[Effect of preterm infant position on weaning from mechanical ventilation].
To determine the effects of prone positioning on cardiorespiratory stability and weaning outcome of preterm infants during weaning from mechanical ventilation.
                From January to December 1999, a sample of 42 preterm infants, with birthweight < 2,000 g, mechanically ventilated in the first week of life, were randomly divided, in the beginning of the weaning process, into two groups according to the position: supine position (n = 21) or prone position (n = 21). Heart rate, respiratory rate, transcutaneous oxygen saturation and ventilatory parameters were recorded every one hour. Length of the weaning process and complications were also assessed.
                In both groups the mean gestational age was 29 weeks, most of the patients presented very low birthweight and respiratory distress syndrome. The mean length of the weaning process was 2 days. There were no differences between the groups regarding respiratory rate, heart rate and transcutaneous oxygen saturation, however, oxygen desaturation episodes were more frequent in supine position (p = 0.009). Ventilatory parameters decreased faster and reintubation was less frequent in the prone group (4% versus 33%). No adverse effects of prone positioning were observed.
                These results suggest that prone position is a safe and beneficial procedure during weaning from mechanical ventilation and may contribute to weaning success in preterm infants.
The results of this systematic review do not provide strong evidence for either the benefits or harms of early oxygen weaning in preterm/LBW infants. Future research should be directed toward addressing the question of what are the most appropriate target levels of oxygenation, in both the early and late neonatal periods, rather than whether oxygen should be weaned early or late.