Renal Flashcards
(236 cards)
1
Q
What primarily determines filtration volume in the kidneys?
A
The number of functioning nephrons and glomerular hydrostatic pressure
2
Q
What is the typical percentage of filtered fluid excreted as urine under normal conditions?
A
<1%
3
Q
What is azotemia, and when is it commonly diagnosed?
A
Decreased glomerular filtration rate (GFR)
4
Q
What endocrine functions do the kidneys perform?
A
- Blood pressure regulation
- Erythropoiesis
- Calcium/phosphate metabolism
5
Q
How does acute kidney injury (AKI) differ from chronic kidney disease (CKD) in terms of duration?
A
AKI: Recent onset; CKD: ≥ 3 months
6
Q
What is the formula to calculate GFR?
A
GFR = Kf × [(P_gc − P_b) − (pi_gc − pi_b)]
7
Q
What are the ideal properties of GFR markers?
A
- Freely filtered by the glomerulus
- Not protein-bound in plasma
- Not reabsorbed or secreted by tubules
- Non-toxic, does not alter GFR
8
Q
What is the gold standard marker for GFR measurement?
A
Inulin
9
Q
What is a limitation of using urea (BUN) as a surrogate marker of GFR?
A
Influenced by non-renal factors such as fever, sepsis, starvation
10
Q
What is the physiological origin of creatinine?
A
Derived from creatine phosphate breakdown in muscle
11
Q
What is the significance of symmetric dimethylarginine (SDMA) in renal function assessment?
A
Earlier increase in GFR decline, not influenced by muscle mass
12
Q
What are the types of proteinuria?
A
- Pre-renal: Excess low-MW proteins
- Post-renal: Lower urinary tract inflammation, infection
- Renal: Glomerular, Tubular
13
Q
What does the presence of calcium oxalate monohydrate crystals in urine suggest?
A
Ethylene glycol toxicity
14
Q
What is the normal range of GFR in dogs?
A
3.5–4.5 mL/min/kg
15
Q
What is the normal range of GFR in cats?
A
2.5–3.5 mL/min/kg
16
Q
What is tubular impairment?
A
Impaired reabsorption
17
Q
What is the sensitivity and specificity of the urine dipstick test?
A
> 80% sensitivity, but poor specificity
18
Q
What is the normal UPCR value for cats?
A
<0.4
19
Q
What UPCR value suggests glomerular disease?
A
> 2.0
20
Q
What is the day-to-day variability change needed to confirm a real change in UPCR?
A
> 35%
21
Q
What is the threshold for considering renal biopsy according to IRIS guidelines?
A
UPCR >3.5
22
Q
What are the indications for renal biopsy?
A
- Persistent substantial proteinuria (UPCR > 3.5)
- Non-responsive proteinuria despite anti-proteinuric therapy
- Progressively worsening proteinuria or renal function despite treatment
- Suspected immune-mediated glomerulopathies
- To assess for irreparable structural damage in AKI
23
Q
What are the contraindications for renal biopsy?
A
- IRIS Stage 4 CKD
- Primary tubulointerstitial disease
- Hydronephrosis or pyelonephritis
- Renal abscessation
- Known coagulopathy or hemostatic disorder
24
Q
What is the common feature of nephrotic syndrome in PLN?
A
- Hypoalbuminemia
- Hypercholesterolemia
- Peripheral edema/Cavitary effusion
- Proteinuria
25
What percentage of PLN dogs are hypercoagulable?
Up to 89%
26
Which conditions are available for genetic testing in renal disease?
* Hereditary nephropathy – Cocker Spaniels
* Focal segmental glomerulosclerosis – Soft-Coated Wheaten Terriers
* Tubulopathies: Cystinuria, Hyperoxaluria, Hyperuricosuria
27
What is the definition of fractional excretion (FE) of solutes/electrolytes?
% of a filtered solute that is excreted in urine
28
What are the clinical implications of glucosuria?
Indicates renal tubular dysfunction (proximal tubule)
29
What is the significance of casts in urine analysis?
Strongest indicators of tubular damage
30
What does urine protein electrophoresis (UPEP) analyze?
Analyzing urinary proteins by molecular weight
31
What does a UPCR >2.0 suggest?
Strong suspicion for glomerular pathology
32
What is the role of biomarkers like NGAL and KIM-1?
* NGAL – tubular injury
* KIM-1 – proximal tubular damage
33
What is the significance of hyposthenuria?
Suggests non-renal cause of PU/PD
34
What is the typical urine pH range for assessing renal tubular acidosis (RTA)?
