Prone ventilation in acute respiratory distress syndrome

Abstract

Prone positioning has been used for many years in patients with acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS), with no clear benefit for patient outcome. Meta-analyses have suggested better survival in patients with an arterial oxygen tension (PaO 2 )/inspiratory oxygen fraction (FIO 2 ) ratio ,100 mmHg. A recent randomised controlled trial was performed in ARDS patients after a 12-24 h stabilisation period and severity criteria (PaO 2 /FIO 2 ,150 mmHg at a positive end-expiratory pressure o5 cmH 2 O). This trial has demonstrated a significant reduction in mortality from 32.8% in the supine group to 16% in the prone group (p,0.001). The reasons for this dramatic effect are not clear but probably involves a reduction in ventilator-induced lung injury due to prone positioning, for which there is ample evidence in experimental and clinical studies.The aims of this article are to discuss: the rationale of prone positioning in patients with ALI/ARDS; the evidence of its use based on trial analysis; and the limitations of its use as well as the current place of prone positioning in the management of patients with ALI/ARDS.From the currently available data, prone positioning should be used as a first-line therapy in patients with severe ALI/ARDS. @ERSpublications Prone positioning and low tidal volume should be the first-line therapy in patients with continued ARDS and severity criteria

Treatment of ARDS With Prone Positioning

“…74 As far as when to revert to supine-only therapy, in PROSEVA, proning was continued for at least 16 hours/day until sustained oxygenation improvement was achieved, defined as PaO 2 /FiO 2 ≥ 150 mmHg with PEEP ≤ 10 cmH 2 O and FiO 2 ≤ 60% for at least 4 hours after repositioning supine. 63 While this protocol is informative, the optimum duration of proning is unknown, and supinating prematurely might lead to derecruitment and potentially even VILI. 9 We recommend continuing proning for least 16 hours per day and ceasing proning when clinical variables (such as PaO 2 /FiO 2 , lung recruitability, ventilatory efficiency, static compliance, resolution of underlying non-pulmonary processes) show clear sustained improvement.…”

ARDS: challenges in patient care and frontiers in research

“…An illustrative example is the application of prone positioning in patients with a PaO 2 /FIO 2 ratio <150 [61]. The physiological consequences of laying a patient in prone position include the recruitment of the dorsal parts of the lungs and derecruitment of the ventral parts of the lung [62,63]. Because of the ventro-dorsal asymmetry of the thorax, prone positioning a patient with ARDS frequently results in an overall recruitment effect [63].…”

“…Because of the ventro-dorsal asymmetry of the thorax, prone positioning a patient with ARDS frequently results in an overall recruitment effect [63]. These phenomena can be utilised in patients with ARDS (see the section on mechanical ventilation) because it will improve gas exchange and reduce ventilator-induced lung injury [62]. However, this procedure is not without complications such as hypotension, pressure sores, accidental extubation and the complications of more sedation [64].…”

Pasienter med ARDS i mageleie

“…Pasienter med ARDS bør legges tidlig i mageleie, før den fibroproliferative fasen (13). Hos pasienter med alvorlig ARDS er det viktig med tidlig igangsettelse av behandlingen, fordi kollapsete lungeavsnitt er enklest å åpne under den akutte eksudative fasen (1,12).…”