Veterinary Medicine - Urinary Tract Diseases Flashcards
Urine stick - What are 3 unreliable parameters?
Nitrates / Nitrites, Leukocytes, USG
Renal patients tend to suffer from Hypotension/Hypertension
Hypertension
US-guided kidney biopsy - Main indications
Proteinuria, Kidney mass
Kidney biopsy - From what region of the kidney are biopsies usually taken? Why?
Renal cortex. As to not damage the Arcuate blood vessels between the cortex and medulla
Low USG - When to suspect inability to concentrate urine? (4)
Persistently low USG, Cat with low USG, Concurrent Pu/Pd, Inappropriately low USG in the face of dehydration
Causes for elevated Creatinine
Pre-Renal: Dehydration. Renal: AKI, CKD. Post-renal: Bladder rupture, Urinary tract block
Causes for elevated Urea
Pre-renal (dehydration), Renal and post-renal causes. GI Bleeding. High protein diet. Catabolic states
Causes for elevated Urea
Pre-renal (dehydration), Renal and post-renal causes. GI Bleeding. High protein diet. Catabolic states
AKI - Ethylene Glycol toxicity - What is the antidote? How does it work?
4-MP Ethanol. Alcohol dehydrogenase works on Ethylene Glycol and to produce Oxalate. Ethanol acts as a substitute-substrate (Competitive inhibition)
AKI - Ethylene Glycol toxicity - Damage to the kidney is reversible (T/F)
False
Why Is AKI usually associated with hypocalcemia?
AKI => Decreased GFR (Oliguria/Anuria) => Phosphorus excretion decreases => Phosphorus binds with calcium => Calcium concentration in the blood decreases
AKI - Grapes / Raisins toxicity - Main panel finding associated with this cause for AKI
Hypercalcemia
AKI - Ethylene Glycol toxicity - Clinical signs
Lethargy, Anorexia, Vomiting, Halitosis, Oliguria / Anuria, CNS signs (e.g. Ataxia, Depression, Stupor)
AKI - What are the characteristics of the ““Recovery stage”” in AKI?
Polyuria. Normalization of azotemia and electrolytes
Contraindications for Mannitol? Why?
Overhydration / Hypertension. Draws fluids from the extra to the intravascular space through osmotic pressure and can further worsen overhydration / hypertension
AKI - Hyperkalemia - Treatment options
Fluids, Dextrose, Insulin, Bicarbonate. *Calcium gluconate - doesn’t treat the hyperkalemia itself but protects the cardiomyocytes from its deleterious effects (e.g. bradycardia, arrhythmias)
AKI Treatment - What is the common acid-base imbalance caused by kidney disease? How to correct it?
Metabolic Acidosis. HCO3- to be added to fluids = Body weight X 0.3 X Base-deficit. Can be corrected over a long period of time (e.g. 12-24 hours in CRI) or shorter times (e.g. half the amount over 1-2 hours, the other half over 4-6 hours)
AKI - Explain the mechanisms behind metabolic acidosis in kidney patients
Decrease in HCO3- production and reabsorption by the kidney. Decrease in H+ excretion by the kidney
AKI Treatment - Why is the usage of D5W especially important in AKI patients as opposed to other patients?
Patients with functioning kidneys can easily regulate increased amounts of electrolytes (e.g. Sodium, Chloride) coming from IV fluids and excrete the surplus in the urine. Kidney patients suffer from decreased to completely halted GFR and therefore are at risk for developing electrolyte imbalances (e.g. Hypernatremia). D5W is comprised of dextrose and free-water not associated with sodium, therefore not burdening the kidneys as much as saline/LRS, and should be added to them to decrease the overall electrolytes intake in oliguric/anuric patients
AKI - What are the general indications/considerations when administering Mannitol? And Furosemide? Explain
Mannitol - When dehydration has been corrected and the patient is still oliguric/anuric. Furosemide - When the patient is overhydrated (Furosemide doesn’t increase the fluid volume in the intravascular space like Mannitol does). Also considered a more effective diuretic and used when Mannitol isn’t producing the desired effect.
AKI - General considerations on when to give fluids and when to give diuretics?
Fluids (Saline/LRS +/- D5W) - Until dehydration is corrected. After that - give based on the amount of urine production (“in Vs. out”) until the kidneys recover. Diuretics - After correction of dehydration + urine production is insufficient. Also, used to correct overhydration due to fluid therapy
Hypertension - What are the most commonly affected organs?
