Improving diagnostic accuracy in the transport of infants with suspected duct‐dependent congenital heart disease

Aim To identify factors that distinguish duct‐dependent congenital heart disease ( DDCHD ) from non‐ DDCHD in newborn infants. Method A retrospective, cohort study. The N ewborn E mergency T ransport S ervice, V ictoria ( NETS ) is a retrieval service for all inter‐hospital neonatal transfers, and the R oyal C hildren's H ospital, M elbourne ( RCH ) is a paediatric cardiac referral centre for the state of V ictoria, A ustralia. All infants ≤10 days and ≥34 weeks gestation with suspected CHD and/or persistent pulmonary hypertension of the newborn ( PPHN ), transferred by NETS from non‐tertiary neonatal units to RCH , over a 4‐year period. Results Of 142 eligible infants, 81 had DDCHD and 61 had non‐ DDCHD , of whom 51 had PPHN . Diagnostic accuracy of DDCHD by the NETS team was 77%. Presence of a heart murmur, abnormal pulses, upper and lower limb blood pressure ( BP ) difference >10  mmHg , cardiomegaly, initial SpO 2 of <92%, PaO 2 <50 mmHg, and pre‐post ductal SpO 2 difference >10% were significantly associated with DDHCD on univariate analysis. No single clinical finding was significantly associated with DDCHD on multivariate analysis. Labile SpO 2 , abnormal lung parenchyma, mean BP <40 mmHg, pH <7.25, lactate >5 and FiO 2 >0.5 were significantly associated with non‐ DDCHD , but at multivariate analysis only labile SpO 2 and mean BP <40 mmHg were associated with non‐ DDCHD . Conclusions Clinical diagnosis of DDCHD outside of a cardiac centre is challenging. No single factor predicts DDCHD . Combined interpretation of clinical, physiological and x‐ray findings may assist.