Erythrocyte osmotic fragility in porcine malignant hyperthermia and effects of halothane.

Malignant Hyperthermia (MH) has been shown to be due to an inherited disorder in cellular membrane systems, which also seem to be affected by halothane. With the erythrocyte osmotic fragility test we tried to find out if the erythrocyte membrane can serve as a diagnostic tool in malignant hyperthermia and as a model for halothane effects on membranes. We obtained MH susceptible and MH resistant pigs and their crossbreeds. The MH susceptible pigs showed the greatest degree of haemolysis in the erythrocyte osmotic fragility test. Furthermore, halothane increased haemolysis more in the erythrocytes of MH susceptible pigs. The MH resistant pigs were only slightly affected in both and the crossbreeds showed intermediate results. The variance occurring within one halothane group could be used to add a further distinguishing characteristic apart from the discrete halothane challenge test and so enable selection within a pure halothane group.