Veterinary hemodialysis: advances in management and technology

International Renal Interest Society Best Practice Consensus Guidelines for Intermittent Hemodialysis in dogs and cats

Intermittent hemodialysis (IHD) is an advanced adjunctive standard of care for severe acute kidney injury (AKI) and other indications. Most animals with AKI are managed medically, however, when the disease is severe, medical management may not control the consequences of the disease, and animals with a potential for renal recovery may die from the consequences of uremia before recovery has occurred. Extracorporeal therapies aid the management of AKI by expanding the window of opportunity for recovery of sufficient kidney function to become dialysis independent. Intermittent hemodialysis (IHD) was introduced into veterinary medicine over 50 years ago, however, updated guidelines for the delivery of IHD have not been published for several decades. To that end, the International Renal Interest Society (IRIS) constituted a Working Group to establish best practice guidelines for the safe and effective delivery of IHD to animals with indications for dialytic intervention. The IRIS Working Group generated 60 consensus statements and supporting rational for a spectrum of prescription and management categories required for delivery of IHD on designated intermittent dialysis platforms (i.e., AKI, chronic hemodialysis and intoxications). A formal consensus method was used to validate the recommendations by a blinded jury of 12 veterinarians considered expert in extracorporeal therapies and actively performing IHD. Each vote provided a level of agreement for each recommendation proposed by the Working Group. To achieve a consensus, a minimum of 75% of the voting participants had to "strongly agree" or "agree" with the recommendation.

Retrospective evaluation of 22 dogs with leptospirosis treated with extracorporeal renal replacement therapies (2018-2021)

BACKGROUND

Outcomes of dogs with acute kidney injury secondary to leptospirosis (AKI-L) treated using renal replacement therapies (RRT) are poorly characterized.

HYPOTHESIS/OBJECTIVES

Describe survival to discharge, short (≤30 days) and long-term (≥6 months) outcomes of AKI-L dogs receiving RRT and determine if there is a significant difference in maximum blood urea nitrogen (maxBUN), maximum creatinine (maxCr), maximum bilirubin (maxBili) and the number of body systems affected between survivors and non-survivors.

ANIMALS

Twenty-two client-owned dogs with AKI-L receiving RRT.

METHODS

Retrospective medical record review of dogs with AKI-L that received RRT between 2018 and 2021.

RESULTS

Sixteen of 22 (73%) dogs survived to discharge. Of the survivors, 13 (81%) were alive >30 days from discharge and 12 (75%) were alive at 6 months from discharge. Factors significantly higher in non-survivors included number of body systems affected (survivors: 1 (19%), 2 (50%), 3 (25%) and 4 (6%) vs non-survivors: 3 (33.3%), and 4 (66.7%); P = .01) and median maxBili (survivors: 1.9 mg/dL; range, 0.1-41.6 vs non-survivors: 21.0 mg/dL; range, 12.3-38.9; P = .02). There was no significant difference in median maxBUN (survivors: 153.0 mg/dL; range, 67-257 vs non-survivors: 185.5 mg/dL; range, 102-218; P = .44) and median maxCr (survivors: 9.8 mg/dL; range, 6.2-15.9 vs non-survivors: 9.8 mg/dL; range, 8.4-13.5; P = .69) between survivors and non-survivors.

CONCLUSIONS AND CLINICAL IMPORTANCE

Regardless of azotemia severity, dogs with AKI-L receiving RRT have a good survival rate to discharge. The number of body systems affected and hyperbilirubinemia might be associated with worse outcomes.

[Role of systemic infections in canine kidney diseases]

Kidney diseases represent a common problem as well as a frequent cause of death in dogs. Infectious agents may be responsible for glomerulopathies and acute kidney injuries. Many infections commonly associated with the development of immune complex glomerulonephritis in central and southern Europe are important as travel-associated diseases in Germany. These include leishmaniosis, dirofilariosis, and ehrlichiosis. Rarely, anaplasmosis, hepatozoonosis, Lyme disease as well as babesiosis caused by small Babesia spp. are detected as cause of canine immune complex glomerulonephritis in Germany. Leptospirosis, canine infectious hepatitis, and babesiosis caused by large Babesia spp. may be responsible for the development of acute kidney injuries associated with tubulointerstitial nephritis. Therefore, further diagnostics aiming at identifying potentially causative infectious agents in dogs with renal disease is important for both prognosis and therapy of the patient.