Varies; requires blood gas analysis for evaluation
35
What is the significance of plasma cells in urine?
Very large cells that appear only with severe damage
## Footnote
Plasma cells are a type of white blood cell that produces antibodies.
36
What is the function of albumin?
Negative APP; routinely assessed
## Footnote
Albumin helps maintain oncotic pressure in the blood.
37
What is the role of transferrin?
Iron transport; HMW
## Footnote
Transferrin is a glycoprotein that binds and transports iron.
38
What does podocin do?
Glomerular slit diaphragm protein
## Footnote
Podocin is crucial for the filtration barrier in the kidneys.
39
What is thromboxane B2?
Lipid metabolite; reflects intrarenal hemodynamics
## Footnote
Thromboxane B2 is involved in vasoconstriction and platelet aggregation.
40
What is adiponectin?
Capillary leakage marker
## Footnote
Adiponectin is involved in regulating glucose levels and fatty acid breakdown.
41
What is ferritin's role?
Iron storage; appears in severe injury
## Footnote
Ferritin is a protein that stores iron and releases it in a controlled fashion.
42
What does NAG (N-acetyl-β-D-glucosaminidase) indicate?
Tubular cell injury marker
## Footnote
NAG is used to assess proximal tubular injury in the kidneys.
43
What is GGT (γ-glutamyltransferase) used for?
Used to monitor gentamicin nephrotoxicity
## Footnote
GGT is an enzyme that, when elevated, indicates renal damage, especially from medications.
44
What does LDH (lactate dehydrogenase) indicate?
Non-specific nephron injury
## Footnote
LDH is an enzyme found in many tissues and can indicate cellular damage.
45
What is the function of AAP (alanyl aminopeptidase)?
Tubular injury marker
## Footnote
AAP is found in the brush border of proximal tubules and indicates renal tubular injury.
46
What is the significance of ALP (alkaline phosphatase)?
Tubular cell lysosomal marker
## Footnote
ALP can indicate biliary obstruction or bone disease but also reflects renal tubular injury.
47
What does retinol-binding protein (RBP) indicate?
Vitamin A transport; ↓ reabsorption = injury
## Footnote
RBP levels decrease in cases of proximal tubular injury.
48
What is β2-microglobulin a marker of?
Indicates proximal tubular dysfunction
## Footnote
β2-microglobulin is a component of MHC class I molecules and is elevated in kidney disease.
49
What does α1-microglobulin indicate?
Reabsorption marker
## Footnote
α1-microglobulin is a protein that can indicate tubular reabsorption capacity.
50
What is NGAL (neutrophil gelatinase-associated lipocalin)?
Marker released after direct tubular injury
## Footnote
NGAL is also elevated in cases of urinary tract infections and inflammation.
51
What does KIM-1 (kidney injury molecule-1) indicate?
↑ with ischemia or toxins
## Footnote
KIM-1 is a membrane protein that is upregulated in kidney injury.
52
What does clusterin (CLU) indicate?
Renal-specific isoform may exist
## Footnote
Clusterin levels can indicate renal tubular damage.
53
What is cystatin B?
Protease inhibitor; ↑ in renal injury
## Footnote
Cystatin B can indicate renal tubular dysfunction.
54
What does the presence of HMW proteins (e.g., IgG, albumin) suggest?
Disruption of the glomerular filtration barrier
## Footnote
This can indicate conditions like nephrotic syndrome.
55
What are indicators of tubular dysfunction?
Glucosuria in euglycemia, aminoaciduria, phosphaturia
## Footnote
These findings suggest proximal tubular injury.
56
What is the clinical significance of the GGT/creatinine ratio?
Useful for detecting gentamicin-induced nephrotoxicity
## Footnote
This ratio helps differentiate between causes of renal damage.
57
What does the term 'advanced biomarker use' refer to?
NGAL, KIM-1, Clusterin, Cystatin B show promise in early detection of AKI
## Footnote
These markers are being researched for their role in monitoring kidney health.
58
What does urinary NGAL and KIM-1 indicate?
AKI, Rise within hours of AKI
## Footnote
These biomarkers can provide early detection of acute kidney injury.
59
What is the role of FGF-23 (Fibroblast growth factor-23)?
Phosphaturic hormone; ↑ with CKD progression
## Footnote
FGF-23 is involved in phosphate metabolism and is elevated in chronic kidney disease.
60
What does the presence of AGEs (Advanced glycation end products) indicate?
Indicates oxidative stress
## Footnote
AGEs are formed through non-enzymatic glycation and are markers of metabolic dysfunction.
