Serge Chalhoub

Anemia of renal disease:What it is, what to do and what's new

Patient group It is estimated that 15–30% of geriatric cats will develop chronic kidney disease (CKD), and that 30–65% of these cats will develop anemia as their renal disease worsens. Anemia of renal disease is multifactorial in its pathogenesis, but the main cause is reduced production of erythropoietin, a renal hormone that controls the bone marrows production of red blood cells, as kidney disease progresses. Practical relevance It is important to recognize the presence of anemia of renal disease so that adequate treatment may be instituted to improve quality of life and metabolic function. Erythrocyte-stimulating agents (ESAs), such as epoetin alfa, epoetin beta and darbepoetin alfa, have been developed to counteract the effects of decreased erythropoietin production by the kidneys. These treatments, which are the focus of this review, have 83% similarity in amino acid sequence to the feline hormone. On average, the target packed cell volume (>25%) is reached within 3–4 weeks of ESA therapy. Clinical challenges The use of ESAs has been associated with a number of complications, such as iron deficiency, hypertension, arthralgia, fever, seizures, polycythemia and pure red cell aplasia (PRCA). Darbepoetin has a prolonged half-life compared with epoetin and thus can be given only once a week, instead of three times a week. The incidence of PRCA appears to be decreased with darbepoetin use when compared with epoetin use in cats. Evidence base There is limited published evidence to date to underpin the use of ESAs in cats. This review draws on the relevant publications that currently exist, and the authors’ personal experience of using these therapies for over 5 years.

ISFM Consensus Guidelines on the Diagnosis and Management of Feline Chronic Kidney Disease

Practical relevance: Chronic kidney disease (CKD) is one of the most commonly diagnosed diseases in older cats. In most cats, CKD is also a progressive disease and can be accompanied by a wide range of clinical and clinicopathological changes. These ISFM Consensus Guidelines have been developed by an independent panel of clinicians and academics to provide practical advice on the diagnosis and management of this complex disease. Clinical challenges: Although CKD is a common clinical problem in cats, the manifestations of disease vary between individuals. Thus there is a need for careful and repeat evaluation of cats with CKD and adjustment of therapy according to individual needs. In addition to addressing problems arising from CKD and improving quality of life (QoL) for the patient, therapy may also target slowing the underlying progression of disease and hence prolonging life. While maintaining QoL is of paramount importance in our patients, this can be challenging when multiple therapies are indicated. In some cases it is necessary to prioritise therapy, given an understanding of what is likely to most benefit the individual patient. Evidence base: In preparing these Guidelines, the Panel has carefully reviewed the existing published literature, and has also graded the quality of evidence for different interventions to help to provide practical recommendations on the therapeutic options for feline CKD. This is a field of veterinary medicine that has benefited from some excellent published clinical research and further research findings will undoubtedly modify the recommendations contained in these Guidelines in the future.

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.

Focused assessment with sonography in nontraumatized dogs and cats in the emergency and critical care setting.

OBJECTIVE To evaluate the use of abdominal- and thoracic-focused assessment with sonography for trauma (AFAST and TFAST) in nontraumatized dogs and cats in the emergency and critical care setting and to compare prevalence of free fluid identified via these techniques between stable and unstable patients. DESIGN Prospective observational study. SETTING University Distributed Veterinary Learning Community. ANIMALS One hundred client-owned dogs and cats presenting to an emergency service with no evidence of trauma. INTERVENTIONS AFAST and TFAST performed within 12 hours of presentation. MEASUREMENT AND MAIN RESULTS Free fluid was identified on AFAST or TFAST in 33% of dogs and cats in this study. Free fluid was identified in 27 of 36 (75%) cardiovascularly unstable or dyspneic patients, compared to 6 of 64 (9%) stable patients. A significantly greater proportion of unstable patients had free fluid compared to stable patients (P < 0.0001). CONCLUSIONS Results of this study support the use of AFAST and TFAST to detect free fluid in nontraumatized dogs and cats in the emergency and critical care setting, particularly patients that are unstable on presentation.Objective To evaluate the use of abdominal- and thoracic-focused assessment with sonography for trauma (AFAST and TFAST) in nontraumatized dogs and cats in the emergency and critical care setting and to compare prevalence of free fluid identified via these techniques between stable and unstable patients. Design Prospective observational study. Setting University Distributed Veterinary Learning Community. Animals One hundred client-owned dogs and cats presenting to an emergency service with no evidence of trauma. Interventions AFAST and TFAST performed within 12 hours of presentation. Measurement and Main Results Free fluid was identified on AFAST or TFAST in 33% of dogs and cats in this study. Free fluid was identified in 27 of 36 (75%) cardiovascularly unstable or dyspneic patients, compared to 6 of 64 (9%) stable patients. A significantly greater proportion of unstable patients had free fluid compared to stable patients (P < 0.0001). Conclusions Results of this study support the use of AFAST and TFAST to detect free fluid in nontraumatized dogs and cats in the emergency and critical care setting, particularly patients that are unstable on presentation.

