Renal Failure Flashcards
Extracted Text
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acute renal failure
-Sudden loss of kidney function resulting in:
-Lack of Acid-base maintenance
-Abnormal fluid and electrolyte management
-Loss of ability for excrete nitrogenous waste
acute renal failure: signs and symptoms
-Uremia:
-Nausea
-Vomiting
-Malaise
-Altered mentation*
-Perfusion defects:
-third spacing
-Edema
-Dizziness
-Electrolyte abnormality- Abdominal pain / ileus
-hypo/hyperkalemia -> ileus bc K influences muscle
-silent bowel
-Pericardial effusion- Pericardial Friction Rub
-Electrolyte abnormality- Arrhythmias
-Platelet dysfunction- Bleeding
-buildup of nitrogenous waste -> platelets dysfunction -> capillary bleeds
-Neurologic findings
acute renal failure: pre-renal
-BUN:creatinine ratio will be > 20:1 due to increased urea reabsorption
-Look at the cause of the failure for other findings
-why isnt blood getting to kidney?
-MC cause (40-80% of ARF cases)
-Due to renal hypo-perfusion:
-Volume depletion
-Dehydration
-GI loss
-Hemorrhage
-Vascular resistance
-Sepsis, anaphylaxis
-Afterload reducing medications (ACE-I and NSAIDS combo (dilation and constriction))* -> glomerulus affected
-Renal artery stenosis- CT angiography
-Low cardiac output
-post MI
-Heart failure, PE, pericardial tamponade
-Ventilator effect from positive end pressure ventilation
-make sure urine output starts up again after surgery
acute renal failure: renal (intrinsic) caused
-Accountable for 50% of cases
-Referral to:
-Nephrologist : if signs have been present for 1-2 weeks but no acute uremia -> physiological issue
-Urologist : if signs of urinary tract obstruction -> surgical/anatomical issue
-Admit to hospital when: Sudden loss of function with abnormalities that cannot be managed as an outpatient safely
acute renal failure: renal (intrinsic) caused -> dx and tx based on condition
-Acute Tubular Necrosis
-Interstitial Nephritis
-Glomerulonephritis
acute renal failure: post renal caused
-Least common cause (5-10%)
-elderly male
-urologist referral usually- surgical issue usually
-Typically easily reversed
-Caused by:
-Urethra obstruction
-Bladder dysfunction/obstruction
-Ureteral obstruction B/L (or unilateral if single kidney)
-BPH in men
catheters
-folley catheter-
-kuday catheter- stiffer to get past obstructions
acute renal failure: post renal caused -> findings and tx
-Anuria or frequent but small volume voids
-Suprapubic pain
-Palpably or percussed distended bladder or enlarged prostate
-High BUN/creatinine ratio (like pre-renal ARF)
-Ultrasound will often find the location of obstruction!!!
-Tx:
-Bladder catheterization to allow for release of urine
-Correction of underlying cause
-Followed by saliuresis (IV saline -> flush out kidneys) and diuresis
-Prompt treatment often leads to complete reverse of injury
acute renal failure: approach to testing
-When ARF is detected, the cause should always be determined so that treatment is focused accordingly
-Immediate diagnosis is critical, if you suspect:
-Decreased renal perfusion- Test for volume status and urine output
-Glomerulonephritis (intrinsic)- Test for urine sediment, serologic tests
-Urinary tract obstruction- Renal ultrasound will be diagnostic
diff dx of ARF
-can take a day
-casts
acute renal failure: clinical criteria for staging/prognosis**
-RIFLE/AKIN criteria
-Risk/Stage 1: 1.5 x increase in serum creatinine from the baseline OR <0.5 for 6-12hrs
-Injury/Stage 2: 2-3 x increase in serum creatinine from the pts baseline OR urine output <0.5 for > 12hr
-Failure/Stage 3- 3+x increase in serum creatinine from pts baseline OR decline of urine output to <0.3mL/kg/hr for 24 hr or anuria for 12 hours
-Correlated with Outcomes:
-Loss
-ESRD risk
-Acute Kidney Injury Network
acute renal failure: stage based management***
-stage 1- why is there renal failure…work up pt
-stage 2- start decreasing meds, consider ICU (pts change status very fast)
-stage 3- renal replacement- dialysis
acute renal failure: contrast induced injury
-Changes in kidney function after administration of intravascular contrast media
-METFORMIN- BAD REACTION -> transition to sliding scale of insulin
-Prevent by prescreening for risk:
-History of prior kidney disease
-Fluid status: dehydration
-Diabetes: is the patient on metformin
-CHF/vascular disease: perfusion ability
-History of gout due to hyperuricemia
-Current use of nephrotoxic medications
-Recent exposure to IV contrast
acute renal failure: contrast induced injury- risk reduction
-NON-PHARMACOLOGIC
-Use lowest dose of IV contrast possible
-Assure adequate hydration prior to and following administration
-Decrease exposure to nephotoxic medications prior to and following
-PHARMACOLOGIC
-Consider IV volume expansion with isotonic saline or sodium bicarbonate in high risk patients has renal protective effect
-Oral n-acetylcysteine may be protective if given prior -> Be aware that allergic reaction may occur in up to 48% of people (not really used)
-Avoid use of diuretics
acute renal failure: tx with dialysis
-Initiate renal replacement therapy if: Life-threatening fluid, electrolyte or acid-base abnormalities exist
-Goals of treatment with dialysis are:
-Maintain homeostasis
-Prevent further injury to kidneys
-Permit renal recovery
-Allow treatment of underlying condition to proceed without complications
-Discontinue when patient is able to maintain by their own ability -> May need to attempt trial of intermittent dialysis (ween pt off) -> need to monitor closely
chronic kidney disease**
-a gradual, progressive loss of the ability to excrete wastes, concentrate urine, and conserve electrolytes
-memorize the stages
chronic renal failure
the continuing irreversible reduction in nephron number (corresponds to CKD Stages 3-5)
