What labs and imaging studies should be ordered for a patient bleeding from the airway?

Management of Airway Bleeding: Laboratory and Imaging Studies

For patients with bleeding from the airway, immediate bronchoscopy should be performed to identify the source of bleeding, followed by appropriate interventions including airway management with single-lumen endotracheal tube and endobronchial treatments for visible central airway lesions. 1

Initial Assessment and Stabilization

• Secure the airway with a single-lumen endotracheal tube to prevent asphyxiation, which is more life-threatening than blood loss itself 1
• Assess the extent of bleeding using an established grading system such as the Advanced Trauma Life Support (ATLS) classification 2
• Obtain large-bore intravenous access to allow for rapid fluid resuscitation if needed 2
• Administer high FiO2 to ensure adequate oxygenation 2

Laboratory Studies

• Complete blood count (CBC) to assess hemoglobin/hematocrit levels 2
• Coagulation studies including prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen levels 2
• Type and cross-match for potential blood transfusion in cases of large-volume hemoptysis 2
• Serum lactate and base deficit measurements to estimate and monitor the extent of bleeding and shock 1, 2
• Note that single hematocrit measurements should not be relied upon as an isolated marker for bleeding 1, 2

Imaging Studies

Primary Imaging

• Chest radiography (posteroanterior and lateral views) should be the initial imaging study to identify potential causes such as mass lesions, infiltrates, or cavitary lesions 3, 4
• Bronchoscopy is the cornerstone diagnostic procedure for identifying the source of bleeding and should be performed promptly 1, 4
  • Flexible bronchoscopy is preferred for hemodynamically unstable patients with life-threatening hemoptysis 4
  • Rigid bronchoscopy may be considered for massive hemoptysis due to better airway control and suctioning capabilities 5

Advanced Imaging

• Contrast-enhanced multidetector computed tomography (MDCT) should be performed in all patients with frank hemoptysis to:
  • Identify the bleeding site 4
  • Detect underlying pathology such as bronchiectasis, tumors, or vascular malformations 3, 4
  • Evaluate bronchial and non-bronchial systemic arteries that may be the source of bleeding 4
• MDCT angiography has largely replaced conventional arteriography for identifying bleeding vessels 4
• For patients with suspected spinal involvement (e.g., if back pain is present), sagittal T1-weighted MRI of the entire spine is recommended 1

Management Based on Bleeding Volume

Large-Volume Hemoptysis

• Secure airway with single-lumen endotracheal tube 1
• Position patient with bleeding side down if the site is known 6
• Perform immediate bronchoscopy to identify the source of bleeding 1
• Apply endobronchial management options including argon plasma coagulation, Nd:YAG laser, or electrocautery for visible central airway lesions 1
• Consider bronchial artery embolization if bronchoscopic measures fail to control bleeding 1, 6

Non-Large-Volume Hemoptysis

• Perform bronchoscopy to identify the source of bleeding 1
• For visible central airway lesions, use endobronchial management options 1
• For distal or parenchymal lesions, external beam radiotherapy is recommended 1

Common Pitfalls and Considerations

• Avoid delays between diagnosis and intervention for patients requiring urgent bleeding control 2, 7
• Do not rely solely on blood pressure as an indicator of blood loss, as some patients compensate well despite significant hemorrhage 2
• Remember that asphyxiation rather than blood loss is the primary cause of mortality in airway bleeding 5
• Consider the possibility of coagulopathy, especially in patients on anticoagulant or antiplatelet medications 1
• For patients with suspected bleeding disorders or those on anticoagulants, use resorbable packing materials if packing is necessary 1

Causes to Consider

• Bronchitis and bronchiectasis (most common causes) 3, 4
• Lung cancer 3, 4
• Tuberculosis and other infectious diseases 5
• Trauma 6
• Vascular malformations 4

By following this systematic approach to laboratory and imaging studies, clinicians can effectively diagnose and manage patients with airway bleeding, prioritizing airway protection and identification of the bleeding source to guide appropriate interventions.