Cuff Leak Test and Airway Obstruction in Mechanically Ventilated ICU (COMIC)
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ClinicalTrials.gov Identifier: NCT03372707 |
Recruitment Status :
Completed
First Posted : December 14, 2017
Last Update Posted : August 26, 2022
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Introduction: Endotracheal intubation and mechanical ventilation are lifesaving interventions that are commonly done in the intensive care unit (ICU). The act of intubating someone can cause laryngeal edema (LE) that, if extensive enough, can cause airway obstruction after a patient is extubated. To date, the only test that is available to predict this complication is the cuff leak test (CLT). However, its diagnostic accuracy is uncertain as there have been no randomized controlled trials (RCT) examining this. The Cuff leak and airway Obstruction in Mechanically ventilated ICU patients (COMIC) Randomized Control Trial will be done to examine the impact of CLT on postextubation stridor and reintubation. Subsequently, describing the diagnostic accuracy of this test.
Methods: This will be a multi-center centered, pragmatic, double blinded RCT. Mechanically ventilated patients in the ICU, who are deemed ready to be extubated will be included. All patients will have a CLT done prior to extubation. The results of the CLT in the intervention arm will be communicated to the treating physician, and decision to extubate will be left to the treating team, while the results of the CLT for patients in the control arm will not be communicated to the treating physician, and the patient will be extubated, regardless of the result of the CLT.
Objective: This is a pilot trial to assess feasibility of conducting a powered RCT. Feasibility outcomes include: consent rate, recruitment rate, and protocol adherence. Clinical outcomes will include postextubation stridor, reintubation, emergency surgical airway, ICU mortality, in hospital mortality, duration of mechanical ventilation, and ICU length of stay in days.
Condition or disease | Intervention/treatment | Phase |
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Laryngeal Edema | Diagnostic Test: Cuff Leak Test | Not Applicable |

Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 100 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Triple (Participant, Investigator, Outcomes Assessor) |
Masking Description: | Patients, Research Coordinators, study investigators, adjudicators, and data analysts will be blinded to the results of CLT in the control group. |
Primary Purpose: | Diagnostic |
Official Title: | Cuff Leak Test and Airway Obstruction in Mechanically Ventilated ICU Patients Pilot Trial |
Actual Study Start Date : | July 5, 2018 |
Actual Primary Completion Date : | May 1, 2019 |
Actual Study Completion Date : | July 1, 2019 |

