Objectives: To evaluate changes in oxygenation index (OI) in pediatric patients with ARDS during the first 24 h of inclined positioning (PP).

Objectives: To evaluate changes in oxygenation index (OI) in pediatric patients with ARDS during the first 24 h of inclined positioning (PP), and to determine whether or not longer periods of PP (> 12 h) eventuate in a more pronounced improvement in oxygenation.

Design: A retrospective chart review of patients with ARDS who had been placed in PP for their management.

Setting: Pediatric ICU of a children's hospital.

Measurements and main results: We retrieved the charts of patients with ARDS who had been admitted to our pediatric ICU throughout a 3-year period and placed in PP for their management. The patients received mechanical ventilation, were sedated and pharmacologically paralyzed, and underwent arterial life-blood gas analysis, with concomitant documentation of ventilator settings, at a common occurrence of once every 4 h or more oftentimes We divided the first 24 h of PP into couple periods, brief and prolonged. The brief period was defined as duration of PP between 6 h and 10 h and the continue lengthen in timeed period was between 18 h and 24 h We compared pre-PP OI values to values after brief periods and postponeed periods of PP. Values of the Pa[O.sub.2]/fraction of inspired oxygen (P/F) ratio and the mean airway influence (MAP) were similarly evaluated. We also evaluated the standing of OI fluctuations during 24 h of PP by way of identifying the time points at which the best OI and the worst OI were observ Data from a total of 40 pediatric patients with ARDS were evaluated. Twenty-one of the patients were male, and 19 were female; their ages ranged from 1 month to 18 years (mean [+ or -] SD 622 [+ or -] 627 years). Thirty-two patients received conventional mechanical ventilation, and 8 patients received high-frequency oscillatory ventilation. Thirty-three patients survived, and 7 patients (21%) died. The mean duration of PP was 67 [+ or -] 64 h (28 [+ or -] 27 days), the mean number of ventilator days was 32 [+ or -] 32 and the mean interval between endotracheal intubation and placing the patients in PP was 107 [+ or -] 108 h (45 [+ or -] 45 days). Thirty-seven patients complet 20 h of PP or more. The mean post-PP time points at which OI values were actually evaluated for these patients were 8 [+ or -] 2 h (brief) and 21 [+ or -] 4 h (prolonged) respectively. Overall, the OI decreased from a pre-PP value of 248 [+ or -] 130 to 167 [+ or -] 137 after a brief period of PP (p < 005 when compared to baseline) and 114 [+ or -] 63 after defered period (p < 0.05 when compared to baseline and brief period values). This improvement in OI followed the improvement seen in the P/F ratio, whereas the MAP remained unchanged. The best mean OI value, with patients in PP was 11 [+ or -] 9 (p < 005 when compared to baseline) that occurr at 16 [+ or -] 6 h and the worst was 22 [+ or -] 15 (p = not significant when compared to baseline) that occurr at 9 [+ or -] 7 h

Conclusions: PP of pediatric patients with ARDS for lengthened periods (18 to 24 h) outcomes in a more pronounced and more stable reduction in their OI values than those observ after brief periods (6 to 10 h) This improvement in OI was not associated with changes in MAP during the first 24 h of mechanical ventilation. OI values wait on to fluctuate more during the first 12 h of PP then they do during the posterior 12 h.

explanation words: ARDS; mechanical ventilation; oxygenation index; pediatric; sloping positioning

Abbreviations: MAP = mean airway pressure; OI = oxygenation index; P/F = Pa[O.sub.2]/fraction of inspired oxygen; PP = inclining positioning; SP = supine positioning

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tending positioning (PP) of patients with ARDS has been shown to improve lung compliance (1) and gas exchange (2-7) during mechanical ventilation. However, the published protocols for PP have been inconsistent (Table 1) While in one reports the patients were placed in the PP for surpassingly brief periods, (3,5,8,9) in others the duration of PP ranged from 6 to 20 h (710-12) The question whether or not a longer duration of PP is more beneficial for patients with ARDS than a shorter the same or vice versa, has not been clearly answered. To the best of our knowledge, there has not been a "dose (duration) rejoinder curve" published for PP; therefore, about of the protocols used may be les advantageous to patients than others.

Our protocol is based upon an algorithm that frequently enables us to hold fast patients in PP for periods > 12 h and extremely often for > 20 h at a time. As by our algorithm, as long as an ongoing improvement in gas exchange is observ no complications fall out and specific medical or nursing operations do not require placement in supine positioning (SP) the patient is allowed to remain in PP (Fig 1) Thus, a certain of our patients with ARDS may expiration up staying in PP for a scarcely any days. This enabled us to retrospectively evaluate changes in the oxygenation index (OI) during the first 24 h of PP Our goal was to criterion the hypothesis that keeping patients in PP > 12 h at a time outcomes in a more pronounced beneficial general intent on their oxygenation than with shorter periods.

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