Diagnosis and Management of Different CKD Stages Flashcards
describe uremia
uremia: accumulation of substances (uremic toxins) usually excreted in the urine under normal physiologic conditions
origin of many uremic toxins:
-dietary protein: amino acids are metabolized by GI bacteria, then liver
with uremia, we have concerns for:
1. clinical signs (dysrexia, nausea, vomiting)
2. CKD progression
3 CV disease
4. microbial diversity altered in CKD; increase of bacteria that produce uremic toxins
desribe antiuremic therapy
- therapeutic renal diets:
-reduced protein substrate and soluble fiber - pre/probiotics: improve bacterial metabolism
- uremic toxin binders: bind toxin precursors in GI
-reduces serum uremic toxin concentrations in cats
-unknown if meaningful clinical benefit
describe uremic syndrome
- most prominent clinical signs of uremia in patients are related to GI tract (due to chemoreceptor trigger zone): nausea, vomiting, dysrexia are common
- this is problematic bc adequate caloric support is crucial for chronically ill patients and CKD results in an increased metabolic state
- urea in saliva can be degraded to ammonia by urease producing bacteria and cause gastric ulcers
describe uremic gastropathy
- decreased renal excretion leads to hypergastrinemia which leads to hyperacidity and uremic gastritis (ulcers, edema)
- not as severe in dogs and cats
-dogs show gastric edema and mineralization
-cats show gastric fibrosis and mineralization
-antacids? yes if clinical suspicion of GI ulceration; not automatically need gastric acid suppression
describe CKD nutritional therapy
- renal diets: most likely to enhance longterm survival and QOL for patients in stage 3 and 4
- key nutrients:
-high quality, reduced quantity protein: beneficial for balance of nitrogenous waste, reducing uremic crises,
proteinuria/glomerular hypertension
-supplemented with omega 3 faty acids: beneficial for glomerular hypertension, proteinuria, inflammation
-reduced phosphate: beneficialy for phosphate retention, CKD mineral and bone disorder
reduced sodium: beneficial for sodium retention and SAH
supplemented with potassium: beneficial for hypokalemia
-added antioxidants: beneficial for nephron hyperfunction, oxidative damage
-added soluble fiber: nitrogenous waste balance (colonic bacteria), constipation
-increased caloric density: acceptability, cachexia
-alkalinizing agents: metabolic acidosis
-supplemented with B vitamins: wasting of water-soluble vitamins
describe the controversies of protein restriction
potential benefits:
-decrease uremia
-decrease renal ammoniagenesis
-decrease tubular hyperfunction by decreasing renal acid load
-decreasing phosphate load
-decreasing TGF-B
-decreasing intraglomerular progression
-decreasing proteinuria
potential detriments:
-loss of lean body mass
-decreased protein synthesis
-protein energy wasting
goal: to decrease dietary protein enough to achieve these benefits but now so much as to contribute to lean body mass loss
describe hypokalemia and CKD
- polyuria causes excessive kaliuresis (less opportunity for reabsorption)
- RAAS activation causes potassium loss
- metabolic acidosis causes intracellular potassium depletion
- common in cats with stage 2 and 3 CKD
- less common in cats with stage 4 bc GFR so reduced that is isn’t lost as much
-less common in dogs on RAAS blockers
describe clinical signs of hypokalemia
moderate: muscle weakness, lethargy, inappetence, constipation
severe: myopathy: cervical ventroflexion and plantigrade stance; arrhythmias
describe treatment of hypokalemia
- renal diets: supplemented with Kt and alkalinizing
- further supplementation:
-oral route is safest and preferred
–potassium citrate (alkalizing) or potassium gluconate daily to effect
–parenteral: KCl; IV for hospitalized patients; may be added to SQ fluids
describe metabolic acidosis
- retention of acids that are normally excreted by the kidneys
-the kidneys lose the ability to excrete the daily acid load as ammonium and titratable acid - can contribute to malaise, inappetence, skeletal muscle loss, and muscle weakness, and hypokalemia
- treatment:
-most renal diets are alkalinizing = first step
-if acidosis persists:
–sodium carbonate
–potassium citrate
–daily supplementation
describe inappetance and CKD
possible reasons:
1. acid-base and electrolyte imbalances
2. severe anemia
3. uremic toxins stimulating CTZ (nausea/vomiting)
4. uremic gastropathy
5. oral disease
6. multiple medications
possible solutions:
1. treat acid-base and electrolyte derangements
2. correct severe anemia
3. treat oral disease
4. modify pilling technique for medication aversion
5. antiemetics/antinausea therapies: ondansetron, maropitant citrate, mirtazapine, capromorelin
6. feeding tubes
describe CKD challenges with water balance
- if animals are obligatorily polyuria they are prone to dehydration
- provide hydrations support:
-fresh water available at all times for drinking
-use canned food, add warm water if needed
-regular SQ fluid admin: LRS more common, only if challenges with oral hydration - dehydration management:
-if there are fluid losses, correct clinical dehydration with isotonic polyionic replacement fluid solutions
describe constipation and CKD
- common in cats with CKD, likely a dysfunction of water balance
-chronic subclinical dehydration increases colonic absorption of water
-hypokalemia decreases colonic motility
-phosphate binders may promote constipation
-concurrent osteoarthritis may affect posturing - evaluation:
-thorough history and PE
-serum biochem
-abdominal radiographs: fecal load and lumbosacral/hip joints - treatment:
-hydration
-correct electrolyte abnormalities
-adjunctive management of OA
then, depending on severity/chronicity:
-added fiber
-oral laxatives
-prokinetics
-enemas
what are all the things to consider in CKD? NEPHRONS and shit
Nutrition
Electrolytes
Ph of blood (acid-base status); proteinuria
Hydration
Retention of wastes (uremia)
Other renal insults-avoid
Neuroendocrine function: hyperparathyroidism, hyproproliferative anemia, and hyeprtension
Serial monitoring: CKD is irreversible and progressive
SHIT: defecation/constipation
what are 4 general recommendations for any stage of CKD?
- discontinue all potentially nephrotixic drugs if possible
- ID and treat and prerenal and postrenal abnormalities
- rule out any treatable conditions like pyelonephritis and renal urolithiasis
- measure blood pressure and UPC
-treat proteinuria/SAH if present - ensure hydration, document that care is needed with blood pressure under anesthesia, increase monitoring frequency (frequent rechecks)
