[Practical approaches for surgical procedures in congenital factor VII deficiency]

A 33 year old female with a congenital deficit in factor VII underwent four operations, all without any haemorrhage. One of then was carried out using substitutive therapy. She had a non-A non-B hepatitis one month after this treatment. Substitutive therapy depends on the assessment of the risk of haemorrhage, which can be estimated by the concentration of factor VII, the severity of spontaneous haemorrhage, the surgical history, and the planned operation. Since the risk of transmitting viruses with freeze-dried blood products would appear to be virtually nil, since 1985, fresh frozen plasma should be avoided for this type of indication. The doses of concentrated factor VII to be used lie between 20 IU.kg-1 every 4 h and 40 IU.kg-1 every 8 h. Such a dose should be administered in either one or several injections, according to whether the risk of haemorrhage is important or not. Substitutive therapy should be continued as long as the risk persists. Using a test dose of factor VII and, afterwards, measuring its biological activity can help to determine the best time for starting the treatment in order to obtain a level of factor VII greater than the minimum required for surgical haemostasis (10%).