Acute increase in plasma osmolality as a cause of hyperkalemia in patients with renal failure

Giuseppe Conte, Antonio Dal Canton, Paola Imperatore, Luca De Nicola, Giuseppe Gigliotti, Nicola Pisanti, Bruno Memoli, Giorgio Fuiano, Ciro Esposito, Vittorio E. Andreucci

Research output: Contribution to journalArticlepeer-review


These studies were performed in patients with chronic renal failure to understand the mechanism(s) of hyperkalemia secondary to hypertonic NaCl infusion. In 10 patients, after intravenous infusion of either 5% or 2.5% NaCl (6 mEq per kg body wt for 120 minutes in both solutions), the maximum increase in plasma potassium averaged 0.6 (range 0.3 to 1.3) mmol/liter (P <0.01) or 0.3 (range 0.2 to 0.6) mmol/liter (P <0.01), respectively. The rise of both plasma potassium and osmolality was significantly higher during 5% NaCl than during 2.5% NaCl infusion (P <0.01). A significant linear correlation (P <0.01) between plasma potassium and osmolality was observed Urinary potassium excretion was increased to a similar extent by 5% NaCl and 2.5% NaCl infusion. The observed hyperkalemia, secondary to NaCl infusion, was independent of venous pH. plasma bicarbonate, anion gap, insulin levels, and urinary norepmephrine and epinephrine excretion, and was associated with a fall in plasma aldosterone concentration. In separate studies, nine patients were treated with desoxycorticosterone acetate (DOCA; 20 mg i.m. for three days) before receiving saline (5%) infusion. DOCA did not prevent the level increase in plasma potassium that remained significantly correlated with plasma osmolality (P <0.01). In conclusion, hypertonic NaCl infusion in patients with renal failure causes a clinically relevant hyperkalemia despite increased renal excretion of potassium. This hyperkalemia is independent of acid-base or hormonal mechanisms known to regulate extrarenal homeostasis of potassium, and is strictly correlated with a rise in plasma osmolality.

Original languageEnglish
Pages (from-to)301-307
Number of pages7
JournalKidney International
Issue number2
Publication statusPublished - Aug 1990

ASJC Scopus subject areas

  • Nephrology


Dive into the research topics of 'Acute increase in plasma osmolality as a cause of hyperkalemia in patients with renal failure'. Together they form a unique fingerprint.

Cite this