Acute Kidney Injury (AKI) Flashcards
What is AKI?
an abrupt decline in kidney function
Where is damage most often in AKI?
renal tubules
What are 3 causes for AKI?
infectious agent
toxin
ischemia (decreased blood flow to kidneys)
Examples of toxins
aminoglycosides
NSAIDs
IV rad contrast agents
ethylene glycol
Examples of infectious causes
leptospirosis
bacterial pyelonephritis
Examples of ischemic causes
heat stroke hypovolemic shock septic shock severe hemorrhage thrombus or embolism
What is the primary pathologic change in AKI?
abrupt decrease in glomerular filtration
What happens when there is a decrease in glomerular filtration?
- less toxins filtered from blood –> more toxins left in blood stream –> damage renal tubules –> normal secretion/absorption of electrolytes/water can’t happen
- less production of filtrate (urine)
- cellular hypoxia and damage to renal tubular cells due to lack of O2 and energy supply
What is another cause for pathologic change that can occur within the kidney in AKI?
tubular obstruction
What happens with tubular obstruction?
- secondary to accumulation of dead cells and debris within tubular lumen
- decreases urine production
- leads to cellular damage that further potentiates tubular dysfunction
- inability to regulate the loss of certain electrolytes and water –> unable to conserve water despite dehydration
GI tract pathology that can result for AKI
toxins accumulate in bloodstream due to decreased glomerular filtration –> direct damage to GI mucosa
Gastrin (hormone responsible for acid secretion within stomach) is not filtered and excreted properly –> gastrin levels rise –> more acid gets secreted as a result –> gastric acidity increases
Both of these things lead to gastric or duodenal ulcer formation
changes to CBC due to AKI
- normal
- leukocytosis if infectious agent
- moderate to severe regenerative anemia if GI ulcer with hemorrhage is present
- hemoconcentration if severe dehydration
What’s the deal with azotemia and AKI?
cannot be properly evaluated unless the body’s ability to concentrate urine is evaluated at the same time, so biochem panel and UA must be obtained at the same moment in time prior to giving IV or SQ fluids
Sudden onset of azotemia in the presence of…
isosthenuria (SG 1.070-1.012) OR inappropriate SG (<1.030)
Electrolyte abnormalities seen with AKI
hyperphosphatemia
hyperkalemia
(kidney unable to excrete P or K)
UA abnormalities with AKI
- cellular casts if renal tubular damage
- WBC and bacteria if pyelonephritis is present
Clinical signs common with AKI
- sudden onset, usually within hours to days of exposure to underlying cause
- good BCS b/c sudden onset
- lethargy/weakness
- anorexia
- vomiting (fresh red blood or dark black digested blood if ulcer present)
- generally look quite ill
List the therapeutic strategies used to treat AKI
- identify and eliminate underlying cause
- IVF therapy
- Peritoneal dialysis
- Hemodialysis
If AKI underlying cause is bacteria
- send off urine for culture and sensitivity
- use appropriate antibiotic
If AKI underlying cause thought to be a toxin
use antidote if available
if AKI underlying cause though to be a medication
evaluate all meds patient is on and discontinue the med that is suspected
Purpose of AKI IVF therapy
- maintain fluid, electrolyte, and pressure balance
- promotes elimination of excessive circulating toxins
- rehydrates patient
- replaces ongoing losses
What meds may be used in addition to IVF therapy?
Hint: 3-4 types of meds are used
- Diuretics and/or vasodilators to attempt to increase blood flow to kidneys and subsequently increase urine flow
- antiemetics if vomiting
- H2 inhibitors to help manage the increased gastric acidity
What is peritoneal dialysis
decreases circulating toxins and excessive electrolytes by drawing them into a solution that has been instilled into the abdominal cavity; solution sits in the cavity until toxins and electrolytes have had time to move from bloodstream to solution
solution is removed from the abdominal cavity via gravity and the process is repeated thru the day and night
What is hemodialysis?
eliminates the toxins and excessive electrolytes in blood by removing the blood from patient and circulating it through a machine that cleanses the blood and returns it to the patient
What nursing things are done to monitor an AKI patient?
- place an indwelling urinary catheter to measure the amount of urine produced to help determine how to manage fluid therapy and medical management
- monitor for overhydration by weighting q4hr and auscultation of lungs q4hr for crackle sound (pulmonary edema); also check PCV and total solids several times daily
