Introduction And Pathophysiology
- Vitamin K deficiency bleeding (VKDB) was formerly known as hemorrhagic disease of the newborn.
- Vitamin K acts as an essential co-factor for the synthesis and activation of coagulation factors II, VII, IX, and X, as well as proteins C and S.
- Neonates have critically low levels of vitamin K at birth.
- This deficiency is attributed to poor placental transfer and low vitamin K content in breast milk.
- Additionally, the neonatal gut is sterile, lacking the normal bacterial flora that synthesize vitamin K.
- Neonates also exhibit poor intestinal absorption of vitamin K and reduced activity levels of the vitamin K epoxide reductase enzyme,.
Classification And Clinical Presentation
- VKDB is classified into three distinct syndromes based on the time of onset and underlying etiology.
- Prolonged, difficult to control bleeding in a relatively well baby is a hallmark of VKDB.
| Type of VKDB | Time of Onset | Causes and Risk Factors | Common Sites of Bleeding | Specific Treatment Considerations |
|---|---|---|---|---|
| Early | First 24 hours after birth | Maternal exposure to medications (anticonvulsants, antibiotics, antitubercular drugs) | Cephalhematoma, umbilical stump, intracranial | Consider FFP for clinical bleeding; Vitamin K alone is usually not effective,. |
| Classic | 1 to 7 days after birth | Lack of prophylactic vitamin K at birth; poor breastfeeding | Gastrointestinal, mucocutaneous, post-circumcision, umbilical stump; rarely intracranial | Parenteral Vitamin K; consider FFP for active clinical bleeding. |
| Late | 1 to 8 weeks after birth | Fat malabsorption (e.g., biliary atresia, alpha-1-antitrypsin deficiency); liver and GI disorders | Gastrointestinal, mucocutaneous, intracranial | Parenteral Vitamin K; consider FFP for clinical bleeding; Recombinant factor VIIa for mild cases,. |
Diagnosis
- Coagulation profiles typically reveal a prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT),.
- The aPTT may occasionally remain normal in the early stages of the deficiency.
- The international normalized ratio (INR) is frequently elevated to values greater than 4.
- Proteins induced by vitamin K absence (PIVKA) are sensitive biomarkers utilized to confirm vitamin K deficiency.
- Diagnosis is clinically confirmed by the rapid normalization of PT within 30 to 60 minutes following a vitamin K injection.
Prevention
- Universal prophylactic administration of vitamin K is recommended immediately after birth for all neonates to prevent VKDB.
- Neonates weighing more than 1500 g should receive a single intramuscular (IM) dose of 1 mg within 6 hours of birth,.
- Preterm infants weighing less than 1500 g should receive a dose of 0.3 mg/kg to 0.5 mg/kg intramuscularly.
- Intravenous (IV) vitamin K is not recommended for routine prophylaxis in preterm infants.
- Currently available oral vitamin K preparations are not recommended for prophylaxis.
Management
Vitamin K Administration
- Active bleeding requires prompt administration of intravenous Vitamin K1 at a dose of 1 to 2 mg,.
- Alternatively, a dose of 250 to 300 µg/kg (up to a maximum of 10 mg) of intravenous vitamin K can be given without delay.
- The intravenous dose must be administered slowly and should not exceed a rate of 1 mg/minute.
- Avoid the intramuscular route in actively bleeding neonates to prevent excessive hematoma formation.
- The subcutaneous route may be utilized if intravenous access is difficult to secure.
- Clinical bleeding typically decreases within 20 minutes of the injection, with clotting factors rising near normal within 2 hours.
Blood Product Transfusion
- Fresh frozen plasma (FFP) is indicated for life-threatening hemorrhage or severe intracranial bleeds,.
- The recommended dose for FFP is 10 to 20 mL/kg to provide immediate replacement of coagulation factors,.