From the Guidelines
If airways are involved with no breath sounds heard, it indicates a complete obstruction of the airway, requiring immediate intervention to prevent hypoxia, tissue damage, and death. This critical emergency can be due to various causes such as foreign body obstruction, severe bronchospasm, mucus plugging, or complete airway collapse. According to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1, recognition of airway obstruction is key to successful outcome, and signs of poor air exchange and increased breathing difficulty, such as a silent cough, cyanosis, or inability to speak or breathe, should prompt immediate intervention.
When assessing a patient with no breath sounds, it is essential to:
- Open the airway using head-tilt chin-lift or jaw thrust maneuvers
- Check for and remove any visible obstructions
- Initiate rescue breathing if the patient is not breathing adequately
- Consider advanced airway management techniques, such as intubation or emergency cricothyrotomy, if other methods fail
The absence of lung sounds despite respiratory efforts is particularly concerning, as it can lead to rapid development of hypoxia, tissue damage, and organ failure, with a high mortality rate, as seen in patients with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) who develop airway involvement 1. In such cases, mechanical ventilation may be required, and the prognosis is poor, with a mortality rate of approximately 40%. Therefore, immediate action is crucial to prevent these complications and ensure the best possible outcome.
From the Research
Airways Involvement and Absence of Breath Sounds
If airways are involved and no breath sounds are heard, it may indicate a serious airway obstruction. According to 2, recognizing and acting early on airway compromise reduces morbidity and mortality in patients with airway obstruction.
Possible Causes
The causes of airway obstruction include:
- Foreign bodies 3, 2
- Toxic/hot fumes 2
- Difficult intubation 2, 4
- Laryngeal spasm 2
- Tumors 2
- Congenital airway anomalies, such as the bridging bronchus 5
Clinical Presentation
Patients with airway obstruction may present with signs and symptoms related to large airway obstruction, such as:
Diagnosis and Management
Diagnosis of airway obstruction is often challenging, and patients may require imaging techniques and surgical management 5. According to 4, bedside airway examination tests, such as the Mallampati test and the upper lip bite test, can be used to assess the physical status of the airway, but their accuracy and benefit remain unclear. In cases of life-threatening airway foreign body aspiration, extracorporeal membrane oxygenation (ECMO) may be a useful adjunct 3.