Clinical Potassium Pilot Study
Condition: Hyperkalemia
MeSH terms: Hyperkalemia
Study type: Interventional

Summary: 
      In this pilot study, 30 prevalent hemodialysis patients will undergo three regular
      hemodialysis sessions during which various potassium assessments will be performed. Pre- (t1)
      and post-dialysis (t2) plasma potassium levels (K+Pl) will be measured using standard
      ion-selective electrodes. These values will be correlated to K+ determine in saliva probes
      (K+Sa) using genetically encoded potassium ion indicators (GEPIIs). Additionally, continuous
      ECG will be recorded during each hemodialysis treatment and potassium assessment (K+ECG) will
      be performed upon ECG-based parameters and correlated to K+Pl.
    

Detailed description: 
      Cardiovascular diseases are among the leading causes of death in industrialized countries.
      Medical therapy for these diseases has seen significant progress, much of which is based on
      agents interfering with the renin-angiotensin-aldosterone system (angiotensin-converting
      enzyme inhibitors, angiotensin receptor antagonists, mineralocorticoid receptor antagonists,
      neprilysin inhibitors). However, these agents bear the side effect of reducing renal
      potassium (K+) excretion and may thus lead to elevation of blood K+ Levels (hyperkalemia).
      Hyperkalemia is a potentially life-threatening condition, which in its most severe forms
      requires immediate medical attention, since there is imminent danger of dangerous arrhythmias
      and sudden cardiac death. Therefore, hyperkalemia is a leading reason to withdraw potentially
      lifesaving therapy in a significant number of patients, which is considered to have a
      negative impact on patient outcomes. Recently, novel intestinal potassium binders have been
      shown to be efficient in reducing incidence and severity of hyperkalemia These compounds have
      very recently been shown to allow extending the benefits of antihypertensive therapy with
      spironolactone to patients with chronic kidney disease with refractory hypertension . Yet due
      to preanalytical problems as well as time and cost-restraints, out-patient monitoring of
      serum or plasma potassium levels has proven problematic.

      The plasma potassium level and kinetics at two timepoints before and after a hemodialysis
      session as determined by either standard of care (i.e. ion selective electrode) will be
      compared to the potassium level measured in (i) saliva (salivary potassium [K+Sa]) or (ii)
      determined based on electrocardiogram (K+ECG). Patients suffering from end-stage renal
      disease undergoing hemodialysis (HD) frequently present with severe hyperkalemia prior to a
      HD session. During HD treatment, K+ levels undergo unphysiologically rapid changes due to K+
      removal via HD as well as due to changes in acid-base status. Thus, HD patients represent a
      unique population in whom significant K+ derangements and rapid K+ Level changes predictably
      occur and where these phenomena can be investigated in a safe environment.
    

Intervention name(s): GEPII; Ion-selective electrodes
Intervention type(s): Device; Device
Intervention description(s): Saliva probes (K+Sa) will be measured using genetically encoded potassium ion indicators (GEPIIs); Plasma potassium levels (K+Pl) will be measured using standard ion-selective electrodes.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: plasma potassium measurement; saliva potassium measurement; hemodialysis; fluorescence assay; ECG-based potassium estimation; Förster resonance energy transfer