An increase in external K+  concentration:: (A) Decrease RMP, (B) Increase RMP by  –10 mv for each 10 mEq/L increase in K+, (C) No change, (D) Increase RMP by –20 mv for each 10 meq/L increase in K+
Answer is A. With hyperkalemia, membrane voltage is depolarized gradually. Depolarization of membrane voltage means decrease in RMP. Remember, a decrease in the membrane potential (RMP) means that the voltage has moved closer to ground (0 mv) or become more positive.