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Ultrasound to Evaluate Failure of Liberation From Mechanical Ventilation (USEFUL)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02723565
Recruitment Status : Completed
First Posted : March 30, 2016
Last Update Posted : March 28, 2019
Information provided by (Responsible Party):
Ewan Goligher, University Health Network, Toronto

Brief Summary:
This study will evaluate the heart, lungs and diaphragm of patients who fail a trial of spontaneous breathing to determine the physiological mechanism of weaning failure.

Condition or disease
Acute Respiratory Failure Respiration, Artificial Weaning

Detailed Description:
The transition to unassisted breathing after invasive ventilation often proves challenging, with over 40% of patients failing their first attempt of unassisted breathing. Persistent ventilator dependence predisposes patients to nosocomial complications and increases the economic burden of critical illness. Ventilator-dependence results from an imbalance between the load and capacity of the respiratory muscle pump. Patients who fail a trial of spontaneous breathing commonly exhibit excess respiratory loads secondary to weaning-induced pulmonary edema, atelectasis or dynamic hyperinflation. Many patients who are dependent on the ventilator also show a striking loss of pump capacity due to diaphragm dysfunction. Though each of these mechanisms respond to specific interventions, it is often difficult for physicians to discern which mechanisms are at play at the bedside. Bedside ultrasound is a potentially useful means of evaluating cardiac, pulmonary and diaphragm function during weaning failure. It is readily available, highly feasible and already widely employed in clinical practice. As yet, no study has evaluated the accuracy and feasibility of combining echocardiography with lung and diaphragm ultrasound to comprehensively evaluate the physiological mechanisms of weaning failure. The objectives of this study are to establish the utility of a rapid thoracic ultrasound exam to diagnose mechanisms of ventilation liberation failure and to assess the relationship between cardiothoracic variability during spontaneous breathing and different physiological mechanism of weaning failure.

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Study Type : Observational
Actual Enrollment : 7 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Ultrasound to Evaluate Failure of Liberation From Mechanical Ventilation
Study Start Date : April 2014
Actual Primary Completion Date : December 2018
Actual Study Completion Date : December 2018

Primary Outcome Measures :
  1. Sensitivity and specificity for diagnosis of physiological mechanisms causing weaning failure [ Time Frame: Physiological measurements for diagnostic classification measured simultaneously with ultrasound measurements ]
    Mechanisms responsible for weaning failure will be diagnosed by field experts using clinical data collected from the chart along with physiological measurements (respiratory mechanics, maximal inspiratory pressure, markers of pulmonary edema including changes in serum total protein and BNP and central venous pressure). The diagnosis derived from a pre-specified ultrasound-based classification system will be compared to the gold standard expert-derived diagnosis.

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:   Non-Probability Sample
Study Population
Patients in the intensive care unit.

Inclusion Criteria:

  • patients over 18 years of age receiving invasive mechanical ventilation for at least 24 hours
  • patients who fulfill standard criteria for readiness for a trial of spontaneous breathing (no or minimal sedation, patient awake and interactive; minimal vasopressor/inotrope requirements (Norepinephrine < or = 0.1, Dopamine < 10, Vasopressin/Epinephrine off); fraction of inspired oxygen < or = 50%; spontaneous inspiratory efforts as indicated by patient-triggered breaths; positive end-expiratory pressure < or = 10 cm H20)
  • patients who fail a trial of spontaneous breathing (transient reduction of ventilator support for any duration up to 2 hours as per local ICU practice - typically PS 5 with PEEP 5 OR CPAP 5 OR T-piece)

Exclusion Criteria:

  • patients with a coagulopathy (INR > 2.5, platelet count < 30x10^6/L) or previously diagnosed bleeding diathesis or are receiving anticoagulant drugs at therapeutic doses (ie. excluding venous thromboembolic prophylaxis)
  • patients with a contraindication to nasogastric tube insertion (esophageal varices, upper GI tract surgery, facial trauma, etc.)
  • patients receiving extra-corporeal life support

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 identifier (NCT number): NCT02723565

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Canada, Ontario
St. Michael's Hospital
Toronto, Ontario, Canada, M5B 1W8
Mount Sinai Hospital
Toronto, Ontario, Canada, M5G 1X5
University Health Network
Toronto, Ontario, Canada, M5G 2N2
Sponsors and Collaborators
University Health Network, Toronto
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Principal Investigator: Ewan C Goligher, MD, PhD University Health Network, Toronto

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Responsible Party: Ewan Goligher, Intensivist, University Health Network, Toronto Identifier: NCT02723565    
Other Study ID Numbers: 14-7400-B
First Posted: March 30, 2016    Key Record Dates
Last Update Posted: March 28, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Respiratory Insufficiency
Respiration Disorders
Respiratory Tract Diseases