ABSTRACT
Hyponatremia is common in chronic kidney disease and in end stage kidney disease (ESKD) but hypernatremia is infrequent in ESKD. The incidence of hypernatremia is higher in ambulatory peritoneal dialysis (PD) than in hemodialysis (HD) patients. In PD patients it is often a result of excessive ultrafiltration but in HD it is often a result of dialysate composition errors. Dialysate composition errors can inadvertently cause either hyponatremia or hypernatremia. We present two cases of symptomatic hypernatremia which manifested as increased thirst, excessive weight gain and worsening hypertension in HD patients. The hypernatremia was caused by a combination of errors in online conductivity reading and a faulty hand held conductivity meter. Symptoms were relieved in both patients after replacement of the dialysis machine.