Sorbent Management for Advanced Renal Replacement Therapy (SMARRT™)

 

SMARRT Cartridges

Sorbent therapy has been utilized in the treatment of acute and chronic renal failure for over 30 years. This unique technology uses columns of specialized chemicals to regenerate used dialysate into fresh, highly pure dialysate that is continuously recirculated back to the dialyzer throughout a treatment. That’s SMARRT therapy.

 

THE SMARRT CARTRIDGE ADVANTAGES

 

A Disposable Water Treatment System

Sorbent cartridges are the heart of sorbent therapy. The SORB and HISORB cartridge lines allow an entire treatment using only 6 liters of dialysate made from ordinary potable tap water. Freedom from complex and cumbersome water purification systems is the result since the cartridges perform this water treatment function.

 

Ultra-small Dialysate Volume

Since only 6 liters of regenerated dialysate are needed for an entire treatment and no fluids are sent to a drain, the system not only conserves resources (and water bills) but is readily transportable compared to conventional dialysis systems.

 

Exceptional Dialysate Purity

Another long standing function of sorbent cartridges is receiving new attention today. SORB and HISORB cartridges are excellent bacteria and endotoxin filters. Dialysate levels of bacteria and endotoxin are maintained < 1 CFU/ml bacteria and < 0.3 EU/ml endotoxin.

 

 

SMARRT CARTRIDGE OPERATION 

Each cartridge contains four separate layers. Used dialysate enters the bottom of the cartridge and is purified as it rises through each succeeding layer. The cartridge effluent is then mixed with a proportioned volume of infusate to add the prescribed amount of calcium, potassium and magnesium. The result is freshly regenerated dialysate. The function of each layer is described below.

 

Purification Layer

The first (bottom) layer consists of activated carbon. This layer removes particulate matter, heavy metals; e.g., copper, mercury, and lead. These substances may be present in the water used to prepare the dialysate. Carbon also adsorbs organic metabolites such as creatinine, uric acid, and middle molecules.

 

Urease Layer

Urease is an enzyme which specifically breaks urea into ammonium carbonate by several steps.

 

Zirconium Phosphate Layer

Zirconium phosphate is used in the cartridge as a cation exchanger in the sodium and hydrogen form. Cations such as ammonium, calcium, magnesium, and potassium are adsorbed by the zirconium phosphate, in exchange for sodium and hydrogen ions. The zirconium phosphate is also a salt of a weak acid and thus has the properties of a buffer. Because of its properties as both a cation exchanger and buffer, the ratio of sodium and hydrogen released will depend upon the pH and anions present.

 

Zirconium Oxide and Zirconium Carbonate Layer

Zirconium oxide acts as an anion exchanger. The zirconium oxide layer in the cartridge is in the acetate form. Anions such as phosphate and fluoride, and to a lesser extent, chloride, are adsorbed and acetate is released. Zirconium oxide is also an excellent adsorbent for heavy metals. Acetate, bicarbonate and sodium are released by this layer.

 

 

SMARRT CARTRIDGE ADVANCES

 

Significant advances in sorbent therapy have led to the recent development of two lines of Advanced Sorbent Cartridges; the SORB™ + and HISORB™ + Cartridges, and the SORB™ HD and the HISORB™ HD Cartridges.

 

Increased Treatment Options with Variable Dialysate Flow Rates & Variable Treatment Times

The SORB+ and HISORB+ cartridges are designed for 3 – 6 hour treatments using dialysate flow rates of 200 – 400 ml/ min. The SORB HD and HISORB HD cartridge set is designed for longer, 6-8 hour treatments using dialysate flow rates of 200 – 300 ml/min.

 

 

 

 

SMARRT CARTRIDGE SELECTION

 

With four sorbent cartridges from which to choose, most patients can be treated with SMARRT therapy. Cartridge selection is based on the amount of urea a patient presents to the cartridge. Cartridge treatment parameters are summarized below.

 

 

 

 

Cartridge Purity Data