Results 42 patients (21 PSV+VG, 21 SIMV+VG) were enrolled. Median GA were 29 weeks and BW were 980,0 and 870,0 gr in each group. Demographic characteristics were similar. 'Appropriate TV' was higher in PSV+VG group. PIP, MAP and FiO 2 were similar in two groups. Hypocarbia, hypercarbia, hyperoxemia and hypoxemia incidences were not different. PSV +VG group were less tachycardic than SIMV+VG group. Acute and chronic prematurity problems including chronic lung disease (CLD) defined as oxygen requirement at 36th GA were not different. Conclusion PSV+VG was associated with higher 'appropriate TV' without any adverse effects and similar CLD occurence. These findings can support the beneficial use of PSV+VG which is more physiologic due to better inspiratory -expiratory synchrony. Background and aims Despite advances in ventilation support, acute lung disease (ALD) remains the leading cause of morbidity, mortality, and disability after preterm birth. There is a need for a spontaneous translational model of ALD after preterm birth. Methods Preterm pigs delivered at gestation days (GD) 98, 100, 102, and 104 days were provided ventilation support using supplemental oxygen (NC), bubble Continuous Positive Airway Pressure (bCPAP; 7-8 cm H 2 O), or mechanical ventilation (MV; Pressure Control Ventilation with Volume Guarantee; 5 ml/kg; PEEP 5 cm H 2 O). Monitoring included pulse oximetry, arterial blood gases, and radiography. Lungs were harvested after 24 h or after premature death for histology and measurements of surfactant protein B, phosphatidylcholine, and cytokines. Results All pigs breathed spontaneously. Lungs at GD 98 and 100 were consolidated with immature alveolar architecture, minimal surfactant protein B expression, and MV was essential for 24 h survival. GD 102 pigs had alveoli lined by pneumocytes and surfactant was released in response to MV. Blood gases and radiography for NC and bCPAP pigs 1-2 h after delivery revealed limited recruitment and mortality at 24 h was 66% (35/ 53) and 69% (9/13), respectively. GD 104 pigs had higher densities of thin walled alveoli that secreted surfactant and MV was not essential. Conclusions Preterm pigs have developmental changes in ventilation inadequacies that mimic those of preterm infants and represent a spontaneous model of ALD that is clinically relevant, compatible with standards of chronic neonatal intensive care, and is an alternative for nonhuman primates and lambs. Background Preterm newborns often need respiratory support for lung liquid clearance and aeration. Previous studies provided tidal volumes during positive pressure ventilation (PPV) and breathing, but very little is known how efficient these are in lung recruitment and gas exchange. Aim was to measure tidal volume, functional residual capacity (FRC) changes and gas exchange during respiratory support in preterm infants at birth. Methods In preterm newborns needing respiratory support the following measurements were performed: 1) expired tidal volumes (Vte (mL/kg)) using respiratory function monitoring...
