A determination of the current causes of hyperkalaemia and whether they have changed over the past 25 years.

Objective: Hyperkalaemia is a potentially lethal electrolyte disorder. The objective of this study was to determine if the causes of hyperkalaemia-related visits to the emergency department (ED) have changed since 25 years.

Methods: All patients presenting to the ED with hyperkalaemia between January 2009 and August 2011 were included in this retrospective, single-centre study. Patients were divided into one of these three categories: mild (5·2≤ K(+)<5·8 mEq/l), moderate (5·8≤K(+)<7·0 mEq/l) or severe hyperkalaemia (K(+)≥7·0 mEq/l). The causes of hyperkalaemia were divided into three groups: renal failure (RF), potassium-increasing drugs (PIDs) or others.

Results: Overall, 139 patients with hyperkalaemia were included in the study (mean K(+) of 6·2 mEq/l): 35% with mild, 49% with moderate and 16% with severe hyperkalaemia. Eighty-three per cent of patients (n = 115) had RF with creatinine levels ≥1·25 mg/dl or estimated glomerular filtration rate (eGFR) levels ≤60 ml/min/1·73 m(2). Serum potassium levels were significantly related with creatinine and eGFR values (P<0·001). The severity of hyperkalaemia was significantly related with creatinine levels ≥1·25 mg/dl (P = 0·002) and eGFR values ≤60 ml/min/1·73 m(2) (P = 0·005). Seventy-five per cent of patients (n = 105) were taking PIDs. Potassium levels were significantly related with PIDs (P<0·001), in particularly spironolactone (P = 0·001) and angiotensin-converting enzyme inhibitors (P = 0·008). The category 'others' included 7% of patients (n = 10).

Conclusions: RF (83%) and PIDs (75%) remain common causes of hyperkalaemia. Hyperkalaemia is significantly related with four variables: creatinine levels, spironolactone, ACEIs and beta-blocker intake. The causes of hyperkalaemia have not changed in recent years.