Effect of prone positioning on oxygenation and lung mechanics in neonates with mechanical ventilation

Objective To investigate the effects of prone positioning on oxygenation and lung mechanics in neonates with mechanical ventilation.Methods Twenty cases of neonates,selected from Shanghai Children′s Hospital(from May 2008 to Feb 2009),were randomized to supine-prone position group (n=10) and prone-supine position group (n=10) using a crossover design.During 6h,these neonates were placed in the supine position for 3h then in the prone position for 3h or in reversed order.The ventilator parameters,results of arterial blood gas and the lung mechanics were recorded.Results Without obvious changes of ventilator parameters,PaO2 improved significantly when the incubated neonates were placed in the prone position for 3h compared to supine [(74.50±15.37)mm Hg vs (67.60±13.66)mm Hg,1mm Hg=0.133kPa,P<0.05).Similarly,oxygenation index of prone positioning for 3h was (201.86±55.96)mm Hg,which was higher than that of (184.38±63.58)mm Hg,the value of supine positioning for 3 h.There were significant differences (P<0.05).Our results showed that 60% (12/20) of the neonates responded to prone positioning,with oxysenation index increasing as much as 17mm Hg on average.Improvement in minute volume,tidal volume and dynamic compliance of the lung were achieved after prone positioning for 3h (P=0.011,0.020,0.045).The airway resistance did not decrease significantly (P=0.422),but the average decreased in the prone position.Conclusion Oxygenation and the lung mechanics are improved significantly in the neonates with prone position compared with supine position. Key words: Prone positioning; Mechanical ventilation; Oxygenation; Lung mechanics; Infant,newborn