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Healio
April 05, 2018
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Severe bronchopulmonary dysplasia includes 3 distinct phenotypes

Preterm infants hospitalized in the neonatal ICU diagnosed with severe bronchopulmonary dysplasia had three distinct phenotypes, as determined by infant pulmonary function testing, according to study results published in Pediatrics.

“Bronchopulmonary dysplasia (BPD) is the most common morbidity in extremely preterm infants,” Edward G. Shepherd, MD, of the Comprehensive Center for Bronchopulmonary Dysplasia and the Neonatal Aerodigestive Program, and the department of pediatrics, The Ohio State University, Columbus, and colleagues wrote. “Despite advances in neonatal care that have led to improved survival of extremely preterm infants, there has been no decrease in the incidence of BPD among survivors.”

“There is significant practice variation in the approach to [severe BPD (sBPD)] both within an institution and among institutions,” the researchers continued “This lack of standardization in care for patients with sPBD arises from the lack of good definition for BPD and the widely variable patient presentation and clinical course.”

Shepherd and colleagues prospectively collected data on infants who were hospitalized in the neonatal ICU with SBPD between May 1, 2003, and June 30, 2016.

Through infant pulmonary function testing (iPFT), the infants were classified into three separate phenotypes, including obstructive (forced expiratory volume at 0.5 seconds [FEV0.5] <80% predicted and total lung capacity [TLC] ≥90% predicted), restrictive (TLC < 90% predicted and FEV0.5 and/or forced vital capacity [FVC] ≥90% predicted) or mixed (TLC <90% predicted and FEV0.5 and/or FVC<90% predicted).

Preterm infants with severe bronchopulmonary dysplasia demonstrated three distinct phenotypes. Patients with the purely restrictive phenotype were more likely to be weaned relatively quickly from positive pressure and were discharged from the hospital without mechanical ventilation.
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There were 110 infants included in the study who had a median gestational age at birth of 25 weeks (interquartile range [IQR], 24-27 weeks) and a median birth weight of 707 g (IRQ, 581-925 g). When IPFT was conducted, the patients had a median postmenstrual age of 52 weeks (IRG, 45-63 weeks) and median weight of 4.4 kg (IRG, 3.7-7.0 kg).

Slightly more than half of the infants (51%) had the obstructive phenotype, whereas 40% had mixed and 9% had the restrictive phenotype.

Most of the infants in the obstructive cohort (86%) and mixed cohort (78%) had moderate or severe obstruction. Among the infants classified as restrictive, 70% experienced moderate restriction, with the rest experiencing mild restriction.

The obstructive cohort had the highest bronchodilator response (74%), followed by mixed (63%) and restrictive (25%).

“Patients with sBPD demonstrated three distinct iPFT phenotypes: obstructive, restrictive and mixed,” the researchers concluded. “The obstructive phenotype was the most prevalent and was associated with greater birth weight. Although seen in only 9% of patients with sBPD, the purely restrictive phenotype and its diagnosis may be important from a therapeutic prospective because these patients can likely be weaned relatively quickly from positive pressure, and none of the purely restrictive patients were discharged from the hospital win mechanical ventilation.”  – by Bruce Thiel

 

Disclosures: The authors report no relevant financial disclosures.

Sources/Disclosures

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Source: Shepherd EG, et al. Pediatrics. 2018;doi10.1542/peds.2017-3350.