What is the diagnostic approach for aspiration after choking on water?

Diagnostic Approach for Aspiration After Choking on Water

The diagnostic approach for suspected water aspiration should include initial clinical assessment followed by appropriate imaging and specialized testing, with videofluoroscopic swallow evaluation or fiberoptic endoscopic evaluation being the gold standard tests for confirming aspiration. 1

Initial Clinical Assessment

• Observe for immediate signs of respiratory distress including coughing, choking, stridor, dyspnea, or changes in voice quality which may indicate water aspiration 1
• Assess level of consciousness, as patients with reduced consciousness are at higher risk for aspiration and require more urgent intervention 1, 2
• Perform the 3-oz water swallow test, which has been validated as an initial screening tool for aspiration risk 1
• Look for clinical signs associated with aspiration after water swallowing:
  • Reflexive cough during or after swallowing
  • Wet/gurgly voice after swallowing (phonation of prolonged "ee")
  • Throat clearing after swallowing
  • Dysphonia (hoarse voice or inability to produce sound)
  • Drooling from mouth
  • Nasal regurgitation 1

Voluntary Cough Assessment

• Evaluate voluntary cough by asking the patient to cough with as much force as possible 1
• Weak or absent voluntary cough has been associated with aspiration risk, though subjective assessment alone has limitations 1
• Note that subjective evaluation of voluntary cough should not be used as the sole predictor of aspiration due to poor reliability 1

Imaging Studies

• Chest radiography should be performed to assess for radiographic evidence of aspiration:
  • Patchy opacities
  • Lower lobe infiltrates
  • Air space disease 1, 3
• Computed tomography (CT) scan should be performed if there is suspicion of complications such as perforation, abscess, or mediastinitis 1
• Contrast swallow studies are not recommended as they may delay other more appropriate investigations 1

Specialized Testing

• Patients with positive screening or high clinical suspicion should be referred to a speech-language pathologist (SLP) for a comprehensive swallowing evaluation 1
• Videofluoroscopic swallow evaluation (VSE) is considered the gold standard test for diagnosing aspiration:
  • Allows direct visualization of the swallowing process
  • Can identify silent aspiration (aspiration without cough reflex)
  • Can assess the effectiveness of compensatory strategies 1
• Fiberoptic endoscopic evaluation of swallowing (FEES) is an alternative to VSE:
  • Allows direct visualization of the pharynx and larynx during swallowing
  • Can be performed at bedside
  • Does not expose the patient to radiation 1

Timing of Evaluation

• For patients with acute aspiration events, evaluation should be conducted as soon as possible 1
• According to high-quality guidelines, swallowing evaluation should be performed:
  • "Within 4 hours" after admission (UK and Ireland National Clinical Guideline)
  • "A few hours after hospital admission" (Wirth et al.)
  • "Within 24 hours" (Sall et al.) 1
• Assessment should occur before any further oral intake of food, fluid, or medication 1

Laboratory Tests

• Complete blood count (CBC) and C-reactive protein (CRP) to assess for infection 1
• Blood gas analysis for base excess and lactate to evaluate respiratory status and metabolic derangements 1

Special Considerations

• Patients with reduced level of consciousness should not be fed orally until consciousness improves 2
• For patients with suspected dysphagia, consultation with a speech-language pathologist is essential 2
• Be aware that "silent aspiration" (aspiration without cough) can occur, particularly in neurologically impaired patients 1, 4

By following this diagnostic approach, clinicians can effectively identify and manage patients who have aspirated water, potentially preventing serious respiratory complications.