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 using 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 VIII activity.
To ensure effective hemostasis in the most frequent complications of hemophilia (hemarthrosis, renal, gingival and nasal bleeding), as well as when removing teeth, the content of factor VIII in plasma should be not less than 20% of activity, with intermuscular hematomas, gastrointestinal bleeding, fractures, trauma - not less than 40% of activity, with most surgical interventions not less than 70% of activity.
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 preparation is administered in the amount of 1 unit per 1 kg of the body weight of the patient, the content of the factor VIII in the blood on average by 1%, according to the formula:
X = Y x Z / 100, where
X is the 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 stoppage of bleeding, the administration of the drug to patients with hemophilia is carried out at intervals of 12-24 hours and in a dose providing an increase in the content of factor VIII by not less than 20% of activity.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 before the operation. 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 further postoperative period to maintain hemostasis, it is sufficient to increase the content of factor VIII to 20% of the activity of the factor VIII.
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.