Case challenges in hemostasis (Proceedings)
Bleeding disorders can pose diagnostic challenges, but a logical approach to testing for bleeding disorders can simplify the process. We'll go through some cases we've encountered and how the laboratory tests have helped determine the cause of the bleeding disorder.
• 9 year old neutered male Labrador• Presented for epistaxis and hemoptysis
• 5 month old female Great Pyrenees
• Presented for anorexia, lethargy, gingival bleeing and epistaxis
• 9 year old Jack Russell Terrier
• Presented for 3 days history of wheezing, coughing and decreased eating and drinking.
• 10 year old neutered male Welsh corgi
• Presented with dyspnea, lethargy, anorexia
• 9 year old spayed female Doberman Pinscher
• Presented with epistaxis for 1 day. Had been given one aspirin that morning.
• 4 year old spayed female Great Dane
• Presented with bleeding gums, hyphema in left eye
• 9 year old spayed female golden retriever
• Presented for lethargy, anorexia and a mass at the elbow.
Approach to diagnosis of a bleeding disorder
A pertinent history should include
• Frequency, duration, severity of progression
• Age at onset, breed, inherited/acquired
• Type of hemorrhage and location
• Environmental factors
• Drug therapy
• Presence of underlying disease that could compromise hemostasis
• Type and sites of bleeding should be considered carefully
• Small, focal hemorrhage (petechiae) in the skin and mucous membranes suggest vessel wall defect, platelet defects or von Willebrand disease. Ecchymosis can be observed in both platelet and coagulation defects.
• Deep hemorrhages in body cavities or muscle (hematoma) suggests coagulation factor deficiency.
• Massive bleeding from a single site without a history of a previous bleeding episode or purpura is more suggestive of a surgical or anatomic defect rather than a coagulation disorder.
Laboratory evaluation of a bleeding disorder
Sodium citrate (light blue top tube) is the anticoagulant of choice for PT and PTT
• Use 9 parts whole blood: 1 part sodium citrate. Tubes must be filled to the fill line or results will be artifactually altered
• Samples should be kept refrigerated and centrifuged within 60 minutes, plasma collected and tested within 2 hours or frozen.
• EDTA is the anticoagulant of choice for platelet counts.