Open Access Open Badges Study protocol

Sleep study, respiratory mechanics, chemosensitive response and quality of life in morbidly obese patients undergoing bariatric surgery: a prospective, randomized, controlled trial

Luis VF Oliveira1*, Isabella C Aguiar1, Raquel P Hirata1, Newton S Faria Junior1, Israel S Reis2, Luciana MM Sampaio1, Claudia S Oliveira1, Paulo TC Carvalho1, Fernando SS Leitao Filho3, Lilian C Giannasi2, Lia Azevedo Pinto4, Carlos Alberto Malheiros5 and Wilson Rodrigues Freitas5

Author affiliations

1 Master's and Doctoral Degree Program in Rehabilitation Sciences, Nove de Julho University, Sao Paulo, Brazil

2 Sleep Laboratory, Nove de Julho University, Sao Paulo, Brazil

3 School of Medicine, Fortaleza University, Fortaleza, Ceara, Brazil

4 Psychology Service, Santa Casa de Misericórdia Hospital, Sao Paulo, Brazil

5 Surgery Department, Santa Casa de Misericórdia Hospital, Sao Paulo, Brazil

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Citation and License

BMC Surgery 2011, 11:28  doi:10.1186/1471-2482-11-28

Published: 17 October 2011



Obesity is a major public health problem in both developed and developing countries alike and leads to a series of changes in respiratory physiology. There is a strong correlation between obesity and cardiopulmonary sleep disorders. Weight loss among such patients leads to a reduction in these alterations in respiratory physiology, but clinical treatment is not effective for a long period of time. Thus, bariatric surgery is a viable option.


The present study involves patients with morbid obesity (BMI of 40 kg/m2 or 35 kg/m2 to 39.9 kg/m2 with comorbidities), candidates for bariatric surgery, screened at the Santa Casa de Misericórdia Hospital in the city of Sao Paulo (Brazil). The inclusion criteria are grade III morbid obesity, an indication for bariatric surgery, agreement to participate in the study and a signed term of informed consent. The exclusion criteria are BMI above 55 kg/m2, clinically significant or unstable mental health concerns, an unrealistic postoperative target weight and/or unrealistic expectations of surgical treatment. Bariatric surgery candidates who meet the inclusion criteria will be referred to Santa Casa de Misericórdia Hospital and will be reviewed again 30, 90 and 360 days following surgery. Data collection will involve patient records, personal data collection, objective assessment of HR, BP, neck circumference, chest and abdomen, collection and analysis of clinical preoperative findings, polysomnography, pulmonary function test and a questionnaire on sleepiness.


This paper describes a randomised controlled trial of morbidly obese patients. Polysomnography, respiratory mechanics, chemosensitive response and quality of life will be assessed in patients undergoing or not undergoing bariatric surgery.

Trial Registration

The protocol for this study is registered with the Brazilian Registry of Clinical Trials - ReBEC (RBR-9k9hhv).