How to identify the source of bleeding?

How to Identify the Source of Bleeding

The most effective approach to identify the source of bleeding is through systematic assessment of the bleeding characteristics, anatomical location, and appropriate diagnostic testing based on clinical presentation. 1

Initial Assessment of Bleeding

• Assess the severity of bleeding by evaluating hemodynamic stability (vital signs, shock index) and physical appearance of blood loss 1, 2
• Determine if bleeding is active or has stopped, as active bleeding requires more urgent intervention 1
• Note the color and consistency of blood:
  • Bright red blood suggests active arterial bleeding or bleeding from a source close to the body surface 1, 3
  • Darker blood may indicate venous bleeding or blood that has been in the body longer 3
  • Coffee-ground appearance may indicate upper gastrointestinal bleeding 4

Anatomical Approach to Bleeding Sources

Nasal Bleeding (Epistaxis)

• Perform anterior rhinoscopy after removing any blood clots to identify the source of bleeding 1
• Most common sites include the anterior nasal septum (Kiesselbach's plexus) and posterior nasal cavity 1
• Bilateral bleeding may indicate systemic causes rather than local trauma 1

Gastrointestinal Bleeding

• Determine if bleeding is upper or lower GI:
  • Hematemesis (vomiting blood) indicates upper GI source 4
  • Melena (black, tarry stool) suggests upper GI bleeding 1
  • Hematochezia (bright red blood per rectum) typically indicates lower GI source, but can occur with brisk upper GI bleeding 1
• For rectal bleeding, perform anoscopy or proctoscopy to distinguish between hemorrhoids and anorectal varices 1

Trauma-Related Bleeding

• In trauma patients with hemorrhagic shock, immediately identify if the source is external (visible) or internal 1
• For patients with unidentified bleeding sources and shock, perform immediate further assessment 1

Diagnostic Approaches Based on Clinical Scenario

For Visible External Bleeding

• Direct visualization and examination of the bleeding site 5
• Assess characteristics of the wound and surrounding tissues 5

For Suspected Internal Bleeding

• Early focused sonography (FAST) should be used for detection of free fluid in patients with suspected torso trauma 1
• Computed tomography for hemodynamically stable patients with suspected head, chest, or abdominal bleeding 1
• Serum lactate and base deficit measurements help estimate and monitor the extent of bleeding and shock 1

For Gastrointestinal Bleeding

• Upper endoscopy for suspected upper GI bleeding 1
• Colonoscopy for lower GI bleeding 1
• Nuclear medicine scanning (tagged red blood cell scan) can detect bleeding rates as low as 0.1-0.5 mL/min 1
• Angiography for severe, active bleeding (requires bleeding rate of at least 1 mL/min) 1

Special Considerations

• In patients with known bleeding disorders, emergency care cards often outline the specific condition and initial treatment 6
• For unexplained bleeding or abnormal coagulation studies, consider hematology consultation 6, 3
• For pregnant patients with first-trimester bleeding, transvaginal ultrasound combined with β-hCG levels helps distinguish between normal pregnancy, miscarriage, and ectopic pregnancy 7

Common Pitfalls to Avoid

• Don't rely on single hematocrit measurements as an isolated marker for bleeding 1
• Avoid delaying treatment for life-threatening bleeding while pursuing diagnostic tests 1, 5
• Don't assume all bleeding from the rectum is hemorrhoidal in origin; perform appropriate examination to confirm the source 1
• For patients on anticoagulants with active bleeding, don't immediately reverse anticoagulation before initiating first-line treatments unless bleeding is life-threatening 1