RESUMO
OBJECTIVE: To compare breathing patterns and lung function in the supine, lateral, and prone positions in oxygen-dependent preterm infants. STUDY DESIGN: Respiratory function in preterm infants receiving nasal continous positive airway pressure therapy for mild respiratory failure was evaluated by respiratory inductive plethysmography. Infants were randomized to supine, left lateral, and prone positions for 3 hours. A nest provided a semiflexed posture for the infants placed in the left lateral position, similar to the in utero position. Tidal volume (Vt), phase angle between abdominal and thoracic movements, rib cage contribution to Vt, and dynamic elevation of end-expiratory lung volume were measured. RESULTS: Fraction of inspired O2 was similar in the 3 positions for 19 infants (mean gestational age, 27±2 weeks; mean birth weight, 950±150 g; mean postnatal age, 17±5 days). However, arterial O2 saturation and Vt were higher in the left lateral and prone positions than in the supine position (P<.05). The phase angle between abdominal and thoracic movements was lower and rib cage contribution to Vt was higher in the left lateral and prone positions than in the supine position (P<.05). Dynamic elevation of end-expiratory lung volume was greater in the supine position than in the left lateral and prone positions (P<.05). CONCLUSION: In oxygen-dependent preterm infants, both the left lateral and prone positions improve lung function by optimizing breathing strategy. In the neonatal intensive care unit, the left lateral position can be used as an alternative to the prone position for mild respiratory failure.
Assuntos
Doenças do Prematuro/fisiopatologia , Pulmão/fisiopatologia , Posicionamento do Paciente , França , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Pletismografia , Respiração , Testes de Função RespiratóriaRESUMO
OBJECTIVE: To determine the hemodynamic impact of fluid restriction in preterm newborns with significant patent ductus arteriosus. STUDY DESIGN: Newborns ≥24 and <32 weeks' gestational age with significant patent ductus arteriosus were eligible for this prospective multicenter observational study. We recorded hemodynamic and Doppler echocardiographic variables before and 24 hours after fluid restriction. RESULTS: Eighteen newborns were included (gestational age 24.8 ± 1.1 weeks, birth weight 850 ± 180 g). Fluid intake was decreased from 145 ± 15 to 108 ± 10 mL/kg/d. Respiratory variables, fraction of inspired oxygen, blood gas values, ductus arteriosus diameter, blood flow-velocities in ductus arteriosus, in the left pulmonary artery and in the ascending aorta, and the left atrial/aortic root ratio were unchanged after fluid restriction. Although systemic blood pressure did not change, blood flow in the superior vena cava decreased from 105 ± 40 to 61 ± 25 mL/kg/min (P < .001). The mean blood flow-velocity in the superior mesenteric artery was lower 24 hours after starting fluid restriction. CONCLUSIONS: Our results do not support the hypothesis that fluid restriction has beneficial effects on pulmonary or systemic hemodynamics in preterm newborns.