Transpulmonary Pressure Guided Mechanical Ventilation Weaning in Obesity

Transpulmonary Pressure Guided Weaning From Invasive Mechanical Ventilation in Obese Patients With Respiratory Failure

This study will look at whether accounting for the amount of pressure generated by the chest wall and abdomen in a obese patient, using a measurement called transpulmonary pressure, can help shorten the amount of time patients spend on the ventilator. By decreasing the amount of time patients spend on the ventilator, they are less likely to develop complications such as infections, weakness or more procedures.

Managing obese patients on the ventilator can be difficult due to the changes in their respiratory mechanics with little evidence as to best practices. This research will assess the utility of transpulmonary pressures in guiding mechanical ventilation in obese patients. This study with specifically look at whether using transpulmonary pressure guided positive end expiratory pressure (PEEP) titration for ventilation and spontaneous breathing trials (SBT) will shorten the time to liberation for obese patients on invasive mechanical ventilation for respiratory failure. The transpulmonary pressures will be calculated daily for all patients. Patients will also be assessed daily for readiness for SBT. In the intervention group, subjects' PEEP will be titrated to achieve an end expiratory transpulmonary pressure of 0-2 cm H2O. This PEEP will be used for the SBT and clinicians will be encouraged to keep their patients on this PEEP after the SBT if they are not extubated. In the control group, patients will also be assessed daily for SBT readiness but will be managed with standard set pressures of 5 to 10 cm H2O of PEEP and 5 to 8 cm H2O of pressure above PEEP. The primary team can perform a T piece trial prior to extubation as clinically indicated.

Inclusion Criteria:

• on invasive mechanical ventilation for respiratory failure for < 48 hours
• obese class II or higher (BMI greater than or equal to 35.0 kg/m2)

Exclusion Criteria:

• contraindications to esophageal balloon catheter placement including esophageal, nasofacial, gastrointestinal abnormalities and platelets <10,000/microliter
• known pleural disease such as persistent pneumothorax, pleural effusion, or pleurodesis
• neuromuscular disease
• requires chronic mechanical ventilation prior to enrollment
• severe neurologic injury
• known difficult airway
• life expectance is less than 48 hours