What is the purpose of a post cardiac arrest bronchoscopy?

Purpose of Post-Cardiac Arrest Bronchoscopy

Bronchoscopy after cardiac arrest serves primarily to confirm correct endotracheal tube placement when other methods are unreliable, and to diagnose and treat airway obstruction that may have caused or complicated the arrest.

Primary Indications

Confirmation of Endotracheal Tube Placement

• Fiberoptic bronchoscopy is specifically mentioned as a method to confirm successful tracheal intubation in adults during cardiac arrest 1
• This becomes particularly valuable when standard confirmation methods (waveform capnography, CO2 detection) may be unreliable due to low pulmonary blood flow during prolonged cardiac arrest 1
• Bronchoscopy provides direct visualization of tube position relative to the carina, which is critical since tubes should be positioned well above the carina 1

Diagnosis and Treatment of Airway Obstruction

• Foreign body airway obstruction (FBAO) causing cardiac arrest requires prompt bronchoscopic diagnosis and removal 2
• In three documented cardiac arrest cases due to FBAO, emergency physician-performed flexible bronchoscopy led to immediate improvements in oxygenation and ventilation, with return of spontaneous circulation after foreign body removal 2
• When ventilation is difficult due to high airway resistance during resuscitation, bronchoscopy can confirm suspected airway obstruction 2

Therapeutic Airway Management

• Bronchoscopy can clear secretions, mucus plugs, and blood that may obstruct ventilation in the post-arrest period 3, 4
• This is particularly relevant since gastric contents may contaminate the trachea during cardiac arrest, potentially causing airway obstruction 1
• The procedure can identify areas of active bleeding and evaluate obstructive airway lesions 3

Clinical Context and Timing

When Standard Methods Fail

• Bronchoscopy becomes indicated when waveform capnography shows false-negative results (absent CO2 despite correct tube placement) due to pulmonary embolism, severe hypotension, gastric content contamination, or severe airflow obstruction 1
• The sensitivity of capnography decreases after prolonged cardiac arrest due to low pulmonary blood flow 1

Post-ROSC Management

• After return of spontaneous circulation, bronchoscopy may be needed to ensure airway patency and proper tube positioning, especially if the patient required multiple intubation attempts or had difficult airway management 1
• Chest radiography should be obtained to check tube position, but bronchoscopy provides more definitive visualization when radiographic findings are equivocal 1

Important Caveats

Risk-Benefit Considerations

• The life-saving benefits of bronchoscopy in cardiac arrest outweigh the small risks of complications such as bleeding, desaturation, and pneumothorax 2
• Attributable mortality rates for bronchoscopy remain low at <0.1% for both fiberoptic and rigid bronchoscopy 5
• However, bronchoscopy should be regarded as an expert procedure and performed with great care, as complications can include cardiac arrhythmias, hypoxemia, and in rare cases, irreversible cardiac arrest 5, 6

Practical Limitations

• Bronchoscopy requires trained personnel and appropriate equipment, which may not be immediately available during active resuscitation 2
• The procedure should not delay critical interventions like chest compressions or defibrillation 7
• In intubated, ventilated patients, bronchoscopy can be performed through a swivel adapter to prevent loss of delivered oxygen and tidal volume 3

Alternative Approaches First

• Standard confirmation methods (waveform capnography, clinical assessment, ultrasound) should be attempted first, as they are faster and less invasive 1
• Bronchoscopy is typically reserved for situations where these methods are inadequate or when specific airway pathology is suspected 1, 2