61
What is the significance of Doppler evaluation in renal imaging?
Measures resistance index (RI) of interlobar/arcuate arteries
## Footnote
Increased RI can indicate ureteral obstruction or renal transplant rejection.
62
What is the normal renal length for cats?
Approximately 3.0–4.5 cm
## Footnote
Renal length may vary, and a size of 5.0 cm is generally not concerning.
63
What does increased echogenicity in kidneys suggest?
Nonspecific; weakly correlates with histologic disease
## Footnote
Increased echogenicity can be seen in conditions like chronic kidney disease.
64
What is the appearance of a simple cyst on ultrasound?
Round, anechoic, thin-walled, with distal acoustic enhancement
## Footnote
Simple cysts are often incidental findings in imaging.
65
What is the significance of the medullary rim sign?
Often normal variant; may indicate leptospirosis
## Footnote
The medullary rim sign is a hypoechoic line that can be seen on ultrasound.
66
What findings suggest pyelectasia (renal pelvic dilation)?
Visible renal pelvic fluid; persistent dilation indicates possible obstruction
## Footnote
Pyelectasia can be a normal finding during diuresis but may indicate disease if persistent.
67
What is the primary purpose of plain radiographs in renal imaging?
Assess renal size, shape, contour, and presence of radio-opaque calculi
## Footnote
However, plain films cannot evaluate internal renal architecture.
68
What is the historical use of IV Urography?
Ureter/pelvis/UVJ; now mostly replaced
## Footnote
IV Urography was once a common diagnostic tool but has been largely supplanted by more advanced imaging techniques.
69
What can ultrasound reveal in renal disease?
Internal architecture, masses, fluid, cysts, pelvic dilation
## Footnote
Ultrasound is a non-invasive imaging technique that provides valuable insights into kidney health.
70
What are the best uses of CT in renal disease?
Ureteral obstruction, renal ectopia, intrarenal masses, detailed anatomy
## Footnote
CT scans provide detailed cross-sectional images of the kidneys and surrounding structures.
71
What does Doppler US estimate in renal disease?
Renal perfusion and vascular resistance estimation
## Footnote
Doppler ultrasound is useful for assessing blood flow and vascular conditions in the kidneys.
72
Which is a more sensitive indicator of CKD: renal cortex thickness or renal length?
Renal cortex thickness
## Footnote
This indicates that changes in the cortex may reflect chronic kidney disease more accurately than overall kidney size.
73
What are subcapsular pseudocysts commonly seen in?
Cats with CKD
## Footnote
These pseudocysts are often a benign finding in cats suffering from chronic kidney disease.
74
What are the four phases of intrinsic AKI?
* Induction Phase
* Extension Phase
* Maintenance Phase
* Recovery Phase
75
What triggers the Induction Phase of intrinsic AKI?
Ischemic or nephrotoxic insult
## Footnote
This phase ends when renal dysfunction becomes evident.
76
What occurs during the Maintenance Phase of intrinsic AKI?
Critical damage has occurred with ↓GFR, azotemia, and uremic signs present
## Footnote
Supportive care is critical as elimination of the insult won’t reverse damage.
77
What is intrinsic AKI characterized by?
Ischemic or toxic injury to nephron structures
## Footnote
Includes acute tubular necrosis and glomerulonephritis.
78
What are common biomarkers for GFR estimation?
* Serum creatinine
* BUN
* SDMA
* Serum cystatin C
79
What is the definition of AKD?
Persistent decrease in kidney function for >7 days but <3 months.
80
What are common causes of Pre-renal AKI?
* Hypovolemia
* Decreased Cardiac Output
* Systemic Vasodilation
* Renal Vasoconstriction
81
How do NSAIDs contribute to drug-induced AKI?
They inhibit vasodilatory prostaglandins, leading to ischemia.
82
What is the primary mechanism of nephrotoxin-induced injury?
Intrarenal vasoconstriction, tubular epithelial cell injury, intratubular obstruction.
83
What is Acute Tubular Necrosis (ATN) often caused by?
* Ischemic injury
* Nephrotoxic injury
84
What are examples of systemic diseases associated with intrinsic AKI?
* Sepsis
* Leptospirosis
* Babesiosis
* Parvovirus
* Hypoadrenocorticism
* Pancreatitis
* Heatstroke
* CRGV
85
What is a common presentation of dogs with heatstroke related to AKI?
63% develop AKI, often with proteinuria.
86
What is a key point about biomarkers in AKI?
They can detect structural injury before azotemia occurs.
87
What does an elevated fractional excretion of sodium (FE Na) indicate?
