Vitamin K deficiency bleeding (VKDB) in infancy

Terminology. Replace the term "Hemorrhagic Disease of the Newborn" (HDN) by "Vitamin K Deficiency Bleeding" (VKDB), as neonatal bleeding is often not due to VK-deficiency and VKDB may occur after the 4-week neonatal period. D efinition. VKDB is bleeding due to inadequate activity of VK-dependent coag ulation factors (IT, VII, IX, X), correctable by VK replacement. Diagnosis. In a bleeding infant a prolonged PT together with a normal fibrinogen leve l and platelet count is almost diagnostic of VKDB; rapid correction of the PT and/or cessation of bleeding after VK administration are confirmative. W arning signs. The incidence of intracranial VKDB can be reduced by early re cognition of the signs of predisposing conditions (prolonged jaundice, fail ure to thrive) and by prompt investigation of "warning bleeds". Classificat ion. VKDB can be classified by age of onset into early (<24 h), classical ( days 1-7) and late (>1 week <6 months), and by etiology into idiopathic and secondary. In secondary VKDB, in addition to breast feeding, other predisp osing factors are apparent, such as poor intake or absorption of VK. VK-Pro phylaxis: Benefits. Oral and intramuscular VK (one dose of 1 mg) protect eq ually well against classical VKDB but intramuscular VK is more effective in preventing late VKDB. The efficacy of oral prophylaxis is increased with a triple rather than single dose and by using doses of 2 mg vitamin K rather than 1 mg. Protection from oral doses repeated daily or weekly may be as h igh as from i.m. VK. VK-Prophylaxis: Risks. VK is involved in carboxylation of both the coagulation proteins and a variety of other proteins. Because of potential risks associated with extremely high levels of VK and the poss ibility of injection injury, intramuscular VK has been questioned as the ro utine prophylaxis of choice. Protection against bleeding should be achievab le with lower peak VK levels by using repeated (daily or weekly) small oral doses rather than by using one i.m. dose. Breast feeding mothers taking co umarins. Breast feeding should not be denied. Supervision by pediatrician i s prudent. Weekly oral supplement of 1 mg VK to the infant and occasional m onitoring of PT are advisable. Conclusion.. VKDB as defined is a we but ser ious bleeding disorder thigh incidence of intracranial bleeding) which can be prevented by either one i.m. or multiple oral VK doses.