Oxygenation Instability Assessed by Oxygen Saturation Histograms during Supine vs Prone Position in Very Low Birthweight Infants Receiving Noninvasive Respiratory Support.

Abstract

To evaluate the effect of prone vs supine position on the oxygenation instability among very low birth weight (VLBW) infants receiving noninvasive respiratory support, as assessed by the average oxygen saturation (SpO₂) histograms. Sixty-nine histograms from 23 VLBW infants were studied prospectively. Each infant was studied during 3 consecutive 3-hour periods of alternating positions; 12 infants started the study while prone and 11 infants started supine, by random order. Histogram classification system was used to quantify oxygenation stability and time spent in different SpO₂ ranges. The fraction of inspired oxygen values were similar in both positions. Unstable histograms were more common in supine vs prone position (20/34 [59%] vs 10/35 [29%]; P = .02, respectively). Analyzing oxygenation stability as per position change revealed that a change from prone to supine increased oxygenation instability, and supine to prone decreased instability (P = .02). In the supine vs prone position, percent of time spent in SpO₂ ≤80% and <90% was higher (5.0 ± 4.2 vs 2.4 ± 3.4 [P < .001] and 24.1 ± 13.7 vs 13.2 ± 10.0 [P < .001], respectively), and percent of time in SpO₂ >94% was lower (39.7 ± 26.0 vs 52.4 ± 23.4 [P = .04]). Prone positioning decreased oxygenation instability and resulted in higher oxygenation among VLBW premature infants on noninvasive respiratory support. SpO₂ histograms allow easy bedside assessment of oxygenation instability, and quantification of the time spent at different SpO₂ ranges.