Infant position in neonates receiving mechanical ventilation

Background A variety of body positions other than the standard supine position have been used in patients undergoing intensive care with hopes of reducing the incidence of pressure ulcers of the skin, contractures or ankylosis and improving the patients' well being. In patients from different age groups undergoing mechanical ventilation (MV) it has been observed that particular positions, such as the prone position, may improve some respiratory parameters. Benefits from these positions have not been clearly defined in critically ill newborns who may require mechanical ventilation for extended periods of time. Objectives To assess the effects of different positioning of newborn infants receiving MV on short-term respiratory outcomes and complications of prematurity. Search methods Databases searched (up to December 2012) were the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 3), Oxford Database of Perinatal Trials, MEDLINE, CINAHL and EMBASE. Handsearches of proceedings of the Society for Pediatric Research from 1990 to July 2011 were used to identify unpublished studies. Clinicaltrials.gov was searched for any ongoing studies. Selection criteria Randomised or quasi-randomised clinical trials comparing different positions in newborns receiving mechanical ventilation. Data collection and analysis Three independent and unblinded review authors assessed the trials for inclusion in the review and extracted the data. Data were double-checked and entered into the Review Manager software (RevMan). Risks of bias of the included studies were assessed using methods of randomisation and allocation concealment, completeness of follow-up and blinding of outcome measurements. Main results Twelve trials involving 285 participants were included in this review. One of the included studies (N = 79) was not evaluated in the previous review. Several positions were compared: prone versus supine, prone versus lateral right, lateral right versus supine, lateral left versus supine, lateral alternant versus supine, lateral right versus lateral left, and good lung dependent versus good lung uppermost. Apart from one of the two studies that compared lateral right versus lateral left positions, one comparing lateral alternant versus supine, and one comparing prone versus the supine position, all the included studies had a crossover design. Comparing prone versus supine position, an increase in arterial oxygen tension (PO2) in the prone position of between 2.75 and 9.72 mm Hg (95% confidence interval (CI)) was observed (one trial). When % haemoglobin oxygen saturation was measured with pulse oximetry, the improvement in the prone position was from 1.18% to 4.36% (typical effect based on four trials). In addition, there was a slight improvement in the number of episodes of desaturation. It was not possible to establish whether this effect remained once the intervention was stopped. Negative effects from the interventions were not described, although these were not studied in sufficient detail. Effects of position on other outcomes were barely investigated. Only one study analysed tracheal cultures of neonates after five days of mechanical ventilation, finding lower bacterial colonization in the alternating lateral position than in those neonates kept in the supine posture. Other effects, either positive or negative, cannot be excluded considering the small numbers of neonates that were studied. Authors' conclusions The prone position was found to slightly improve the oxygenation in neonates undergoing mechanical ventilation. However, we found no evidence concerning whether particular body positions during the mechanical ventilation of the neonate are effective in producing sustained and clinically relevant improvements.