Vitamin K deficiency is a pathological condition characterized by a decrease in the content of vitamin K in the body. The main clinical manifestations are due to the deterioration of blood clotting function – nosebleeds, hemorrhagic rashes on the skin, hemorrhages in internal organs. In women, menstruation becomes abundant. The diagnosis is made on the basis of symptoms, anamnestic data, coagulogram, laboratory confirmation of vitamin deficiency. Treatment is carried out by the administration of vitamin K preparations. Patients with severe bleeding are prescribed plasma transfusion, coagulation factors, and hemotransfusion.
ICD 10
E56.1 P53
Meaning
Vitamin K (antihemorrhagic) is a fat–soluble vitamin necessary for the synthesis of blood clotting factors (proconvertin, prothrombin, IX, X factors). It is also involved in the formation of bone tissue proteins (osteocalcin), proteins of the blood anticoagulation system (protein C and S). There are two natural forms of vitamin: phylloquinone, which enters the human body with food (green leafy vegetables, vegetable oils, liver) and menaquinone, which is produced by intestinal bacteria. Therefore, even with a very poor diet, hypovitaminosis is usually not observed, since the intestinal microflora covers the daily need for vitamin.
Causes
The lack of vitamin itself (true vitamin K deficiency) is quite rare. A much bigger problem is the so-called functional vitamin K deficiency, which develops during the use of indirect anticoagulants (vitamin K antagonists). Etiological factors of hypovitaminosis:
- Intestinal dysbiosis. Most often, vitamin K deficiency occurs due to the death of normal intestinal microflora caused by taking medications – antibiotics, sulfonamides. Antibiotics from the penicillin group have a particularly detrimental effect on vitamin-producing bacteria.
- Taking anticoagulants. The main drug that blocks the conversion of vitamin K into the active form, which is involved in the synthesis of clotting factors, is warfarin. It is prescribed for the treatment of diseases accompanied by the formation of blood clots (atrial fibrillation, heart defects). However, if it is used incorrectly, an overdose may occur, which leads to dangerous massive bleeding.
- Diseases of the gastrointestinal tract. Diseases of the liver and biliary tract (cholecystitis, cirrhosis) predispose to hypovitaminosis. This is due to the fact that the absorption of fat-soluble vitamin requires the presence of bile acids in the intestine, as well as the fact that the main reserves of vitamin are in the liver. With intestinal pathologies (celiac disease, Crohn’s disease), the absorption of various nutrients, including vitamins, worsens.
Risk factors include the newborn period, since at this time the intestines are just beginning to be populated with bacteria synthesizing vitamin K. Moreover, children who eat breast milk are more susceptible to hypovitaminosis than those who receive formula milk. This is due to the fact that many artificial mixtures, unlike mother’s breast milk, contain a sufficient amount of vitamin K.
Pathogenesis
A decrease in the content of vitamin in the blood (or its active form) leads to a decrease in the synthesis of coagulation factors. As a result, the cascade of reactions of blood clot formation is blocked, the stability of the vascular wall worsens, and there is a very high risk of bleeding. Vitamin deficiency is also accompanied by suppression of osteoblast production of osteocalcin, the main non–collagenic component of the organic matrix of bone tissue.
Osteoporosis occurs, which increases the likelihood of fractures. The complexity of the pathogenetic mechanisms of vitamin K deficiency lies in the fact that, in addition to inhibiting the coagulation system, there is a decrease in the concentration of endogenous anticoagulants – protein C,S. Therefore, under certain circumstances, two opposite phenomena can be combined – bleeding and thromboembolic complications.
Classification
According to the degree of bleeding, there are mild, moderate and severe vitamin K deficiency. The hemoglobin level is taken as the criterion (respectively 90-120 g / l, 60-90 g/ l, below 60 g/ l) There is also a special, very rare form of hypovitaminosis in young children – hemorrhagic disease of newborns (HDN). There are the following forms of HDN:
- Early. The most rare variety. Develops as a result of the mother taking warfarin during pregnancy. Manifests in the first 24 hours of a child’s life.
- Classic. A typical form of HDN. The main reason is the insufficient intake of milk. Bleeding appears on 2-7 days.
- Late. The heaviest type of HDN. Occurs in children under 6 months of age with congenital cholestatic diseases or inflammatory bowel pathologies.
Symptoms
The clinical picture consists mainly of hemorrhagic syndrome. There are nosebleeds, bleeding gums. The skin is covered with various elements (petechiae, ecchymoses, hematomas). Hemarthrosis is not uncommon with minor injuries. It is characterized by the development of bleeding a few days after surgical operations (especially when removing a tooth).
