CHANGES IN THE BLOOD ELECTROLYTES OF ANAESTHETIZED DOGS CAUSED BY SUXAMETHONIUM

IN a previous paper (Stevenson, 1960) the changes in the blood electrolytes which may occur as a result of anaesthesia in dogs have been discussed. This paper describes how such changes may be modified by the use of suxamethonium chloride as a muscle relaxant during anaesthesia. Perry and Zaimis (1954) showed that suxamethonium causes the release of potassium from perfused voluntary muscle, while Klupp, Kraupp, Honetz, Kobinger and Loudin (1954) demonstrated that in dogs depolarizing muscle relaxants, including suxamethonium, will cause an increase in the plasma potassium concentration which they claimed to be biphasic. These workers claimed that the potassium concentration could be restored to the normal value by the administration of d - tubocurarine subsequent to the injection of suxamethonium . Paton (1956) has shown in cats that the injection of suxamethonium will cause an increase in the plasma potassium concentration due to release from skeletal muscle which is associated with a partial depolarization of the muscle surface. METHODS