Background Duct dependent congenital heart disease (DDCHD) may be difficult to distinguish from other diagnoses, notably persistent pulmonary hypertension (PPHN). Affected infants born in regional hospitals require transfer to a tertiary paediatric centre for echocardiographic diagnosis. Identification of predictive factors to distinguish DDCHD would assist in appropriate early management during transport.
Aims To describe transport of infants with suspected DDCHD and investigate early predictors of DDCHD.
Methods A retrospective study of infants with suspected DDCHD/PPHN transferred by NETS. Clinical, physiological and investigation data were compared between DDCHD and non-DDCHD (including PPHN) groups.
Results Of 142 eligible infants, 81 had DDCHD and 61 had non-DDCHD, of whom 51 had PPHN. There was no significant difference in median gestation, birth weight, sex, or distance of transfer between DDCHD and non-DDCHD groups. DDCHD infants were more often transferred by air than land.
At univariate analysis, presence of heart murmur, abnormal pulses, upper and lower limb BP difference > 10 mmHg, cardiomegaly, initial SpO2 of < 92% and pre-post ductal SpO2 difference > 10% were significantly associated with DDCHD. Labile SpO2, abnormal lung parenchyma, mean blood pressure < 40 mmHg, pH < 7.25, lactate > 5, PaO2 < 50 mmHg and FiO2 > 0.5 were significantly associated with non-DDCHD.
On multivariate analysis, only labile SpO2 and mean BP <40 mmHg were significantly associated with non-DDCHD.
Conclusion Labile saturations and mean BP<40 mmHg at the time of referral were significantly associated with non-DDCHD/PPHN. Other clinical features and physiological measures did not distinguish DDCHD from non-DDCHD.