Purpose: To investigate the development of diaphragmatic dysfunction in ventilated extremely preterm infants (EPI) using diaphragm ultrasound (DU). Methods: EPI of less than 28 weeks' gestational age who required mechanical ventilation within six hours of birth were included in this prospective, observational study. The DU was performed once a day until four days of life. End-inspiratory and end-expiratory thicknesses of the diaphragm were measured and the diaphragm thickening fraction was calculated.Results: A total of 20 EPI were enrolled. After intubation, there was a progressive reduction in endinspiratory thicknesses of the diaphragm from baseline to day 1 (P < 0.001), but not from day 1 to day 2 (P = 0.078), day 2 to day 3 (P = 1.0), or day 3 to day 4 (P = 1.0). There was also a signi cant reduction in the diaphragm thickening fraction from baseline to day 1 (P < 0.001), but not from day 1 to day 2 (P = 1.0), day 2 to day 3 (P = 1.0), or day 3 to day 4 (P = 1.0).Conclusions: This study provides the rst evidence of diaphragmatic dysfunction in ventilated EPI. We demonstrated a rapid progression of ventilator-induced diaphragmatic dysfunction, with a signi cant reduction in diaphragm thickness and thickening fraction within 24 hours of ventilation.

To assess the impact of gravity and time on the changes in the distribution patterns of loss of aeration and atelectasis development in very preterm infants. STUDY DESIGN: Preterm infants less than 32 weeks gestation were included in this prospective, observational study. Infants were assessed via serial lung ultrasound (LUS) score in four lung zones, performed on days 7, 14, 21, and 28 after birth. RESULT: Eighty-eight patients were enrolled. There was a significant main effect of gravity (P < 0.001) and time (P = 0.01) on the LUS score between gravity-dependent lungs and non-dependent lungs. Moreover, there was a significant main effect of gravity (P = 0.003) on atelectasis development between the lungs. CONCLUSION: Gravity and time have an impact on the changes in the distribution patterns of gravity-induced lung injuries in preterm infants.

Purpose: To investigate the development of diaphragmatic dysfunction in ventilated extremely preterm infants (EPI) using diaphragm ultrasound (DU). Methods: EPI of less than 28 weeks’ gestational age who required mechanical ventilation within six hours of birth were included in this prospective, observational study. The DU was performed once a day until four days of life. End-inspiratory and end-expiratory thicknesses of the diaphragm were measured and the diaphragm thickening fraction was calculated. Results: A total of 20 EPI were enrolled. After intubation, there was a progressive reduction in end-inspiratory thicknesses of the diaphragm from baseline to day 1 (P < 0.001), but not from day 1 to day 2 (P = 0.078), day 2 to day 3 (P = 1.0), or day 3 to day 4 (P = 1.0). There was also a significant reduction in the diaphragm thickening fraction from baseline to day 1 (P < 0.001), but not from day 1 to day 2 (P = 1.0), day 2 to day 3 (P = 1.0), or day 3 to day 4 (P = 1.0). Conclusions: This study provides the first evidence of diaphragmatic dysfunction in ventilated EPI. We demonstrated a rapid progression of ventilator-induced diaphragmatic dysfunction, with a significant reduction in diaphragm thickness and thickening fraction within 24 hours of ventilation.

Background: Gravity affects the distribution of lung injuries due to gravity-induced nonhomogeneous ventilation leading to lung collapse and subsequently non-uniform lung lesions. Moreover, lung injury gradients gradually develop over time. However, changes in injury distribution after birth have not been investigated in very preterm infants. Methods: Preterm infants of less than 32 weeks’ gestational age were included in this prospective observational study. Gravity-dependent lungs (DL) were defined as dorsal lungs in a supine position or ventral lungs in a prone position, and non-dependent lungs (NDL) were defined as ventral lungs in a supine position or dorsal lungs in a prone position. Infants were assessed using lung ultrasound (LUS), which was performed on days 7, 14, 21, and 28 post-birth. Each anterior and posterior lung was scanned and received an LUS score of 0–3 points. LUS scores of the DL and NDL were compared. Total LUS scores were provided using a 0–6 point scale, which was obtained by adding the scores for each region of each lung. Results: Eighty–eight patients were enrolled in this study. On days 7, 14, and 21, LUS scores between the DL and NDL groups were significantly different (day 7, P = 0.01; day 14, P < 0.001; and day 21, P = 0.003). However, on day 28, there was no significant difference between groups (P = 0.064). Conclusions: LUS can be used to detect gravity-induced lung injury gradients in very preterm infants. Moreover, LUS revealed a trend of gradient improvement over time.