Monitoring Lung Recruitment Maneuver in Anesthetized Morbidly Obese

Non-invasive Assessment of Lung Recruitment in Morbid Obese Patients Undergoing Bariatric Surgery

Morbid obese patients present changes in respiratory physiology caused by weight overload. Intraoperative atelectasis is a pulmonary complication that affects not only gas exchange but also respiratory mechanics. The present study was aimed to test the role of different parameters for monitoring the treatment of atelectasis by a lung recruitment maneuver.

This is a prospective study perform in 30 anesthetized morbidly obese undergoing bariatric surgery. Lung mechanics and volumetric capnography will be non-invasively assessed during laparoscopy. Esophageal pressure will be measured by an esophageal balloon to measure transpulmonary pressure. A lung recruitment maneuver will be done. The optimum level of positive end-expiratory pressure (PEEP) is defined as the PEEP level when transpulmonary pressure remains positive during the PEEP titration trial of the recruitment maneuver. Lung collapse is detected when transpulmonary pressure becomes negative. The behavior of the studied volumetric capnography and lung mechanics parameters will be compared with the reference transpulmonary pressure signal.

Inclusion Criteria:

• Body mass index (BMI) > 40 kg/m2
• Written inform consent
• Scheduled for bariatric surgery
• American Society of Anesthesia physical status II-III

Exclusion Criteria:

• Acute pulmonary disease
• Emergency surgery