The use of darbepoetin to stimulate erythropoiesis in anemia of chronic kidney disease in cats: 25 cases.

BACKGROUND: Anemia is present in 30-65% in cats with chronic kidney disease (CKD) and few long-term treatment options exist. Darbepoetin is effective in treating anemia of kidney disease in humans and may be used in cats. HYPOTHESIS/OBJECTIVE: To evaluate the use of darbepoetin, a recombinant analog of human erythropoietin, to stimulate erythropoiesis, and to effectively treat anemia of kidney disease in cats. ANIMALS: Twenty-five of 66 cats that received ≥ 2 doses of darbepoetin at the Animal Medical Center between January 2005 and December 2009 were included in this study. METHODS: Cats were included in the study if they received darbepoetin and follow-up data were available for at least 56 days and had CKD as a primary clinical diagnosis. Cats were excluded if they were treated with darbepoetin but did not have kidney disease. Response to treatment was defined as reaching or exceeding a target packed red blood cell volume or hematocrit of 25%. RESULTS: Fourteen of 25 cats responded. Thirteen of those 14 cats received a dosage of 1 µg/kg/wk or higher. Presumptive adverse effects included vomiting, hypertension, seizures, and fever. CONCLUSIONS AND CLINICAL RELEVANCE: Darbepoetin is effective for treatment of anemia of kidney disease in cats. Pure red cell aplasia appears to be less common with darbepoetin than with epoetin usage.

Use of carbamylated hemoglobin concentration to differentiate acute from chronic renal failure in dogs.

OBJECTIVE: To determine usefulness of carbamylated hemoglobin (CarHb) concentration for differentiation of acute renal failure (ARF) from chronic renal failure (CRF) in dogs. SAMPLE POPULATION: Samples from dogs with ARF or CRF and from nonazotemic control dogs. PROCEDURE: CarHb concentration was determined in heparinized blood samples by measuring the micrograms of valine hydantoin (VH) per gram of hemoglobin (Hb), using a high-performance liquid chromatography assay, in which carbamyl valine is converted to VH via acid hydrolysis. RESULTS: CarHb concentration was significantly higher in dogs with ARF and CRF, compared with values in control dogs (ARF vs control, P < 0.05; CRF vs control, P < 0.001). Furthermore, CarHb concentration was significantly (P < 0.001) higher in dogs with CRF, compared with that in dogs with ARF. Carbamylated hemoglobin concentration did not correlate with serum urea nitrogen or creatinine concentration. Using a cutoff value of 100 micrograms of VH/g of Hb, the sensitivity and specificity of CarHb concentration for differentiating ARF from CRF was 96.1 and 84.2%, respectively. CONCLUSIONS: CarHb concentration was useful in the differentiation of ARF from CRF in the dogs of this study. CLINICAL RELEVANCE: CarHb concentration may be used to increase the accuracy of identifying ARF, so that early, aggressive management can be instituted, thereby increasing the chance of recovery.

Applications and outcome of hemodialysis in cats: a review of 29 cases.

Hemodialysis (HD) has been used in the management of renal failure in dogs, but its feasibility has not been reported for uremic cats. Therefore, we investigated the technical possibility, efficacy, and complications of intermittent HD in cats with severe uremia. A total of 160 HD treatments were performed on 29 cats with acute renal failure (ARF) (n = 15), chronic renal failure (CRF) (n = 6), or acute on CRF (n = 8) between November 1993 and June 1996. Hemodialysis treatments were performed with transcutaneous dialysis catheters using a bicarbonate-based delivery system, sodium modeling, and volumetric-controlled ultrafiltration. Presenting serum chemistries (mean +/- SD) for all cats were creatinine, 16.4 +/- 7.5 mg/dL; blood urea nitrogen (BUN), 229 +/- 87 mg/dL; phosphate, 15.4 +/- 5.4 mg/dL; potassium, 6.0 +/- 1.6 mEq/L; and HCO3-, 16.0 +/- 4.4 mEq/L. For intensive HD treatments, pre-HD versus post-HD creatinine changed from 10.3 +/- 4.4 to 1.6 +/- 0.9 mg/dL and BUN from 105 +/- 33 to 8 +/- 10 mg/dL. One or more adverse events occurred during 111 (69%) treatments. Dialysis-related events included hypotension, dialysis dysequilibrium, clotting, and bleeding. Nine of 15 (60%) cats with ARF and 1 cat with CRF recovered sufficiently to survive without ongoing need for HD. For the remaining cats, the proximate causes of death were dialysis related in 9 cats, uremia related in 6 cats, and iatrogenic or unknown in 4 cats. Hemodialysis is technically feasible and effectively controls the biochemical disturbances of uremic cats. It is especially valuable for the management of severe ARF, permitting recovery in a large number of cats refractory to conventional therapy. Technical complications and chronic debility, however, may limit its usefulness for cats with advanced CRF.

Role of hemodialysis in the management of dogs and cats with renal failure.

Hemodialysis is a technically sophisticated therapy used to remove accumulated uremia toxins and correct the electrolyte, hydrogen ion, and fluid imbalances associated with renal failure. Hemodialysis is indicated when the morbidity or potential mortality from either acute or chronic renal failure cannot be alleviated by conventional therapies. Additionally, it is useful for the rapid removal of excessive fluid loads associated with congestive heart failure or iatrogenic fluid administration and the elimination of dialyzable poisons like ethylene glycol. The requirements for hemodialysis include repeated access to the vasculature, an artificial kidney, and a dialysis delivery system. Technologic advancements in all these requirements make the delivery of hemodialysis feasible, effective, and safe for both dogs and cats. To date, the limitation of facilities offering dialytic therapy has restricted its use in uremic animals but current improvements in dialysis techniques and the increased sophistication of specialty practice make hemodialysis a realistic adjunct to the conservative management of uremia in veterinary medicine.