Tubular injury.
88
What are the four major mechanisms of intrinsic renal injury?
* Diseases of Large Renal Vessels
* Glomerular and Microvascular Injury
* Acute Tubular Necrosis (ATN)
* Tubulointerstitial Injury
89
What characterizes intrinsic AKI compared to pre-renal AKI?
Injury to the renal parenchyma with persistent biomarkers despite restoration of perfusion.
90
What are the clinical management strategies for AKD?
* Monitor volume status
* Adjust drug dosing
* Watch for nephrotoxicity
91
What is a significant clinical clue for intrinsic AKI?
Persistent azotemia or proteinuria despite rehydration.
92
What is the mortality rate associated with sepsis and AKI in dogs?
Very high mortality
93
Which conditions should be tested for in dogs with AKI and systemic signs?
Leptospirosis and CRGV
94
What should be monitored daily in cases of aminoglycoside toxicity?
Signs of tubular injury
95
What is the main mechanism of Calcineurin Inhibitors?
Vasoconstriction of afferent and efferent arterioles
96
What do Calcineurin Inhibitors increase and decrease in terms of vascular agents?
↑ vasoconstrictors and ↓ vasodilators
97
What is a reported effect of chronic use of Calcineurin Inhibitors in humans?
AKI and renal fibrosis
98
What type of hypersensitivity can cause AKI and skin lesions?
Type III delayed hypersensitivity
99
What chemotherapeutic agent is known for direct tubular toxicity?
Cisplatin
100
What is the risk associated with sucrose-containing IVIG?
Osmotic nephrosis
101
What is the toxic principle of grapes, raisins, and currants in dogs?
Unknown, possibly tartaric acid
102
What is the survival rate for dogs affected by grape toxicity?
53% of reported cases
103
What are the signs of lily toxicity in cats?
* Vomiting
* PU/PD
* Ataxia
* Facial/paw edema
* Disorientation
* Azotemia
* Glucosuria
* Proteinuria
104
What is the recommended treatment for lily toxicity in cats?
Early GI decontamination + 48h IV diuresis
105
What are the lethal doses of ethylene glycol for cats and dogs?
* Cats: 1.4 mL/kg
* Dogs: 4.4 mL/kg
106
What are the toxic metabolites of ethylene glycol?
* Glycolic acid
* Glyoxylic acid
* Oxalic acid
107
What are the three phases of ethylene glycol toxicity?
* CNS depression
* Latent phase
* AKI phase
108
What diagnostic marker indicates high anion gap metabolic acidosis in ethylene glycol toxicity?
High anion gap metabolic acidosis
109
What are the clinical signs associated with melamine-cyanuric acid toxicity?
* Anorexia
* Vomiting
* Lethargy
* PU/PD
* AKI
110
What are the toxic effects of Vitamin D3 (cholecalciferol) intoxication?
Hypercalcemia leading to AKI due to nephrocalcinosis
111
What is the primary treatment for Vitamin D3 intoxication?
Bisphosphonates (e.g., pamidronate)
112
What is the diagnostic significance of serum creatinine in AKI?
Indicates decreased GFR (late marker)
113
What laboratory findings are typical in AKI?
* ↑ Creatinine
* ↑ BUN
* ↑ Phosphorus
114
What type of casts indicate tubular inflammation?
WBC casts
115
What is indicated by granular casts in urine?
Degenerated cellular casts
116
What are common signs of uroabdomen?
* Shock
* Bruising
* Abdominal distension
117
What is the typical osmolality in pre-renal AKI?
↑ (often >500 mOsm/kg)
## Footnote
Higher osmolality indicates concentrated urine due to pre-renal causes.
118
What is the sensitivity of antegrade pyelography for ureteral obstruction?
94%
## Footnote
High sensitivity makes this modality valuable in diagnosing ureteral obstruction.
119
What does an effusion creatinine level of ≥2x serum indicate?
Diagnostic for uroabdomen
## Footnote
This criterion helps differentiate between normal and abnormal fluid collections.
120
What are the indications for renal biopsy in AKI?
When the cause of AKI is unclear or glomerulonephritis is suspected
## Footnote
Renal biopsy is not first-line and follows non-invasive diagnostics.
121
What is the role of cardiac troponin I in AKI?
↑ in dogs with AKI and arrhythmias, not associated with outcome
## Footnote
This biomarker can indicate cardiac stress but does not predict prognosis.
122
What is the primary purpose of fluid therapy in AKI?
