Lung Protective Ventilation in Pulmonary Thromboendarterectomy (PTE) Patients

Study Overview
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Brief Summary
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Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by unresolved thromboemboli in the pulmonary arteries, which lead to pulmonary hypertension and, left untreated, right heart failure. This disease can be potentially cured by performing a pulmonary thromboendarterectomy (PTE) to remove the blood clots. The surgery is not without risk and the most worrisome complication is the development of a form of acute lung injury called reperfusion lung injury, which occurs in about 40 percent of patients. The landmark publication of the ARDSNET study demonstrated that a low tidal volume strategy of mechanical ventilation, decreased morbidity and mortality in patients who had acute respiratory distress syndrome (ARDS). Since then there have been some studies examining the role of a low tidal volume strategy in all patients who are mechanically ventilated. Some studies have demonstrated a decreased incidence of acute lung injury while others have failed to do the same. In patients at high risk for developing acute lung injury, such as patients undergoing PTE, there may be a benefit to using low tidal volumes to reduce the incidence of reperfusion lung injury. To assess the efficacy of a low tidal volume ventilation strategy in patients undergoing PTE, 134 patients will be randomized at the time of surgery to either low tidal volumes (6ml/kg of ideal body weight), or standard tidal volumes (10ml/kg of ideal body weight). Patients will be followed clinically to assess for the development of reperfusion lung injury. This will be defined as the development of hypoxemia (PaO2/FiO2 ratio less than 300) and chest infiltrates in the area of reperfused lung with no other identifiable etiology within the first 72 hours of surgery. Patients will also be assessed for other factors known to contribute to acute lung injury including: plateau pressures, peak inspiratory pressures, fluid balance, and number of transfusions received. Secondary endpoints of the study will be: time to successful spontaneous breathing trial, ventilator free days, ICU free days, hospital free days, and mortality.

Official Title
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A Prospective Single Blind Controlled Study to Assess the Efficacy of a Lung Protective Ventilation Strategy in the Prevention of Reperfusion Lung Injury Following PTE

Conditions
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Chronic Thromboembolic Pulmonary Hypertension, Acute Lung Injury

Intervention / Treatment
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* Other: Ventilation Strategy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 years of age Evidence of CTEPH Acceptable surgical candidate Exclusion Criteria: BMI > 40 Patient undergoing lung biopsy or CABG at time of surgery

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low tidal volume<br>Tidal volume of 6 mL/Kg ideal body weight | Other: Ventilation Strategy<br>* Comparison of low vs standard tidal volumes in patients undergoing PTE<br>|
| Active Comparator: Usual care<br>Tidal volume of 10 mL/Kg ideal body weight | Other: Ventilation Strategy<br>* Comparison of low vs standard tidal volumes in patients undergoing PTE<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of Reperfusion Lung Injury |  | 72 Hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ICU free days |  | 28 days | 
| Hospital Free Days |  | 28 days | 
| Mortality |  | 28 Days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Thromboembolic Pulmonary Hypertension, Lung Injury, Ventilation Strategies