Renal - Acute Kidney Disease Flashcards
What acute kidney injury?
A sudden decline in renal function leading to the retention of nitrogenous wastes
What is AKI in regards to creatinine?
It is a small increase in creatinine
Generally, what are the pre-renal causes of AKI?
inadequate delivery of blood flow to the kidneys which decreases GFR
Generally what are the renal causes of AKI?
direct damage to some part of the kidney (majority of cases are tubular damage)
Generally what are the post-renal causes of AKI?
Decreased GFR due to increased hydrostatic pressure secondary to obstruction
What are the most commonly seen intrinsic factors of AKI?
leptospirosis, pyelonephritis, ischemia, and toxic
What are the risk factors for (hospital-acquired) AKI?
volume depletion/hypoperfusion, anesthesia and surgery, sepsis, and nephrotoxic drugs, and pre-existing renal disease
What are the four phases of the pathophysiology of AKI?
initiation, extension, maintenance, and recovery
What occurs during the initiation phase of AKI?
Renal insult occurs; phase ends when there is a definable decrease in function
What occurs during the extension phase of AKI?
Injury is perpetuated by hypoxia, inflammation, etc.
What occurs during the maintenance phase of AKI?
Critical damage has occured; duration is variable (weeks)
What occurs during the recovery phase of AKI?
Renal damage is repaired; duration variable (weeks to months)
When is the best time to intervene with treatment for AKI?
During the initiation phase
What history is associated with AKI?
Acute-onset (hours-days) of clinical signs, vomiting, diarrhea, loss of appetite, lethargy, and variable urination changes
May or may not have toxin exposure
On PE what will you see in patients with AKI?
Usually good body condition
Variable hydration
+/- uremic breath/halitosis, oral ulceration
+/- renal enlargement or pain
+/- other physical exam findings depending on underlying disease
What CBC changes may be found in AKI patients?
+/- anemia
What may you find on chemistry in an AKI patient?
Azotemia, hyperphosphatemia, metabolic acidosis, variable K values (hyperkalemia with oliguria/anuria)
What may you find on UA in a patient with AKI?
Isosthenuria or minimally concentrated urine
Proteinuria or glucosuria may be present
Casts will indicate ongoing damage
What additional diagnostics should you consider with AKI patients?
Leptospirosis testing if indicated, urine culture, ethylene glycol testing, abdominal testing, blood pressure
What are the treatment goals for patients with AKI?
Stop the ongoing injury, aid in the recovery of kidney cells, and support the patient by managing complications
What should you do first in patients with AKI?
Diagnose and treat for specific underlying etiology whenever possible
What non-specific supportive care can be provided until renal recovery?
Fluid balance, electrolytes, acid base status, blood pressure, GI complications, and nutrition
How is urine output in AKI?
It can be increased, normal, or decreased to absent
What urine output is associated with polyuria?
> 2 ml/kg/hr
What urine output is associated with oliguria?
<0.5-1 ml/kg/hr
What are the different components of fluid replacement requirements?
Maintenance, replacement, and ongoing losses
Fluid maintenance for AKI is primarily made up of what?
urine output
What are you replacing in AKI patients (fluids)?
volume to be replaced in a dehydrated patient
What ongoing losses are you replacing in AKI patients?
vomitting, diarrhea, polyuria, and drain output
How does hyperkalemia affect the electrical potential in cells?
It makes the resting membrane potential less negative
What ECG changes are associated with hyperkalemia?
Bradycardia, tall spiked T waves, widened QRS, short QT interval, and small/absent P waves
What can be administered to manage hyperkalemia?
Calcium gluconate, insulin/dextrose, bicarbonate, and albuterol
How does calcium gluconate affect hyperkalemia?
It counteracts the effect of potassium on the cardiac cells
How does insulin/dextrose affect hyperkalemia?
It promotes a K shift from the extracellular to intracellular space
How does bicarbonate affect hyperkalemia?
It promotes alkalosis which promotes an intracellular shift
How does albuterol affect hyperkalemia?
It promotes an intracellular K shift
True or False: Hypertension is not a common finding in AKI patients.
False - it can affect up to 80% of dogs with AKI
What is hypertension exacerbated by in AKI patients?
fluid overload
If systolic blood pressure is >180mmHg in AKI patients, what should you do?
Correct over-hydration if possible and treat with amlodipine
Why does metabolic acidosis occur in AKI patients?
Failing kidneys are unable to excrete H or reabsorb HCO3
What can be administered in severe cases of severe acidosis?
sodium bicarbonate
Why is nausea and vomiting commonly associated with AKI?
How is it treated?
Uremic toxins stimulate the chemoreceptor trigger zone
anti-emetic medications
How do you treat GI bleeding that may or may not be associated with AKI?
with proton-pump inhibitors +/- sucralfate
What nutritional support should be given to AKI patients?
Since they are highly catabolic they should get assisted enteral nutrition (feeding tube) if they are hospitalized
What may cause anemia in AKI patients?
GI bleeding, thrombopathy due to uremia, repeated blood sampling, and loss secondary to dialysis
What treatment may be indicated for anemia in AKI patients?
Blood transfusion or erythropoetin supplementation
What is the prognosis for AKI?
~50% mortality rate - 25-50% of survivors will have persistent azotemia
What are the poor prognostic indicators for AKI?
Oliguria/anuria and hyperkalemia
What is renal replacement therapy?
The removal of uremic toxins and electrolytes with hemodialysis
Excessive fluid is removed using differences in osmotic pressure
