Increased volume of tracheal aspirate fluid predicts the development of bronchopulmonary dysplasia Sota Iwatani ⁎, Masami Mizobuchi, Satoshi Tanaka, Kei Inomata, Hitomi Sakai, Seiji Yoshimoto, Hideto Nakao Department of Neonatology, Hyogo Prefectural Kobe Children's Hospital Perinatal Center, 1-1-1 Takakuradai, Suma-Ku, Kobe, Hyogo 654‐0081, Japan abstract article info Article history: Received 6 May 2012 Received in revised form 21 August 2012 Accepted 28 August 2012 Keywords: Bronchopulmonary dysplasia Extremely low gestational age newborns Mechanical ventilation Tracheal aspirate fluid Background: Elevated cytokine concentrations were observed in tracheal aspirate fluid (TAF) of infants on mechanical ventilation who subsequently developed bronchopulmonary dysplasia (BPD). However, there are few reports that systematically evaluate the amount of TAF as an indicator of BPD development. Aim: To clarify whether TAF volume during the first week of life predicts BPD development in extremely low gestational age newborns (ELGANs). Study design: We analyzed 51 infants, born at gestational age of b 28 weeks and ventilated for more than 7 days after birth, among whom, 26 were diagnosed with BPD based on the clinical definition of oxygen de- pendence at 36 weeks postmenstrual age (BPD group) and 25 were included in the non-BPD group. Sum of TAF scores (STS) was calculated by semi-quantification of TAF volume at each suctioning and the suctioning frequency during the first week of life. Results: STS was significantly higher in the BPD group than in the non-BPD group (median (interquartile range): 77 (29–126) vs. 28 (22–59), p b 0.001). STS (cut-off, 60) with area under the curve in receiver oper- ating analysis of 0.75 was significantly predictive of BPD development. Multivariate logistic regression anal- ysis adjusted for perinatal characteristics showed that STS ≥60 was a significant risk factor for BPD development (odds ratio, 7.50; confidence interval, 1.16–48.40, p = 0.034). Conclusion: Increased TAF volume during the first week of life was an independent predictor for BPD devel- opment in ventilated ELGANs, indicating that increased pulmonary capillary permeability may influence the pathogenesis of BPD. © 2012 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Bronchopulmonary dysplasia (BPD), also known as chronic lung dis- ease of prematurity, is typically defined as the need for supplemental oxygen at 36 weeks postmenstrual age [1]. Nearly two-thirds of infants, in whom BPD developed, had extremely low birth weight and were born before gestational age (GA) of 28 weeks [2]. Affected infants were more likely to have long-term pulmonary problems, to be re- hospitalized during the first year of life, and to have delayed neuro- development [3]. The pathogenesis of BPD is multifactorial, with both prenatal and postnatal factors involved. The main factors predisposing neonates to BPD include prematurity, fetal inflammation, absence of antenatal steroids, oxygen therapy, mechanical ventilation, postnatal infection, patent ductus arterious (PDA), and genetic factors [4,5]. BPD develop- ment is associated with pulmonary inflammation, as demonstrated by large number of inflammatory cells and increased levels of pro- inflammatory cytokines in the lung of infants who develop BPD than in those of infants who do not [6]. Several prognostic markers have been reported as predictors of BPD, such as proinflammatory cy- tokines (IL-6, IL-8, and TNF-α) and other mediators in cord blood, serum, and tracheal aspirate fluid (TAF) of infants [7–9]. However, to date, there is no reliable prognostic marker to predict BPD develop- ment. In this study, we hypothesized that TAF volume, as an indicator of inflammation and microvascular permeability [10] would be in- volved in BPD development in preterm infants during the first week of life. Accordingly, we aimed to determine whether TAF volume dur- ing the first week of life could predict BPD development in extremely low gestational age newborns (ELGANs). 2. Patients and methods 2.1. Study population/Study design This was a retrospective study that analyzed the data for infants born at the NICU of Hyogo Prefectural Kobe Children's Hospital Peri- natal Center between November 2008 and June 2010. All infants with a GA of b 28 weeks and who required intubation at birth and ventilation for more than 7 days were prospectively enrolled. BPD diagnosis was defined as the need for supplemental oxygen at Early Human Development 89 (2013) 113–117 ⁎ Corresponding author. Tel.: +81 78 732 6961; fax: +81 78 735 0910. E-mail address: iwatani_kch@hp.pref.hyogo.jp (S. Iwatani). 0378-3782/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.earlhumdev.2012.08.007 Contents lists available at SciVerse ScienceDirect Early Human Development journal homepage: www.elsevier.com/locate/earlhumdev