059 - Relative contribution of early postnatal risk factors in progression to moderate-to-severe bronchopulmonary dysplasia in extremely low birth weight neonates: A prospective observational cohort study

Publication Number: 59.6367

Amish Jain, University of Toronto Temerty Faculty of Medicine, Toronto, ON, Canada; Faith Zhu, Faith Zhu, Staff Neonatologist, Mount Sinai Hospital, Toronto, Toronto, ON, Canada; Laura Thomas, Mount Sinai Hospital, Toronto, Toronto, ON, Canada; Michelle Baczynski, Mount Sinai Hospital, Toronto, ON, Canada; Aisling M. Smith, The Rotunda Hospital, Dublin, Dublin, Ireland; Adrianne R. Bischoff, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Amy Stanford, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Ashraf Kharrat, Mount Sinai Hospital, Toronto, ON, Canada; Sébastien Joye, University hospital of Lausanne, LAUSANNE, Vaud, Switzerland; Poorva Deshpande, Mount Sinai Hospital, Toronto, ON, Canada; Sagee Nissimov, Shamir Medical Center, Ramat Hasharon, HaMerkaz, Israel; Seungwoo Lee, Mount Sinai Hospital, Toronto, ON, Canada; Bonny Jasani, The Hospital for Sick Children, Toronto, ON, Canada; Dany E. Weisz, University of Toronto, Toronto, ON, Canada; Patrick J. McNamara, University of Iowa Stead Family Children's Hospital, IOWA CITY, IA, United States; Prakesh S. Shah, Mount Sinai Hospital, Toronto, ON, Canada

Background: Extremely low birth weight neonates [ELBWs, birth weight (BW) < 1000 g] are at high risk of bronchopulmonary dysplasia (BPD). Knowledge of relative contribution of risk factors occurring during early NICU course may inform mitigation and quality improvement strategies relevant to contemporary practice.

Objective: To identify potential modifiable postnatal risk factors associated with moderate-to-severe BPD (msBPD) in ELBWs and estimate their respective strength of relationship.

Design/Methods: We conducted a secondary analysis of data generated by a multicenter observational cohort study that prospectively recruited 351 ELBWs across four tertiary NICUs (2 in Canada, 1 in the United States, 1 in Ireland), collected relevant clinical data for the first 3 weeks in NICU, and performed targeted neonatal echocardiography (TNE) during 3rd week of age (TNE-1) and at 32 weeks postmenstrual age (PMA, TNE-2). Presence and size of patent ductus arteriosus (PDA) and patent foramen ovale (PFO) was recorded at each TNE. For this analysis, 334 patients who survived until 36 weeks PMA were included and divided into two groups for comparison based on the primary outcome of msBPD, defined by Jenson’s criteria (requiring >2L/min non-invasive or any invasive respiratory support at 36 weeks PMA). Multivariable logistic regression (MLR) was conducted for the outcome of msBPD using predefined potential risk factors during the first 3 weeks in NICU: invasive mechanical ventilation (IMV) days, culture positive sepsis or necrotising enterocolitis ≥stage 2a (NEC), needing treatment with inotropes or inhaled nitric oxide, persistent PDA with diameter ≥ 1.5mm on TNE-1, PFO with diameter ≥2.0 mm on TNE-2. Further demographic factors were included if relevant on univariate analysis. Beta coefficients were reported for identified variables.

Results: The cohort’s mean (SD) gestational age (GA) and birth weight was 26.0 (2.0) weeks and 755 (164) grams, respectively; 143 (43%) formed the msBPD group. While most baseline characteristics were similar between groups, important differences were seen in studied postnatal risk factors (Table 1); PFOs were more frequent in the control group. MLR revealed sepsis/NEC, prophylactic indomethacin (pINDO), IMV days, and birth weight was associated with msBPD, in decreasing order of strength of beta coefficients (Table 2). Persistent PDA (TNE-1) and PFO (TNE-2) were not associated with msBPD.

Conclusion(s): This large prospective study identifies reducing sepsis/NEC and IMV days, and use of pINDO as potential targets to mitigate the burden of msBPD for ELBWs in contemporary neonatal practice.

Table 1. Univariate comparison of baseline demographics and postnatal potentially modifiable factors during early NICU stay between ELBW neonates survived until 36 weeks postmenstrual age with or without a diagnosis of moderate-severe BPD (msBPD)
Data presented as number (frequency), mean (standard deviation), or median (interquartile range), as appropriate. ELBW extremely low birth weight neonates; SGA small for gestational age; PROM prolong rupture of membranes; NICU neonatal intensive care unit; iNO inhaled nitric oxide; PDA patent ductus arteriosus; PFO patent foramen ovale.

Table 2. Multivariate logistic regression analysis to identify postnatal potentially modifiable factors associated with the outcome of moderate-severe bronchopulmonary dysplasia in extremely low gestational age neonates
NEC necrotising enterocolitis; iNO inhaled nitric oxide; PDA patent ductus arteriosus; PFO patent foramen ovale; PMA postmenstrual age. Including PDA diameter and PFO diameter as continuous variables demonstrated similar findings