Restore and maintain intravascular volume, renal perfusion, and correct acid-base and electrolyte disturbances
## Footnote
Fluid therapy is crucial for managing AKI and preventing complications.
123
What should be avoided in fluid selection for AKI?
* 0.9% NaCl
* Synthetic colloids (e.g., HES)
## Footnote
These fluids are linked to higher risk of AKI or complications.
124
What is the normal urine output classification?
1–2 mL/kg/hr
## Footnote
Understanding urine output is essential for assessing renal function.
125
What are the common medications for managing hyperkalemia?
* Calcium gluconate
* Insulin + dextrose
* Beta-agonists (e.g., albuterol)
* Bicarbonate
* Dialysis
## Footnote
These agents help stabilize cardiac function and lower serum potassium.
126
What is the indication for using mannitol in AKI?
Attempting to convert oliguria/anuria to polyuria
## Footnote
Mannitol may help reduce tubular swelling but is not recommended if the patient is dehydrated.
127
What is an important consideration when using furosemide in AKI?
It promotes renal potassium excretion in non-oliguric patients
## Footnote
Furosemide is effective for fluid overload but not for anuric patients.
128
What are the complications of peritoneal dialysis?
* Peritonitis
* Catheter occlusion
* Excessive protein loss
* Pleural effusion
* Dialysis disequilibrium syndrome (DDS)
## Footnote
These complications highlight the need for careful monitoring during PD.
129
What is the survival rate for 30 days in dogs undergoing hemodialysis?
42%
## Footnote
Hemodialysis offers improved outcomes for severe AKI but varies by individual case.
130
What is a common gastrointestinal complication in uremia?
* Nausea
* Vomiting
* Anorexia
* Ileus
## Footnote
These complications necessitate the use of antiemetics in treatment.
131
What is the effect of renal dysfunction on drug dosages?
Affects absorption, metabolism, and excretion of medications
## Footnote
Adjustments are necessary to avoid toxicity and ensure efficacy.
132
What is the classification for absolute oliguria?
<1 mL/kg/hr
## Footnote
Absolute oliguria indicates severe renal impairment and is associated with higher mortality.
133
What are the two advanced techniques for uremic toxin clearance?
Hemodialysis (HD) and Continuous Renal Replacement Therapy (CRRT)
## Footnote
These techniques utilize a semipermeable membrane and a large-bore dual-lumen catheter.
134
What is the 30-day survival rate for dogs with AKI?
42%
## Footnote
The 30-day survival rate for cats is 48%.
135
What is the 1-year survival rate for cats with AKI?
38%
## Footnote
The 1-year survival rate for dogs is 33%.
136
What factors influence the prognosis of AKI?
Etiology and presence of oliguria or anuria
## Footnote
Anuria is a significant negative prognostic factor.
137
What is the approximate mortality rate of AKI in humans?
~50%
## Footnote
This rate has remained unchanged over decades despite dialysis availability.
138
What is the pooled mortality rate for dogs with AKI?
45%
## Footnote
The pooled mortality rate for cats is 53%.
139
How do dogs with infectious causes of AKI compare to those with toxic or ischemic causes?
They tend to fare better
## Footnote
Infectious causes include conditions like leptospirosis.
140
What is the risk increase of death for anuric dogs compared to non-anuric dogs?
20-fold
## Footnote
This statistic highlights the severity of anuria as a prognostic factor.
141
What percentage of surviving dogs with AKI normalize their serum creatinine?
19%
## Footnote
Normalization occurs within 13 days in 75% of these cases.
142
What percentage of canine AKI survivors eventually develop chronic kidney disease (CKD)?
55%
## Footnote
In cats, only 25% normalize creatinine, and half of all survivors remain azotemic.
143
What percentage of veterinary AKI patients achieve full renal recovery?
20–25%
## Footnote
Even without full recovery, patients can have prolonged survival and good quality of life.
144
What is Chronic Kidney Disease (CKD)?
Presence of structural and/or functional abnormalities in one or both kidneys that persist for ≥3 months.
## Footnote
CKD is typically irreversible and progressive, even with appropriate therapy.
145
What are some reversible contributors to azotemia that may coexist with CKD?
* Pyelonephritis
* Ureteral obstruction
* Dehydration
## Footnote
A thorough diagnostic workup is crucial to identify and treat these reversible contributors.
146
What is the prevalence of CKD in dogs?
Ranges from 0.5% to 3.74% in primary care settings.
147
What is the prevalence of CKD in cats aged ≥15 years?
15–30% of cats ≥15 years old have CKD.
148
What are the common causes of CKD in dogs?