With the loss of a large volume of blood, a person begins to worry about the symptoms of low blood pressure (dizziness, flashing flies in front of his eyes, palpitations), he may lose consciousness. In women, menstruation becomes more abundant, prolonged. Hypovitaminosis is especially severe in newborns with a very high frequency of internal hemorrhages (pulmonary, gastrointestinal, intracranial).
Complications
There are mainly mild and moderate vitamin K deficiency. Adverse events are mainly associated with bleeding. Severe life-threatening complications (hemorrhagic shock) in the case of “true” vitamin K deficiency in adults practically does not develop. High death rates are observed in the case of intracerebral hemorrhage in the late form of hemorrhagic disease of newborns (30-50%).
The mortality rate in patients with insufficiency of active vitamin K while taking warfarin is about 1.5%. Functional vitamin deficiency is very rare (0.3%) in the first days of warfarin treatment can cause “paradoxical thrombosis” due to suppression of protein S and C synthesis (endogenous anticoagulants). Osteoporosis contributes to the fracture of the limbs, even with a minor injury.
Diagnostics
Patients with hypovitaminosis are treated by internists or hematologists. Cases of HDN are dealt with by neonatologists. During a general examination of the patient, the degree of pallor of the skin and mucous membranes is assessed. During auscultation, a systolic murmur is heard at the apex of the heart. Anamnestic data are important (taking medications, mentioning the presence of chronic diseases of the gastrointestinal tract). Additional examination includes:
Blood tests. In the general blood test, signs of posthemorrhagic anemia are detected – a decrease in the level of erythrocytes, hemoglobin, and a high content of reticulocytes. The coagulogram shows an elongation of blood clotting time, prothrombin time, and a decrease in the prothrombin index. An increase in international normalized relations (INR) is characteristic. Determination of the concentration in the blood of vitamin K itself is rarely performed.
Instrumental research. In case of suspicion of internal bleeding, imaging methods of examination are prescribed in order to identify its source. These include fibrogastroduodenoscopy, pelvic ultrasound, pleural cavities, as well as computed tomography of the brain, bronchoscopy.
Differential diagnosis of vitamin K deficiency is performed with other diseases accompanied by hemorrhagic syndrome – thrombotic thrombocytopenic purpura, immune thrombocytopenia, disseminated intravascular coagulation syndrome. Hemorrhagic disease in newborns should be distinguished from hereditary coagulopathies – hemophilia, Willebrand disease, Randu-Osler disease.
Treatment
Depending on the severity, patients can be treated both outpatient and inpatient in the department of therapy or hematology. The main indicators for determining the severity of the patient’s condition are hemoglobin level, shock index (the ratio of heart rate per minute to systolic blood pressure). Patients with pronounced signs of hemorrhagic shock are taken to the intensive care unit.
Conservative therapy
The basis of pathogenetic treatment is parenteral administration of vitamin K (phytomenadion). With mild bleeding, this is enough. With a more pronounced hemorrhagic syndrome, accompanied by moderate hypotension, freshly frozen plasma, coagulation factors (a concentrated preparation of the prothrombin complex, cryoprecipitate) are additionally injected. In case of massive bleeding, blood transfusions, washed or thawed erythrocyte mass are carried out.
To combat external bleeding, the use of a hemostatic sponge, the application of bandages with fibrin, thrombin is effective. If the bleeding has developed against the background of the use of warfarin, then it must be canceled. After stabilization of the patient, it is necessary to resume taking warfarin, starting with minimum dosages, under the control of INR, or replace it with another anticoagulant (dabigatran, rivaroxaban).
Surgical treatment
Surgical intervention is necessary for massive internal hemorrhage. In case of bleeding from the upper gastrointestinal tract or lungs, endoscopic hemostasis is used by laser or cryocoagulation. In the case of hemothorax, a puncture of the pleural cavity and evacuation of hemorrhagic contents is performed. With intracranial hemorrhage, the skull is trepanated and the hematoma is removed.
Prognosis and prevention
Vitamin K deficiency in the vast majority of cases is a benign condition. Serious complications are rare. After parenteral administration of vitamin, plasma transfusion, recovery quickly occurs. A threat to life is a functional insufficiency (suppression of activity) of vitamin while taking warfarin. A very high percentage of mortality is observed in patients with a late form of HDN (from 30 to 50%). For prevention, it is recommended to take preventive doses of vitamin K during the course of treatment with antibiotics, a diet using foods rich in vitamin K during pregnancy. People taking warfarin should regularly check the INR indicator in the coagulogram for timely dose adjustment.