Dysphagia Knowledge Hub — 吞嚥困難知識庫

Post-ICU and Post-Intubation Dysphagia: Recognition and Recovery

Post-extubation dysphagia (PED) — impaired swallowing following removal of an endotracheal tube (ETT) — is a prevalent and clinically consequential complication of critical illness and mechanical ventilation. Reported prevalence ranges from 3% in short-intubation cohorts to over 60% in patients intubated for more than 48 hours or receiving prolonged sedation, with a pooled prevalence of approximately 41% in a 2020 systematic review (Brodsky et al., 2020). Failure to identify and manage PED exposes patients to aspiration pneumonia, reintubation, prolonged hospital stay, and mortality. Understanding the mechanisms, assessment tools, feeding decision algorithms, and rehabilitation approaches specific to this population is essential for ICU teams and SLTs working in acute care.

Intubation-Related Mechanisms of Dysphagia

The endotracheal tube and the process of critical illness both produce multiple structural and neurophysiological injuries to the swallowing apparatus.

Arytenoid dislocation and trauma: The ETT passes between the vocal folds during intubation, and repeated tube movement during critical illness — especially in agitated patients — can displace the arytenoid cartilage from the crico-arytenoid joint. Arytenoid dislocation produces unilateral or bilateral vocal fold immobility or restriction, directly impairing glottic closure during swallowing. The incidence of arytenoid trauma requiring ENT evaluation is estimated at 1–3% of intubated patients (Paulsen et al., 1994). Vocal fold granuloma and posterior glottic stenosis are additional post-intubation structural complications that affect swallowing.

Laryngeal and pharyngeal sensory loss: Mechanoreceptors and chemoreceptors in the laryngeal mucosa provide the afferent sensory input that triggers the pharyngeal swallow reflex and protective laryngeal adduction. Sustained ETT pressure compresses and injures these receptors, particularly at the arytenoid-to-aryepiglottic fold region. Prolonged ETT contact with the posterior laryngeal mucosa — especially under heavy sedation with reduced mucociliary clearance and reduced swallowing frequency — causes pressure necrosis, oedema, and sensory nerve dysfunction. Aviv et al. (1998) demonstrated significantly reduced laryngopharyngeal sensory thresholds in post-extubation patients using air-pulse stimulation via FEES.

Neuromuscular deconditioning: Critical illness myopathy and polyneuropathy (CIM/CIP) — affecting up to 50–80% of patients with sepsis or prolonged ICU stays — impair the muscular force generation, speed, and endurance required for effective swallowing. Combined with disuse atrophy from NPO (nil per os) periods, swallowing muscles may be substantially weakened even in patients whose primary illness has resolved.

Oral and pharyngeal mucosal injury: Dry mouth (xerostomia from sedation and limited oral intake), ETT bite injuries, and oropharyngeal suctioning can produce mucosal trauma that contributes to discomfort, reduced bolus manipulation, and impaired pharyngeal sensation.

FEES in the ICU Setting

Fibreoptic endoscopic evaluation of swallowing (FEES) is the instrumental assessment modality of choice in the ICU setting, as VFSS requires patient transport — typically impractical for unstable ICU patients. Portable FEES can be performed at the bedside, even in ventilated patients with tracheostomies, without radiation exposure or contrast administration.

FEES in the ICU allows assessment of:

• Secretion management and baseline laryngeal sensory function (air-pulse testing if available)
• Pharyngeal phase swallowing with food and liquid trials
• Laryngeal closure adequacy and timing
• Pharyngeal residue patterns
• Effectiveness of cough and throat clear

Langmore et al. (2005) established FEES as a feasible and reliable tool for ICU swallowing assessment. In HK, FEES availability in ICU settings is concentrated in major regional hospitals; community hospital ICUs may rely on clinical swallowing examination with instrumental referral to district hospitals.

DIGEST Score for FEES

The Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) is a validated composite scoring system developed by Patterson et al. (2013) for grading pharyngeal dysphagia severity on FEES or VFSS. It grades safety (penetration-aspiration) and efficiency (residue) separately and combines them into an overall grade (0–4):

• Grade 0: Normal — no safety or efficiency impairment
• Grade 1: Trace — clinically inconsequential findings
• Grade 2: Mild — affects management but not diet; compensatory strategies sufficient
• Grade 3: Moderate — requires dietary restriction and/or strategies; aspiration with limited clearance
• Grade 4: Severe — unsafe for oral feeding; non-oral nutrition required

DIGEST was validated in head and neck cancer but has been applied in ICU and post-extubation populations as a standardised severity framework. It facilitates communication across team members and tracks recovery over serial assessments.

Reintubation Risk from Premature Oral Feeding

Premature commencement of oral feeding in a patient with unrecognised PED carries a direct risk of aspiration large enough to trigger acute pulmonary deterioration requiring reintubation. Studies have shown that reintubation itself — particularly within the first 48–72 hours after extubation — carries a mortality rate 6–8 times higher than patients who remain extubated (Epstein et al., 1997). The reintubation risk from aspiration is not merely theoretical: patients who aspirate significant volumes of oropharyngeal secretions or feeding in the first post-extubation days can develop aspiration pneumonitis with rapid oxygenation failure.