* Juvenile nephropathy/renal dysplasia
* Tubulointerstitial nephritis
* Glomerular disease
## Footnote
Glomerular disease may be underdiagnosed due to limited biopsy use.
149
What percentage of proteinuric dogs were found to have immune-complex glomerulonephritis (ICGN) in a study?
48.1%.
150
What is the primary pathway of CKD pathology in cats?
Tubulointerstitial inflammation, atrophy, and fibrosis with secondary glomerulosclerosis.
151
What parameters are used for IRIS staging of CKD?
* Serum creatinine
* Proteinuria
* Systemic arterial blood pressure
## Footnote
These parameters guide treatment planning and prognostication.
152
What characterizes Stage 1 CKD in dogs?
Serum creatinine: <1.4 mg/dL; SDMA: <18 μg/dL.
153
What clinical signs may be present in Stage 2 CKD in cats?
Clinical signs may be absent or mild.
154
What is the serum creatinine range for Stage 3 CKD in dogs?
2.9–5.0 mg/dL.
155
What is the significance of proteinuria in CKD?
It is a negative prognostic indicator and correlates with faster CKD progression.
156
What are the key pathophysiologic dysfunctions in CKD?
* Disordered excretion of electrolytes and water
* Reduced excretion of organic solutes (uremic toxins)
* Impaired renal hormone synthesis (e.g., erythropoietin, calcitriol)
157
What is the cornerstone of CKD treatment?
Medical management aiming to minimize metabolic complications, slow progression, and enhance quality of life.
158
What is CKD-Mineral and Bone Disorder (CKD-MBD)?
A condition affecting bone and soft tissues due to dysregulation of phosphorus, calcium, magnesium, PTH, FGF23, and calcitriol.
159
What happens to FGF23 levels as GFR declines?
FGF23 clearance declines, leading to FGF23 resistance.
160
What is a common consequence of calcitriol deficiency in CKD?
Hypocalcemia.
161
What percentage of cats were found to have renal secondary hyperparathyroidism (RSHP) in a study?
84%.
162
What is the prevalence of RSHP in dogs by IRIS stage 3?
96%.
163
What is the relationship between FGF-23 and CKD progression?
Elevated FGF-23 is associated with increased risk of CKD progression and mortality.
164
What is the overall prevalence of RSHP in dogs?
75.9%
165
What is the prevalence of RSHP in dogs at IRIS stage 4?
100%
166
What condition is considered a uremic toxin that correlates with prognosis in CKD?
PTH
167
What is a central driver of CKD-MBD progression?
Phosphorus retention
168
True or False: Hyperphosphatemia is associated with poor survival in humans, cats, and dogs.
True
169
In cats, each 1 mg/dL increase in serum phosphorus correlates with what percentage increase in disease progression risk?
41%
170
What is the Ca × P product threshold in humans that correlates with increased mortality?
>72 mg²/dL²
171
In cats with CKD, what percentage had increased total calcium (tCa)?
10–32%
172
What percentage of dogs in stage 3 CKD had decreased ionized calcium (iCa)?
40%
173
True or False: Increased calcium complexing may contribute to discrepancies between tCa and iCa.
True
174
What role does magnesium (Mg²⁺) play in CKD?
Regulatory role in vascular calcification inhibition and fibrocytokine release
175
What percentage of cats with CKD had total hypomagnesemia overall?
12%
176
What is the most common manifestation of renal osteodystrophy in dogs?
Fibrous osteodystrophy of the mandible and maxilla
177
What condition is renal mineralization considered a part of in feline CKD?
CKD-MBD
178
What percentage of non-azotemic control cats had renal mineralization according to a histopathology study?
21%
179
What type of nephrolith is most common in cats?
Calcium oxalate
180
What is the clinical significance of nephroliths in CKD cats?
Potential dislodgement into the ureter leading to obstruction
181
What is the key feature of renal diets for CKD management?
Restricted phosphorus and moderate high-quality protein
182
Fill in the blank: Phosphorus goals for IRIS stage 2 should be less than _______ mg/dL.
<4.5
183
What is the mechanism of phosphate binders?
Bind dietary phosphorus in the GI tract
184
What is the effect of CKD on gut microbiota?
Increased colonic protein fermentation and uremic toxin production
185
True or False: Sevelamer carbonate is preferred over sevelamer hydrochloride due to less risk of acidosis.
True
186
What is the recommended phosphorus target for Stage 3 CKD?
2.5 – 5.0 mg/dL
187
What is the clinical importance of monitoring ionized calcium when using calcium-based binders?
