ELECTROCARDIOGRAPHIC CHANGES AND CONCENTRATION OF POTASSIUM IN SERUM FOLLOWING INTRAVENOUS INJECTION OF POTASSIUM CHLORIDE

Abstract

KCl in isotonic soln. was injected in-traven. into 4 dogs under morphine analgesia, at rates of 0.40 to 0.78 ccs. per kgm. per min., and in another expt. an 8 X isotonic soln. was injected at 0.20 cc. per kg. per min. Serial electrocardiograms were taken from Lead II and frequent blood samples were withdrawn to permit detn. of the conc. of K in the serum. The various electrocardio-graphic changes which appeared did so at critical levels of serum K concs. of 5 to 7 mM. per liter, depression of the S-T segment appeared at 8 to 10 mM. per liter. Intra-ventricular block began at concs, of 10 mM. per liter, the P waves disappeared at 9 to 11, and cardiac arrest took place at 14 to 16 mM. per liter.