Vitamin K deficiency

Question 1

Where is there bleeding in hemorrhagic disease of the newborn?

Answer 1

unexpected bleeding often with GI hemorrhage, ecchymosis, intracranial hemorrhage

Question 2

Types of vit k deficiency?

Answer 2

o Early onset: first 24 hr post-birth
- associated with maternal meds that inhibit vitamin K activity (AEDs)

o Classic: 2-7 days
- low intake of vitamin K

o Late onset: 2-12 weeks, up to 6 months

• chronic malabsorption and low vitamin K intake
• Occurs almost exclusively in breastfed infants
• manifests predominantly as intracranial hemorrhage (50% chance)
• IV/IM vitamin K doesn’t completely protect infants from classic VKDB (especially if breastfed and oral vit K intake low)

Question 3

Preterm infants higher risk for VKDB due to:

Answer 3

• hepatic immaturity

- delayed gut colonization with microflora

Question 4

What does IM vitamin K prevent?

Answer 4

Early and classic VKDB

Question 5

Dosing of IM vitamin K?

Answer 5

o =<1500g: 0.5 mg
o >1500g: 1.0 mg
o within 6 hours of birth after initial stabilization and appropriate maternal/newborn interaction

Question 6

What do you do about parents who refuse IM vitamin K?

Answer 6

1. Counsel on serious health risks of VKDB
2. If still decline, recommend PO vit K 2.0 mg at time of first feeding, 2-4 wk, and 6-8 wk
   o Advise parents:
    PO vit K less effective than IM vit K (IM vit K may have better storage and slow release)
    make sure infant receives all follow-up doses
    Infant remains at risk for late VKDB (potentially with intracranial hemorrhage) despite use of PO vitamin K

Question 7

What can you provide for vitamin K prophylaxis in infants in the ICU?

Answer 7

single IV dose of 0.2 mg IV may not be as protective as 0.2-0.5 mg IM

• however, preferrably IM (there may be sustained release from the muscle following IV which leads to faster clearance)