Conventional Hemodialysis Versus Post-Dilution Hemofiltration in Incident RRT
Condition: Dialysis; Complications; Hemodialysis Complication; Cerebral Edema; Cognitive Impairment
MeSH terms: Brain Edema; Cognitive Dysfunction
Study type: Interventional

Summary: 
      Patients with chronic kidney disease (CKD) with criteria for renal replacement therapy (RRT)
      including uremic syndrome, have a stable state of hyperosmolarity due to urea despite not
      being an osmotically inactive ion. Also, these patients have alterations in urea transporters
      in the central nervous system (CNS) conferring a risk of neurological involvement due to an
      abrupt decrease in serum urea causing manifestations of the post-dialytic syndrome.

      Hemodialysis results in rapid removal of urea from the blood, much faster than the
      equilibrium rate between the brain and the bloodstream through the blood-brain barrier,
      resulting in an osmotic gradient that favors movement from water to the brain, causing
      cerebral edema, intracranial hypertension and dialysis-associated imbalance syndrome.
      Conventional hemodialysis (HD) uses diffusion and primarily decreases small solutes, while
      hemofiltration (HF) is based on convection that provides clearance mainly of medium-size
      molecules and small solutes with a slower rate of reduction.
    

Detailed description: 
      Currently, there is little information about which is the safest modality in the first
      session of intermittent hemodialysis. Other than dialysis-associated imbalance syndrome,
      there is no evidence exploring the neurocognitive effects of the first hemodialysis session.
      Cognitive impairment is defined as a new deficit in two or more areas of cognitive function
      and its progression is associated with impaired kidney function. Most of the dysfunctions
      reported are in the domains of orientation, attention and executive functions. Therefore, the
      recognition of cognitive impairment can be done with tools such as the Minimental State
      Examination (MMSE) and the Montreal Cognitive Assessment (MOCA) test. Brain magnetic
      resonance imaging (MRI) can identify brain lesions such as 'silent' infarcts, microbleeds and
      white matter abnormalities in patients with CKD with and without RRT. Diffusion-weighted MRI
      before and after HD has shown brain edema in rats with dialysis-associated imbalance
      syndrome. In fact, there is evidence from brain MRI that before first HD session patients
      have interstitial cerebral edema, which worsens after the first HD treatment.

      Because there is no clear evidence to support the choice of the modality in the first session
      and the prescription is still based on personal experiences and shared views. Therefore, we
      conducted a pilot study to determine the safest hemodialysis modality with the lowest risks
      and neurocognitive effects for patients with CKD and first HD treatment.
    

Intervention name(s): Hemofiltration
Intervention type(s): Other
Intervention description(s): Postdilutional Hemofiltration
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Treatment
Keywords: hemodialysis; hemofiltration; cognitive impairment; post-dialytic syndrome; brain magnetic resonance imaging