Life-Threatening Mediastinal Hematoma Formation After Removal of the Hemodialysis Catheter in a Boxer: A Case Report

A 4-year-old female Boxer was referred for renal replacement therapy 2 days after observed grape ingestion. An 11-French dual-lumen dialysis catheter was placed into the right jugular vein and continuous renal replacement therapy was initiated for 66 h. Afterwards the patient received enoxaparin subcutaneously as a thromboprophylaxis. Four hours after removal of the dialysis catheter the patient developed severe dyspnea with hypercapnia and signs of hemorrhagic shock. Bedside ultrasound and X-rays of the thorax revealed a soft tissue opacity dorsally of the trachea, located in the mediastinum. The findings were consistent with mediastinal bleeding and hematoma formation. Blood gas examination indicated hypoventilation. The dog was managed conservatively with multiple blood transfusions and mechanical ventilation. The patient survived to discharge, and the hematoma was fully absorbed in the radiographs after 17 days. Patients with impaired kidney function should receive individualized enoxaparin dosage adjusted to anti-Xa levels and should be strictly monitored for complications. Mediastinal hemorrhage and hematoma formation should be considered as a potential complication in patients receiving a jugular vein catheter.

Extracorporeal Therapies in the Emergency Room and Intensive Care Unit

Extracorporeal treatments create opportunity for removing disease causing solutes within blood. Intoxications, renal failure, and immune-mediated diseases may be managed with these treatments, often providing new hope for patients with severe or refractory disease. Understanding solute pharmacokinetics and the limitations of each type of extracorporeal technique can allow for the selection of the optimal treatment modality.

Retrospective evaluation of the use of hemodialysis in dogs with suspected metaldehyde poisoning (2012-2017): 11 cases

OBJECTIVE

To evaluate dogs treated with hemodialysis for severe metaldehyde intoxication and to compare them with conventionally-managed patients.

DESIGN

Retrospective study (2012-2017).

SETTING

University teaching hospital.

ANIMALS

Data from 18 dogs with severe metaldehyde intoxication were analyzed. Eleven dogs were treated with intermittent hemodialysis and 7 managed conventionally.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Metaldehyde poisoning was diagnosed based on clinical signs and toxicological analysis or presence of turquoise material in the gastrointestinal content. Clinical signs, additional treatments, dialysis prescription, duration of anesthesia and hospitalization, complications, and outcome were documented. Results were analyzed by t-test, Mann-Whitney U-test, and Chi-square test. P < 0.05 was considered significant. Dialysis was performed for median (range) 180 min (150-420 min) with median of 2.28 L/kg (1.66-4.48 L/kg) blood volume processed. In the hemodialysis group, anesthesia was discontinued at a median of 3.0 hours (1.5-6.7 h) after starting dialysis. The conventional-group received general anesthesia for a median of 17.5 hours (7.0-30.5 h). No further anticonvulsive treatment was necessary for the hemodialysis group. Time to hospital discharge was shorter in dialyzed dogs (median 18 h; 15-41 h) compared to conventionally treated dogs (median 89 h; 61-168 h; P = 0.0014). Aspiration pneumonia was reported in 5 conventionally treated dogs and none of the dialyzed dogs (P = 0.001). Five dialyzed dogs developed hematoma at the dialysis catheter site. One dog in each group was euthanized.

CONCLUSION

Hemodialysis significantly decreases the requirement for anesthesia and length of hospitalization in dogs with metaldehyde intoxication. Aspiration pneumonia occurred less often in dialyzed patients. Prospective studies are warranted to confirm the clinical utility of hemodialysis in dogs with metaldehyde poisoning.