Arm | Intervention/treatment |
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Experimental: Intervention Arm
Patients randomized to the intervention arm will have the results of the Cuff Leak Test (CLT) (whether failed or passed) communicated to the treating physician; the treating physician will decide whether to proceed with extubation or not based on the CLT results. It is at the discretion of the treating physician to provide corticosteroids (4-5 mg of intravenous dexamethasone every six hours for up to 24 hours, with the last dose given one hour preceding extubation) and/or delay extubation by 24 hours should the patient fail the CLT.
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Diagnostic Test: Cuff Leak Test
The Respiratory Therapist (RT) will perform the CLT on all enrolled patients. The patients will first be switched to volume assist-control (V-AC) with a respiratory rate of 10 breaths/min (to allow patient assist), constant flow of 60 l/min, and tidal volume set to match the average tidal volume currently being delivered during supportive ventilation. The RT will document the average exhaled volume over 3-5 breaths after switching to V-AC. The test will be performed by deflating the ETT balloon cuff with a 10 cc syringe, and: a) auscultation with a stethoscope to identify audible air leak around the ETT, and b) measuring the difference between the average exhaled volume prior to cuff deflation and the average exhaled volume over 3-5 breaths after cuff deflation. |
No Intervention: Control Arm
In the control arm of this trial; the treating physicians and healthcare workers will be blinded to the results of the Cuff Leak Test (CLT); therefore, the Respiratory Therapist (RT) will proceed with extubation without delay or administering systemic steroid, regardless to the CLT results.
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- Consent Rate [ Time Frame: 1 year ]A successful consent rate will be defined as 70% of substitute decision makers (SDMs) or patients approached to consent, choosing to participate in the trial. This will be calculated as the overall proportion of SDMs or patients consenting out of those approached (with 95% CI). Note that a mixed consent model will be obtained. In Canada and Saudi Arabia, a priori or deferred consent model will be used. In Poland, a waved consent model will be used.
- Recruitment Rate [ Time Frame: 1 year ]A successful recruitment rate will be defined as achieving enrollment of 40 patients, conventionally expressed as four patients per month over the duration of the trial. While the pilot trial is ongoing, recruitment will be reviewed weekly and the screening records will be reviewed monthly with the cases of missed eligible patients reviewed. If applicable, barriers to enrollment will be addressed to maximize recruitment. The recruitment metric will be measured and interpreted at the end of the pilot trial by calculating the mean number of recruited patients per active screening month.
- Protocol Adherence [ Time Frame: 1 year ]Successful adherence will be defined as ≥80%. The adherence will be calculated as the proportion of patients that were assigned to the control arm being extubated after CLT being performed and the portion of people that assigned to the intervention arm who are given the prescribed steroids for a failed CLT. As this pilot trial is ongoing, investigators will review adherence monthly and investigate the reasons for compliance failure. All reasons for either failure to extubate after a failed CLT in the control arm will be investigated. The RC will review the Respiratory Therapists' notes, and the medication profile to determine actual compliance. All reasons for non-compliance will be recorded for both groups using distinguishing clinical reasons (eg. Palliation, death, consent withdrawal, errors).
- Postextubation stridor [ Time Frame: 48 hours after original extubation ]Defined as an audible high pitched inspiratory noise caused by turbulent airflow through the narrowed airway that is detectable with or without a stethoscope within 48 hours of extubation.
- Clinically significant postextubation stridor [ Time Frame: 48 hours after original extubation ]Defined as stridor (see definition above) that requires medical intervention such as the administration of systemic steroids, racemic epinephrine, or Heli-ox.
- Reintubation [ Time Frame: 72 hours after original extubation ]Defined as reintubation within 72 hours of original extubation while in the ICU.
- Emergency surgical airway [ Time Frame: 30 days ]Defined as performing urgent tracheotomy or cricothyroidotomy for a life-threatening airway obstruction
- In ICU mortality [ Time Frame: 1 year ]
- In hospital mortality truncated at 30 days [ Time Frame: 30 days ]
- Duration of mechanical ventilation [ Time Frame: 1 year ]Defined as time on the ventilator after randomization in days.
- ICU length of stay in days [ Time Frame: 1 year ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Eligible patients will be mechanically ventilated adults (>18 years) who are admitted to the ICU and an order to extubate has been provided by the treating physician.
Exclusion Criteria:
- A palliative care, a one-way extubation, or a decision to withdraw advances life support order has been written.
- Pregnancy.
- Patients at high risk for LE: burn patients, smoke inhalation injuries (as defined as singed facial hair or nasal hair, carbonaceous secretions/sputum, and known to be in an enclosed fire), blunt or penetrating trauma involving the neck and airway, postoperative head and neck surgeries, and patients admitted with airway edema to the ICU (e.g; anaphylaxis).
- Patients with either a difficult or traumatic endotracheal intubation.
- Patients receiving mechanical ventilation via tracheostomy.
- Known preexisting tracheolaryngeal abnormalities such as: vocal cord paralysis, tracheolaryngeal neoplasm, tracheomalacia, tracheolaryngeal stenosis, or previous head and neck surgeries.
- Patients receiving systemic corticosteroids of greater than 30 mg of PO prednisone or equivalent, within 4 days prior to the decision to extubate.
- Patients who failed extubation attempt within the current ICU admission.
- History of postextubation airway obstruction.
- The ICU physician declined enrolling the patient.
- Patient had a failed CLT in the previous 24 hours.

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): NCT03372707
Canada, Ontartio | |
St Joseph's Hospital | |
Hamilton, Ontartio, Canada, L8N 46 | |
Poland | |
Jagiellonian University Medical College | |
Kraków, Lesser Poland, Poland, 31-066 | |
Saudi Arabia | |
Imam Adbulrahman Bin Faisal University | |
Dammam, Eastern Province, Saudi Arabia, 34212 |
Principal Investigator: | Kimberley A Lewis, MD | McMaster University | |
Principal Investigator: | Waleed Alhazzani, MD | McMaster University |
Publications:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | McMaster University |
ClinicalTrials.gov Identifier: | NCT03372707 |
Other Study ID Numbers: |
20170701 |
First Posted: | December 14, 2017 Key Record Dates |
Last Update Posted: | August 26, 2022 |
Last Verified: | August 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Cuff leak test Post-extubation airway obstruction Laryngeal edema |
Airway Obstruction Laryngeal Edema Respiratory Insufficiency Respiration Disorders |
Respiratory Tract Diseases Laryngeal Diseases Otorhinolaryngologic Diseases |