survival to discharge.

Methods: Retrospective cohort study at King’s College Hospital, London, UK of infants admitted with CDH in 10 years (2011-2021). The non-invasive method of the oxyhaemoglobin dissociation curve was used to determine the V_A/Q and shunt in the first 24 h of life, pre-operation, pre-extubation and in the deceased infants, before death.

Results: Eighty-two infants with CDH (71 left-sided) were included with a median (IQR) gestation of 38.1(34.8-39.0) weeks. Fifty-three (65%) survived to discharge from neonatal care. The median (IQR) V_A/Q in the first 24 h was lower in the deceased infants [0.09(0.07-0.12)] compared to the ones who survived [0.28(0.19-0.38), p < 0.001]. In the infants who survived, the V_A/Q was lower in the first 24 h [0.28 (0.19-0.38)] compared to pre-operation [0.41 (0.3-0.49), p < 0.001] and lower pre-operation compared to pre-extubation [0.48 (0.39-0.55), p = 0.027]. The shunt was not different in infants who survived compared to the infants who did not.

Conclusions: Ventilation-to-perfusion ratio was lower in infants who died in the neonatal period compared to the ones that survived and improved in surviving infants over the immediate postnatal period.

Impact: The non-invasive method of the oxyhaemoglobin dissociation curve was used to determine the ventilation/perfusion ratio V_A/Q in infants with congenital diaphragmatic hernia (CDH) in the first 24 h of life, pre-operation, pre-extubation and in the deceased infants, before death. The V_A/Q in the first 24 h of life was lower in the infants who did not survive to discharge from neonatal care compared to the ones who survived. In the infants who survived, the V_A/Q improved over the immediate postnatal period. The non-invasive calculation of V_A/Q can provide valuable information relating to survival to discharge.

© 2022. The Author(s).