The Prone Position in ARDS Patients: A Clinical Study

doi:10.1378/chest.94.1.103

Chest

Volume 94, Issue 1, July 1988, Pages 103-107

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The gas exchange and hemodynamics were evaluated before, during, and after a two-hour period of prone position in 13 moderate-severe ARDS patients. Lung computerized tomography was obtained in both the supine and prone positions in two of these patients. Average arterial oxygenation improved after prone positioning (p<0.01). A PaO₂ improvement of at least 10 mm Hg after 30 minutes of prone position was used as a criterion to discriminate between responders and nonresponders to the postural change. Eight patients met the “responders” group criterion, and in the five nonresponder patients, the PaO₂ did not change significantly throughout the study. Computerized tomograms in the prone position showed disappearance of posterobasal densities and appearance of new densities in the anterior regions, in both patients studied. One of these was a responder, the other a nonresponder. A brief test period in prone position is indicated in ARDS patients to identify those who may benefit from this postural treatment. The definite mechanism of the arterial oxygenation improvement observed remains to be clarified.

Section snippets

Material and Methods

Thirteen patients with bilateral ARDS were studied; age, sex, main diagnosis, and outcome are reported in Table 1. The severity of the respiratory insufficiency at the time of the study is described by the total static lung compliance (TSLC), the functional residual capacity (FRC), the venous admixture (Qva/Q), and the ventilatory conditions in which the study was carried out (Table 2).

Standard chest x-ray film confirmed the bilateral lung involvement, while the prevalence of dorsobasal

Results

In the overall population, the PaO₂ rose significantly (p<0.01) after prone positioning (Fig 1); PaCO₂ and the hemodynamic parameters were substantially unaffected.

Eight patients met the responders group inclusion criteria (patients 1 to 8 in Table 1, Table 2), showing a PaO₂ increase after 30 minutes of prone position from 70±8 to 90±8 mm Hg (p<0.01). Five patients (9 to 13) did not experience any PaO₂ improvement (PaO₂ from 81±22 to 67±13 mm Hg, ns) and were included in the nonresponder group.

Discussion

Our findings confirm previous retrospective reports of gas exchange improvement in patients with moderate to severe respiratory failure when turned from the supine to the prone position. In this prospective study, the average arterial oxygenation significantly rose after prone positioning, when considering the overall population. However, in contrast with previous reports, not all patients benefitted from the postural change, and we therefore divided the population into two groups: responders

References (13)

J Ibanez et al.
The effect of lateral position on gas exchange in patients with unilateral lung disease during mechanical ventilation
Intensive Care Med
(1981)
L Gattinoni et al.
Morphological and functional changes induced by PEEP in ARF
Intensive Care Med
(1986)
RJ Maunder et al.
Preservation of normal lung region in the adult respiratory distress syndrome: analysis by computed tomography
JAMA
(1986)
AC Bryan
Comments of a devil's advocate
Am Rev Respir Dis
(1974)
WW Douglas et al.
Improved oxygenation in patients with acute respiratory failure: the prone position
Am Rev Respir Dis
(1974)
MA Phiel et al.
Use of extreme position changes in acute respiratory failure
Crit Care Med
(1976)

There are more references available in the full text version of this article.

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Prone Positioning in Postoperative Cardiac Surgery Patients: A Narrative Review
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Limited data are available on the use of the prone position in cardiac surgery. Concerns in performing this maneuver in open cardiac surgery due to the risk of post-sternotomy wound infections and hemodynamic instability do not seem to be supported by existing evidence. Indeed, available data show that prone positioning may improve gas exchange in cardiac surgery patients as well. However, previous studies of prone positioning in this setting were heterogeneous in patient characteristics and outcomes evaluated. As a result, whether prone positioning also may be effective in reducing mortality in patients with postoperative acute respiratory failure, particularly in those who underwent surgery under extracorporeal circulation, remains to be clearly elucidated.
The aim of this article is to provide an overview of available literature, which seems to suggest the efficacy of prone positioning, and to make an in-depth analysis of the studies on this topic by evaluating the efficacy of this maneuver on hard endpoints.
Donor prone positioning protects lungs from injury during warm ischemia
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A large proportion of controlled donation after circulatory death (cDCD) donor lungs are declined because cardiac arrest does not occur within a suitable time after the withdrawal of life-sustaining therapy. Improved strategies to preserve lungs after asystole may allow the recovery team to arrive after death actually occurs and enable the recovery of lungs from more cDCD donors. The aim of this study was to determine the effect of donor positioning on the quality of lung preservation after cardiac arrest in a cDCD model. Cardiac arrest was induced by withdrawal of ventilation under anesthesia in pigs. After asystole, animals were divided into 2 groups based on body positioning (supine or prone). All animals were subjected to 3 hours of warm ischemia. After the observation period, donor lungs were explanted and preserved at 4°C for 6 hours, followed by 6 hours of physiologic and biological lung assessment under normothermic ex vivo lung perfusion. Donor lungs from the prone group displayed significantly greater quality as reflected by better function during ex vivo lung perfusion, less edema formation, less cell death, and decreased inflammation compared with the supine group. A simple maneuver of donor prone positioning after cardiac arrest significantly improves lung graft preservation and function.
Salvage therapies for refractory hypoxemia in ARDS
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Acute Respiratory Distress Syndrome (ARDS) is a condition of varied etiology characterized by the acute onset (within 1 week of the inciting event) of hypoxemia, reduced lung compliance, diffuse lung inflammation and bilateral opacities on chest imaging attributable to noncardiogenic (increased permeability) pulmonary edema. Although multi-organ failure is the most common cause of death in ARDS, an estimated 10–15% of the deaths in ARDS are caused due to refractory hypoxemia, i.e.- hypoxemia despite lung protective conventional ventilator modes. In these cases, clinicians may resort to other measures with less robust evidence –referred to as “salvage therapies”. These include proning, 48 h of paralysis early in the course of ARDS, various recruitment maneuvers, unconventional ventilator modes, inhaled pulmonary vasodilators, and Extracorporeal membrane oxygenation (ECMO). All the salvage therapies described have been associated with improved oxygenation, but with the exception of proning and 48 h of paralysis early in the course of ARDS, none of them have a proven mortality benefit. Based on the current evidence, no salvage therapy has been shown to be superior to the others and each of them is associated with its own risks and benefits. Hence, the order of application of these therapies varies in different institutions and should be applied following a risk-benefit analysis specific to the patient and local experience. This review explores the rationale, evidence, advantages and risks behind each of these strategies.
Dead space ventilation-related indices: bedside tools to evaluate the ventilation and perfusion relationship in patients with acute respiratory distress syndrome
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This study was supported in part by IRCCS, Ospedale Policlinico di Milano Progetto finalizzato 1986, No. 533.01

Manuscript received July 22; revision accepted January 9.

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Chest

Clinical InvestigationsThe Prone Position in ARDS Patients: A Clinical Study

Section snippets

Material and Methods

Results

Discussion

The effect of lateral position on gas exchange in patients with unilateral lung disease during mechanical ventilation

Intensive Care Med

Morphological and functional changes induced by PEEP in ARF

Intensive Care Med

Preservation of normal lung region in the adult respiratory distress syndrome: analysis by computed tomography

JAMA

Comments of a devil's advocate

Am Rev Respir Dis

Improved oxygenation in patients with acute respiratory failure: the prone position

Am Rev Respir Dis

Use of extreme position changes in acute respiratory failure

Crit Care Med

Clinical Investigations
The Prone Position in ARDS Patients: A Clinical Study