Skip to main content
  • Poster presentation
  • Open access
  • Published:

Feasibility and effectiveness of prone position in morbidly obese ARDS patients: a case-control clinical study


Obese patients are at risk of developing atelectasis and acute respiratory distress syndrome (ARDS) [1]. The prone position (PP) may reduce atelectasis, and improves oxygenation and outcome in severe hypoxemic patients in ARDS [2], but little is known about its effect in obese ARDS patients.


Morbidly obese patients (body mass index (BMI) ≥35 kg/m2) in PP with ARDS (PaO2/FiO2 ratio ≤200 mmHg) were matched to nonobese (BMI <30 kg/m2) ARDS patients in a case-control clinical study. The primary endpoints were safety and complications of PP; the second endpoints were the effect on oxygenation (PaO2/FiO2 ratio at the end of PP), length of mechanical ventilation and ICU stay, nosocomial infections and mortality.


Between January 2005 and December 2009, 149 patients were admitted for ARDS. Thirty-three obese patients were matched with 33 nonobese patients. Median PP duration was 9 (6 to 11) hours in obese patients and 8 (7 to 12) hours in nonobese patients (P = 0.28). We collected 51 complications, of which 25 in obese patients and 26 in nonobese patients. The number of patients with at least one complication was similar across groups (n = 10, 30%). The PaO2/FiO2 ratio (Figure 1) increased significantly more in obese patients (from 118 ± 43 to 222 ± 84 mmHg) than in nonobese patients (from 113 ± 43 mmHg to 174 ± 80 mmHg, P = 0.03). Length of mechanical ventilation, ICU stay and nosocomial infections did not differ significantly, but mortality at 90 days was significantly lower in obese patients (27 vs. 48%, P < 0.05).

Figure 1
figure 1

Individual variations of PaO 2 /FiO 2 ratio between supine and prone positions in obese and nonobese patients.


PP seems safe in obese patients and may improve oxygenation more than in nonobese patients. Obese patients could be a subgroup of ARDS patients who may benefit most from PP.


  1. Gong MN, et al.: Thorax. 2010, 65: 44-50. 10.1136/thx.2009.117572

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  2. Charron C, et al.: Intensive Care Med. 2011, 37: 785-790. 10.1007/s00134-011-2180-x

    Article  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article

De Jong, A., Molinari, N., Sebbane, M. et al. Feasibility and effectiveness of prone position in morbidly obese ARDS patients: a case-control clinical study. Crit Care 17 (Suppl 2), P116 (2013).

Download citation

  • Published:

  • DOI: