Jean-Pierre Frat Vale ´rie Gissot Ste ´phanie Ragot Arnaud Desachy Isabelle Runge Christine Lebert Rene ´ Robert for the Association des Re ´animateurs du Centre-Ouest (ARCO) study group Impact of obesity in mechanically ventilated patients: a prospective study Received: 7 March 2007 Accepted: 31 May 2008 Published online: 1 August 2008 Ó Springer-Verlag 2008 This article is discussed in the editorial available at doi: 10.1007/s00134-008-1246-x. The authors have no financial interest in any aspect of this report. Electronic supplementary material The online version of this article (doi:10.1007/s00134-008-1245-y) contains supplementary material, which is available to authorized users. J.-P. Frat ( ) ) Á R. Robert Medical ICU, CHU Poitiers, rue de la Mile ´trie, 86021 Poitiers cedex, France e-mail: j.p.frat@chu-poitiers.fr Tel.: +33-5-49444007 Fax: +33-5-49443862 V. Gissot Medical ICU, CHU Bretonneau, 37044 Tours cedex, France S. Ragot Clinical Research Center, CHU Poitiers, rue de la Mile ´trie, 86021 Poitiers cedex, France A. Desachy Medical-Surgical ICU, Centre Hospitaliers d’Angoule ˆme, 16470 Saint Michel, France I. Runge Medical-Surgical ICU, Hopital de la Source, BP 6709, 45067 Orle ´ans cedex, France C. Lebert Medical-Surgical ICU, Ho ˆpital de la Roche Sur Yon, Les Oudairies, 85000 La Roche Sur Yon, France Abstract Objective: To analyze the influence of severe obesity on mortality and morbidity in mechani- cally ventilated intensive care unit (ICU) patients. Design: Prospec- tive, multi-center exposed/unexposed matched epidemiologic study. Setting: Hospital setting. Patients: Severely obese patients (body mass index (BMI) C 35 kg/m 2 ), mechani- cally ventilated for at least 2 days were matched with unexposed non- obese patients (BMI \ 30 kg/m 2 ) for center, gender, age (±5 years), and the simplified acute physiology (SAPS) II score (±5 points). We recorded tracheal intubation, catheter placement, nosocomial infections, development of pressure ulcers, ICU and hospital outcome. Results: Eighty-two severely obese patients (mean BMI, 42 ± 6 kg/m 2 ) were compared to 124 nonobese patients (mean BMI, 24 ± 4 kg/m 2 ). The ICU course was similar in both the groups, except for the difficulties during tra- cheal intubation (15 vs. 6%) and post- extubation stridor (15% vs. 3%), which were significantly more fre- quent in obese patients (P \ 0.05). The ICU mortality rate did not differ between obese and nonobese patients (24 and 25%, respectively); nor did the risk-adjusted hospital mortality rate (0.76, 95% confidence interval 0.41–1.16 in obese patients versus 0.82, 95% confidence interval 0.54– 1.13 in nonobese patients). Condi- tional logistic regression confirmed that mortality was not associated with obesity. Conclusion: The only dif- ference in morbidity of obese patients who were mechanically ventilated was increased difficulty with tracheal intubation and a higher frequency of post-extubation stridor. Obesity was not associated either with increased ICU mortality or with hospital mortality. Keywords Obesity Á Mortality Á Morbidity Á Mechanical ventilation Á Intensive care unit Á Post-extubation stridor Intensive Care Med (2008) 34:1991–1998 DOI 10.1007/s00134-008-1245-y ORIGINAL