The effect of potassium supplementation and concomitant medications on potassium homeostasis for hospitalized patients

PURPOSE

Hospitalized patients receive potassium (K+) supplementation for hypokalemia, with clinicians often estimating a rise in serum K+ levels of 0.1 mEq/L per 10 mEq delivered. However, there is limited evidence to support this expectation. Patients also concomitantly take medications that may alter K+ levels, and it is not known to what degree these may impact interventions to correct K+ levels via supplementation. The objective of this study was to identify the impact of oral and/or intravenous K+ supplementation on serum K+ levels, including the influence of selected concomitant medications, in adult hospitalized patients.

METHODS

A single-center, retrospective descriptive study of adult hospitalized patients receiving K+ supplementation at a tertiary hospital between 2021 and 2022 was conducted. Patients were included if they received at least one dose of potassium chloride while admitted to the general medicine ward. The primary outcome was the daily median change in serum K+, normalized per 10 mEq of supplementation administered. The secondary outcome was the impact of selected concomitant medication use on supplement-induced changes in serum K+.

RESULTS

A total of 800 patients and 1,291 daily episodes of K+ supplementation were evaluated. The sample was approximately 53% women, was 78% white, and had a median age of 68 years. The overall daily median change in serum K+ level was 0.05 mEq/L per 10 mEq of supplementation delivered. Patients received a median of 40 mEq of supplementation per day, primarily via the oral route (80.6%). Among the concomitant medications assessed, loop diuretics significantly dampened the impact of K+ supplementation.

CONCLUSION

Supplementation of K+ in non-critically ill hospitalized patients is variable and dependent on concomitant medication use.

BRASH Syndrome: Bradycardia, Renal Failure, AV Blockade, Shock, and Hyperkalemia

BACKGROUND

BRASH syndrome, or Bradycardia, Renal Failure, AV blockade, Shock, and Hyperkalemia, has recently become recognized as a collection of objective findings in a specific clinical context pertaining to emergency medicine and critical care. However, there is little emergency medicine and critical care literature specifically evaluating this condition.

OBJECTIVE

We sought to define and review BRASH syndrome and identify specific management techniques that differ from the syndromes as they present individually.

DISCUSSION

BRASH syndrome is initiated by synergistic bradycardia due to the combination of hyperkalemia and medications that block the atrioventricular (AV) node. The most common precipitant is hypovolemia or medications promoting hyperkalemia or renal injury. Left untreated, this may result in deteriorating renal function, worsening hyperkalemia, and hemodynamic instability. Patients can present with a variety of symptoms ranging from asymptomatic bradycardia to multiorgan failure. BRASH syndrome should be differentiated from isolated hyperkalemia and overdose of AV-nodal blocking medications. Treatment includes fluid resuscitation, hyperkalemia therapies (intravenous calcium, insulin/glucose, beta agonists, diuresis), management of bradycardia (which may necessitate epinephrine infusion), and more advanced therapies if needed (lipid emulsion, glucagon, or high-dose insulin infusion). Understanding and recognizing the pathophysiology of BRASH syndrome as a distinct entity may improve patient outcomes.

CONCLUSIONS

BRASH syndrome can be a difficult diagnosis and is due to a combination of hyperkalemia and medications that block the AV node. Knowledge of this condition may assist emergency and critical care providers.