Hyperkalaemia: occurred in 1% of in-patients.

Clinical bottom line (level 4)

  1. About 1% of hospital in-patients had hyperkalaemia (> or = 5.5 mmol/L).
  2. Drugs (61%) and renal failure (43%) were the commonest causes of hyperkalaemia.
  3. Around 20% of samples found on laboratory testing to have high potassium levels, were haemolysed.
Moore and Bailey: New Zealand Medical Journal 1989; 102: 557-558
Expires February 2004

The study

Case series with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, New Zealand

86 patients (aged 70% aged over 50 years, 53% male) in-patients with hyperkalaemia ( = 5.5 mmol/L)

Excluded if
  • haemolysed, old or contaminated samples
  • neonates





    • Outcomes studied:
  • prevalence of hyperkalaemia in hospital
  • acute renal failure as cause of hyperkalaemia
  • chronic renal failure as cause
  • diabetic ketoacidosis as cause
  • other cause
  • no clear cause
  • drugs considered to be contributory

    • 123 patients had hyperkalaemia, but case notes were only available for 86.

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    prevalence of hyperkalaemia in hospital ? 123/10797 1.14%
    (0.94% to 1.34%)
    acute renal failure as cause of hyperkalaemia ? 37/86 43.0%
    (32.6% to 53.5%)
    chronic renal failure as cause ? 21/86 24.4%
    (15.3% to 33.5%)
    diabetic ketoacidosis as cause ? 5/86 5.81%
    (0.87% to 10.8%)
    other cause ? 11/86 12.8%
    (5.73% to 19.9%)
    no clear cause ? 12/86 14.0%
    (6.63% to 21.3%)
    drugs considered to be contributory ? 52/86 60.5%
    (50.1% to 70.8%)

    • 41% of patients died during their hospital admission. Anither 42% died subsequently. There was no indication as to whether or not hyperkalaemia caused any of these deaths.

    Comments

    1. Prevalence is similar to that noted by Paice et al in a UK teaching hospital.

    Citation

    1. Moore ML, and Bailey RR: Hyperkalaemia in patients in hospital. New Zealand Medical Journal 1989; 102: 557-558
    Contributor: Chris Ball and Clare Wotton, February 2000
    Reviewer:

    Clinical Question.
    Patient in-patients
    Intervention or Exposure prevalence
    Outcome hyperkalaemia