High Positive End-Expiratory Pressure Is Associated with Improved Survival in Obese Patients with Acute Respiratory Distress Syndrome.

Pubmed ID: 27984004

Pubmed Central ID: PMC5839112

Journal: The American journal of medicine

Publication Date: Feb. 1, 2017

Affiliation: Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of Arizona College of Medicine, Tucson; University of Arizona Health Sciences, Tucson.

MeSH Terms: Humans, Male, Female, Middle Aged, Retrospective Studies, Obesity, Positive-Pressure Respiration, Tidal Volume, Respiratory Distress Syndrome

Grants: P30 ES006694, T32 ES007091

Authors: Bime C, Fiero M, Lu Z, Oren E, Berry CE, Parthasarathy S, Garcia JGN

Cite As: Bime C, Fiero M, Lu Z, Oren E, Berry CE, Parthasarathy S, Garcia JGN. High Positive End-Expiratory Pressure Is Associated with Improved Survival in Obese Patients with Acute Respiratory Distress Syndrome. Am J Med 2017 Feb;130(2):207-213. Epub 2016 Oct 28.

Studies:

Abstract

BACKGROUND: In acute respiratory distress syndrome, minimizing lung injury from repeated collapse and reopening of alveoli by applying a high positive end-expiratory pressure improves oxygenation without influencing mortality. Obesity causes alveolar atelectasis, thus suggesting that a higher positive end-expiratory pressure might be more protective among the obese. We hypothesized that the effect of applying a high positive end-expiratory pressure on mortality from acute respiratory distress syndrome would differ by obesity status. METHODS: This was a retrospective analysis of 505 patients from the Assessment of Low tidal Volume and elevated End-expiratory volume to Obviate Lung Injury Trial, a multicenter randomized trial that compared a higher vs a lower positive end-expiratory pressure ventilatory strategy in acute respiratory distress syndrome. We examined the relationship between positive end-expiratory pressure strategy and 60-day mortality stratified by obesity status. RESULTS: Among obese patients with acute respiratory distress syndrome, those assigned to a high positive end-expiratory pressure strategy experienced lower mortality compared with those assigned to a low strategy (18% vs 32%; P = .04). Among the nonobese, those assigned to high positive end-expiratory pressure strategy experienced similar mortality with those assigned to low strategy (34% vs 23%; P = .13). Multivariate analysis demonstrated an interaction between obesity status and the effect of positive end-expiratory pressure strategy on mortality (P <.01). CONCLUSIONS: Ventilation with higher levels of positive end-expiratory pressure was associated with improved survival among the subgroup of patients with acute respiratory distress syndrome who are obese.