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
Clinically reviewed by Dr Shameer Deen, MBBS, MS, MRCS
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.
Inside MedNext for this topic
- 35 chapters in Pathology
- 5,500+ MCQs
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Cheat SheetsAll Pathology cheat sheets
Browse the complete authored set for this subject.
Open the complete revision pathway
You have scanned the cheat sheet. Now test whether the key facts stuck with a quick recall quiz on this topic.
Test this topicBrowse all cheat sheets