To avoid hypocalcemia
188
What are the key uremic toxins contributing to CKD progression?
Indoxyl sulfate and p-cresyl sulfate
## Footnote
These toxins are significant in the pathophysiology of chronic kidney disease.
189
What promotes toxin production in CKD?
Gut dysbiosis
## Footnote
Modulation of the microbiome is a theoretical therapeutic target.
190
What are common clinical signs of CKD in dogs and cats?
Dysrexia, nausea, vomiting, weight loss, and muscle wasting (cachexia).
191
What percentage of cat owners reported abnormal appetite?
43%
## Footnote
Of those, 77% had to coax their cats to eat more than 50% of the time.
192
What are contributing factors to cachexia in CKD?
* Inadequate caloric intake due to anorexia or dysrexia
* Uremic toxins and gastrointestinal effects
* Hormonal/metabolic derangements (e.g., acidosis)
* Increased basal metabolic rate associated with CKD
* Poor body condition score (BCS)
193
What is hypergastrinemia and when does it occur?
Hypergastrinemia occurs as GFR declines in CKD.
194
What gastric lesions are more prominent in cats with CKD?
Gastric fibrosis and mineralization.
195
Is prophylactic use of H2 blockers or PPIs recommended for IRIS stages 1–3?
No, it is not recommended.
196
What is the mechanism of action of Maropitant?
NK1 receptor antagonist that blocks emetic signaling in CTZ and GI tract.
197
What appetite-regulating hormones stimulate hunger?
Orexigenic hormones (e.g., ghrelin). Usually decreased in CKD
198
What are the indications for esophagostomy feeding tubes?
Persistent weight loss, failure to meet caloric goals, progressive muscle wasting.
199
What are common contributing factors to constipation in CKD?
* Dehydration
* Hypokalemia
* Phosphate binders
* Osteoarthritis
* Anorexia and inadequate fiber intake
200
What is the mechanism of action of polyethylene glycol (PEG/Miralax)?
Osmotic agent that draws water into the colon.
201
What is the prevalence of hypokalemia in cats with CKD?
20–30% of cases.
202
What are the clinical signs of severe hypokalemia?
* Myopathy
* Cervical ventroflexion
* Plantigrade stance
203
What is the preferred form of potassium supplementation in stable cats?
Potassium gluconate.
204
What is the goal for serum potassium in CKD management?
Maintain serum K⁺ >4.0 mEq/L.
205
What is the recommended IV fluids potassium concentration for maintenance?
13–20 mEq/L
## Footnote
This is the typical range for maintaining potassium levels in IV fluids.
206
What is the maximum infusion rate limit for potassium chloride?
≤0.5 mEq/kg/hr
## Footnote
This limit is crucial to prevent complications during potassium administration.
207
What condition should be considered if hypokalemia persists despite supplementation?
Primary hyperaldosteronism (cats)
## Footnote
This condition can lead to excessive potassium loss.
208
In which group is hyperkalemia more common, dogs or cats?
Dogs
## Footnote
Particularly in those with advanced CKD or on certain medications.
209
What are the common management strategies for hyperkalemia in dogs?
* Reduce dietary K⁺
* Sodium polystyrene sulfonate
* Zirconium cyclosilicate
## Footnote
Sodium polystyrene sulfonate has risks including GI necrosis.
210
What percentage of cats with CKD develop systemic hypertension?
Up to 17%
## Footnote
This is significant during the disease course.
211
What are possible mechanisms contributing to systemic hypertension in CKD?
* RAAS activation
* Impaired sodium excretion
* Endothelial dysfunction
* Increased sympathetic tone
## Footnote
These factors complicate the management of CKD.
212
What are the target organ damages associated with systemic hypertension in CKD?
* Kidneys: Accelerated CKD progression
* Eyes: Retinal hemorrhage, detachment, blindness
* Heart: Left ventricular hypertrophy
* CNS: Encephalopathy, seizures, stroke, death
## Footnote
These complications highlight the importance of controlling hypertension.
213
When should treatment for hypertension be initiated in CKD patients?
* BP ≥160 mmHg consistently
* BP >200 mmHg once
* Evidence of target organ damage present
## Footnote
Fundic exams are critical for detecting retinal changes.
214
What are the treatment goals for systemic hypertension in CKD?
Target SBP <150 mmHg
## Footnote
Aggressive reduction is indicated for ocular or neurologic complications.
215
What are the clinical signs of anemia in CKD?
* Pallor
* Weakness
* Anorexia
* Exercise intolerance
## Footnote
These signs indicate reduced oxygen delivery to tissues.
