Providing Optimal PEEP During Mechanical Ventilation for Obese Patients Using Esophageal Balloon

Effect of Esophageal Pressure Measurement to Determine Optimal Positive End-expiratory Pressure Compared to Usual Care in Obese Patients Receiving Mechanical Ventilation

This is a research study to determine if identifying an optimal level of positive end-expiratory pressure (PEEP) targeted specifically to individualized patient characteristics will shorten the time on the ventilator.

Participants will have catheter placed through the nose into the esophagus to measure the pressure inside the chest. This catheter will remain until the patient is freed from the ventilator. Participants will be randomized to usual care or to have the level of PEEP determined by the esophageal balloon pressure readings. The total time spent on the ventilator will be recorded.

Study Design:

Randomized-controlled clinical trial. Patients will be enrolled within 4 days of mechanical ventilation and randomized 1:1 to titration of PEEP based on esophageal balloon pressures or based on the "High PEEP" ARDSnet PEEP/fraction of inspired oxygen (FiO2) table. All patients will have esophageal balloons placed with baseline measurement of Ptp. Patients randomized to the intervention arm will then undergo titration of PEEP based on Ptp measurements to achieve "Optimal PEEP," defined as end expiratory Ptp of 0 to +2 cm water (H2O).

Inclusion Criteria:

• Body mass index greater than or equal to 40
• Acute respiratory failure requiring mechanical ventilation

Exclusion Criteria:

• Refusal to give consent by the subject or their legally authorized representative
• Abdominal compartment syndrome
• Chest tube for pneumothorax
• Having been on a ventilator for >4 days
• Suspicion of or known intracranial hypertension
• Anticipated extubation within 24 hours
• Chronic ventilator dependence
• Condition that precludes placement of an esophageal balloon (esophageal or nasopharyngeal pathology preventing insertion of the esophageal balloon catheter, severe thrombocytopenia or coagulopathy)
• Incarceration