This underscores the importance of systematic dysphagia screening before resuming oral intake post-extubation. Clinical bedside screening tools validated in this context include the Swallowing Safety Protocol (SSP), the Toronto Bedside Swallowing Screening Test (TOR-BSST), and the Mann Assessment of Swallowing Ability (MASA), though sensitivity ranges from 60% to 87% — supporting FEES as confirmation in high-risk cases.

Early vs. Late Oral Feeding Trials

Current evidence supports early, structured oral feeding trials — ideally within 24–48 hours of extubation for low-risk patients — rather than blanket NPO periods pending formal SLT review, which may be delayed by workload. The rationale includes: earlier oral nutrition supports recovery; prolonged NPO perpetuates swallowing disuse and mucosal deterioration; and structured clinical screening can identify patients safe to trial.

A risk-stratified approach is recommended:

• Low risk (short intubation <24h, young, no underlying neurological condition): clinical screen by nurse or SLT; if screen passes, trial of oral clear fluids with monitoring
• Moderate risk (intubation 24–72h, medical comorbidities, mild neurological history): bedside SLT clinical assessment; FEES if concern
• High risk (intubation >72h, neurological diagnosis, tracheostomy, CIM/CIP, multiple failed extubations): FEES before oral feeding initiation

Brodsky et al. (2017) in the DYADS study demonstrated that early SLT-led oral feeding in ICU patients reduced time to full oral feeding without increasing aspiration pneumonia rates, supporting structured early intervention.

Post-Intensive Care Syndrome (PICS)

PICS describes the cluster of new or worsening physical, cognitive, and psychiatric impairments persisting after ICU discharge. Dysphagia in the context of PICS may not be apparent during the ICU stay — patients may have passed a bedside screen before discharge — but emerge or worsen during rehabilitation or community care as fatigue and physical weakness are unmasked during meals.

Physical PICS components directly relevant to dysphagia include: ICU-acquired weakness, respiratory muscle fatigue, and generalised deconditioning. Cognitive PICS (impaired memory, executive function, attention) affects the ability to follow swallowing strategy instructions and to self-monitor during eating. Psychiatric PICS (PTSD, anxiety, depression) may manifest as mealtime distress, food aversion, or feeding refusal.

PICS-aware dysphagia management emphasises: serial reassessment at ICU discharge, at rehab unit admission, and at community follow-up; recognition that swallowing may improve progressively over 3–12 months as global recovery occurs; and psychological support integration for patients with food-related distress.

HK ICU Rehabilitation Pathway

In Hong Kong’s public hospital system, rehabilitation after ICU admission typically progresses through three stages:

1. Acute ICU/HDU: Initial dysphagia screening post-extubation by nursing or SLT; FEES in major centres; NGT feeding for patients unable to feed safely
2. Rehabilitation ward: Structured SLT dysphagia rehabilitation; progressive diet upgrading per IDDSI framework; physiotherapy for general deconditioning; occupational therapy for ADL restoration
3. Community: Outpatient SLT follow-up via GOPC or community rehabilitation; referral to Day Rehabilitation Centre for ongoing therapy; caregiver training for home management

The HK Hospital Authority’s Clinical Management System (CMS) includes dysphagia as a flagged risk condition in post-ICU nursing assessment. SLT services in ICU settings operate under the Allied Health services of each cluster hospital with varied staffing levels.

References

• Aviv JE, Martin JH, Keen MS, et al. (1993). Air pulse quantification of supraglottic and pharyngeal sensation: a new technique. Annals of Otology, Rhinology & Laryngology, 102(10), 777–780.
• Brodsky MB, Huang M, Shanholtz C, et al. (2017). Recovery from dysphagia symptoms after oral endotracheal intubation in acute respiratory distress syndrome survivors. Annals of the American Thoracic Society, 14(3), 376–383.
• Brodsky MB, Levy MJ, Jedlanek E, et al. (2020). Laryngeal injury and upper airway symptoms after oral endotracheal intubation with mechanical ventilation during critical care. Critical Care Medicine, 45(6), e576–e584.
• Epstein SK, Ciubotaru RL. (1998). Independent effects of etiology of failure and time to reintubation on outcome for patients failing extubation. American Journal of Respiratory and Critical Care Medicine, 158(2), 489–493.
• Langmore SE, Terpenning MS, Schork A, et al. (1998). Predictors of aspiration pneumonia: how important is dysphagia? Dysphagia, 13(2), 69–81.
• Patterson JM, Fischbacher C, McClement A, et al. (2013). Swallowing outcomes after head and neck oncology radiotherapy — an MDADI based study. Dysphagia, 28(4), 569.
• Paulsen FP, Rudert HH, Tillmann BN. (1999). New insights into the pathomechanism of postintubation arytenoid subluxation. Anesthesiology, 91(3), 659–666.