Aldosterone-identified targets for optimal sodium and potassium supplementation in intestinal failure

Parenteral support (PS) is a life-saving organ replacement therapy for patients with intestinal failure (IF). However, practical strategies to establish optimal PS sodium and potassium remain poorly defined. We investigated whether elevated plasma renin and aldosterone reflect suboptimal electrolyte supplementation and could help guide physiologically optimal sodium and potassium supplementation in patients with IF.

Real-world monitoring data from adult IF patients receiving long-term PS were analyzed using mixed-effects models for repeated measurements. Associations between parenteral sodium and potassium supplementation, urinary sodium and potassium excretion, and plasma renin and aldosterone were studied across short bowel patients with a jejunostomy (SB-J) or with colon in continuity (SB-CiC).

In 618 visits from 110 patients, elevated aldosterone levels occurred frequently and were more common in SB-J (adjusted OR for hyperaldosteronism: 5.2; 95% CI 1.5 to 17.8; p = 0.009). Even after adjusting for sodium and volume depletion, SB-J had significantly higher aldosterone levels (2.1-fold higher; 95% CI 1.5 to 2.9; p < 0.001). Urinary potassium excretion increased with greater potassium infusion and was significantly higher in SB-J (adjusted difference: 28 mmol/d; 95% CI 9 to 47; p < 0.001). A urinary sodium >20 mmol/L, combined with a sodium-to-potassium ratio >1, ruled out hyperaldosteronism with a negative predictive value of 93%.

Aldosterone not only reflects sodium depletion but is also stimulated to excrete overzealous intravenous potassium supplementation in patients with IF. Targeting a urinary sodium concentration of >20 mmol/L and a urinary sodium-to-potassium ratio of >1 can help to guide physiologically optimal sodium and potassium support in IF. Subsequently, parenteral potassium support of less than 1.0 mmol/kg/d is likely sufficient for most patients with IF.