hand book for dental surgeons - Indian Dental Association ...

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Hand book for dental surgeons on dental management of persons with hemophilia and other haemostatic disorders
HAEMATOLOGY AND HAEMOSTATIC DISORDERS
Normal platelet count is 150000-450000 platelets per microlitre of blood. Symptoms do not arise and
bleeding time remains normal until it is greater than 100000/micro litre. Mild prolongation bleeding time
occurs when it is between 50000-100000/micro litre. Easy bruising manifested by skin purpura occurs after
minor trauma and bleeding after mucous membrane surgery occurs when it is less than 50000/micro litre
Spontaneous bleeding occurs when its value is less than 20000/micro litre. When qualitative platelet
abnormality is present then there is normal platelet count and prolonged bleeding time. Bleeding time over 10
minutes has increased risk of bleeding. Extensive bleeding occurs when bleeding time is greater than 15-20min.
Due to cyclical variation level of V Wb factor occasionally bleeding time may be normal so repeated testing
may be necessary to establish diagnosis.
Plasma coagulation function is readily assessed by partial thromboplastin time (PTT). Prothrombin time
(PT), thrombin time, clot solubility test and clot lyses test.
When there is prolonged partial thromboplastin time ( normal is 25-35 seconds) and no clinical bleeding,
then one could suspect deficiency of factor 12, HMWK, PK. When it is associated, with mild or rare bleeding
then factor 11 deficiency might be present and when there is frequent severe bleeding then deficiency of factor
8 & 9 should be suspected. Prolonged prothrombin time (normal is 10-15 sec) indicates deficiency of factor 7,
vitamin k (early) or warfarin ingestion. When PT & PTT both are prolonged, it indicates deficiency of factor 2,
5 & 10, vitamin k (late) or warfarin ingestion.
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Hand book for dental surgeons on dental management of persons with hemophilia and other haemostatic disorders