News Release

New study examines ventilator treatment strategies for patients with severe respiratory disorders

Peer-Reviewed Publication

JAMA Network

A comparison of two treatment methods for critically ill patients with severe, rapid-onset lung disorders treated with mechanical ventilators found no significant difference in the risk of death, but did find that the newer method reduced the rates of severe persistent low oxygen levels and reduced the need for additional “rescue” therapies, according to a study in the February 13 issue of JAMA.

Acute lung injury (such as from severe pneumonia or trauma) and acute respiratory distress syndrome (ARDS; the most serious form of acute lung injury), can be devastating complications of critical illness. Although mechanical ventilation provides essential life support, it can worsen lung injury. Low tidal volume (volume of air that is drawn with each breath) ventilation reduces the risk of death in critically ill patients with acute lung injury and ARDS. Adding therapies to effectively splint open collapsed lung segments may further reduce the risk of death, the authors write.

Maureen O. Meade, M.D., M.Sc., of Hamilton Health Sciences and McMaster University, Hamilton, Ontario, Canada, and colleagues examined the effect on death of an experimental “lung open ventilation” (LOV) strategy combining low tidal volumes, recruitment maneuvers (periodic sighs on the ventilator to open the lung) and high levels of positive end-expiratory pressure (PEEP; to keep the lung open) compared with an established low-tidal-volume strategy (control group) in 983 patients with moderate and severe lung injury. The randomized trial (the LOV study) was conducted between August 2000 and March 2006 in 30 intensive care units in Canada, Australia and Saudi Arabia.

All-cause hospital death rates were 36.4 percent in the experimental group and 40.4 percent in the control group. Barotrauma rates (injury to the lung caused by the pressure of the ventilator) were 11.2 percent and 9.1 percent, respectively.

“… for patients with acute lung injury and ARDS, we found similar mortality in patients with a multi-faceted protocolized lung-protective ventilation strategy designed to open the lung compared with an established low-tidal-volume protocolized ventilation strategy. We found no evidence of significant harm or increased risk of barotrauma despite the use of higher PEEP. In addition, the ‘open-lung’ strategy appeared to improve oxygenation, with fewer hypoxemia-related deaths and a lower use of rescue therapies by the treating clinicians. Our results, in combination with the two other major trials, justify use of higher PEEP levels as an alternative to the established low-PEEP, low-tidal-volume strategy,” the authors write.

(JAMA. 2008;299[6]:637-645. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.


Treatment Approach May Have Some Benefits, But Does Not Significantly Reduce Risk of Death for Patients on Ventilators

A therapy designed to set PEEP at a certain level did not significantly lower the rate of death for patients on mechanical ventilation, but did improve lung function and reduce the duration of organ failure, according to a study in the February 13 issue of JAMA.

Alain Mercat, M.D., of CHU d’Angers, Angers, France, and colleagues compared a strategy for setting PEEP aimed at increasing alveolar (pertaining to the air sacs in the lungs) recruitment while limiting hyperinflation to one aimed at minimizing alveolar distension (stretching) in 767 patients with acute lung injury (ALI). The randomized trial (the Express study) was conducted in 37 intensive care units in France from September 2002 to December 2005.

The researchers found that the 28-day death rate in the minimal distension group was 31.2 percent (n = 119) vs. 27.8 percent (n = 107) in the increased recruitment group. The hospital mortality rates in these two groups were 39.0 vs. 35.4 percent, respectively. The increased recruitment group had a higher median number of ventilator-free days (7 vs. 3) and organ failure-free days (6 vs. 2) compared with the minimal distension group. This strategy also was associated with higher compliance values, better oxygenation, less use of additional therapies and larger fluid requirements.

(JAMA. 2008;299[6]:646-655. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.


Editorial: Refining Ventilatory Treatment for Acute Lung Injury and Acute Respiratory Distress Syndrome

In an accompanying editorial, Luciano Gattinoni, M.D., F.R.C.P., and Pietro Caironi, M.D., of the Universita degli Studi di Milana, Milan, Italy, comment on the studies in this week’s JAMA for treating acute lung injury and ARDS.

“The LOV study and the Express study not only should conclude the era of comparing PEEP levels in unselected populations with ALI and ARDS, but also underscore the need for a new definition of ARDS aimed at identifying patients with greater lung edema [accumulation of fluid in the tissue] and larger recruitability. Higher and lower levels of PEEP should be tested in this more selective population to obtain a definitive answer. In the meantime, the data from these two studies favor the use of higher levels of PEEP in the early phase of ALI and ARDS.”

(JAMA. 2008;299[6]:691-693. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including financial disclosures, funding and support, etc.


Editorial: Testing Protocols in the Intensive Care Unit

Jean-Daniel Chiche, M.D., of the University Rene Descartes, Paris, and Derek C. Angus, M.D., M.P.H., of the University of Pittsburgh, and Contributing Editor, JAMA, write concerning the challenges of complex interventions in critically ill patients in an editorial in this week’s JAMA.

“… both the Lung Open Ventilation Study and the Express Study demonstrated that is was possible to convert the physiologic principles on which experts base their care into a set of reproducible instructions and then test these instructions in a broad multicenter environment. Although neither study demonstrated a significant improvement in mortality, their findings appear to have implications for future practice. Finally, these studies made important steps toward increasingly rigorous assessment of increasingly sophisticated protocols for the best care of critically ill patients.”

(JAMA. 2008;299[6]:693-695. Available pre-embargo to the media at www.jamamedia.org)

Editor’s Note: Please see the article for additional information, including financial disclosures, funding and support, etc.

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