Week 5D: Acute Kidney Injury (AKI) Flashcards
On which order does acute kidney injury occur?
Hours to days
What does “RIFLE” stand for?
Risk, injury, failure, loss, ESRD (end stage renal disease)
Risk: SERT criteria and UO criteria
-Increased CR 1.5
-UO < 0.5 x 6h
Injury: SERT criteria and UO criteria
-Increased CR 2
-UO<0.5, 12h
Failure: SERT criteria and UO criteria
-Increased CR x3
-UO<0.3, 12h or anuria 12 hr
Loss: SERT criteria and UO criteria
Persistant ARF, with complete loss of renal function for more than 4 weeks
What is the most common type of AKI and define it
Prerenal, any condition which decreases blood flow, blood pressure, or kidney perfusion before arterial blood flow reaches the kidney
Why does urine output decrease in pre renal AKI?
Arterial hypo perfusion due to low CO, hemorrhage, vasodilation, thrombosis, or other causes reduces blood flow to kidney the GFR decreases
Intrarenal AKI
Any condition that produces ischemic or toxic insult directly at parenchymal nephron tissues
Common cause is ATN from ischemia, nephrotoxin exposure or sepsis
Postrenal AKI
Any obstruction that hinders the flow or urine beyond the kidney and through the remainder of the urinary tract
What happens in the initial (1/3) stage in the clinical course of an AKI?
Increased creatinine and BUN, decreased urine output, lasting hours to days
How long may a maintenance phase last in AKI?
days to weeks
Describe what happens in the recovery phase of an AKI?
Return of BUN, creatinine, and GFR towards normal
Maintenance Phase: urinary changes
-Oliguria
-Anuria
-Urinalyssi shows casts, RB, WBC, SG around 1.010.
What does it mean if there is protenuria in the maintenance phase of AKI?
Failure is related to glomerular membrane dysfunction
What happens to a patients fluid balance when in the maintenance phase of AKI?
Fluid volume excess, as output has decreased, retention occurs
Maintenance phase: metabolic acidosis
Kidneys cannot synthesize ammonia and this is required in the hydrogen metabolism. There is also defective reabsorption and regeneration of bicarbonate
What happens in the sodium balance of a client’s AKI in maintenance phase
Damaged tubules cannot conserve Na
What builds up in the kidneys in the maintenance phase of AKI?
potassium, BUN, CR, nitrogenous waste in brain and nervous tissue
What are some hematological disorders seen with AKI
Anemia, uremia, WBC changes and altered immunity
What vitamin cannot be activated in AKI?
Vitamin D
When does the recovery phase of AKI begin?
When urine output gradually increases
When does the recovery phase of AKI end?
Acid-base, electrolytes, BUN and Cr normalizing
Why are older populations more at risk for AKI?
-fewer nephrons
-Impaired organ function
-Kidneys less able to accommodate changes in fluid volume, solute overload
What are some common causes of AKI in older populations?
Dehydration, hypotension, diuretic therapy, amino glycoside therapy, obstructive disorders, surgery, infection
What are the goals of care in AKI?
-TREAT UNDERLYING CAUSES
this is the priority
In the case of fluid overload, what diuretics would you treat the client with?
Loop (lasix), thiazide (hydrochlorothiazide), osmotic (mannitol)
How can you tell if the client’s lasix dose is adequate?
If the urinary output is more than 200ml within 2 hrs
What is the goal with volume replacement therapy?
Replace fluid and electrolyte losses and prevent ongoing losses
What drug is the first line of choice in the case of fluid depletion?
Crystalloids: 0.9NaCl, 0.45NaCl
Colloids: albumin, pentaspan
Describe the course of crystalloids and colloids in the treatment of fluid depletion
Initially, 1-3 litres of fluid, assessment to the patient’s response is critical
What is the criteria for pharmacological intervention and non-pharmacological intervention when addressing hyperkalemia in a patient with AKI
Non-pharm: <5.5 mmcl/L
Pharm: >5.5mmol/L
How would we treat hyperkalemia (non-pharm) in AKI
-Stop supplement
-Low potassium diet
What are some pharmacological measures for hyperkalemia?
-Insulin w. glucose
-Calcium gluconate
-Removal of K from body (diuretics, GI cation exchangers (kayexelate)
-Dialysis
When do we use dialysis is AKI?
K>6.5
When is a client in metabolic acidosis and what do we do in AKI?
-RRT
-pH <7.1
-Consider giving bicarbonate
How do we assess for uremia in AKI?
Anorexia, nausea, vomiting, metallic taste, altered mental status
What are some home medications that are contraindicated in AKI
-NSAIDS
-ACE inhibitors
-ARB
-Nephrotoxins
-Renally cleared
-Review dosage
Renally cleared meds
Metformin, gabapentin, cefepime, morphine
Nephrotoxins
Aminoglycoside antibiotics, amphotericin, tenofovir
What is higher priority - hypocalcemia or hyperphosphatemia?
Hyperphosphatemia
How do you treat symptomatic hypocalcemia?
Intravenous calcium
How do you treat hyperphosphatemia?
Calcium carbonate, restrict diet, RRT
How do you treat hypomagnesia?
IV, PO supplements
How do you treat hypermagnesia?
LImit intake, diuretics, RRT
Describe the follow up care for AKI
Daily weights, fluid intake and output, daily electrolytes and Creatinine, follow up assessment to guard recurrent AKI, CKD, end stage renal disease
