The solution of cryoprecipitate is used taking into account the compatibility of ABO blood groups. A bag of frozen cryoprecipitate solution for thawing is placed in a water bath at a temperature of 35-37 ° C. The drug dissolves completely at this temperature for 7 minutes. The resulting yellowish solution should not contain flakes and should be used immediately after dissolution. The drug is injected intravenously slowly with a syringe or a transfusion system with a disposable filter.
The dose of cryoprecipitate depends on the initial content of factor VIII in the patient's blood, the nature and localization of bleeding, the degree of risk of surgical intervention, the presence of a specific inhibitor in the patient's blood that can neutralize the activity of factor VIII. The dose of cryoprecipitate is expressed in units of factor activity VIII.
To ensure effective hemostasis in the most frequent complications of hemophilia (hemarthrosis, kidney,gingival and nasal bleeding), as well as when removing teeth, the content of factor VIII in the plasma should be not less than 20%, with intermuscular hematomas, gastrointestinal bleeding, fractures, trauma - no less than 40%, with most surgical interventions not less than 70% .
The number of doses of cryoprecipitate necessary to increase the concentration of factor VIII in the blood to a predetermined level is calculated taking into account that when the drug is administered in the amount of 1 unit per kg of body weight, the patient increases the factor VIII content in the blood by an average of 1%, according to the formula:
X = Y x Z / 100, where
X - dose of cryoprecipitate; Y - body weight of the patient in kg; Z - the necessary content of factor VIII in the blood of the patient, 100 - the minimum content of factor VIII in units of activity in a single dose.
After complete stopping of bleeding, the administration of the drug to patients with hemophilia is carried out at intervals 12-24 hour and in a dose providing an increase in the content of factor VIII by at least 20%. Such treatment is continued for several days until the complete relief of inflammatory changes or a visible decrease in the size of the hematoma.
In surgical interventions, the haemostatic dose of the drug is administered 30 minutes prior to surgery. With massive bleeding, the blood loss is compensated.The cryoprecipitate solution is reintroduced at the end of the operation at a dose equal to half the original dose. Within 3-5 days after the operation it is necessary to maintain the concentration of factor VIII in the patient's blood in the same range as during the operation. In the subsequent postoperative period, to maintain hemostasis, it is sufficient to increase the content of factor VIII to 20%.
The duration of hemostatic therapy is in most cases 7-14 days and depends on the nature of the surgical intervention, the localization of bleeding, and reparative tissue features.