Clinical trial NCT07017205: Microaspiration and Endotracheal Tubes
Official title: Evaluation of Microaspiration in Different Endotracheal Tubes During Scheduled Surgeries: A Randomized Controlled Trial.
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: NA
Conditions: Endotracheal Tube Cuff
Microaspiration
Endotracheal Tube Cuff Pressure
Lead sponsor: Argentinian Intensive Care Society
Sponsor class: OTHER
First posted: 2025-06-12
Enrollment: 72
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: SCREENING

Brief summary: This prospective, randomized controlled study aims to evaluate the effectiveness of two different types of endotracheal tubes (ETTs) in preventing microaspiration during elective surgeries requiring general anesthesia and orotracheal intubation. Microaspiration, the leakage of oropharyngeal secretions past the ETT cuff into the lower airways, is a key factor contributing to respiratory complications such as ventilator-associated pneumonia.

The study will compare a standard ETT (Hi-Lo Shiley™) with a technologically advanced model (TaperGuard Evac™), which features a tapered cuff and subglottic suction system. A total of 144 adult patients scheduled for surgeries longer than one hour will be randomized to receive one of these ETTs during intubation. A blue dye will be instilled above the glottis after intubation to detect the presence of microaspiration. Tracheal secretions will be collected at two time points: shortly after intubation and before extubation, to determine whether the dye has passed the cuff.

The primary outcome is the detection of blue dye in tracheal secretions, indicating microaspiration. Secondary outcomes include the incidence and severity of post-extubation pain and dysphonia, assessed at several intervals within the first 24 hours after surgery.

Cuff pressure will be continuously monitored in the TaperGuard group using a specialized device, while the control group will undergo standard manual cuff inflation. Additional data such as demographic variables, comorbidities, airway scores, and intraoperative ventilatory parameters will be collected to explore potential influencing factors.

By comparing a conventional versus a technologically enhanced ETT, this study seeks to generate clinical evidence on which devices most effectively minimize aspiration and improve patient safety in the surgical setting. The findings are expected to guide clinical decision-making and inform airway management protocols in patients undergoing elective surgeries.

Detailed description: Microaspiration of oropharyngeal secretions during orotracheal intubation is a well-documented risk factor for respiratory complications, particularly ventilator-associated pneumonia (VAP). Despite the implementation of standardized preventive measures such as cuff pressure monitoring and subglottic suctioning, aspiration continues to occur, especially with conventional endotracheal tube (ETT) designs that may allow fluid leakage due to cuff folding or ineffective airway sealing.

This randomized controlled trial aims to evaluate the incidence of microaspiration and post-extubation complications in patients intubated with either a standard cylindrical-cuff ETT (Hi-Lo Shiley™, Medtronic) or an advanced tapered-cuff ETT with subglottic suction (TaperGuard Evac™, Medtronic). The study will take place at the British Hospital of Buenos Aires over a 3-month period, and include adult patients (≥18 years) undergoing elective surgical procedures requiring general anesthesia and orotracheal intubation for more than one hour.

A total of 72 patients will be randomized in permuted block of 4-6 randomization (via REDCap®), ensuring balanced group assignment. After induction of anesthesia and intubation, 2 mL of blue dye will be applied at the oropharyngeal level in all patients to simulate secretions. Tracheal aspirates will be collected intraoperatively at two defined time points: (1) within 10 minutes after stabilization post-intubation and (2) immediately prior to extubation. The primary endpoint is the presence of blue-dyed secretions in the lower airways, determined by blinded investigators. This serves as an objective marker of microaspiration.

Secondary outcomes include the incidence and severity of post-extubation pain and dysphonia, which will be evaluated using validated tools at 1, 2, 3, and 24 hours after extubation. Pain will be assessed with a Numerical Rating Scale (NRS, 0-10), and dysphonia using the GRBAS scale, focusing on the "Grade" component (0-3). The presence of adverse events after extubation that could lead to reintubation (e.g., stridor, respiratory failure, altered consciousness) will also be monitored.

Both groups will undergo standard anesthetic management by experienced professionals. In the intervention group, cuff pressure will be continuously monitored using the "Pressure Easy® Cuff Pressure Controller" (Medtronic) to maintain safe pressure levels between 25-30 cmH₂O. In the control group, cuff inflation will follow routine clinical practice with passive syringe inflation. All airway assessments (Mallampati, Cormack-Lehane, Macocha, thyromental distance), demographic data, comorbidities (including the Charlson Comorbidity Index and BMI), intraoperative parameters (ventilation settings, surgical position, neuromuscular blockade), and surgical details will be collected.

Sample size was calculated using G\*Power® based on prior literature indicating a potential 30% reduction in microaspiration incidence with tapered-cuff tubes (80% vs. 50%). A total of 72 patients per group provides sufficient power (1-β = 0.80, α = 0.05) to detect statistically significant differences.

Data will be entered into a dedicated REDCap® eCRF. Quality assurance measures include predefined data ranges, double entry, and random audits. Confidentiality will be ensured by de-identifying all records with alphanumeric codes, and data access will be limited to authorized personnel. The study complies with the Declaration of Helsinki, ICH-GCP guidelines, and Argentine regulations on human research and data protection (Laws 25.326 and 26.529).

The expected contribution of this study is to provide robust, in vivo evidence regarding the comparative efficacy of standard versus advanced ETTs in reducing microaspiration and post-extubation complications. Findings may influence clinical practice, particularly in selecting airway devices for surgical patients, and could potentially reduce the incidence of intubation-related respiratory complications.

Eligibility criteria: Inclusion Criteria:

* Adult patients (\>18 years old) scheduled for surgery lasting at least one hour.
* ASA I-III classification.
* Signed informed consent.

Exclusion Criteria:

* Pre-existing airway pathology (e.g., tracheomalacia, granulomas, stenosis, tumors).
* Anticipated difficult intubation (Macocha Score \> 3 points).
* Selective lung ventilation / one-lung ventilation.
* Current participation in another clinical trial.

Elimination Criteria:

* Accidental extubation.
* Cardiorespiratory arrest or death.

Primary outcomes:
measure: Penetration of blue-dyed oropharyngeal secretions into the distal airway
timeFrame: From enrollment to the end of Surgery: Tracheal aspirate samples will be collected at two defined time points: the first between 10 and 30 minutes after intubation and hemodynamic stabilization, and the second immediately prior to extubation.
Secondary outcomes:
measure: Determine the incidence of post-extubation pain.
timeFrame: The pain will be assessed at the following post-extubation time points: 1 hour, 2 hours, 3 hours, and 24 hours.
measure: Determine the incidence of post-extubation dysphonia.
timeFrame: These dysphonia will be assessed at the following post-extubation time points: 1 hour, 2 hours, 3 hours, and 24 hours.
Other outcomes:
Locations:
city: Caba
country: Argentina
facility: Hospital Britanico de Buenos Aires
state: Buenos Aires
Study officials:
References:
citation: Blot SI, Poelaert J, Kollef M. How to avoid microaspiration? A key element for the prevention of ventilator-associated pneumonia in intubated ICU patients. BMC Infect Dis. 2014 Nov 28;14:119. doi: 10.1186/1471-2334-14-119.