Findings
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 on mechanical ventilation. All 3 phenotypes revealed a subset of patients who responded to bronchodilator therapy, and responders had a lower FEV0.5 at baseline than did nonresponders. Our findings reveal that sBPD as it is currently defined includes different phenotypes that may require different therapeutic approaches. In patients with sBPD who are not clinically improving, we would suggest that iPFT may be considered to determine their phenotypes to help guide ongoing therapies. Given that most NICUs do not have access to a pulmonary function testing laboratory, in the long-term, it would be helpful to develop easier bedside testing to differentiate these phenotypes, and we suggest that this should be a focused area of future research. Finally, the iPFT for phenotypes could also be used to direct future therapeutic trials in patients with sBPD.
Procedures
N = 56, 10, and 44, respectively, for all data except Crs, for which N = 48, 5, and 32, respectively. Symbols refer to P values from Dunn’s post hoc test or direct comparisons using the ? 2 test. FEF25%–75%, forced expiratory flow midexpiratory phase; FEF50%, forced expiratory flow 50; FEF75%, forced expiratory flow 75; FEF85%, forced expiratory flow 85; FRC, functional residual capacity; RV, residual volume; -, not applicable.
We found that the vast majority of patients with sBPD who were referred for iPFT had some element of obstruction, and this result is consistent with previous reports of patients with BPD who were studied during the NICU period. In an early report, Baraldi et al 14 found that in a small cohort of infants born at ?1250 g who developed BPD, resistance of the respiratory system (Rrs) was higher at 6 months of age than in normative data and that all infants demonstrated some degree of flow limitation at repeat testing at 2 years of age. In a more recent cohort 15 that included 43 extremely preterm infants studied at 7 ± 6 months of age, researchers found that these infants had airflow obstruction. Schmalisch et al 16 studied 186 infants born at <28 weeks' gestation with the diagnosis of severe neonatal lung disease, which was defined as needing mechanical ventilation for >24 hours at 52 ± 11 weeks, and found that they exhibited airflow obstruction, although it should be pointed out that most of these patients would not likely have had the diagnosis of sBPD as defined herein. Filbrun et al 17 reported on a slightly older (59 ± 18 weeks) cohort of patients who were relatively well and found that even this group of infants demonstrated airflow obstruction. Robin et al 18 reported similar results in a cohort of 28 infants with BPD who were studied at 68 ± 36 weeks of age. Thus, although the majority of patients in the cohorts studied previously would not have met the definition of sBPD, taken together, these data reveal that most preterm infants with BPD have evidence of airflow obstruction at the time of iPFT. Our data reveal that 91% of infants with sBPD during the initial NICU stay have an obstructive component to their phenotypes, with 51% of patients with sBPD having the purely obstructive phenotype.
There are lots of limits to the research which should be thought. Earliest, the new cohort does not include all of the patients with sBPD who have been accepted to your BPD provider at the time physique of data but only those who were known to possess iPFT. In our institution, patients is introduced to own iPFT if they are not on a good clinical trajectory that is suggestive regarding continued, slow, and you will regular update. Thus, the latest cohort yes is sold with people customers to the severest kinds of BPD. 19 Next, there clearly was a relatively number of shed iPFT studies. not, all of our cohort is the largest cohort away from customers which have sBPD while in the the initial NICU hospitalization that has milfaholic-coupon been stated.