Clinical Trial: Open Lung Strategy in Critically Ill Morbid Obese Patients

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Open Lung Strategy in Critically Ill Morbid Obese Patients Lung Imaging and Heart-lung Interaction

Brief Summary: The goal of this interventional crossover study in morbidly obese intubated and mechanically ventilated patients is to describe the respiratory mechanics and the heart-lung interaction at titrated positive end-expiratory pressure levels following a recruitment maneuver with transthoracic echocardiography and electric impedance tomography imaging.

Detailed Summary:

Obese patients under mechanical ventilation are more likely to develop atelectasis as a consequence of the increased abdominal weight. Atelectasis is the primary responsible for respiratory insufficiency and impossibility to wean obese patients from respiratory support.

In a previous study we demonstrated the efficacy of the application of titrated PEEP levels following a recruitment maneuver in obese patients, i.e. improvement in respiratory mechanics and gas exchanges without negative hemodynamic effects.

The application of lung and heat imaging will allow us to quantitatively describe:

  • Increase in aerated lung tissue (reduction of atelectasis)
  • Reduction of over-inflation of the ventilated regions
  • Recoupling of ventilation and perfusion
  • Improvement in right heart function by reduction of right heart afterload

Sponsor: Massachusetts General Hospital

Current Primary Outcome: Lung elastance [ Time Frame: intraoperative ]

Difference in lung elastance measured in cmH2O/L


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Lung mechanics - Compliance [ Time Frame: intraoperative ]
    Difference in respiratory system, lung and chest wall compliance measured in mL/cmH2O
  • Lung mechanics - Airway resistances [ Time Frame: intraoperative ]
    Difference in resistances of the airways measured as cmH2O/L/sec (Raw)
  • Lung imaging - Lung collapse and lung over-distention [ Time Frame: intraoperative ]
    Percentage of lung tissue collapsed and/or over-distended at different PEEP levels. Both collapse and over distention are measured as decrease in regional compliance measured through electrical impedance tomography
  • Lung imaging - Electrical impedance tomography ventilation data [ Time Frame: intraoperative ]
    Difference in aeration (end expiratory lung impedance) and in distribution of ventilation (regional compliance) measured as difference in global an regional electrical impedance distribution
  • Hemodynamics - Blood pressure [ Time Frame: intraoperative ]
    Changes in invasive arterial blood pressures (BP, mmHg)
  • Hemodynamics - Heart rate [ Time Frame: intraoperative ]
    Changes in heart rate (HR, bpm)
  • Hemodynamics - Central venous pressure [ Time Frame: intraoperative ]
    Changes in central venous pressure (CVP, mmHg)
  • Intra-abdominal pressure [ Time Frame: intraoperative ]
    Changes in bladder pressure measured in mmHg
  • Gas Exchange - Oxygenation [ Time Frame: Baseline (PEEP 10 cmH2O), at titrated PEEP level, at titrated PEEP level after a recruitment maneuver and 24 hours after the performance of the study protocol ]
    Difference in oxygenation measured in mmHg of PaO2/FiO2
  • Gas Exchange - Arterial carbon dioxide [ Time Frame: Baseline (PEEP 10 cmH2O), at titrated PEEP level, at titrated PEEP level after a recruitment maneuver and 24 hours after the performance of the study protocol ]
    Difference in arterial carbon dioxide measured in mmHg (PaCO2)
  • Lung volumes - respiratory dead space [ Time Frame: Baseline (PEEP 10 cmH2O), at titrated PEEP level and at titrated PEEP level after a recruitment maneuver ]
    Difference in dead space fraction measured as the ratio of death volume over the total tidal volume (Vd/Vt)
  • Lung imaging - Electrical impedance tomography perfusion data [ Time Frame: Baseline (PEEP 10 cmH2O) and at titrated PEEP level after a recruitment maneuver ]
    Differences in distribution in lung perfusion measured as regional percentage of the total cardiac output
  • Right heart function - TAPSE [ Time Frame: Baseline (PEEP 10 cmH2O), at titrated PEEP level and at titrated PEEP level after a recruitment maneuver ]
    Differences in Tricuspid Annular Plane Systolic Excursion measured through two-dimensional transthoracic echocardiography (apical four-chamber view)
  • Right heart function - S' [ Time Frame: Baseline (PEEP 10 cmH2O), at titrated PEEP level and at titrated PEEP level after a recruitment maneuver ]
    Differences in the systolic excursion of the tricuspid annulus measured by tissue doppler imaging
  • Right heart function - Tei index [ Time Frame: Baseline (PEEP 10 cmH2O), at titrated PEEP level and at titrated PEEP level after a recruitment maneuver ]
    Differences in global right ventricular function obtained from right ventricle tissue doppler imaging
  • Hemodynamics [ Time Frame: 24 hours after the performance of the study protocol ]
    Arterial blood pressure, urinary output, water balance, requirement for vasopressors, serum creatinine will be collected
  • Duration of mechanical ventilation [ Time Frame: 30 days after the performance of the study protocol ]
    Number of days on mechanical ventilation
  • ICU and hospital length of stay [ Time Frame: 30 days after the performance of the study protocol ]
    Numbers of days spent in the intensive care unit and numbers of days of in-hospital care
  • Incidence of tracheostomy [ Time Frame: 30 days after the performance of the study protocol ]
    Necessity of tracheostomy for prolonged ventilatory support among the study population
  • Survival [ Time Frame: 30 days after the performance

    Original Secondary Outcome: Same as current

    Information By: Massachusetts General Hospital

    Dates:
    Date Received: July 17, 2015
    Date Started: April 2016
    Date Completion: December 2018
    Last Updated: February 8, 2017
    Last Verified: February 2017