Brain, Eyes, Kidney, Heart
AKI - Hypertension - Treatment options
Amlodipine (Usually 1st choice in both dogs and cats in AKI), Hydralazine, Nitroprusside, ACE-i /ARB (secondary drugs, not enough as sole treatment for hypertension due to AKI)
AKI - Prognosis - from the time of initial insult to the kidneys - over what period of time can the kidneys continue to heal (i.e. Creatinine decrease on follow up)
3 Months. after that - further decrease in creatinine is unlikely
AKI - Etiology-specific prognosis - Leptospirosis | Pyelonephritis | Ethylene Glycol | Lilly | Grapes, Raisins | Gentamycin | NSAIDS, ACE Inhibitors
Leptospirosis - Good & Reversible. Pyelonephritis - Good. Ethylene Glycol - Not reversible. Lilly - Severe, not reversible. Grapes/Raisins - Good & Reversible. Gentamycin - Potentially reversible. NSAIDs, ACE-i - Reversible
CKD - What is the corner stone of treating CKD? How does it help?
Renal-diet. -Contains less protein that is broken down to produce Urea -Less phosphorus -Less sodium -More omega-3 fatty acids
AKI Treatment - Describe general overview of AKI treatment and give examples for treatment options
-Treat underlying issue if possible! -Rehydrate if necessary -Promote urine flow - diuretics (Mannitol/Furosemide) -Once euvolemic - In vs. Out -Treat hyperkalemia (Bicarbonate/Dextrose + Insulin || Calcium Gluconate) -Treat hypertension (Amlodipine) -Treat acidosis (Bicarbonate) -Treat GI Symptoms (Anti-Emetics, GI Protectants, Pro-Motile, Appetite stimulant) *Dialysis if possible/indicated/no response to conventional treatment
CKD - General treatment - Various pathologies that may have to be addressed in a CKD patient
Treat underlying cause if possible. Fluids if tends to get dehydrated (usually SQ). Renal diet, Anti-emetics, Appetite stimulants. Treat hypertension (first choice: Dogs - ACE-i, Cats - Amlodipine). Treat hyperphosphatemia (Renal diet, Phosphorus binders). Treat Anemia (Blood transfusion, Darbepoetin). Treat acidosis (Bicarbonate). Treat electrolyte imbalances
CKD - Clinical signs
Decreased appetite, Weight loss, Vomiting, Nausea, PUPD, Pale mucus membranes, Halitosis
CKD - Stage 1 - Creatinine-levels, Lab findings
<1.4 mg/dL (dogs). <1.6 mg/dL (cats). -Low USG -Proteinuria -Underlying kidney pathology that has not caused azotemia yet (e.g. Neoplasia, Polycystic kidney disease)
CKD - Stage 2 - Creatinine-levels? Lab findings
1.4-2.8 mg/dL (dogs). 1.6-2.8mg/dL (cats). Aside from azotemia and stage 1 abnormalities - usually no additional lab finding and clinical signs mild to absent
CKD - Stage 3 and 4 - Creatinine levels, Lab findings
Stage 3: 2.9 - 5 mg/dL. Stage 4: > 5mg/dL. Anemia, Electrolyte Imbalance, Acidemia
CKD - What are the 3 elements of CKD staging
Creatinine levels, Degree of proteinuria (UPC), Blood pressure
CKD Treatment - Why is low protein diet important in CKD patients
Leads to decreased urea production and thus decreases the deleterious effects of increased urea: Nausea, Vomiting, GI ulceration, Bleeding tendencies. Also - reduces phosphate load. Reduces acidosis
Hyperphosphatemia occurs in AKI/CKD and is treated in AKI/CKD
Occurs in both (usually to a greater degree in AKI due to lack of compensatory mechanisms). Treated only in CKD
Explain the calcium and phosphate changes in CKD
Phosphate concentration in the blood increases => Hyperphosphatemia => Phosphate binds to ionized calcium => Hypocalcemia. Hypocalcemia + Hyperphosphatemia => Increase in PTH => Secondary hyperparathyroidism. Through the regulation of PTH - calcium concentrations is kept at normal-low levels and the degree of hyperphosphatemia is lessened.
CKD Treatment - Hyperphosphatemia
Renal diet. Phosphate binders (e.g. Aluminum Hydroxide)
CKD Treatment - Hypertension
Dogs - ACE-i (First choice), Amlodipine (2nd choice). Cats - Amlodipine (First choice)