Group v hemorrhagic diseases

HEMORRHAGIC DISEASE OF THE NEWBORN

(HDN)

HEMORRHAGIC DISEASE OF THE NEWBORN

• Hemorrhagic disease of the newborn is a rare bleeding problem that can occur after birth. Hemorrhaging (excessive bleeding) is a potentially life-threatening condition.

• It is often called vitamin K deficiency bleeding, or VKDB; since Vitamin K plays a key role in blood clotting, and most babies are born with low stores of the vitamin in their system.

• vitamin K deficiency there is an impaired production of coagulation factors II, VII, IX, X by the liver. The hemorrhaging is a potentially life-threatening.

CATEGORIES OF HDN

VKDB is categorized according to the timing of first symptoms: – early onset (within 24 hours), which is very rare -

Results of low levels of prothrombin and other vitamin K dependent clotting factors, (Factors II, VII, IX and X) caused by vitamin K deficiency

– classic onset (two to seven days), which is also very rare

– late onset (two weeks to six months) – Immaturity of liver affects production of clotting factors

Abnormal bleeding

Causes of HDN

• Newborns have low vitamin K stores at birth • Vitamin K passes the placenta poorly• The levels of vitamin K in breast milk are low• The gut flora as not yet been developed (vitamin K is

normally produced by bacteria in the intestines).

1) Vit. K deficiency

• Essential for production of active forms of factors II, VII, IX, X and anticoagulants such as protein C & S

• Def d/t– Inadequate intake– Malabsorption ( coeliac dz, cystic fibrosis,

obstructive jaundice)– Vit K antagonists (eg. Warfarin)

2) Liver Disease

• Billiary obstruction impaired vit K absorption l/t decrease synthesis FII,FVII,FIX and X.

• Severe hepatocellular disease, reduced FV, fibrinogen & plasminogen activator.

• Dysfunctional fibrinogen (dysfibrinogenaemia)• Low thrombopoietin production l/t

thrombocytopenia• Hypersplenism associated with portal HTN l/t

thrombocytopenia

Diagnosis• The diagnostic criteria for vitamin K deficiency

bleeding include:• Prolonged prothrombin time (PT)/Elevated international

normalized ratio (INR) (gold standard) • Prolonged activated partial thromboplastin time (aPTT)• Fibrinogen levels and a platelet count within in normal range for

newborns

• The diagnosis is confirmed if the INR normalizes after administration of vitamin K and the bleeding is stopped.

Why Is It Done?• The prothrombin time (PT) and international normalized ratio

(INR) are measures of the extrinsic pathway of coagulation ( INR is a calculation made to standardize prothrombin time. INR is based on the ratio of the patient's prothrombin time and the normal mean prothrombin time)

• PT measures factors I (fibrinogen), II (thrombin), V, VII, and X. • Prothrombin, or factor II, made by the liver. Vitamin K is

needed to make it & other clotting factors.

The prothrombin time can be prolonged as a result of deficiencies in vitamin K, warfarin therapy, malabsorption, or lack of intestinal colonization by bacteria (such as in newborns). In addition, poor factor VII synthesis (due to liver disease) or increased consumption (in disseminated intravascular coagulation) may prolong the PT.

Tests and Exams• Significant bleeding in neonates should prompt clinical

evaluation.

• ‘Initial empirical therapy consists of platelet and/or factor supplementation, which is often administered while diagnostic studies are under way’

• Laboratory evaluation of the hemorrhage in newborns should include

Sepsis evaluation determination of the ( Blood clotting tests) platelet

count, PT, aPTT, TT, and fibrinogen concentration.

Risk factorsVitamin K deficiency causes VKDB. A baby’s risks vary,

depending upon when symptoms occur.Early-OnsetEarly-onset of VKDB occurs within the first 24 hours after

birth. Risk factors include:• mother taking anti-seizure drugs that interfere with

vitamin K metabolism (phenytoin, phenobarbital, caramezepine, or primidone)

• mother taking blood thinning medication such as Coumadin or aspirin

• mother taking antibiotics, such as cephalosporins

Late-OnsetLate-onset is seen in babies up to 2 months old. Risk factors

include:• low levels of vitamin K in breast milk• biliary atresia (slow bile flow)• cystic fibrosis• celiac disease• chronic diarrhea• hepatitis• A1-antitrypsin deficiency (may cause lung and liver disease)

Clinical presentation of HDN

The disease causes an increased risk of excessive bleeding. The most common sites of bleeding are the; – umbilicus– mucous membranes– gastrointestinal tract– circumcision – Venipunctures (puncture in the vein for therapeutic

purpose e.g IV)– Intracranial bleeding can cause brain damage or death.

prevention

Prevention

• Many newborns- deficient in vit. K, whether measured in cord blood or indirectly by measuring the levels of vitamin K–dependent coagulation proteins. Recommends giving every baby a shot of vitamin K immediately after birth. This practice has helped prevent the condition.

• The early onset form of the disease may be prevented by giving vitamin K shots to pregnant women who take anti-seizure medications.(mechanisms by which anticonvulsant drug l/t vit. K deficiency bleeding in neonates :not clearly understood)

• Most infants born to well-nourished mothers have adequate vitamin stores at birth– Vitamin K is naturally produced by intestinal bacteria which newborn’s lack

resulting in the deficiency– Suppression of intestinal bacteria by various antibiotics is responsible for this

deficiency– Infants receive Vitamin K either orally or intramuscularly

The End