Bleeding disorders

How do bleeding disorders occur?

Before talking about the bleeding disorders Let's see what happens when a hemorrhage occurs. When an artery, vein, or capillary is injured or ruptured, a system is activated to plug the leakage of blood through the wound, a process called hemostasis. Haemostasis consists of two phases:

• Primary hemostasis, the interaction that is established between the wall of the affected vessel and platelets, which join together with other substances and create a mesh to try to stop the bleeding; likewise, they secrete a series of substances to attract more platelets and factors that stabilize the structure they create.
• Secondary hemostasis, based on proteins, coagulation factors, which allow the formation of a stable clot in the mesh that the platelets have formed.

Once the bleeding has stabilized or in cases where there is unnecessary clotting, the fibrinolysis system is activated, a mechanism that allows the clot that has been created to be undone when it is no longer necessary.

If there is a disorder either in the platelets or in the coagulation factors, either due to a quantitative deficit or qualitative alterations, hemostasis and coagulation cannot be carried out properly, so there will be an ease for them to occur. bleeding disorders

How are bleeding disorders classified?

The bleeding disorders, depending on their origin, they can be classified as:

•Secondary to thrombocytopenia:

Due to a decrease in platelet production, as in megaloblastic anemia, medullary aplasia, myelodysplastic syndromes, leukemias or Fanconi anemia, among others.

Due to a decrease in the half-life of platelets, due to an increase in their destruction (as in idiopathic thrombopenic purpura) or to an increase in consumption (as in thrombocytopenic thrombotic purpura, haemolytic uremic syndrome or infections).

By a sequestration of platelets, as it happens when the spleen works more than it should (hypersplenism).

• Secondary to a thrombocytopathy:

Bernard-Soulier disease, autosomal recessive inherited disease.

Glanzman's thrombasthenia, also an autosomal recessive inherited disease.

Von Willenbrand disease, which can be congenital or acquired due to various diseases (kidney tumors or lymphoid leukemias and lymphomas).

Acquired by drugs, liver cirrhosis, uremia or myeloproliferative syndromes.

• Secondary to coagulopathies:

X-linked recessive inherited disease.

Disorders due to deficits of other coagulation factors.

Advanced phases of disseminated intravascular coagulation.

Idiopathic thrombopenic purpura (ITP) acutely affects children mainly after a respiratory tract infection; there is a chronic form that affects young people and has a worse prognosis than the acute form. Antibodies are created against the platelets themselves and destroyed by macrophages in the spleen.

Thrombocytopenic thrombotic purpura (TTP) is of unknown cause and is associated with airway infections, oral contraceptives, pregnancy, or lupus. An injury occurs on the inside of the vessel that releases proteins that inhibit platelet aggregation.

In hemophilia, a genetic alteration occurs that leads to a deficiency of coagulation factor VIII, which means that in the event of bleeding, the mechanisms of secondary hemostasis to stop it cannot be established.

In disseminated vascular coagulation (DIC), due to severe generalized infections, certain tumors, autoimmune diseases or severe trauma, excess coagulation and thrombi initially occur, but as platelets and clotting factors are depleted, in advanced stages they give hemorrhages.

Symptoms

Faced with a coagulation defect, either due to alteration of platelets or coagulation factors, the symptoms that will occur will basically be hemorrhages and bruises, of greater or lesser severity depending on the cause of the bleeding disorder.

TTP is associated with hemolytic anemia due to involvement of the capillaries, which cause the red cells to break when passing through them, as well as fever, kidney disorders and neurological involvement. There is another entity, hemolytic uremic syndrome (HUS), where hemolytic anemia and thrombopenia also occur, but renal involvement predominates while neurological alterations are less frequent.

Von Willenbrand disease also presents bleeding disorders, especially ecchymoses and hemorrhages at the ENT level.

In hemophilia, the most common alteration of clotting factors, soft tissue bruising and bleeding occur with any minimal trauma. After surgery, bleeding can be very heavy.

There is an entity called Rendu-Osler-Weber disease, an autosomal dominant hereditary disease that affects capillaries and not platelets or coagulation factors, but this alteration means that, as they are very thin-walled capillaries, they break when minor trauma and platelets have difficulties to adhere, causing repeated bleeding, especially at the nasal, oral, intestinal, genitourinary or respiratory level.

Diagnosis

A bleeding disorder should be suspected in anyone who has bleeding or bruising without traumatic cause or who is excessively abundant in relation to the extent of the traumatic cause. In any case, sometimes alterations in the number of platelets or in clotting factors are detected incidentally in a routine blood test.

In addition to an exhaustive questioning of the patient to assess whether there is a family history of bleeding, a correct physical examination should be performed in search of hemorrhagic lesions on the skin and mucosa, as well as to rule out other pathologies that may lead to an alteration in coagulation, such as lymphadenopathy or other alterations suggestive of autoimmune diseases, anemia, hematological cancerous processes or infections.

In the blood analysis, the total number of platelets will be evaluated, as well as different times that will allow to determine the effectiveness of the coagulation response when a hemorrhage occurs. The main parameters are:

• Bleeding time, which assesses primary hemostasis, that is, platelet response; its alteration usually indicates thrombopenia or von Willenbrand disease.
• Prothrombin time or Quick, assesses one of the coagulation pathways; its alteration is usually due to factor VIII defects.
• Activated partial thromboplastin time or cephalin, assesses another of the two coagulation pathways; its alteration is usually due to factor VIII defects.
• Thrombin time, assesses the final phase of coagulation; its alteration is usually due to factor II (fibrinogen) defects.

Various laboratory and genetic studies will make it possible to determine specific entities or selective deficits of certain coagulation factors.

Treatment

Treatment will be that of the cause of the blood disorder whenever possible. In the case of ITP, treatment with steroids at increasing doses will be started. If they do not work well, a splenectomy or treatment with immunosuppressants can be performed.

In the case of TTP, plasmapheresis will be performed to cleanse the blood of the substances that trigger excessive platelet consumption. Plasmapheresis works well; if not, treatment with corticosteroids, cytostatics, or splenectomy can be attempted.

For the treatment of coagulation factor defects we will give these factors intravenously. In the event of massive bleeding that requires urgent intervention, antifibrinolytics may be administered, substances that prevent the formed thrombus from dissolving to contain the bleeding.

Precautionary measures

There are no preventive measures for inherited bleeding disorders. You can try to avoid certain drugs that can cause blood disorders and especially, in case of suffering from a coagulation disorder, avoid risk situations that may lead to trauma and bleeding.