Laboratory Evaluation for Bleeding from Nose and Mouth
For a patient presenting with bleeding from both the nose and mouth, immediately obtain a complete blood count (CBC), prothrombin time/INR, activated partial thromboplastin time (aPTT), and type and screen, as this presentation suggests potential hemodynamic compromise requiring urgent assessment. 1, 2
Initial Critical Laboratory Tests
The combination of nasal and oral bleeding indicates either severe epistaxis with blood draining posteriorly into the oropharynx, or a systemic bleeding disorder requiring immediate laboratory evaluation:
Essential First-Line Labs
Complete Blood Count (CBC) - Assess for anemia from blood loss, thrombocytopenia, or hematologic malignancy that could explain the bleeding 1, 3
Prothrombin Time (PT/INR) - Critical for patients on warfarin or with liver disease; supratherapeutic INR may require reversal agents for severe refractory bleeding 1, 3
Activated Partial Thromboplastin Time (aPTT) - Screens for hemophilia, von Willebrand disease, and other coagulation factor deficiencies 3, 4
Type and Screen - Essential preparation given the bleeding severity and potential need for transfusion 2, 3
Risk-Stratified Additional Testing
If Patient is on Anticoagulation
INR must be checked immediately if the patient takes warfarin, as supratherapeutic levels may require specialty consultation, medication discontinuation, or reversal agents 1
Document use of direct oral anticoagulants (DOACs) or antiplatelet agents (aspirin, clopidogrel), though specific reversal options for DOACs remain limited 1, 3
If Bleeding Disorder is Suspected
Consider additional coagulation studies if the patient has:
- Personal or family history of abnormal bleeding 1, 3
- No prior bleeding history but current severe bleeding (suggests acquired coagulopathy) 3
- Recurrent bilateral epistaxis (consider hereditary hemorrhagic telangiectasia) 1, 2
Additional tests for suspected bleeding disorders:
Von Willebrand factor antigen and activity - For patients with personal/family history of mucosal bleeding 3, 4
Fibrinogen level - Screens for dysfibrinogenemia and disseminated intravascular coagulation 3
Specific factor assays - If aPTT is prolonged, to identify hemophilia or rare factor deficiencies 3, 4
If Systemic Disease is Suspected
Liver function tests (AST, ALT, bilirubin, albumin) - Liver dysfunction impairs synthesis of coagulation factors 1, 3
Renal function (BUN, creatinine) - Chronic kidney disease is a documented risk factor for severe epistaxis and uremic platelet dysfunction 1, 2
Critical Management Considerations
Do not delay first-line local hemostatic measures (compression, cautery, packing) while awaiting laboratory results, as these interventions should be initiated immediately even in the presence of suspected coagulopathy 2, 3
Common Pitfalls to Avoid
Do not assume bleeding is purely local - The combination of nasal and oral bleeding warrants systemic evaluation, as 45% of hospitalized epistaxis patients have underlying systemic diseases contributing to bleeding 1
Do not overlook medication history - 15% of epistaxis patients are on long-term anticoagulation, and antiplatelet agents can cause persistent bleeding 1
Do not forget to assess hemodynamic status - Pallor, tachycardia, hypotension, or orthostatic changes indicate significant blood loss requiring hospital-level care and potential transfusion 1, 2
Interpretation Framework
Normal coagulation studies with severe bleeding - Consider platelet function disorders, von Willebrand disease, or vascular abnormalities requiring specialized testing 3, 4
Isolated prolonged aPTT - Evaluate for hemophilia, von Willebrand disease, or acquired hemophilia 3
Isolated prolonged PT/INR - Consider warfarin effect, vitamin K deficiency, or liver disease 3
Both PT and aPTT prolonged - Suggests disseminated intravascular coagulation, severe liver disease, or multiple factor deficiencies 3