Utility of the oxygenation index in management of congenital diaphragmatic hernia: a report from a Thai University Surgical Centre.

Background: Oxygenation index (OI) is associated with severity of newborn pulmonary hypertension (PH) in congenital diaphragmatic hernia (CDH). Higher OI may indicate worst degree(s) of PH.

Objectives: This study reports OI dynamic(s) over the first 72 h of life and its correlation with (1) perioperative morbidity and (2) CDH mortality.

Methods: Medical records of inborn CDH babies during 2002-2022 were examined. OI on Days (s) 1-3 and perioperative OI trends were recorded. Operation (primary vs patch repair) and survival rates (%) were studied.

Results: Fifty-five CDH newborns (54.5% male: 45.5% female)-mean birth GA 37.5 ± 2.7 wks. had a mean birth weight 2813 ± 684 g with prenatal diagnosis in 32.7% cases. 52/55 (94.5%) were intubated at birth and HFOV deployed in 29 (55.8%). Those requiring HFOV had higher OI on DOL1 (24.8 ± 17 vs 10.3 ± 11.5; p < 0.05), DOL 2 (26.3 ± 22.9 vs 6.7 ± 12.1; p < 0.05) and DOL 3 (21.9 ± 33.8 vs 5.5 ± 9.3; p = 0.04). Operation was undertaken in 36/55 (65.5%). Preoperative mortality group had significant higher OI on DOL 2 (42.1 ± 21.0 vs 14.9 ± 9.3; p = 0.04). CDH defects were-Type A N = 27 (75%), Type B N = 7 (19.4%) and Type C N = 2 (5.6%). Overall mortality was 40% (22/55). Statistically significant OI trends were recorded in non-survival vs. survival groups on DOL 1 (31.6 ± 16.8. vs 10.5 ± 9.0; p < 0.05, DOL 2 (38.1 ± 21.9 vs 6.3 ± 7.1; p < 0.05), and DOL 3 (38.8 ± 39.4; p = 0.012).

Conclusions: OI dynamics are highly predictive for accurate monitoring of CDH cardiorespiratory physiology and crucially may guide ventilatory management as well as timing of surgery.