SMARRT™ Overview

Single-pass and sorbent systems both provide hemodialysis treatments for patients with acute or chronic kidney disease. Both systems deliver dialysate to the dialyzer in prescribed amounts to cleanse the blood of impurities, correct the patient’s body chemistry, and remove excess fluid. The key difference between the two systems is the sorbent cartridge. It is the sorbent cartridge that makes the Allient System different from traditional single-pass systems and creates the unique advantages of sorbent dialysis. Sorbent dialysis differs from traditional single-pass dialysis in that:

• Sorbent systems use less water than single-pass machines and do not require special plumbing. Single-pass systems use approximately 120 liters of water during a typical 4-hour treatment. In single-pass dialysis, a water treatment system is required to continuously pump purified water into the system to be blended with the bicarbonate and acid bath to create the final dialysate. This requires special plumbing to connect the single-pass machine to both the water treatment system and to a drain into which the used dialysate and rejected source water are disposed.
  
  By utilizing sorbent technology, the Allient System is able to provide highly-pure dialysate for 3- to 8-hour treatments using only 6 liters of potable tap water. The sorbent cartridge acts as a built-in dialysate purification system. Dialysate levels of bacteria and endotoxin are maintained < 1 CFU/ml bacteria and < 0.3 EU/ml endotoxin. The cartridge purifies the initial dialysate and continuously recirculates and regenerates the dialysate throughout the treatment.
  
   
• Sorbent systems provide a gentle way to achieve an electrolyte and chemical balance. Single-pass machines deliver a constant dialysate prescription to the patient. This forces the patient’s body chemistry to change to match the dialysate prescription. This can cause some of the common side effects often associated with single-pass dialysis, such as nausea, cramping, and hypotension.
  
  During a sorbent treatment, urea is dismantled within the cartridge and combined with other solutes to replenish the sodium chloride and sodium bicarbonate required to correct the patient’s body chemistry. Because the patient’s body fluid volume is much larger than the dialysate volume, the patient is able to control the dialysate.
  
  The sorbent cartridge performs multiple tasks: it serves as a dialysate purification system, maintains dialysate pH balance, and binds uremic wastes.

Dialysate Flow Path

Six liters of potable tap water and prescribed amounts of sodium chloride, sodium bicarbonate, and dextrose are used to create the initial dialysate solution. This mixture is then passed through the sorbent cartridge. As it flows through the cartridge, bacteria, pyrogens, endotoxins, metals, and organic solutes (such as pesticides) are removed from the initial dialysate. The purified dialysate is stored in the dialysate reservoir bag until it is circulated to the dialyzer. Once it leaves the dialyzer, the spent dialysate and the patient’s ultrafiltrate fluid pass through the sorbent cartridge, where both are converted into partially regenerated dialysate, known as cartridge effluent. The cartridge effluent is combined with infusate to form a fully regenerated dialysate, which then flows back into the dialysate reservoir bag, ready to be sent back to the dialyzer.