Often simply referred to as dialysis, hemodialysis is a procedure in which metabolic waste is artificially removed from the bloodstream by a machine utilizing a dialysate fluid and a dialyzer (artificial kidney). Dialysis can also offer the added benefit of removing fluid build-up in patients that have retained fluid during their conventional treatments.
Dialysis in veterinary patients helps provide the time necessary for the kidneys to heal from trauma and for determining whether their kidney function will recover from the injury, whether it be from an acute injury or toxic exposure.
Acute Kidney Injury:
The conventional approach to acute injury involves the administration of intravenous (IV) fluids. However, in some situations additional therapy is warranted, including but not limited to leptospirosis, pyelonephritis, ischemic damage and others. Some of the indications for dialysis include: volume overload, electrolyte abnormalities, anuria (no urine production) despite efforts to correct hydration, and severe azotemia.
Dialysis, with and without the addition of a charcoal filter, has been proven successful for many toxin exposures. Examples of toxins responsive to dialysis include:
- Ethylene glycol
- NSAIDs (Non-Steroidal Anti-Inflammatory Drugs such as aspirin, acetaminophen and others).
- Chemotherapeutic agents
Therapeutic Plasma Exchange (TPE)
TPE, also known as plasmapheresis, is a procedure in which harmful substances (eg, auto-antibodies, excessive cancer-related proteins) are removed from the bloodstream. TPE involves removing plasma (a component of the bloodstream), filtering the harmful substances out, and replacing the loss with healthy / unaffected plasma. This treatment can be used for immune-mediated disease, certain types of cancer (eg, multiple myeloma), and toxicities that are highly protein-bound.
Immune-mediated hemolytic anemia (IMHA):
The most common indication for TPE therapy in dogs is in the treatment of immune-mediated hemolytic anemia that is unresponsive or not amenable to immunosuppressive therapy or when the disease is severe enough to warrant multiple blood transfusions.
Other immune-mediated diseases:
TPE can be used to help treat patients with immune-mediated thrombocytopenia, Lyme-related nephritis, systemic lupus erythematosus (SLE), pemphigus foliaceous, myasthenia gravis and polyradiculoneuritis.
TPE can be used to remove excessively high levels of large proteins (globulins) associated with this cancer and decrease the associated risk of complications such as high blood pressure, retinal detachment and neurologic abnormalities, among others.