Urinary system & renal emergencies Flashcards
In oliguric renal failure, what is the main goal of therapy and what diuretic strategy is used?
To increase urine production, reduce tubular obstruction and increase kaliuresis.
Osmotic and loop diuretics i.e. frusemide and mannitol (after rehydration) are used.
Urosepsis
Sepsis associated with a complicated UTI (bacterial pyelopnephritis, pyonephrosis, renal abscess, fungal infection, bladder perforation, prostatic/testicular infections)
Most common uropathogen
E. coli (<50% of all cases)
Local host defense mechanisms preventing ascending UTI
Normal microturition
Extensive renal blood flow
Normal urinary tract anatomy
Urethral and uteral peristalsis
Mucosal defense
Antimicrobial properties of urine
Systemic immunocompetence
Risk factors for UTI
Abnormal urinary anatomy
Urinary obstruction
Nephrolithiasis
Prior UTI
Renal failure
Neurologic disease
DM
Hyperadrenocorticism
Immunosuppresion
Clinical and lab findings in urosepsis patients
lethargy
fever of hypothermia
hyperaemic MM
tachycardia
tachypnoea
bounding pulses
positive blood culture
leukogram (+- left shift)
Azotaemia
Urine sediment
MODS (and signs of MODS)
Aggressive treatment of urosepsis
IVFT
Broad-spectrum antimicrobials
Addressing the underlying cause
Pyelonephritis
The kidneys and ureters are affected most commonly by ascending bacteria
Signs of pyelonephritis
Febrile
Anorexia
Lethargy
Dehydration
Recent weight loss
Enlarged and painful kidneys
PU/PD
Vomiting
Lab and imaging findings with pyelonephritis
Azotaemia
Neutrophilic leukocytosis with left shift
Metabolic acidosis
mild to moderate pelvic and ureteral dilation
Poorly concentrating urine
Bacteriuria
Pyuria
Proteinuria
Haematuria
+- granular casts
Treatment of pyelonephritis
Removal predisposing factors
IVFT
Broad-spectrum antimicrobials (4-8 weeks)
Urine C&S
Nephrectomy
Ureteral stent
Bladder rupture
Usually occurs after blunt force trauma, penetrating injuries, aggressive catheterisation, prolonged urethral obstruction or excessive force when palpating the bladder.
Signs of bladder rupture
Vomiting
Anorexia
Depression
Abdominal pain
Systemic inflammation
Diagnosis of uroabdomen/uroperitoneum
Comparing abdominal fluid to peripheral blood creatinine and/or potassium ratios. A fluid to serum potassium ratio > 1.4 to 1 has 100% sensitivity and specificity for uroabdomen. A fluid to serum creatinine ratio > 2 to 1 has a 100% specificity and 86% sensitivity
Prostatic infection
bacterial colonisation via ascension of urethral flora or hematogenous route.
Clinical signs of prostatic infection
Anorexia & weight loss
Vomiting
Tenesmus & rectal pain
Lethargy
Fever
Dehydration
Injected MM
Caudal abdominal discomforrt
Haematuria
Pyuria
Stranguria/incontinence
Lab findings of prostatic infection
Mature neutrophilia and evidence of left shift
Septicaemia
Endotoxaemia
Inflammatory changes in prostatic fluid
Imaging findings of prostatic infection
Prostatomegaly
Localised peritonitis
Cyst like structures
Treatment of suppurative prostatitis and prostatic abscessation
IVFT
Treat cardiovascular shock
Antimicrobial therapy
The RAAS system works to:
a. increase perfusion to the kidneys
b. decrease blood pressure
c. increase sodium excretion
d. decrease serum potassium levels
A
Which of the following is an example of intrinsic kidney injury?
a. Hypovolemic shock
b. Urinary obstruction
c. Grape toxicity
d. Ureteroliths
C
Sodium bicarbonate, insulin, and beta-2 adrenergic agonists can all be administered to treat:
a. azotemia
b. hyperkalemia
c. oliguria
d. stage 2 AKI
B
Which of the following antibiotics is an acute renal toxin?
a. Amikacin
b. Metronidazole
c. Penicillin
d. Cefazolin
A
In veterinary acute kidney injury staging, stage 3 patients have a:
a. creatinine increase of <100% from baseline
b. creatinine increase of 150–199% from baseline
c. creatinine increase of 200–299% from baseline
d. creatinine increase of >300% from baseline
D
When performing peritoneal dialysis, dextrose concentrations of 2.5% are used in which patients?
a. Normovolemic
b. Dehydrated
c. Mildly overhydrated
d. Severely overhydrated
C
Glucose is reabsorbed in which section of the nephron?
a. Proximal convoluted tubule
b. Loop of Henle
c. Distal convoluted tubule
d. Collecting duct.
