Objective: To evaluate the efficacy and safety of nasal continuous positive airway pressure (NCPAP) using devices with variable flow or bubble continuous positive airway pressure (CPAP) regarding CPAP failure, presence of air leaks, total CPAP and oxygen time, and length of intensive care unit and hospital stay in neonates with moderate respiratory distress (RD) and birth weight (BW) ≥ 1,500 g. Methods:Forty newborns requiring NCPAP were randomized into two study groups: variable flow group (VF) and continuous flow group (CF). The study was conducted between October 2008 and April 2010. Demographic data, CPAP failure, presence of air leaks, and total CPAP and oxygen time were recorded. Categorical outcomes were tested using the chi-square test or the Fisher's exact test. Continuous variables were analyzed using the Mann-Whitney test. The level of significance was set at p < 0.05. Results:There were no differences between the groups with regard to demographic data, CPAP failure (21.1 and 20.0% for VF and CF, respectively; p = 1.000), air leak syndrome (10.5 and 5.0%, respectively; p = 0.605), total CPAP time (median: 22.0 h, interquartile range [IQR]: 8.00-31.00 h and median: 22.0 h, IQR: 6.00-32.00 h, respectively; p = 0.822), and total oxygen time (median: 24.00 h, IQR: 7.00-85.00 h and median: 21.00 h, IQR: 9.50-66.75 h, respectively; p = 0.779). Conclusion:In newborns with BW ≥ 1,500 g and moderate RD, the use of continuous flow NCPAP showed the same benefits as the use of variable flow NCPAP.J Pediatr (Rio J). 2011;87(6):499-504: Infant, newborn, ventilation, neonatal intensive care units. ResumoObjetivo: Avaliar a eficácia e segurança da pressão positiva contínua na via aérea (CPAP) utilizando aparelhos de fluxo variável e fluxo contínuo em selo d'água, quanto a falha do CPAP, ocorrência de escape de ar, tempo de uso de CPAP e de oxigênio e tempo de internação em unidade de terapia intensiva e hospitalar em neonatos com desconforto respiratório (DR) moderado e peso de nascimento (PN) ≥ 1.500 g. Métodos:Quarenta recém-nascidos que necessitavam de CPAP foram randomizados em dois grupos: um grupo tratado com fluxo variável (FV) e outro com fluxo contínuo (FC). O estudo foi realizado entre outubro de 2008 e abril de 2010. Foram registrados dados demográficos, falha do CPAP, ocorrência de escape de ar, tempo de uso de CPAP e de oxigênio, entre outros. Os desfechos categóricos foram analisados com o teste do qui-quadrado ou exato de Fisher e as variáveis contínuas com o teste de Mann-Whitney, com significância de p < 0,05. Resultados:Não houve diferença quanto aos dados demográficos, falha do CPAP (21,1 e 20,0% para o FV e o FC, respectivamente; p = 1,000), síndrome de escape de ar (10,5 e 5,0%, respectivamente; p = 0,605), tempo de CPAP [mediana: 22,0 h, intervalo interquartil (IIQ): 8,00-31,00 h e mediana: 22,0 h, IIQ: 6,00-32,00 h, respectivamente; p = 0,822), e tempo de uso de oxigênio (mediana: 24,00 h, IIQ:7,00-85,00 h e mediana: 21,00 h, IIQ:9,50-66,75 h, respectivamente; p = 0,779). Conclusão:Em r...

BackgroundMany animal models have been developed to study bronchopulmonary dysplasia (BPD). The preterm rabbit is a low-cost, easy-to-handle model, but it has a high mortality rate in response to the high oxygen concentrations used to induce lung injury. The aim of this study was to compare the mortality rates of two models of hyperoxia-induced lung injury in preterm rabbits.MethodsPregnant New Zealand white rabbits were subjected to caesarean section on gestational day 28 or 29 (full term  = 31 days). The premature rabbits in the 28-day gestation group were exposed to room air or FiO2 ≥95%, and the rabbits in the 29-day gestation group were exposed to room air or FiO2  = 80% for 11 days. The mean linear intercept (Lm), internal surface area (ISA), number of alveoli, septal thickness and proportion of elastic and collagen fibers were quantified.ResultsThe survival rates in the 29-day groups were improved compared with the 28-day groups. Hyperoxia impaired the normal development of the lung, as demonstrated by an increase in the Lm, the septal thickness and the proportion of elastic fibers. Hyperoxia also decreased the ISA, the number of alveoli and the proportion of collagen fibers in the 28-day oxygen-exposed group compared with the control 28-day group. A reduced number of alveoli was found in the 29-day oxygen exposed animals compared with the control 29-day group.ConclusionsThe 29-day preterm rabbits had a reduced mortality rate compared with the 28-day preterm rabbits and maintained a reduction in the alveoli number, which is comparable to BPD in humans.

The reversal of lung collapse is one of the challenges of lung injury prevention in pediatric acute respiratory distress syndrome. In this case, lung recruitment maneuver (RM) with positive end-expiratory pressure under computed tomography guidance is the procedure of choice, but cumulative ionizing radiation exposure is a major radiologic concern, especially in infants. Real-time guidance of lung recruitment under bedside lung ultrasound (US) assessment in adults has shown to be an effective procedure for performing RM that avoids ionizing radiation overexposure. We report a case of US-guided lung recruitment procedure applied in an infant with severe acute respiratory distress syndrome and advocate that the lung US-guided RM in infants is a feasible and safe procedure.

OBJECTIVES:Nasal continuous positive airway pressure is used as a standard of care after extubation in very-low-birth-weight infants. A pressure of 5 cmH2O is usually applied regardless of individual differences in lung compliance. Current methods for evaluation of lung compliance and air distribution in the lungs are thus imprecise for preterm infants. This study used electrical impedance tomography to determine the feasibility of evaluating the positive end-expiratory pressure level associated with a more homogeneous air distribution within the lungs before extubation.METHODS:Ventilation homogeneity was defined by electrical impedance tomography as the ratio of ventilation between dependent and non-dependent lung areas. The best ventilation homogeneity was achieved when this ratio was equal to 1. Just before extubation, decremental expiratory pressure levels were applied (8, 7, 6 and 5 cmH20; 3 minutes each step), and the pressure that determined the best ventilation homogeneity was defined as the best positive end-expiratory pressure.RESULTS:The best positive end-expiratory pressure value was 6.3±1.1 cmH20, and the mean continuous positive airway pressure applied after extubation was 5.2±0.4 cmH20 (p = 0.002). The extubation failure rate was 21.4%. X-Ray and blood gases after extubation were also checked.CONCLUSION:This study demonstrates that electrical impedance tomography can be safely and successfully used in patients ready for extubation to suggest the best ventilation homogeneity, which is influenced by the level of expiratory pressure applied. In this feasibility study, the best lung compliance was found with pressure levels higher than the continuous positive airway pressure levels that are usually applied for routine extubation.