Silent Aspiration Following Extubation in the ICU

Background:

Post-extubation dysphagia (PED) is common in critically ill patients and is often multifactorial in origin, resulting from trauma, neuromuscular weakness, altered sensation, impaired cognition, and desynchronized breathing-swallowing coordination. Silent aspiration - defined as entry of oropharyngeal material below the vocal folds without overt clinical signs such as coughing or choking - has been reported in up to 69.3% of ICU patients undergoing instrumental assessment. Despite this, current clinical practice at many centers does not mandate instrumental swallow evaluation for patients who pass routine bedside nursing swallow screening.

Study Design:

This is a prospective observational study conducted in the ICU at Cleveland Clinic Abu Dhabi (CCAD). Informed consent will be obtained from all patients or their next of kin prior to enrollment.

Participants:

Adult ICU patients who have been mechanically ventilated for 5 or more days and are subsequently extubated will be eligible for enrollment. Exclusion criteria include: (1) tracheostomy; (2) do-not-reintubate orders; (3) pregnancy; and (4) absence of informed consent.

Procedures:

All enrolled patients will undergo the standard bedside nursing swallow screen per institutional protocol (CCAD PolicyTech). For the purpose of this study, Fiberoptic Endoscopic Evaluation of Swallowing (FEES) will be performed in all enrolled patients up to 72 hours of extubation, regardless of bedside screening results. FEES is a well-established, safe, and portable instrumental assessment that allows direct visualization of pharyngeal and laryngeal structures and detection of aspiration, including silent aspiration. FEES will only be performed after approval by the treating attending physician, and patients with contraindications (e.g., high bleeding risk, high oxygen requirements) will be excluded from the procedure.

Assessments:

FEES findings will be reported using standardized validated scales including the Penetration-Aspiration Scale (PAS), Dysphagia Severity Rating Scale (DSRS), Pharyngeal Residue Severity Rating Scale (PRSS), Murray Secretion Scale, and Airway Protection Scale. Clinical data collected will include age, sex, admitting diagnosis, reasons for intubation, duration of mechanical ventilation, oxygen requirements, bedside swallow screen findings, and clinical outcomes including aspiration pneumonia, reintubation, ventilator-free days, ICU and hospital length of stay, and mortality.

Statistical Analysis:

Descriptive statistics will be used to report the incidence of silent aspiration. Diagnostic accuracy (sensitivity, specificity, Cohen's kappa) of bedside nursing screening will be calculated using FEES as the reference standard. Multivariable logistic regression will identify independent predictors of silent aspiration and its association with clinical outcomes. A minimum sample of 274 patients will be recruited (based on an expected 20% incidence, 95% CI, 5% margin of error, 10% loss to follow-up).