Guidelines
- IRIS Staging of CKD
- IRIS Treatment Recommendations for CKD
- IRIS Grading of AKI
- IRIS Canine Proteinuria Consensus Project
The IRIS Board made three significant changes to CKD Guidelines during 2014 and 2015. A summary of these new recommendations is presented here. The full version of 2015 Guidelines will be uploaded during our website relaunch by the end of 2015.
Substaging by Arterial Blood Pressure
We recommend replacement of the existing abbreviations for blood pressure substages (AP0-AP1) with descriptive terms as follows:
| Systolic blood pressure (mm Hg) | Diastolic blood pressure (mm Hg) | Risk of future target organ damage | BP substage | |
|---|---|---|---|---|
| Original | New | |||
| <150 | <95 | Minimal | AP0 | Normotension |
| 150 - 159 | 95 - 99 | Mild | AP1 | Borderline hypertension |
| 160 - 179 | 100 - 119 | Moderate | AP2 | Hypertension |
| >180 | >120 | Severe | AP3 | Severe hypertension |
Treatment of Proteinuria
We recommend that IRIS CKD Stage 1 patients with persistent proteinuria (UPC ≥ 0.5 for dogs or 0.4 for cats) are not only monitored and thoroughly investigated but also receive standard treatment for proteinuria as currently recommended for IRIS CKD Stages 2 to 4. This parallels the IRIS consensus statement on standard treatment for glomerulonephritis (J Vet Intern Med 2013;27:S27–S43).
Interpreting Blood Concentrations of Symmetric Dimethylarginine (SDMA) in CKD
SDMA concentrations in blood (plasma or serum) may be a more sensitive biomarker of renal function than blood creatinine concentrations. A persistent increase in SDMA above 14 µg/dl suggests reduced renal function and may be a reason to consider a dog or cat with creatinine values <1.4 or <1.6 mg/dl, respectively, as IRIS CKD Stage 1.
In IRIS CKD Stage 2 patients with low body condition scores, SDMA ≥25 µg/dl may indicate the degree of renal dysfunction has been underestimated. Consider treatment recommendations listed under IRIS CKD Stage 3 for this patient.
In IRIS CKD Stage 3 patients with low body condition scores, SDMA ≥45 µg/dl may indicate the degree of renal dysfunction has been underestimated. Consider treatment recommendations listed under IRIS CKD Stage 4 for this patient.
These comments are preliminary and based on early data from the use of SDMA in veterinary patients. We expect them to be updated as the veterinary profession gains further experience using SDMA alongside creatinine, the long-established marker in diagnosis and monitoring of canine and feline CKD.
IRIS Staging of CKD
As the leader in veterinary nephrology, IRIS has a responsibility to provide practicing veterinarians with evidence-based guidance for diagnosing, treating, and managing kidney disease. Our responsibility includes providing the most useful direction on how to interpret diagnostic information. The inclusion of SDMA values in the IRIS CKD Staging Guidelines is the next step in improving not only early diagnosis of CKD but also tailoring treatment of CKD to individual patients. The IRIS Board recommends using both serum creatinine and SDMA to enhance our ability to evaluate renal excretory function. These two surrogate markers are complimentary to each other. Another change the IRIS board has recently made is the expansion of Stage 2 for dogs and a corresponding reduction in size of Stage 3 for dogs. This change was made to reduce the large variability in clinical signs and treatment needs for dogs in the previously large IRIS Stage 3 category.
Staging of chronic kidney disease (CKD) is undertaken following the diagnosis of CKD in order to facilitate appropriate treatment and monitoring of the patient. Staging is based initially on fasting blood creatinine, assessed on at least two occasions in the stable patient. The patient is then substaged based on proteinuria and systemic blood pressure.
Based on these categories, some empirical recommendations can be made about the type of treatment it would be logical to use for these cases. In addition, predictions based on clinical experience might be made about the likely response to treatment.
» IRIS Staging of CKD (modified 2023) - (PDF)