The effect of positioning on arterial oxygenation in children with atelectasis after cardiac surgery

Abstract

Objective: To determine the effect of body position on arterial oxygenation in children with unilateral atelectasis after cardiac surgery.

Design: Prospective, quasi-experimental, random assignment.

Setting: Midwestern university-affiliated tertiary pediatric medical center.

Patients: 25 children who underwent cardiac surgery and who presented with unilateral atelectasis within 2 weeks of operation. Age range was one month to 10 years (mean 34 months).

Outcome measures: The partial pressure of oxygen.

Intervention: Data collection was initiated within 24 hours of the diagnosed unilateral atelectasis. Arterial blood gases were drawn from intraarterial lines after subjects were placed for 15 minutes in the supine, right lateral, and left lateral decubitus positions (atelectatic lung dependent or nondependent), the order being randomized.

Results: Analysis of variance for repeated measures was used in the data analysis. The mean PaO2 for the supine, nondependent, and dependent positions were 115, 118, and 112, respectively. No statistical differences at p less than 0.05 level of significance were demonstrated for the body positions under study. Age and degree of atelectasis were analyzed as covariates to determine the possible correlation with the PaO2 and the change in PaO2. Age inversely correlated with the PaO2, r = -0.24 (p less than 0.05), indicating the older subjects had a lower PaO2. The degree of atelectasis demonstrated correlation with the change in PaO2, r = -0.26 (p less than 0.05) indicating the subjects with greater degree of atelectasis had a lesser change in PaO2.

Conclusions: These results differ from similar studies on the effect of positioning in adult subjects. This finding suggests that the effect of positioning of children who have had cardiac surgery should be evaluated on an individual basis with close monitoring for changes in clinical condition and oxygen saturation and periodic arterial oxygen blood sampling until further studies can provide conclusive direction.