Real-time urinary electrolyte monitoring after furosemide administration in surgical ICU patients with normal renal function

Luca Zazzeron, Davide Ottolina, Eleonora Scotti, Michele Ferrari, Paola Bruzzone, Silvio Sibilla, Cristina Marenghi, Luciano Gattinoni, Pietro Caironi

Research output: Contribution to journalArticle

Abstract

Background: Although the loop-diuretic furosemide is widely employed in critically ill patients with known long-term effects on plasma electrolytes, accurate data describing its acute effects on renal electrolyte handling and the generation of plasma electrolyte alterations are lacking. We hypothesized that the long-term effects of furosemide on plasma electrolytes and acid–base depend on its immediate effects on electrolyte excretion rate and patient clinical baseline characteristics. By monitoring urinary electrolytes quasi-continuously, we aimed to verify this hypothesis in a cohort of surgical ICU patients with normal renal function. Methods: We retrospectively enrolled 39 consecutive patients admitted to a postoperative ICU after major surgery, and receiving single low-dose intravenous administration of furosemide. Urinary output, pH, sodium [Na+], potassium [K+], chloride [Cl] and ammonium [NH4 +] concentrations were measured every 10 min for three to 8 h. Urinary anion gap (AG), electrolyte excretion rate, fractional excretion (Fe) and time constant of urinary [Na+] variation (τNa+) were calculated. Results: Ten minutes after furosemide administration (12 ± 5 mg), urinary [Na+] and [Cl], and their excretion rates, increased to similar levels (P −] decreased less rapidly than [Na+], leading to a reduction in urinary AG and pH and an increment in urinary [NH4 +] (P −] over the first 3-h period was higher than baseline urinary and plasmatic [Cl] (P − and FeNa+ increased (P + were associated with greater increases in FeNa+ after furosemide (P = 0.03 and P = 0.007), whereas higher values of mean arterial and central venous pressures were associated with a longer τNa+ (P −]. Conclusions: Low-dose furosemide administration immediately modifies urinary electrolyte excretion rates, likely in relation to the ongoing proximal tubular activity, unveiled by its inhibitory action on Henle’s loop. Such effects, when cumulative, found the bases for the long-term alterations observed. Real-time urinary electrolyte monitoring may help in tailoring patient diuretic and hemodynamic therapies.

Original languageEnglish
Article number72
JournalAnnals of Intensive Care
Volume6
Issue number1
DOIs
Publication statusPublished - Dec 1 2016

Keywords

  • Furosemide
  • Loop-diuretics
  • Metabolic alkalosis
  • Urinary chloride
  • Urinary sodium

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

Fingerprint Dive into the research topics of 'Real-time urinary electrolyte monitoring after furosemide administration in surgical ICU patients with normal renal function'. Together they form a unique fingerprint.

  • Cite this

    Zazzeron, L., Ottolina, D., Scotti, E., Ferrari, M., Bruzzone, P., Sibilla, S., Marenghi, C., Gattinoni, L., & Caironi, P. (2016). Real-time urinary electrolyte monitoring after furosemide administration in surgical ICU patients with normal renal function. Annals of Intensive Care, 6(1), [72]. https://doi.org/10.1186/s13613-016-0168-y