The Effect of Intermittent Hemodialysis on the Hematological and Serum Biochemistry Profile in Dogs With Chronic Kidney Disease

Intermittent hemodialysis (IHD) is a type of kidney replacement therapy commonly prescribed in veterinary medicine for cases of drug removal, fluid, acid-base, and electrolyte disorders, acute kidney injury, and cases of chronic kidney disease (CKD) in uremic crisis. This study aimed to evaluate the effects of intermittent hemodialysis in dogs with IRIS stage 4 CKD in contrast to dogs treated only with standard medical management, without dialysis, to improve their quality of life. Twenty-five dogs previously diagnosed with IRIS stage 4 CKD were selected for the study according to the inclusion criteria. Dogs were randomized to 2 distinct groups: the control group (n = 11), which underwent a conventional clinical treatment for CKD; and the hemodialysis group (n = 14), which underwent intermittent hemodialysis in addition to the clinical treatment. Both groups had a period of 15 days of clinical and laboratory evaluation. Laboratory analysis consisted of chemistry and hematological evaluation before and after both treatments at a minimum interval of 48 hours. Clinical parameters and eventual complications were assessed every 30 minutes during the IHD. When compared with conventional treatment, IHD was highly efficient in removing urea, creatinine, and phosphorus, but presented a hematological risk to the patient, requiring constant monitoring of hematological and biochemical profiles in order to correct alterations. Therefore, IHD is a highly recommended treatment if adequately monitored by trained professionals.

Clinical Practice Guidelines: An Opinion of the Legal Implication to Veterinary Medicine

The strengthening of the bond between humans and animals has changed the landscape of the veterinary profession. This has, in turn, led the legal system to assess damages in veterinary malpractice and liability cases more carefully, paying attention to the possibility of using clinical practice guidelines (CPGs) to prove whether the defendant veterinarian contravened or not the standard of care. In this era of evidence-based veterinary medicine, CPGs are becoming an integral part of many aspects of veterinary practice, even if CPGs do not have the force of law and are situated halfway between ethical rules and legal requirements. Although guidelines have been used for several years, there seems to be a general lack of recognition of the medical and legal ramifications of CPGs for veterinarians. This creates ambiguity and inconsistency in the care that veterinary practitioners provide, compromises the care animals receive, and prevents the courts from assessing veterinarian competence in a systematic and rational way. On the basis of these considerations, this article discusses the legal implications of CPGs in veterinary medicine for dogs and cats and explores how the law may treat CPGs in the future. Redefining the CPGs should be a priority for veterinary profession. NOTE: The authors chose to use the terms "companion animal," "pet," and "small animal" interchangeably throughout this article, as all three are commonly in use and refer to the same animals (dogs and cats).

Regional Citrate Anticoagulation for Intermittent Hemodialysis in Dogs

Background

The traditional systemic heparinization used for anticoagulation in extracorporeal therapies may cause fatal complications in animals at risk of bleeding.

Hypothesis/Objectives

To develop and validate a protocol of regional citrate anticoagulation (RCA) for intermittent hemodialysis in dogs.

Animals

A total of 172 dogs treated with hemodialysis for acute kidney injury.

Methods

In vitro titration was performed, adding trisodium citrate and calcium chloride to heparinized canine blood. A tentative protocol was used first in 66 treatments with additional heparinization and subsequently in 518 heparin‐free treatments. Safety and adequacy of RCA were assessed based on clinical and laboratory monitoring, dialyzer pressure gradient, treatment completion, and visual scoring of the extracorporeal circuit.

Results

Addition of 1 mmol/L citrate to heparinized blood decreased the ionized calcium concentration by 0.23 mmol/L (95% confidence interval [CI], 0.16–0.30) and 1 mmol/L calcium increased it by 0.62 mmol/L (95% CI, 0.45–0.79). Heparin‐free treatments were initiated with infusion of trisodium citrate (102 mmol/L) at 2.55 mmol/L blood and calcium chloride (340 mmol/L) at 0.85 mmol/L. Citrate and calcium administrations were adjusted in 27 and 34% of the treatments, respectively. Overall, anticoagulation was satisfactory in 92% of the treatments, with expected azotemia reduction in 95% (urea) and 86% (creatinine), stable dialyzer pressure gradient in 82%, and clean extracorporeal circuits in 92% of the treatments. Eighteen treatments (3.5%) were discontinued prematurely, 9 because of clotting and 9 for reasons unrelated to the RCA procedure.

