Dialysate Temperature in Peritoneal Dialysis
Condition: Peritoneal Dialysis Complication
Study type: Interventional
Phase: Phase 4

Summary: 
      Patients on continuous ambulatory peritoneal dialysis (PD) are encouraged to warm dialysate
      to 37°C before peritoneal infusion; main international PD guidelines do not provide specific
      recommendation, and patients generally warm dialysate batches partially or do not warm them
      at all. Warming of dialysate is a time-consuming procedure, not free from potential risks
      (i.e. degradation of glucose), and should be justified by a clear clinical benefit. The
      investigators designed a single blind randomized controlled trial where PD patients were
      randomized to receive a peritoneal equilibration test either with dialysate at a controlled
      temperature of 37°C (intervention group) or with dialysate warmed with conventional methods
      (control group). Primary end-point was a higher peritoneal creatinine clearance in patients
      in the intervention group.
    

Detailed description: 
      Peritoneal dialysis (PD) currently represents the main choice for home renal replacement
      treatment for patients with end stage renal disease. One of the limitations of PD technique
      is represented by the difficulty in achieving target dialytic clearances and PD adequacy for
      some patients, especially with increasing PD vintage. A potentially relevant issue in PD
      clearances is the effect of dialysate temperature on depuration. Indeed, it is common for
      clinicians to advise patients in Continuous Ambulatory Peritoneal Dialysis (CAPD) to warm the
      dialysate before infusion into the peritoneal cavity, with different methods (microwave oven,
      warming cabin, warming pad). Nevertheless, main international PD guidelines do not provide
      specific recommendations on this topic. Only guidelines from the British Columbia Renal
      Agency (Canada) dedicate a specific chapter to the temperature of dialysate, recommending its
      warming to 37°C before peritoneal infusion, mainly in order to avoid an "uncomfortable
      lowering of body temperature". On the other hand, warming of PD batches could lead to hot
      spots formation inside the batch, especially with microwaves, and to degradation of glucose
      leading to the formation of toxic glucose degradation products (GDPs). Also, notable
      differences in room temperature exist according to geographical latitude and year season, and
      there are no clear and detailed reports in the literature regarding intolerable effects of
      the infusion of dialysate at room temperature. It must be acknowledged that it is common
      practice for patients to warm dialysate batches only partially or not to warm them at all.
      Moreover, warming pads that are most commonly used by CAPD patients do not effectively warm
      the dialysate up to 37°C. In the Peritoneal Dialysis Unit at Azienda
      Ospedaliero-Universitaria di Modena, it was recently observed that average dialysate
      temperature at infusion was 31.1°C, even if the pad was calibrated to 37°C [unpublished
      data]. With respect to the effects on toxins clearances through the peritoneal membrane, a
      higher dialysate temperature could theoretically favor vasodilation of peritoneal membrane
      microcirculation, potentially increasing the passage of substances. Severe microcirculatory
      dysfunction has been reported in PD patients and any intervention designed to ameliorate
      microcirculatory flow at peritoneal level could be beneficial. Surprisingly, reports
      regarding the effects of dialysate temperature on peritoneal clearances in PD in humans are
      surprisingly scarce. In 1967 Gross et al reported an increase in the exchange of substances
      between peritoneal fluid and blood upon warming of the PD fluid to 37°C (compared to 20°C) in
      a patient treated with intermittent peritoneal dialysis; the increase in urea clearance with
      the 37°C solution was 35% on average. In contrast, Indraprasit et al did not encounter
      differences in peritoneal creatinine clearance utilizing dialysate at room temperature
      (27-31°C) and warmed at 37°C in a group of 18 patients in PD. Confirmation of the effects of
      dialysate temperature on peritoneal clearances would be of great interest in order to
      maximize the depurative potential of PD and to justify patients' effort to warm the batches.

      In order to determine the real effects of dialysate temperature on peritoneal clearances and
      transport characteristics, abdominal discomfort and vital signs, the investigators designed a
      randomized controlled trial comparing two strategies of peritoneal dialysate warming.

      Study design and participants PD patients, both in CAPD and automated PD, in regular
      follow-up at the Nephrology Unit of the University Hospital of Modena, were randomized to
      receive a single dialysis exchange, either with dialysate at a controlled temperature of 37°C
      (intervention group) or with dialysate at warmed with conventional methods at uncontrolled
      temperature (control group). Randomization was generated through the use of the Random
      Allocation software11.

      Primary end-point of our study was peritoneal creatinine clearance. Secondary end-points
      were: peritoneal urea clearance, creatinine and urea mass transfer area coefficient (MTAC),
      abdominal discomfort, blood pressure and body temperature.

      A power analysis was performed while designing the study using the few data available in the
      literature; setting the alpha-error level at 0.05 for a 2-tailed t-test with a statistical
      power of 95% (beta-error 0.05) the estimated sample needed was 14 patients (7 per group).
    

Intervention name(s): peritoneal dialysate at 37°C temperature
Intervention type(s): Drug
Intervention description(s): during a PET test, patients received peritoneal dialysate warmed at 37°C before infusion
Intervention MeSH terms: Dialysis Solutions
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: peritoneal dialysis; dialysate temperature; peritoneal creatinine clearance