Studying the Effect of Dialysate Temperature on Toxin Removal and Hypotension
Condition: Dialysis Amyloidosis; Hypotension
MeSH terms: Hypotension; Amyloidosis
Study type: Interventional

Summary: 
      Hemodialysis (HD) is widely used treatment for end stage renal diseases (ESRD) patients. The
      chief aims of HD are solute and fluid removal. Decades of practice have improved HD care, but
      more can be done to improve morbidity and mortality. Enhancing toxin removal is an important
      consideration for improved patient outcomes. Also, decreasing the incidence of intra-dialytic
      hypotensive (IDH) episodes (dominant in Singapore patient cohort) can significantly reduce
      associated morbidities and mortality. A simple maneuver for clinicians is the dialysate
      temperature. Literature suggests that a lower dialysate temperature (35ºC) results in reduced
      hypotensive episodes by vasoconstriction. Conversely, higher dialysate temperature resulting
      in higher blood temperature decreases the peripheral resistance, leading to increased toxin
      removal, but may cause IDH episodes partly due to vasodilation. Optimal manipulation of the
      dialysate temperature is therefore primary handles to obtain the improved patient outcomes.
      In this study, the effect of dialysate temperature (cool vs. warm dialysate) on toxin removal
      will be studied. In both the interventions, outcome measure will be patient hemodynamic
      response and amount of toxins removed. The spent dialysate will be collected to study the
      quantum of toxin removed.
    

Detailed description: 
      Cool dialysate, by vasoconstriction, is simple maneuver to control and/or prevent incidence
      of intra-dialytic hypotension (IDH). During dialysis fluid is continuously removed. IDH
      occurs when plasma refilling rate is smaller than the set ultra-filtration rate. When plasma
      refiling rate is small, continuous fluid removal bring patient to the threshold state where
      patient does not have sufficient fluid in central compartment. This leads to the cascade of
      events, viz., low blood pressure, muscle cramps, dizziness, being first few manifestation. To
      minimize the occurrence of such events, clinicians often prescribe cool dialysate resulting
      in vasoconstriction, which ensures sufficient fluid volume in central body compartment so
      that continuous fluid loss does not impact patient hemodynamics severely.

      It is important to note that vasoconstriction may also inhibit the toxin movement from remote
      peripheral compartments to central blood compartment, and thus less toxin will be removed. On
      the other hand warm dialysate leading to vasodilation will mobilize the toxins in remote
      peripheral compartments and increase the toxin influx in central blood compartment. Few
      researchers have investigate the effect of dialysate temperature on urea removal, but urea is
      not a true marker of toxin milieu. In this pilot clinical research, we will compare the
      effect of dialysate temperature on removal of both small and large sized uremic toxins. Our
      objective is not to study the effect of dialysate temperature on incidence of IDH, so we will
      recruit subjects who are stable on dialysis and have no prior history of IDH episodes.
    

Intervention name(s): Cool dialysate; Warm dialysate
Intervention type(s): Procedure; Procedure
Intervention description(s): Each recruited patient undergoes a cool dialysate session ( 35.5ºC) and a warm dialysate session (37ºC). The sessions are minimum a week apart to remove the carryover effect.; All recruited patients will undergo two study sessions - Cool dialysis (35.5ºC) and Warm dialysis (37ºC)
Other intervention name(s): Cool dialysate at 35.5ºC; Warm dialysate at 37ºC; Warm dialysate at 37ºC
Intervention MeSH terms: Dialysis Solutions
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Supportive Care
Keywords: Dialysate temperature; Spent dialysate; Toxin removal; Intra-dialytic hypotension; Inter-compartmental resistance