COMIC Pilot Trial

Abstract:

Rationale: Laryngeal edema is a known complication of endotracheal intubation that may cause airway obstruction upon extubation. The only test available to predict this complication is the cuff leak test (CLT).

Objectives: Given the uncertainty of the CLT's clinical utility, we conducted the COMIC (Cuff Leak Test and Airway Obstruction in Mechanically Ventilated ICU Patients) pilot study to examine the feasibility of undertaking a larger trial.

Methods: COMIC is a multicentered, parallel-group randomized trial performed in Canada, Saudi Arabia, and Poland. We enrolled mechanically ventilated adults admitted to the intensive care unit who were deemed ready for extubation. Those allocated to the intervention arm had the results of their CLT communicated to the healthcare team, who then decided to proceed with extubation or not. In those randomized to the control arm, the CLT results were not communicated to the healthcare team and patients were extubated, regardless of the CLT result. The primary outcomes focused on feasibility.

Results: One hundred patients (56 in the intervention and 44 in the control arm) were enrolled. All feasibility criteria were met, including 1) recruitment rate of 7.6 patients/month, 2) consent rate of 88.3% (95% confidence interval [CI], 82.1-94.5%), and 3) protocol adherence of 98% (95% CI, 95-100%). There were two episodes of clinically significant stridor in the intervention group and four patients who required reintubation in each group.

Conclusions: The results of the COMIC pilot trial support the feasibility of a larger trial to determine the effect of the CLT on reintubation and clinically important stridor.

Clinical trial registered with www.clinicaltrials.gov (NCT03372707).

Timelines: Event

COMIC International Survey

Lewis et al. 2021

Ann Am Thorac Soc, 2021 May;65(1)

DOI: 10.1111/aas.13838

Abstract:

Background:

The cuff leak test (CLT) is used to assess laryngeal edema prior to extubation. There is limited evidence for its diagnostic accuracy and conflicting guidelines surrounding its use in critically ill patients who do not have risk factors for laryngeal edema.

Objective:

The primary study aim was to describe intensivists’ beliefs, attitudes, and practice regarding the use of the CLT.

Methods:

A 13‐item survey was developed, pilot‐tested, and subjected to clinical sensibility testing. The survey was distributed electronically through MetaClinician®. Descriptive statistics and multivariable regression analysis were performed to examine associations between participant demographics and survey responses.

Results:

1184 practicing intensivists from 17 countries in North and South America, Europe, Oceania, and Asia participated. The majority (59%) of respondents reported rarely or never perform the CLT prior to extubating patients not at high risk of laryngeal edema, which correlated with 54% of respondents reporting they believed a failed CLT did not predict reintubation. Intensivists from the Middle East were 2.4 times more likely to request a CLT compared to those from North America. Intensivists with base training in medicine or emergency medicine were more likely to request a CLT prior to extubation compared to those with base training in anesthesiology.

Conclusion:

Use of the CLT prior to extubating patients not at high risk of laryngeal edema in the intensive care unit is highly variable. Practice appears to be influenced by country of practice and base specialty training.

Lewis & Alhazzani. 2017

Saudi Critical Care Journal, 2017 Nov;1(6):22-24

DOI: 10.4103/sccj.sccj_27_17

COMIC Review Article

Abstract:

Endotracheal intubation and mechanical ventilation are lifesaving interventions that are commonly performed in the intensive care unit (ICU). The trauma of endotracheal intubation itself, the prolongued pressure exerted by the endotracheal tube on the larynx, and miscellaneous factors such as fluid overload can result in laryngeal edema (LE). Extubation of a patient with undiagnosed LE can results in respiratory failure secondary to an upper airway obstruction and may require reintubation. Respiratory failure requiring reintubation is associated with morbidity and mortality. The cuff leak test (CLT) is the only method intensivists use to predict the presence of LE. Despite the CLT's first description in 1988, the correct way to interpret the results (either qualitatively or quantitatively) is unknown, and its diagnostic accuracy has been called into question. In fact, the CLT could be detrimental to patients if it has a high false positive rate (i.e. no air leak is detected indicating LE when none actually exists). Incorrectly diagnosing patients with LE may result in prolongued mechanical ventilation that predisposes patients to barotrauma, ventilator-associated infections, exposure to systemic steroids, and a prolongued stay in the ICU. Given the paucity of data, the Cuff Leak and Airway Obstruction in Mechanically Ventilated ICU Patients (COMIC) research group is conducting a survey to understand international practice surround the use of the CLT prior to extubation, as well as a randomized controlled trial that will capture the accuracy of the test and determine the bet method to measure cuff leak.