HYPERKALEMIA ASSOCIATED WITH HEMORRHAGIC-SHOCK IN RABBITS - MODIFICATION BY SUCCINYLCHOLINE, VECURONIUM AND BLOOD-TRANSFUSION

In haemorrhagic patients, hyperkalaemia may occur after succinylcholine administration. We investigated in haemorrhagic rabbits whether vecuronium caused hyperkaelemia and if blood transfusion prevented succinylcholine-induced hyperkalaemia. Rabbits were lightly anaesthetized with halothane/N2O and 30-35 ml/kg blood were withdrawn to cause arterial pH to decrease to approximate to 7.0-7.1. Group C (n=12) received 3 ml saline, Group S (n=13) received succinylcholine 1 mg/kg, Group V (n=7) received vecuronium 0.25 mg/kg and Group T (n=9) was transfused with 10 ml/kg blood 10 min prior to receiving succinylcholine 1 mg/kg. K+ analysis was repeated at 5 min, and at 10 min in most animals. Haemorrhage increased K+ (mmol . l(-1), mean+/-SD): Group C, 3.4+/-0.3 to 6.8+/-1.8; Group S, 3.8+/-0.5 to 6.9+/-2.3; Group V, 3.8+/-0.3 to 7.1+/-1.9; Group T, 3.6+/-0.5 to 7.6+/-2.9. K+ decreased in Group T (to 5.4+/-1.8) after blood transfusion. K+ increased at 5 min in Group S (to 8.7+/-2.6) and at 10 min for Group C (to 8.4+/-1.7) and Group T (to 7.2+/-2.3). The K+ increase at 5 min for Group S (1.8+/-0.8) was significantly higher than those for Group C (1.0+/-0.6) or Group V (0.9+/-0.4), but was not different From that of Group T (1.5+/-0.7). We conclude that haemorrhage and succinylcholine cause hyperkalaemia in rabbits. Muscle relaxation itself does not appear to be a factor, but transfusion may lessen the hyperkalaemia.