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Chest Wall Influence on Respiratory System Mechanics in Morbidly Obese Patients

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ClinicalTrials.gov Identifier: NCT02105220
Recruitment Status : Completed
First Posted : April 7, 2014
Last Update Posted : March 25, 2015
Sponsor:
Information provided by (Responsible Party):
Robert M. Kacmarek, Massachusetts General Hospital

Brief Summary:

The goal of this study is to describe the influence of the chest wall on the respiratory system mechanics in morbidly obese patients and in patients with high intra-abdominal pressure.

The effects of increasing and decreasing positive end-expiratory pressure (PEEP) on chest wall and total respiratory system mechanics, lung volumes and gas exchange will be evaluated, both during controlled and assisted mechanical ventilation.

Patients will be studied, first, during the acute phase of respiratory failure, when requiring intubation and controlled mechanical ventilation. Then, patients will be evaluated again during weaning from the ventilator to assess the influence of PEEP in assisted ventilation prior to extubation.


Condition or disease Intervention/treatment
Obesity Intra-Abdominal Hypertension Other: Respiratory mechanics assessment

Detailed Description:

The goal of this study is to describe the influence of the chest wall on the respiratory system mechanics. Investigators want to describe how extreme obesity and Intra-Abdominal Hypertension (IAH) affect normal respiratory system behavior. The effects of increasing and decreasing positive end-expiratory pressure (PEEP) on respiratory system mechanics, lung volumes and gas exchange will be evaluated, both during controlled and assisted mechanical ventilation.

Investigators will record and compare lung volumes, airway and transpulmonary pressure, gas exchange and hemodynamic changes caused by variations of PEEP. Patients will be studied, first, during the acute phase of respiratory failure, when requiring intubation and controlled mechanical ventilation. Patients will then again be evaluated during weaning from the ventilator to assess the influence of PEEP in assisted ventilation prior to extubation.

Investigators believe that assessment of the transpulmonary pressure and lung volumes is essential to correctly evaluate respiratory system function in patients in which the relationship between the lung and chest wall is altered. Improper mechanical ventilation leads to lung damage. High ventilatory volume/pressure are associated with lung overdistension, while low volume/pressure leads to lung collapse and cyclic opening and closing of alveoli. All of these mechanisms have been associated with ventilator induced lung injury and poorer outcomes. Adequate PEEP and transpulmonary pressure are fundamental in preventing this vicious cycle.


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Study Type : Observational
Actual Enrollment : 14 participants
Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Chest Wall Influence on Respiratory System Mechanics in Morbidly Obese Patients
Study Start Date : August 2013
Actual Primary Completion Date : January 2015
Actual Study Completion Date : March 2015

Resource links provided by the National Library of Medicine


Group/Cohort Intervention/treatment
Obese

We will enroll patients with BMI≥40 kg/m2 to describe the impact of obesity on chest wall compliance and respiratory mechanics.

Respiratory mechanics assessment: We will assess respiratory mechanics through different end expiratory pressure settings and recording airway and esophageal pressure tracings.

Other: Respiratory mechanics assessment
Data collection on respiratory mechanics, end expiratory lung volumes, gas exchanges, work of breathing. Data will be obtained by setting different end expiratory pressures and recording esophageal and airways pressure tracings.

Intraabdominal Hypertension

We will enroll patients with IAP≥12 mmHg to describe the impact of intraabdominal hypertension on chest wall compliance and respiratory mechanics.

Respiratory mechanics assessment: We will assess respiratory mechanics through different end expiratory pressure settings and recording airway and esophageal pressure tracings.

Other: Respiratory mechanics assessment
Data collection on respiratory mechanics, end expiratory lung volumes, gas exchanges, work of breathing. Data will be obtained by setting different end expiratory pressures and recording esophageal and airways pressure tracings.




Primary Outcome Measures :
  1. End Expiratory Lung Volumes [ Time Frame: 2 hours ]
    EELV variation at different levels of PEEP in mechanically ventilated and sedated morbidly obese patients and patients with intraabdominal hypertension


Secondary Outcome Measures :
  1. Respiratory mechanics [ Time Frame: 24 hours ]
    Evaluation of effects of PEEP level set by ICU staff on respiratory mechanics after 24 hours from enrollment Evaluation of PEEP level set by ICU staff

  2. Work of breathing [ Time Frame: 20 minutes ]
    Evaluation of work of breathing variation at different level of PEEP during spontaneous breathing and ventilation weaning in morbidly obese patients

  3. Respiratory mechanics [ Time Frame: 2 hours ]
    Respiratory mechanics variation at different levels of PEEP in mechanically ventilated and sedated morbidly obese patients and patients with intraabdominal hypertension

  4. Gas Exchange [ Time Frame: 2 hours ]
    Gas exchange variation at different levels of PEEP in mechanically ventilated and sedated morbidly obese patients and patients with intraabdominal hypertension

  5. Respiratory mechanics [ Time Frame: 20 minutes ]
    Evaluation of respiratory mechanics at different level of PEEP during spontaneous breathing and ventilation weaning in morbidly obese patients

  6. Gas exchange [ Time Frame: 20 minutes ]
    Evaluation of gas exchange variation at different level of PEEP during spontaneous breathing and ventilation weaning in morbidly obese patients

  7. End Expiratory Lung Volume [ Time Frame: 24 hours ]
    Evaluation of effects of PEEP level set by ICU staff on EELV after 24 hours from enrollment

  8. Gas Exchange [ Time Frame: 24 hours ]
    Evaluation of effects of PEEP level set by ICU staff on gas exchange after 24 hours from enrollment



Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
We will enroll morbidly obese intubated patients and/or patients affected by intraabdominal hypertension admitted to medical ICUs and surgical ICUs at Massachusetts General Hospital. Patients with contraindication to esophageal balloon placement or with severe respiratory failure will be excluded from the study.
Criteria

Inclusion Criteria:

  • 18 years or older
  • Requiring intubation and mechanical ventilation
  • BMI≥40 kg/m2 or IAP≥12 mmHg

Exclusion Criteria:

  • Known presence esophageal varices
  • Recent esophageal trauma or surgery
  • Severe thrombocytopenia (PTL≤10,000/mm3)
  • Severe coagulopathy (INR≥2)
  • Presence of pneumothorax
  • Pregnancy
  • Patients with diagnosed moderate to severe ARDS or with poor oxygenation index (PaO2/FiO2 < 200 mmHg)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02105220


Locations
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United States, Massachusetts
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
Sponsors and Collaborators
Massachusetts General Hospital
Investigators
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Principal Investigator: Robert M Kacmarek, PhD RRT Massachusetts General Hospital

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Responsible Party: Robert M. Kacmarek, PhD RRT, Massachusetts General Hospital
ClinicalTrials.gov Identifier: NCT02105220     History of Changes
Other Study ID Numbers: 2013P001413
First Posted: April 7, 2014    Key Record Dates
Last Update Posted: March 25, 2015
Last Verified: March 2015
Keywords provided by Robert M. Kacmarek, Massachusetts General Hospital:
Respiratory mechanics
Esophageal pressure
Functional residual capacity
positive end-expiratory pressure
Additional relevant MeSH terms:
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Intra-Abdominal Hypertension
Vascular Diseases
Cardiovascular Diseases
Compartment Syndromes
Muscular Diseases
Musculoskeletal Diseases
Respiratory System Agents