What is the diagnosis, signs, symptoms, and treatment of upper airway obstruction in the Cardiovascular Intensive Care Unit (CVICU)?

Upper Airway Obstruction in CVICU: Diagnosis, Signs, Symptoms, and Management

Upper airway obstruction in the CVICU requires immediate recognition and intervention to prevent hypoxic brain damage and death. Prompt identification of signs and symptoms followed by appropriate management is critical for patient survival 1, 2.

Diagnosis and Causes

Upper airway obstruction is defined as blockage of any portion of the airway above the thoracic inlet 2. Common causes in the CVICU include:

• The tongue (most common cause, especially in comatose patients or those who have suffered cardiopulmonary arrest) 2
• Laryngeal edema (post-extubation) 1
• Foreign bodies (including poorly positioned airway devices) 1, 2
• Trauma (including post-surgical) 2
• Infection (less common in adults but still relevant) 3
• Hematoma (post-surgical) 2
• Angioedema 3

Signs and Symptoms

Early Recognition Signs

• Stridor (inspiratory or biphasic) 1, 3
• Dysphonia or voice changes 1
• Suprasternal retractions 3
• Increased work of breathing 1
• Tachypnea 1

Progressive Signs

• Monophonic wheezing loudest over central airway 1
• Difficulty handling secretions 1
• Use of accessory muscles 1
• Paradoxical chest/abdominal movements 1
• Cyanosis (late sign) 1

Critical Signs (Requiring Immediate Intervention)

• Silent cough 1
• Inability to speak 1
• Decreased level of consciousness 1
• Oxygen desaturation despite supplemental oxygen 1
• Bradycardia (pre-terminal) 1

Management Algorithm

Immediate Actions

1. Position the patient appropriately - Head tilt-chin lift or jaw thrust to elevate the tongue from the posterior pharynx 1, 2
2. Provide supplemental oxygen - 100% oxygen via face mask 1
3. Prepare for potential airway intervention - Have equipment ready for intubation or surgical airway 1

Mild to Moderate Obstruction

• Maintain patient in upright position if possible 1
• Consider humidified oxygen 1, 3
• Remove any visible foreign body if identified 1
• Monitor closely for signs of deterioration 1

Severe Obstruction

• Call for immediate anesthesia/airway expert assistance 1
• Prepare for definitive airway management 1
• Avoid multiple unsuccessful intubation attempts as these may worsen edema 4
• Consider awake techniques in cooperative patients with partial obstruction 1

Failed Airway Management Plan

If intubation fails and ventilation becomes impossible ("Can't Intubate, Can't Ventilate" scenario):

1. Attempt LMA or other supraglottic device as rescue 1
2. If still unsuccessful, proceed immediately to surgical airway 1
   • Cannula cricothyroidotomy with jet ventilation, or
   • Surgical cricothyroidotomy with a cuffed tube 1

CVICU-Specific Considerations

• Post-extubation monitoring - Observe patients closely for at least 30 minutes after extubation for signs of laryngeal edema 1
• Airway device management - Supraglottic airways should only be removed by qualified staff with an anaesthetist immediately available 1
• Discharge criteria from PACU to CVICU - Patients must be fully conscious with patent airway, protective reflexes, and stable vital signs 1
• Equipment readiness - Always have difficult airway equipment immediately available in CVICU 1, 4
• Team communication - Clear handover regarding airway concerns between OR and CVICU teams 1

Pitfalls and Caveats

• Don't rely on wheezing alone - Wheezing can be an unreliable indicator of airway obstruction 1
• Avoid repeated laryngoscopy attempts - This can worsen edema and convert partial to complete obstruction 4
• Recognize that cricoid pressure may worsen airway obstruction and should be reduced if it impedes laryngoscopy 1
• Don't delay definitive management - Upper airway obstruction can progress rapidly to complete obstruction 2, 4
• Consider post-surgical anatomy - Cardiac surgery patients may have anatomical distortions affecting airway management 1
• Remember normal PaO₂ with upper airway obstruction may be misleading - patients can maintain normal oxygenation until sudden decompensation 1

By following this structured approach to diagnosis and management, CVICU clinicians can effectively address upper airway obstruction and prevent potentially fatal outcomes.