Coagulation Cases Mike Webb Division of Clinical Hameatology 1 March 2010
Jan 11, 2016
Coagulation Cases
Mike WebbDivision of Clinical Hameatology
1 March 2010
• So what does it take to make a healthy blood clot? – Platelets – The blood vessels themselves – Clotting factors
Good vs bad• Healthy blood clot:
– At the site of a broken blood vessel, the point of injury. – A healthy clot stays put and does not cause a runaway clotting episode. – A healthy clot knows when it's time to dissolve.
• Pathological clot: – It causes vascular narrowing or outright occlusion.– Often inappropriately forms– It may embolize.
Evaluation of haemostasis
• History:• Site• Recent onset vs. life-long pattern. • Alcohol consumption. • Use of NSAIDs.• Males and females equally affected? • Grandparents? • Does it skip a generation? • Bad arthritis of the ankles or knees in a male grandparent
may indicate a clotting factor problem (IX or VIII).
Plt vs factor
Laboratory Evaluation of Hemostasis
Laboratory Evaluation of Hemostasis
• FBC and smear• PT/PTT• Plt function• Specialized tests• Quality of the blood specimen
• Volume• Clot• Hemolyzed
Platelets number vs function
PT/PTT:
Simple!!PTT = XII, XI, IX, VIIIPT = VII
Common = I,II,V,X
• PTT = XII, XI, IX, VIII
PT = VII
Common = I,II,V,X
Prolonged PT or PTT
• Not enough of a single or combination of factors.
• Does NOT tell you why.
Why?
1. DeficencyCongenital
Factor VIII, IX
Acquired Liver dieaseWarfarin
2. InhibitorLupusHeparinAcquired Ab vs VIII, IX
Defn vs Inhibitor:Mixing studies
Which factor?
PTT = XII, XI, IX, VIII
PT = VII
Common = I,II,V,X
Tommy active four-year old
• Scalp wound that won't heal. • Bled more than expected from his circumcision. • The mother's father had terrible arthritis of his knees and
ankles: – He was wheelchair-bound by the age of 45. – Died of a 'bleeding ulcer' at age 51.
• Physical exam – normal except for scalpwound.
• Lab results• FBC - normal • PT = 11 sec (ref = 10 - 15sec) • PTT = 54 sec (ref = 25-36sec)
PTT = XII, XI, IX, VIII
PT = VII
Common = I,II,V,X
What do we know?
• Diagnosis?• Special investigations?
Hemophilia
• Congenital defn of either• VIII = A• IX = B
• A usually more common and severe• Both VIII and IX deficiencies are sex-linked
recessive traits.
Mode of inheritance:
Forty-eight year-old man with ease of bruising.
• Mr. BA complains of ease of bruising• He was fine until about 8 months ago. • FBC normal with round macrocytes.• PT is 18 sec (N=10-15) • aPTT is 48 sec (N= 25 - 36)
PT/PTT prolongedPTT = XII, XI, IX, VIII
PT = VII
Common = I,II,V,X
Both PT and PTT prolonged??
• Diagnosis • Special Investigations
Results
Tiffany is a 15 year-old girl with a rash
Her mom says she had a cold about 2 weeks ago. – She was fairly sick with upper respiratory symptoms
for about 3 days. – She improved quickly, and returned to school.
• Now she has a 'rash' from navel down both legs. • Today, she is otherwise healthy and is afebrile. • Tiffany has a little sister who is well. • No one else in the family is sick. • Exam NAD but for rash
Rash on legs
• Lab tests– PT = 11 seconds (ref = 11.4 seconds) – aPTT = 29 seconds (ref = 23 - 32 seconds)
• FBC• WCC – 8• Hgb – 13 • Plt – 9 (N = 150-450)
Viral exanthem vs. petechiae?• Tiffany's spots are regional, not all over her body. • In fact, they seem gravity dependent. • They vary slightly in color from red to blue-brown.
Mrs. KL 28 yr old teacher complains of ease of bruising
• Bleeds excessively with dental procedures • She also has menorrhagia • She claims if she takes just one aspirin, she will
bruise for a week. • Her family history is significant for bleeding
problems. – Some of her relatives, both male and female, have a
bleeding tendency. – She's very concerned because an aunt supposedly
died in childbirth from a hemorrhage.
Lab results
• PT = 11.2 seconds (ref = 10-15) • aPTT = 42 seconds (ref = 25-36) • FBC - normal• Factor VIII (enzymatic)
– 45% (ref 50-150%)
von Willebrand disease • VWD - most common inherited bleeding disorder. (1% of population)• Abnormality in quantity or quality of vWF
• Binds platelets to endothelium• Protects Factor VIII from degredation
vWD
• Symptoms are very mild or lack of recognition (heavy menstrual bleeding)
• Bleeding symptoms:– Easy bruising – Skin bleeding – Prolonged bleeding from mucosal surfaces
• May mimic hemophilia• Ingestion of aspirin or NSAIDS may precipitate bleeding
vWD
• Lab tests:• Normal FBC• Normal PT• Normal or prolonged PTT• Specialized tests
• von Willebrand factor • vWF Antigen: decreased • Ristocetin cofactor activity• Platelet aggregation to Ristocetin
50 yr old man for hip replacement
• On heparin pre-op for DVT prophylaxis• Malena stool and epigastic pain• FBC – normal• PT – 18 (N-10-15sec)• PTT >180 (N- 25-36sec)
???
Treatment?
• Stop heparin!• Antidote – protamine sulphate
Tommy Late bleeder
• Known with haemophilia A• 28 yrs old presents with painful knee• No improvement to factor replacement
• Mixing studies• PT 14 (10-15sec)• PTT 105 to 104 (25-36sec)• Factor VII = 2%• NOW WHAT???
Late bleeder
PTT = XII, XI, IX, VIII
PT = VII
Common = I,II,V,X
Normal FBC,PT/PTT
• vWD• Plt dysfunction• Vasculitis
Prolonged PTT (normal PT)
• Intrinsic pathway abn:– Hemophilia– vWD– Heparin– Lupus anticoag– Auired inhibitors
Prolonged PT (normal PTT)
• Extrinsic pathway:– Vit K defn– Liver disease
Prolonged PT and PTT
• Combined defn• Warfarin• Heparin• DIC• Liver disease• Deficency / inhibitor of common pathway