216
What is the prevalence of metabolic acidosis in cats with CKD?
15% in IRIS stage 3, 53% in IRIS stage 4
## Footnote
This highlights the severity of metabolic disturbances in later CKD stages.
217
What are the therapeutic options for alkalinization in CKD?
* Renal diets
* Potassium citrate
* Sodium bicarbonate
## Footnote
Each option has specific benefits and should be tailored to the patient's needs.
218
What is the prognosis for cats in IRIS Stage 4 CKD?
35 days median survival
## Footnote
This indicates a poor prognosis at this advanced stage.
219
What percentage of cats had progressively increasing creatinine?
47% (101/213)
## Footnote
This indicates that not all cats with chronic kidney disease show a consistent increase in creatinine levels.
220
How does CKD progression in cats compare to dogs?
CKD progression is slower in cats than in dogs
## Footnote
This difference may influence treatment strategies and prognosis.
221
In dogs with familial nephropathies, how do they tolerate high creatinine levels?
They may tolerate high creatinine levels for longer
## Footnote
This suggests a difference in renal function resilience between species.
222
What is the median survival time for cats in IRIS Stage 2b (Creatinine 2.3–2.8 mg/dL)?
1151 days (95% CI: 1014–1565)
## Footnote
This reflects a relatively good prognosis at this stage.
223
What is the median survival time for dogs with CKD across all stages?
226 days
## Footnote
This indicates a generally poorer prognosis compared to cats.
224
How much higher is the mortality rate in dogs at Stage 3 compared to Stage 1/2?
2.6× higher mortality
## Footnote
This highlights the increased risk associated with advancing CKD stages.
225
List some prognostic indicators for cats with CKD.
* Hyperphosphatemia
* ↑ FGF-23
* Proteinuria
* Anemia
* Body weight/muscle mass
* Uremic toxin levels
## Footnote
These indicators help assess the severity and progression of the disease.
226
What additional prognostic indicators are noted for dogs compared to cats?
* Hypertension
* ↑ Ca × P product
* Low BCS and muscle mass
## Footnote
These factors provide a broader understanding of CKD effects in dogs.
227
What is the definition of perinephric pseudocysts?
Accumulation of fluid between renal cortex and capsule (no epithelial lining, hence “pseudo”)
## Footnote
This condition is commonly associated with CKD in cats.
228
What is the clinical relevance of perinephric pseudocysts?
May cause abdominal discomfort, reduce GFR (by mass effect)
## Footnote
This can lead to worsening kidney function and quality of life.
229
What management options are available for perinephric pseudocysts?
* Temporary relief via ultrasound-guided aspiration
* Surgical fenestration or laparoscopic drainage for permanent resolution
## Footnote
These approaches aim to alleviate symptoms and improve kidney function.
230
What are ideal candidates for kidney transplantation in cats?
* Stable cats in late IRIS stage 3 or early stage 4 CKD
* Not suitable: end-stage uremia or severe azotemia
## Footnote
Selecting appropriate candidates is crucial for successful outcomes.
231
What are contraindications for kidney transplantation in cats?
* FeLV or FIV infection
* Moderate to severe cardiac disease
* Neoplasia
* Recurrent infections
* Fractious temperament
* Other significant comorbidities
* Inability of the owner to provide post-op care
## Footnote
These factors can complicate the transplantation process and affect outcomes.
232
What immunosuppressive medications are used post-transplant in cats?
* Cyclosporine (lifelong)
* Prednisolone (started at surgery, tapered over months)
## Footnote
Lifelong immunosuppression is necessary to prevent allograft rejection.
233
What are some acute complications following kidney transplantation in cats?
* Hemorrhage
* Uroabdomen
* Thromboembolism
* Seizures
* Delayed allograft function
* Acute rejection
## Footnote
Monitoring for these complications is essential for postoperative care.
234
What are signs of acute rejection in transplanted cats?
* Malaise
* Anorexia
* Worsening azotemia
* Leukocytosis
* Fever or hypothermia
* Enlarged graft
## Footnote
Prompt intervention is necessary upon observing these signs.
235
What is the median survival time for cats after renal transplantation?
613–653 days in two separate studies
## Footnote
This represents a significant improvement over medical management.
236
What chronic complications can arise after kidney transplantation?
* Chronic allograft nephropathy (occurs in ~70% of feline grafts)
* Retroperitoneal fibrosis (up to 21% of recipients)
* Infections due to lifelong immunosuppression
* Neoplasia and diabetes mellitus (increased risks)
## Footnote
Awareness of these potential complications is critical for long-term management.
