A Right-to-Left or Bidirectional Ductal Shunt in Preterm Neonates: Grave Implication?

ABSTRACT

We delineate the natural history of a right-to-left or bidirectional (RL/BD) patent ductus arteriosus (PDA) in preterm infants and compare outcomes of an RL/BD and a left-to-right (LR) ductal shunt. We performed a retrospective chart review of preterm infants (<32 weeks), who, between 2 and 30 days of age, had an RL/BD PDA >1.5 mm (study group; n = 74) or an LR PDA (n = 87) on echocardiogram (ECHO). In the study group, 27% of infants who were of significantly lower gestational age and birth weight had a “prolonged” RL/BD PDA on two or more ECHOs. Infants with RL/BD PDA required significantly greater surfactant (98.6% versus 94.2%) and less PDA therapy (27% versus 92%) and had higher mortality (48.6% versus 21.8%) compared with those with LR PDA. On regression analysis, lower gestation (odds ratio [OR] 1.45; 95% confidence interval [CI]: 1.15 to 1.83) and RL/BD PDA (OR 4.74; 95% CI: 2.18 to 10.3) were significantly associated with mortality. The independent association between an RL/BD PDA shunt and mortality warrants further investigation. Insights into the etiology of pulmonary hypertension may optimize outcomes in this population.

KEYWORDS

Patent ductus arteriosus - right to left shunt - bidirectional shunt

REFERENCES

• 1 Schmidt B, Davis P, Moddemann D Trial of Indomethacin Prophylaxis in Preterms Investigators et al. Long-term effects of indomethacin prophylaxis in extremely-low-birth-weight infants.  N Engl J Med. 2001;  344 1966-1972
• 2 Clyman R I. Mechanisms regulating the ductus arteriosus.  Biol Neonate. 2006;  89 330-335
• 3 Bancalari E, Claure N, Gonzalez A. Patent ductus arteriosus and respiratory outcome in premature infants.  Biol Neonate. 2005;  88 192-201
• 4 Hamrick S E, Hansmann G. Patent ductus arteriosus of the preterm infant.  Pediatrics. 2010;  125 1020-1030
• 5 Clyman R I, Chorne N. Patent ductus arteriosus: evidence for and against treatment.  J Pediatr. 2007;  150 216-219
• 6 Ramos F G, Rosenfeld C R, Roy L, Koch J, Ramaciotti C. Echocardiographic predictors of symptomatic patent ductus arteriosus in extremely-low-birth-weight preterm neonates.  J Perinatol. 2010;  30 535-539
• 7 Sehgal A, McNamara P J. Does echocardiography facilitate determination of hemodynamic significance attributable to the ductus arteriosus?.  Eur J Pediatr. 2009;  168 907-914
• 8 Su B H, Watanabe T, Shimizu M, Yanagisawa M. Echocardiographic assessment of patent ductus arteriosus shunt flow pattern in premature infants.  Arch Dis Child Fetal Neonatal Ed. 1997;  77 F36-F40
• 9 Evans N J, Archer L NJ. Doppler assessment of pulmonary artery pressure and extrapulmonary shunting in the acute phase of hyaline membrane disease.  Arch Dis Child. 1991;  66 (1 Spec No) 6-11
• 10 Houston A B, Lim M K, Doig W B et al.. Doppler flow characteristics in the assessment of pulmonary artery pressure in ductus arteriosus.  Br Heart J. 1989;  62 284-290
• 11 Kumar V H, Hutchison A A, Lakshminrusimha S, Morin III F C, Wynn R J, Ryan R M. Characteristics of pulmonary hypertension in preterm neonates.  J Perinatol. 2007;  27 214-219
• 12 Fraisse A, Geva T, Gaudart J, Wessel D L. Doppler echocardiographic predictors of outcome in newborns with persistent pulmonary hypertension.  Cardiol Young. 2004;  14 277-283
• 13 Musewe N N, Poppe D, Smallhorn J F et al.. Doppler echocardiographic measurement of pulmonary artery pressure from ductal Doppler velocities in the newborn.  J Am Coll Cardiol. 1990;  15 446-456
• 14 Carlo W A, Finer N N, Walsh M C SUPPORT Study Group of the Eunice Kennedy Shriver NICHD Neonatal Research Network et al. Target ranges of oxygen saturation in extremely preterm infants.  N Engl J Med. 2010;  362 1959-1969
• 15 Ethington P, Smith P B, Katakam L, Goldberg R N, Cotton C MM. Treatment of patent ductus arteriosus with bidirectional flow in neonates.  E-PAS. 2009;  (abstract)
• 16 Tanaka Y, Hayashi T, Kitajima H, Sumi K, Fujimura M. Inhaled nitric oxide therapy decreases the risk of cerebral palsy in preterm infants with persistent pulmonary hypertension of the newborn.  Pediatrics. 2007;  119 1159-1164