Posts Tagged ‘screening test’

Impact-R as Screening Test for Hemophilia A

Thursday, January 5th, 2012

Impact-R, a cone and plate analyzer for platelet adhesion and platelet aggregation may be utilised as a screening test for bleeding disorders such as Hemophilia A.

What is Hemophilia A?

Hemophilia A is a blood disorder that causes prolonged bleeding due to a deficiency of blood clotting Factor VIII.

Hemarthrosis of the elbow joint.

Symptoms are spontaneous bleeding, bruising, blood in the urine, gastrointestinal bleeding, epistaxis, prolonged bleeding from cuts and following surgeries such as circumcision and dental extraction, hemarthroses or bleeding into joints such as the knee. Symptoms may not be apparent in infants but will soon show when the baby starts to crawl or walk. Severity of the symptoms may vary. Major bleeding could be fatal such as those that happen if the patient is involved in a motor vehicular accident or sports-related injuries.

Hemophilia A is a hereditary disorder that is X-linked recessive. The disease manifests only in males because of their single X chromosome, whereas, females have two X-chromosomes. Very rarely, females manifest the disease if both X chromosomes are affected. This happens when the father is a haemophiliac and the mother is a carrier. Affected males mated to non-carriers will have male offspring that do not have the disease and female offspring that are carriers. Carrier females mated to un-affected males will have 50% chance of having male children with the disease and 50% chance of having female children who will be carriers.

The Use of Impact-R

Impact-R could be of use as a bedside screening test in children whose mothers have male relatives that have Hemophilia. It is a simple and rapid test that can determine defects in coagulation affecting platelet function. Studies have to be done, however, to determine the positive and negative predictive value of Impact-R as a screening test for Hemophilia A.

Impact-R as Screening Tool for Bleeding Disorders in Children

Sunday, December 25th, 2011

What is a screening test? It is a device used to detect disease or a precursor of a disease in persons who do not have signs and symptoms. The decision to screen should be based on a careful history and assessment of risk factors.

Children with a family history of bleeding disorders may well benefit from a

Alexei Nikolaevich, heir to the Russian throne, had Hemophilia B.

screening test. The child’s future health and quality of life will depend on the diagnosis of a serious medical condition ahead of the time when signs and symptoms manifest. Children with a family history of congenital platelet function defects, clotting factor deficiencies, and defects in primary or secondary aggregation are among those that will put a screening test to good use.

A study by Revel-Vilk, evaluated the use of the Impact-R as a one such screening test. They concluded that the Impact-R is highly effective in excluding a bleeding disorder in patients with normal result. However, in case of abnormal Impact-R results, further testing is necessary to diagnose the condition.