The caring for a patient who has developed kidney failureWhich test finding leads the nurse to contact the nephrologist and arrange emergency hemodialysis?

A. 1500 ml of retained urine in bladder
B. Serum potassium level of 7.4 meq/L
C. Large amounts of protein in the urine
D. WBC of 6500

B. Serum potassium level of 7.4 meq/L