Pathology Cheat Sheet
Find Consumption or Deficiency
DIC and vitamin K deficiency for NEET-PG: consumption coagulopathy, D-dimer, schistocytes, factors II VII IX X, prolonged PT, and newborn haemorrhage.
MedNext Academy | 3 min read
Find Consumption or Deficiency
DIC and vitamin K deficiency for NEET-PG: consumption coagulopathy, D-dimer, schistocytes, factors II VII IX X, prolonged PT, and newborn haemorrhage.
Disseminated intravascular coagulation and vitamin K deficiency, two acquired coagulopathies with characteristic laboratory patterns.
High-yield lines
- Disseminated intravascular coagulation is widespread activation of coagulation causing microthrombi and consumption of platelets and factors.
- DIC is triggered by sepsis, obstetric emergencies, malignancy, and massive trauma.
- DIC causes simultaneous thrombosis and bleeding as clotting factors are consumed.
- Laboratory findings in DIC are low platelets, prolonged PT and aPTT, low fibrinogen, and raised D-dimer.
- The peripheral smear in DIC shows schistocytes from microangiopathic haemolysis.
- Raised D-dimer reflects fibrin degradation and is a key marker of DIC.
- Vitamin K is required to gamma-carboxylate clotting factors II, VII, IX, and X and proteins C and S.
- Factor VII has the shortest half-life, so the prothrombin time is affected earliest in vitamin K deficiency.
- Vitamin K deficiency prolongs the prothrombin time first and later the aPTT, with a normal platelet count.
- Causes of vitamin K deficiency include newborn status, malabsorption, biliary obstruction, and warfarin.
- Haemorrhagic disease of the newborn results from physiological vitamin K deficiency and is prevented by neonatal vitamin K.
- Warfarin inhibits vitamin K epoxide reductase and reproduces the vitamin K deficiency pattern.
Mapped competency codes
- PA21.4
- PA21.5
Continue into the full chapter
This summary maps to PA21-hemorrhagic-disorders.
Frequently Asked Questions
What are the laboratory findings of DIC?
Low platelet count, prolonged prothrombin time and aPTT, low fibrinogen, elevated D-dimer, and schistocytes on the blood smear.
Which clotting factors depend on vitamin K?
Factors II, VII, IX, and X, along with the anticoagulant proteins C and S, all of which require vitamin K for gamma-carboxylation.
Why does the prothrombin time prolong first in vitamin K deficiency?
Because factor VII, part of the extrinsic pathway measured by the prothrombin time, has the shortest half-life and falls earliest.
How is haemorrhagic disease of the newborn prevented?
By routine administration of vitamin K to newborns, correcting the physiological vitamin K deficiency of early infancy.
Continue reading
Cheat SheetsAll Pathology cheat sheets
Browse the complete authored set for this subject.
Open the complete revision pathway
Explore clinician-written learning resources, structured revision and practice across the MedNext platform.
Open in the MedNext appSee plans

