Introduction: Bronchopulmonary dysplasia (BPD) is characterized by lung injury with varying degrees of disrupted alveolarization, vascular remodeling, inflammatory cell proliferation, and pulmonary edema. Diuretics are often used to ameliorate the symptoms or progression of BPD. Our primary objective was to use lung ultrasound (LUS) to determine if diuretics decrease pulmonary edema in infants with BPD. The secondary objective was to assess changes in respiratory support during the first week after initiation of diuretics. Methods: Premature infants requiring non-invasive respiratory support and starting diuretic therapy for evolving BPD were compared with a similar group of infants not receiving diuretics (control). For the diuretic group, LUS exams were performed before and on days 1, 3 and 6 after initiation of treatment. For the control group, LUS was performed at equivalent time points. A composite pulmonary edema severity (PES) score of 0 to 5 was calculated based on the total number of B-lines in 6 scanned areas. Respiratory support parameters (FiO2, nasal cannula flow or CPAP) were also recorded. Results: Infants in the diuretic (n=28) and control (n=23) groups were recruited at median corrected gestational ages of 34.2 (33.3-35.9) and 34.0 (33.4-36.3) weeks, respectively ( p=0.82). PES scores, FiO2, and respiratory flow support decreased significantly from day 0 to 6 ( p<.0001, p=0.001, and p=0.01, respectively) in the diuretic group, but not in the control group. Conclusion: Diuretic use is associated with decreased pulmonary edema and improved oxygenation in infants with BPD during the first week of treatment.

Abstract Background: Nasal CPAP introduces positive pressure of air into both trachea and stomach, which may affect gastric emptying. The rate of gastric emptying can be estimated by US by two validated techniques: “antral cross-sectional area” (2-dimensional estimate of the surface area at the gastric antrum), and “spheroid gastric volume” (3-dimensional estimate of the stomach content volume). No study examined gastric emptying rate in infants on bubble CPAP (bCPAP). Objective: To compare gastric emptying rates in neonates on machine-derived nasal CPAP (MD-nCPAP) with those on bCPAP. Methods: Ultrasound measurements of the amount of milk in the stomach were performed before feeding and at 1, 2, and 3 hours after the start of feeding, using both the ACSA and spheroid methods. Rates of gastric emptying were calculated during the “early” (1-2 hours) and “late” (2-3 hours) phases after feeding. Results: We recruited 32 infants (25-34 weeks gestational age). Seventeen infants were treated with MD-nCPAP [median birth weight 1015 g (IQR: 870 to 1300), gestational age 28 weeks (IQR: 27 to 29), postnatal age 20 days (IQR: 14 to 28)], while 15 infants were treated with bCPAP [median birth weight 960 g (IQR: 855 to 1070), gestational age 27 weeks (IQR: 26 to 28), postnatal age 17 days (IQR: 15 to 25)]. Gastric emptying rates (% emptied/min) were significantly faster in the “early” compared to the “late” phase for all infants. There were no significant differences in the rates of gastric emptying (either “early” or “late”) or volumes of gastric residuals between infants receiving MD-nCPAP or bCPAP, measured by either method. Conclusions: Gastric emptying is faster during the “early” compared to the “late” phase. Gastric emptying rates are not different in infants receiving MD-nCPAP vs bCPAP.