Conclusions and Clinical Importance

Regional citrate anticoagulation allows safe and efficient heparin‐free hemodialysis in dogs at risk of bleeding.

Blood Transfusions in Dogs and Cats Receiving Hemodialysis: 230 Cases (June 1997-September 2012)

Background

Multiple factors exist that contribute to anemia in dogs and cats receiving hemodialysis, can necessitate transfusion.

Objectives

To describe blood product usage in dogs and cats with acute and chronic kidney disease that were treated with intermittent hemodialysis to determine risk factors associated with the requirement for blood product transfusion.

Animals

83 cats and 147 dogs undergoing renal replacement therapy at the Animal Medical Center for acute or chronic kidney disease.

Methods

Retrospective medical record review of all dogs and cats receiving renal replacement therapy for kidney disease, from June 1997 through September 2012.

Results

Blood products (whole blood, packed RBCs, or stromal‐free hemoglobin) were administered to 87% of cats and 32% of dogs. The number of dialysis treatments was associated with the requirement for transfusion in cats (adjusted OR 2.21, 95% CI 1.13, 4.32), but not in dogs (adjusted OR 0.98, 95% CI 0.95, 1.03). Administration of a blood product was associated with a higher likelihood of death in dogs (OR 3.198, 95% CI 1.352, 7.565; P = .0098), but not in cats (OR 1.527, 95% CI 0.5404, 4.317, P = .2).

Conclusions and Clinical Importance

Veterinary hospitals with a hemodialysis unit should have reliable and rapid access to safe blood products in order to meet the needs of dogs and cats receiving dialysis.

European consensus statement on leptospirosis in dogs and cats

Leptospirosis is a zoonotic disease with a worldwide distribution affecting most mammalian species. Clinical leptospirosis is common in dogs but appears to be rare in cats. Both dogs and cats, however, can shed leptospires in the urine. This is problematic as it can lead to exposure of humans. The control of leptospirosis, therefore, is important not only from an animal but also from a public health perspective. The aim of this consensus statement is to raise awareness of leptospirosis and to outline the current knowledge on the epidemiology, clinical features, diagnostic tools, prevention and treatment measures relevant to canine and feline leptospirosis in Europe.

Long-term outcome of cats and dogs with acute kidney injury treated with intermittent hemodialysis: 135 cases (1997-2010)

OBJECTIVE

To determine the long-term outcome for small animal patients with acute kidney injury (AKI) treated with intermittent hemodialysis (IHD).

DESIGN

Retrospective case series.

ANIMALS

42 cats and 93 dogs treated with IHD for AKI.

PROCEDURES

Medical records of cats and dogs treated with IHD for AKI from January 1997 to October 2010 were reviewed. Standard methods of survival analysis with Kaplan-Meier product limit curves were used. The log-rank, Mann-Whitney, and Kruskal-Wallis tests were used to determine whether outcome, number of IHD treatments, or duration of hospitalization was different when dogs and cats were classified according to specific variables.

RESULTS

The overall survival rate at the time of hospital discharge was 50% (21/42) for cats and 53% (49/93) for dogs. The overall survival rate 30 days after hospital discharge was 48% (20/42) for cats and 42% (39/93) for dogs. The overall survival rate 365 days after hospital discharge was 38% (16/42) for cats and 33% (31/93) for dogs. For all-cause mortality, the median survival time was 7 days (95% confidence interval, 0 to 835 days) for cats and 9 days (95% confidence interval, 0 to 55 days) for dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Cats and dogs with AKI treated with IHD have survival rates similar to those of human patients. Although there was a high mortality rate prior to hospital discharge, those patients that survived to discharge had a high probability of long-term survival.

Extracorporeal renal replacement therapy and blood purification in critical care

OBJECTIVE

To review indications methods of renal replacement therapies (RRT) and practical considerations for the creation of a RRT program.

DATA SOURCES

Current human and veterinary literature review with a focus on advanced renal physiology and clinical experience in RRT and acute/chronic kidney diseases.

