The Jehovah’s Witnesses are a religious group founded in the USA in the 1870s. There are an estimated 145,000 Jehovah’s Witnesses in the UK. They refuse all blood and usually all blood products. These patients allow blood to be retransfused if it has not lost contact with the circulation (e.g. bypass). In the case of children, doctors can apply to the courts for permission to give blood against the parent’s wishes. In an emergency, blood can be given to children without consulting the courts. Children under the age of 16 can consent to blood but cannot refuse it.
Management of anaesthesia for Jehovah’s Witnesses (1999). Association of Anaesthetists guidelines