A
Which of the following is not nephrotoxic in dogs?
a. Ethylene glycol
b. Xylitol
c. Raisins
d. Ibuprofen
B
Which of the following is not a cause of postrenal azotemia?
a. Urethral obstruction
b. Prostatic disease
c. Ureteroliths
d. Hypovolemic shock
D
patient producing 0.4^mL/kg/h of urine would be classified as what level of urine output?
a. Anuric
b. Oliguric
c. Normal
d. Diuresis
B
Which of the following diseases is best treated with intermittent hemodialysis over CRRT?
a. Ethylene glycol toxicity
b. AKI
c. Heat stroke
d. Chronic kidney disease
D
Which of the following patients may need packed red blood cells to prime the CRRT pump?
a. A cat with lily toxicity
b. A Labrador with AKI
c. A husky with ibuprofen toxicity
d. A rottweiler with sepsis
A
A patient suffering from AKI and fluid overload would benefit from which of the following treatments?
a. Continuous venovenous hemodialysis
b. IV fluids prior to CRRT
c. Slow continuous ultrafiltration
d. Continuous venovenous hemofiltration
C
Which of the following drugs is renal replacement therapy not an ideal treatment for?
a. Amikacin
b. Bupivacaine
c. Phenobarbital
d. Sotalol
B
Diffusion is defined as which of the following?
a. Movement of solutes from a higher concentration to a lower concentration
b. Movement of fluid through a semi-permeable membrane via a pressure gradient
c. Movement of solutes with water flow
d. Adhesion of molecules from a liquid to a solid surface
A
Which of the following is a complication of CRRT?
a. Hyperthermia
b. Hypertension
c. Hyperkalemia
d. Hemodilution
D
A complication of dialysis that stems from the development of cerebral edema due to rapid changes in osmolality of the blood is called what?
a. Cerebral ischemia
b. Dialysis disequilibrium
c. Azotemia
d. Hyperelectrolytism
B
Why is anticoagulant therapy a mainstay of hemodialysis treatment?
a. To thin the blood to go through the dialysis catheter
b. To prevent clot formation in the extracorporeal circuit
c. To balance the thrombus-inducing effects of the dialysate
d. To maintain a state of homeostasis
B
Which of the following toxins is most likely to warrant treatment with dialysis?
a. Xylitol
b. Zinc
c. Ethylene glycol
d. THC
C
Which molecule would not be found in a dialysate?
a. Dextrose
b. Sodium
c. Chloride
d. Albumin
D
Kidney function
Maintain homeostasis by blood filtration, reabsorption and excretion
What regulates the excretion & retention of water?
Antidiuretic hormone (ADH) released from the pituitary gland
Normal kidney size
2.5-3X larger than L2
Kidney location
Retroperitoneal cavity
Nephron
Basic functional unit of the kidney
Cats: 190,000
Dogs: 415,000
Renal corpuscle
Filters the blood in the first stage of urine production, producing glomerular filtrate
PCT
resorptive and secretory functions producing primitive urine. Glomerular filtrate -> tubular filtrate.
Reabsorbs 50-55% filtrated water, phosphorus, glucose and sodium.
L.O.H
electrolyte exchange, absorption & secretion
Absorbs Na, Cl, Ca, Mg but is impermeable to water making filtrate hypo-osmolar.
DCT
Empties tubular filtrate into a series of collecting ducts into the renal pelvis and onto the ureter.
Sodium & chloride further absorbed but NO absorption of water.
Sensitive to parathyroid hormone (regulates Ca reabsorption)
Collecting ducts
Determines urine volume as this is the primary acting site of ADH, regulates K and plays a role in acid-base.
Fluid hypo-osmolar approx. 100mOsm/kg
How much blood supply from the heart does the kidney receive?
25%
Renal artery
Comes from the abdominal aorta entering the hilus of the kidney and further subdividing into smaller arteries & arterioles (afferent & efferent)
Afferent glomerular arterioles
Carry blood to the glomerular capillaries of the renal corpuscle
Efferent glomerular arterioles
surround the nephron and transfer oxygen to the cells
Renal vein
Leaves the kidney hilus and joins the abdominal portion of the vena cava (purest blood in the body)
Mean renal arterial pressure and glomerular capillary pressure
100mmHg & 50-55mmHg
Filtration of blood
Occurs in the renal corpuscle