Vascular Access for Extracorporeal Renal Replacement Therapy in Veterinary Patients

Vascular access is the first and most basic requirement for successful extracorporeal renal replacement therapy (ERRT). Dual-lumen catheters are the most commonly used method of vascular access for ERRT in veterinary patients. An adequately functioning dialysis catheter allows for smooth and efficient patient management, whereas a poorly functioning catheter frustrates the technician, doctor, and patient. These catheters are fairly quick to place but require meticulous care for optimal function. The most common complications are thrombosis and infection. Monitoring catheter performance should be a routine part of dialysis patient care.

A comparison of tissue oxygen saturation measurements by 2 different near-infrared spectroscopy monitors in 21 healthy dogs

OBJECTIVE To determine whether a difference exists in tissue oxygen saturation (StO2 ) measurements between 2 near-infrared spectroscopy monitors on the sartorius muscle in healthy dogs. DESIGN Prospective experimental study. SETTING University veterinary teaching facility. ANIMALS Seventeen healthy student volunteered dogs and 4 healthy veterinary medicine teaching dogs. INTERVENTIONS An Inspectra 650 and INVOS 5100C StO2 probe were simultaneously placed on the medial right and left sartorius muscles of each dog for 2 minutes of real-time recording while standing and in left lateral recumbency. Left and right probe locations were reversed for both standing and lateral measurements. The peak value over the first 30 seconds on the Inspectra was also recorded. MEASUREMENTS AND MAIN RESULTS Peak StO2 values on the Inspectra over 30 seconds yielded an average of 89.9 ± 4.8%. There was no significant difference between groups above or below 9 kg, or between male and female dogs. The 2-minute averaged mean for the Inspectra was statistically higher than the INVOS (87.7 ± 5.47% and 64.1 ± 5.51%, respectively). The linear mixed-effects model showed that there is a 1.82% decrease in StO2 when standing compared to left lateral recumbency, which was elicited on both machines. On average, the INVOS underestimated the StO2 by 23.7% compared to the Inspectra. CONCLUSIONS The INVOS significantly underestimates StO2 when compared to the Inspectra. Given this difference is on average 23.7%, StO2 cut off values used to guide therapy based on Inspectra readings cannot be applied to the INVOS. While there was a statistically significant difference in standing versus lateral positions on both devices, it is unlikely to be clinically significant. Studies using different devices should not be directly compared, and it is important to use the same monitor when taking serial measurements.

Equipment Commonly Used in Veterinary Renal Replacement Therapy

Hemodialysis is a highly technical procedure that requires specialized equipment that is not used in other areas of veterinary medicine. Certain hemodialysis-specific monitoring equipment is also employed.

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.

Establishment of reference values of the caudal vena cava by fast‐ultrasonography through different views in healthy dogs

Background Clinical assessment of intravascular volume status is challenging. In humans, ultrasonographic assessment of the inferior vena cava diameter, directly or as a ratio to the aortic diameter is used to estimate intravascular volume status. Objectives To ultrasonographically obtain reference values (RV) for caudal vena cava diameter (CVCD), area (CVCa) and aortic ratios using 3 views in awake healthy dogs. Animals One hundred and twenty‐six healthy adult dogs from clients, students, faculty, or staff. Methods Prospective, multicenter, observational study. Two observer pairs evaluated CVCD by a longitudinal subxiphoid view (SV), a transverse 11th‐13th right hepatic intercostal view (HV), and a longitudinal right paralumbar view (PV). Inter‐rater agreements were estimated using concordance correlation coefficients (CCC). For body weight (BW)‐dependent variables, RVs were calculated using allometric scaling for variables with a CCC ≥ 0.7. Results The CCC was ≤0.43 for the CVC/aorta ratio at the PV and ≤0.43 in both inspiration and expiration for CVC at the SV. The RVs using allometric scaling for CVCa at the HV for inspiration, expiration, and for CVCD at the PV were 6.16 × BW0.762, 7.24 × BW0.787, 2.79 × BW0.390, respectively. Conclusions and Clinical Importance The CVCD, measured at the HV and PV in healthy awake dogs of various breeds has good inter‐rater agreement suggesting these sites are reliable in measuring CVCD. Established RVs for CVCD for these sites need further comparison to results obtained in hypovolemic and hypervolemic dogs to determine their usefulness to evaluate volume status in dogs.

Effects of Yunnan Baiyao on blood coagulation parameters in beagles measured using kaolin activated thromboelastography and more traditional methods

Abstract Yunnan Baiyao is anecdotally widely used in veterinary medicine for its pro-coagulation properties. There are no studies determining its effect on clotting tests. The purpose of this study was to determine the effect of oral Yunnan Baiyao (YB) on hemostasis by measuring coagulation via kaolin activated citrated whole blood thromboelastography (TEG), prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and d-dimers. The study was a prospective, randomized controlled crossover trial. Eight healthy University of Calgary owned beagles were treated orally with either Yunnan Baiyao or placebo every 12 h for 5 treatments. Blood was collected immediately before treatment, 2 h after the last treatment, and 24 h after the last treatment. TEG analysis was run 30 ± 5 min after blood collection. All other coagulation analyses were sent to a reference laboratory for further analysis. No treatment adverse effects were observed. Oral YB increased R-time significantly within the YB group, but the increase was still within canine reference ranges. No other changes were observed. Oral YB at the dosage and frequency administered in this study did not produce any significant improvement in hemostatic parameters. There is a need for further research and scientific evidence for YB use and dosage.