Vitamin K Deficiency – Step 2 CK Exam
Vitamin K deficiencies are most commonly seen in critically ill patients who are NPO and on antibiotics.
- A co-factor in the synthesis of factors 2,7,9, and 10
- Also a co-factor for protein C and S in the liver
- The best sources of vitamin K are leafy green veggies
- Vitamin K is synthesized by intestinal bacterial flora
CAUSES OF DEFICIENCY:
- Broad Spectrum Antibiotics – Suppression of the gut flora
- Patients on TP nutrition – Occurs unless vitamin K is added to nutrition
- Fat soluble vitamin malabsorption – In small bowel disease, irritable bowel syndromes, and obstructive jaundice
- Warfarin – A vitamin K antagonists which cause the production of inactive clotting factors
- HEMORRHAGE – This may develop into serious, life-threatening bleeds
- PT PROLONGATION – Initially the PT is prolonged (because factor 7 has the shortest half-life at 3-5hrs), and as the other factors diminish the PTT will be prolonged.
- REPLACE VITAMIN K – The PT will normalize within a few days
- FRESH FROZEN PLASMA – Should be transfused in a severe bleeding condition and when situation is an emergency