Prone positioning for acute respiratory distress syndrome in the surgical intensive care unit: Who, when, and how long?

A Comprehensive Review of Prone Position in ARDS

“…2,3,24,56,80,81,101 Of the observational studies reviewed that measured P aO 2 /F IO 2 , the mean increase ranged from 21 to 161 mm Hg (19 -168% improvement). 26,27,[29][30][31][32][33]36,37,82,[84][85][86][87][88][89][90][91][92][93][94][95][96][97]42,103,105,108 The magnitude of improvement in P aO 2 /F IO 2 among morbidly obese subjects versus nonobese subjects with ARDS was found to be significantly greater (104 mm Hg vs 61 mm Hg, respectively, P ϭ .04) and was also observed in a larger proportion of subjects (77% vs 50%, respectively, P ϭ .044). 105 Similar positive responses also have been reported in subjects without ARDS, where the mean P aO 2 /F IO 2 increase was from 39 -192 mm Hg (24 -267% improvement).…”

“…A number of observational studies reported that C RS was unaltered or modestly decreased when turning from SP to PP in both surgical subjects 22,23 and those with ARDS. [24][25][26][27][28][29][30] Other studies have reported improved C RS upon being placed in PP, 31,32 after an extended period of PP, 24 or once subjects were returned to SP. 33 There is also evidence suggesting that patients with extrapulmonary sources of ARDS (ARDS exp ) may be more likely to exhibit decreased C RS when placed in PP, 26 possibly attributable to an accentuation of the characteristically decreased chest wall compliance (C CW ) found in that condition.…”

“…PP may be most effective in improving oxygenation when initiated early (eg, Յ3 d) during the exudative phase, when congestive and compressive atelectasis are predominant features, 29,31 as opposed to the intermediate phase of ARDS (eg, Ͼ1 week), when fibrosis and Type II cell hyperplasia are more prevalent. 116 For example, initiating PP within 3 d of ARDS onset resulted in substantial improvement in P aO 2 /F IO 2 compared with initiation at approximately 5 d. 97 The same study found that subjects with hydrostatic pulmonary edema had a similar oxygenation response to early ARDS, whereas those with pulmonary fibrosis (similar to the intermediate phase of ARDS) showed no improvement.…”

“…There is evidence suggesting that in both patients with ARDS p and those with ARDS exp , initial nonresponders to PP may become responders on subsequent attempts. 3,33 In subjects with ARDS related to trauma and high-risk surgery, Johannigman et al 29 described a consistently high rate (86%) of significantly improved oxygenation over 6 d of PP therapy. Likewise, Fridrich et al 24 reported that approximately half of their subjects with trauma-related ARDS were slow responders who required Ͼ1 week of extended PP sessions (ϳ20 h).…”

“…2 42 aspiration, 90 following extensive surgery, 29 trauma, 33 acute brain injury, 100,101 presence of morbid obesity, 105 or severe burns and inhalational injuries 94 ), or severity of lung injury. 33,36,85 Significant improvement in oxygenation also has been reported in pediatric ARDS, [106][107][108][109] neonates with or without respiratory distress syndrome, [110][111][112] subjects with other causes of hypoxemia, 87 and cardiothoracic 113,114 and other surgical subjects 23 as well as in those with hydrostatic pulmonary edema 97 and COPD.…”