DATA SYNTHESIS

Renal replacement therapies encompass intermittent hemodialysis, continuous renal replacement therapy as well as some "hybrid" techniques. Each method of RRT has practical and theoretical advantages but currently there is no evidence that one technique is superior to the other.

CONCLUSIONS

RRT is a valuable therapeutic tool for treatment of acute kidney injury and chronic kidney disease. The implementation of an RRT program needs to take into consideration multiple parameters beyond the choice of an RRT platform.

Intermittent hemodialysis for small animals

Hemodialysis is a life-saving medical modality that cleanses the blood using an artificial kidney, called a dialyzer. Hemodialysis uses contact between the patient's blood and the semipermeable membrane of the extracorporeal dialyzer to remove compounds such as blood urea nitrogen, creatinine, electrolytes, minerals, anions, cations, certain drugs and toxins, and excess fluid from the bloodstream. The extracorporeal dialyzer distinguishes hemodialysis from peritoneal dialysis, which uses a patient's peritoneum as the dialysis membrane. There are 2 main types of hemodialysis: intermittent hemodialysis and continuous renal replacement therapy. This article focuses on intermittent hemodialysis for acute and chronic kidney injury.

Urea kinetics and intermittent dialysis prescription in small animals

Hemodialysis improves survival for animals with acute kidney injury beyond what would be expected with conventional management of the same animals. Clinical evidence and experience in human patients suggest a role for earlier intervention with renal replacement to avoid the morbidity of uremia and to promote better metabolic stability and recovery. For a large population of animal patients, it is the advanced standard for the management of acute and chronic uremia, life-threatening poisoning, and fluid overload for which there is no alternative therapy.

Therapies for feline chronic kidney disease. What is the evidence?

Practical relevance Successful treatment and prevention of kidney disease in pet animals requires a multidimensional approach to identify and eliminate causes or exacerbating factors, provide professional examination and care on a regular basis, and plan and implement a comprehensive treatment program when necessary.

Evidence base Over the years, many therapeutic and preventive interventions have been developed or advocated for chronic kidney disease (CKD), but evidence of efficacy or effectiveness is often lacking or highly variable. Accordingly, the main objective of this systematic review was to identify and critically appraise the evidence supporting various approaches to managing feline CKD; namely, fluid therapy, calcitrioi therapy, antihypertensive therapy, ACE inhibitor therapy, erythropoietic hormone replacement therapy, potassium supplementation, antioxidant supplementation, alkalinization therapy, dietary phosphorus restriction and intestinal phosphate binders, therapeutic renal foods, assisted feeding, dialysis and renal transplantation.

Canine Dal blood type: A red cell antigen lacking in some Dalmatians

BACKGROUND

Based upon alloantibodies produced after sensitizing dogs with transfused blood, more than a dozen blood group systems have been recognized thus far, and some have been classified as dog erythrocyte antigens (DEA).

HYPOTHESIS

A new canine red cell antigen was suspected, based on the development of specific alloantibodies in a Dalmatian previously sensitized by blood transfusions.

ANIMALS

Twenty-six Dalmatians (including 1 Dalmatian in need of blood compatibility studies); 55 canine blood donors.

METHODS

Serologic tests, including blood typing, crossmatching, and direct Coombs' test were performed by standard tube techniques and a novel gel column technology adapted from human blood banking.

RESULTS

By day 40 after transfusion of an anemic Dalmatian, all major crossmatch tests to 55 non-Dalmatian dogs were incompatible. The 2 initial donors, who were compatible before transfusion, were also now incompatible, suggesting the development of an alloantibody to a common red cell antigen. No siblings were available, but 4 of 25 unrelated Dalmatians were crossmatch compatible, suggesting that they were missing the same red cell antigen. The patient was blood typed DEA 1.1, 3, 4, and 5 positive, but DEA 7 negative. Further blood typing and crossmatching results did not support an association to any of these known blood types. The alloantibodies produced were determined to be of the immunoglobulin G class.

CONCLUSIONS AND CLINICAL IMPORTANCE

Based upon the identification of an acquired alloantibody in a Dalmatian, a presumably new common blood type named Dal was identified. Dalmatians lacking the Dal antigen are likely at risk of delayed and acute hemolytic transfusion reactions.