Utility of the Oxygenation Index in Management of Congenital Diaphragmatic Hernia – a Report From a Thai University Surgical Centre

Abstract

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 hours of life and its correlation with (i) perioperative morbidity and (ii) 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: 55 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.