Abstract
To compare the mean oxygenation index on day1 (MOId1) with the best OI on day1 (BOId1) in predicting 30-day mortality in congenital diaphragmatic hernia (CDH). In addition, to determine whether serial OIs in the first 48 h after birth and preoperative OI (PreOp-OI), were associated with optimal timing of surgery, ventilation requirement and hospital stay in infants with CDH.
The medical records of infants with antenatally diagnosed CDH during 2009–2015 were retrospectively reviewed. Receiver operator characteristic curves were constructed to identify MOId1 and BOId1 cutoff levels to predict 30-day mortality. In those who underwent surgery, the mean OI on each of the first two days (MOId1, MOId2) and PreOp-OI were correlated using Spearman (rs) with the age at surgery, the duration of ventilation and length of stay. Statistical significance was P < 0.05* and < 0.001**.
Survivors (n = 44) and nonsurvivors (n = 24) were comparable in gestational age, birth weight and defect laterality. Nonsurvivors had higher median BOId1 (15.4 vs 2.9; P < 0.01) and MOId1 (48 vs 7.5; p < 0.01) than survivors. Mortality was best predicted by two cutoffs [BOId1 > 6 (sensitivity 92%, specificity 89%); and MOId1 > 17 (sensitivity 96%, specificity 96%)].
Forty-four infants underwent surgery at a median postnatal age of five (range 2–19) days. MOId1 and MOId2 both correlated significantly with the age at surgery (rs = 0.4**, rs 0.5**) but not ventilation period and length of stay. PreOp-OI correlated significantly with age at surgery, duration of ventilation and length of stay (rs = 0.32*, rs = 0.47**, rs = 0.37*). A PreOp-OI <3 was predictive of optimal timing for surgery with improved duration of ventilation (8 vs 22, P = 0.001) and length of stay (26 vs 47, P = 0.004). However, 11/44 (25%) patients would not achieve a PreOp-OI < 3 by day 7+ of life and might still require surgery, one of them died.
Both MOId1 and BOId1 are highly predictive of mortality in CDH. Oxygenation indices in the first 48 h poorly predicted the timing of surgery. PreOp-OI <3 may be a cutoff for optimal timing for surgery in infants for CDH repair.
Prognostic Study.
Level III.