Distinguishing duct dependent congenital heart disease (DDCHD) from other causes of hypoxaemia, notably persistent pulmonary hypertension (PPHN), represents a diagnostic and therapeutic dilemma for neonatal transport teams, specifically in relation to use of prostaglandin E1 (PGE₁). In non-DDCHD, PGE₁ is considered unnecessary and likely to produce unwanted side-effects including apnoea and hypotension.1

We report our observations of the effects of PGE₁ infusion in a group of babies with evidence of PPHN but without DDCHD.

We reviewed the data on all infants ≤10 days and ≥34 weeks gestation with suspected DDCHD and/or PPHN transferred by the Newborn Emergency Transport Service (NETS), Victoria, from non-tertiary neonatal units to the regional paediatric cardiac centre at the Royal Children's Hospital Melbourne between 1 May 2007 and 31 May 2011. Cases were identified from NETS and cardiac databases. Final diagnosis was based on echocardiogram.

Of 142 eligible infants, 81 infants had DDCHD. Of 61 non-DDCHD infants, 51 had PPHN, and 10 infants had neither DDCHD nor PPHN. PGE₁ was commenced in 71 (50%) of all infants; 52 (63%) of DDCHD group, 9 (18%) of the PPHN group and all others. Median (range) PGE₁ dose was 20 (5–100) nanograms/kg/min.

Overall, PGE₁ use was not associated with higher rates of ventilation or inotrope use (table 1). However, within the DDCHD subgroup, PGE₁ use was associated with higher rates of ventilation (44% vs 14%, p=0.01) and inotrope use (29% vs 3%, p=0.01).

PGE₁ use was associated with significantly shortened length of stay in PPHN (figure 1) (3 (1–14) vs 14 (13–27) days, p=0.004), but not in DDCHD patients (19 (21–37) vs 13 (13–32) days, p=012).

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Figure 1

Length of stay in PGE₁ versus noPGE₁ groups. *Signifies significant p value. DDCHD, duct dependent congenital heart disease; PGE₁, prostaglandin E1; PPHN, pulmonary hypertension.

There was no significant difference in mortality between PGE₁ and no-PGE₁ groups in either PPHN or DDCHD subgroups (N (%): PPHN PGE₁ vs PPHN noPGE₁: 1 (11) vs 9 (21), p=0.66; DDCHD PGE₁ versus DDCHD no PGE₁: 6 (11) vs 3 (10), p=1.0).

Our data suggest that concerns regarding inadvertent PGE₁ use in non-DDCHD may be misplaced and indeed 75% reduction in length of hospital stay for those with PPHN treated with PGE₁ supports the beneficial effect of PGE₁ in PPHN. This is consistent with previous observations of improved oxygenation in PPHN treated with PGE₁ analogue.2 The mechanism of this effect could be the known pulmonary vasodilating effects of PGE₁,3 and the benefits of maintaining ductal patency as a ‘blow-off’ valve to improve function in the pressure and volume-loaded right ventricle.4

As previous studies have also reported safe transport of infants receiving PGE₁ without need for ventilation,5 ,6 we suggest that there may be no need to try to establish a formal diagnosis of DDCHD versus PPHN prior to transfer, but rather to treat with PGE₁ regardless of the diagnosis since both stand to benefit.