Acute Renal Failure
To compensate for elevated serum phosphate and in response to decreased absorption from the intestine, calcium levels
decrease
Prerenal azotemia (60% of ARF) is caused by reduced blood flow to the kidney resulting in...
decrease in GFR and urine output
What causes increased instances and mortality with ARF in the elederly
decrease in number of functional nephrons decrease renal blood flow atherosclerosis of renal arteries
What can increased the metabolic rate and catabolism and should be prevented/treated promptly
fever and infection
Treatment of intrarenal ARF
supportive therapy removal of causative agent aggressive mgmt of shock and infection
How often should a weight be obtained for ARF clients
daily
When hyperkalemia, metabolic acidosis, pericarditis, FVE, pulmonary edema occur, what may be needed to maintain homeostasis
dialysis or continuous renal replacement therapy
What can prevent the client from moving and turning without assistance
drowsiness and lethargy
The nurse observes for FVE manifested by
dyspnea, crackles, tachycardia, hypertension and distended neck veins generalized edema in presacral and pretibial areas
CVP will be
elevated
As urine output decrases, clients are at risk for...
hyperkalemia as the kidneys cannot excrete K
As metabolic acidosis develops, normal renal buffering mechanisms fail resulting in....
hyperventilation Kussmaul - more rapid and deep attempting to blow off CO2 and restore normal serum pH
The recovery phases signals
improvement of renal function and energy levels
Serum phosphate levels
increase
If caloric intake is insufficient to prevent the breakdown of body protein, additional nitrogenous waste accumulates causing
increased uremic sx
Most serious complication of ARF
infection
Mgmt of ARF includes
maintaining fluid and lyte balance avoiding fluid excesses supporting pt until renal tissue is repaired and function is restored
myoglobinuria
myoglobin (protein released from muscle with injury) and hgb are liberated causing obstruction, renal toxicity and ischemia trauma, crush injuries, burns can be described as rhabdomyolysis (breakdown of skeletal muscle)
Urine with ARF
oliguria is typically present hematuria may be present SG is low r/t inability to concentrate urine urine sodium is low urinary casts and other cellular debris may be present
Four phases of ARF
onset/initiation oliguric diuresis recovery
Treatment of prerenal azotemia
optimize renal perfusion with fluids or treatment of decreased cardiac output
What may be needed to maintain a patent airway
oral or endotracheal suction
Lab values during the diuretic phase...
plateau and begin to decline
Three types of ARF
prerenal azotemia - hypoperfusion to kidneys intrarenal causes - damage to renal parenchyma or nephron postrenal causes - outflow of urine is obstructed
Other causes of Intrarenal ARF
prolonged renal ischemia from -pigment nephropathy -myoglobinuria/rhabdomyolysis -hemoglobinuria -infectious processes
What may be needed during oliguric phase since a minimum of 400ml/day of urine output is needed
renal replacement therapy
Hyperventilation as compensation for acidosis can lead to...
respiratory fatigue or failure requiring mechanical ventilation
Oliguric period is accompanies by an increase in serum concentrations of ....
wastes - urea, creatinine, organic acids electrolytes - K, Mg, P
S/Sx of hyperkalemia
weakness, diarrhea, dysrhythmias, cardiac arrest
A negative nitrogen balance can cause what sx
weight loss
When should calcium acetate be administered
with meals
can ARF be reversed
yes if identified and treated before fxn is permanently impaired
Insensible loss is estimated at
1 liter
How much of a weight gain is indicative of retention
1/2 to 1 lb/day
Metabolism and the oxidation process produces about ........ mL of fluid per day and may ........(increase/decrease) fluid requirements
200 to 500 mL decrease
What percentage of clients do not recover kidney function and may develop chronic renal failure
5 to 19 %
The recovery phases can take ..........
6 to 12 mos
Average time period for oliguric period
7 to 14 days
Most common cause of Intrarenal ARF
Acute tubular necrosis ATN 12 % of ATN cases are caused by nephrotoxic agents
Labs & urine findings with Postrenal ARF
BUN increased Creat increased Urine output - may be decreased or sudden anuria Urine sodium - often decreased to </= 20 mEq/L Urine osmolality - increased or equal to serum Urine SG - varies
Lab & urine findings with Intrarenal ARF
BUN increased Creat increased Ratio 10:1 Urine output - often decreased Urine sodium - increased to > 40 mEq/L Urine osmolality - approx 350 mOsm similar to serum Urine SG - low normal
The presence of prerenal azotemia is a probable indicator for hospitalization for CAP. Which of the following is an initial laboratory result that would alert a nurse to this condition? -Blood urea nitrogen (BUN)-to-creatinine ratio (BUN:Cr) >20. -BUN of 18 mg/dL. -Serum creatinine of 1.2 mg/dL. -Glomerular filtration rate (GFR) of 100 mL/min.
Blood urea nitrogen (BUN)-to-creatinine ratio (BUN:Cr) >20.
Assessing a client in oliguric anurix stage of ARF. Resp rate 28/min, client reports nausea, dull headache, palpitation, general mailaise. Which is priority action? -Admin an analgesic -Check latest electrolyte levels -Admin an antiemetic -Check oxygen level
Check latest electrolyte levels. Symptoms indicate hyperkalemia
Increased urine output in diuretic phase signals that
GFR has started to recover
A patient undergoing a CT scan with contrast has a baseline creatinine level of 3 mg/dL, identifying this patient as at a high risk for developing kidney failure. What is the most effective intervention to reduce the risk of developing radiocontrast-induced nephropathy (CIN)?
Hydrating with saline intravenously before the test
Symptomatic hyperkalemia is treated with
IV dextrose, insulin and calcium replacement (to shift K back into the cells)
Azotemia can cause what sx
N/V
Which period of acute renal failure is accompanied by an increase in the serum concentration of substances usually excreted by the kidneys?
Oliguria
The nursing student is assigned to care for a client with a diagnosis of acute kidney injury (AKI), diuretic phase. The nursing instructor asks the student about the primary goal of the treatment plan for this client. Which goal, if stated by the nursing student, would indicate an adequate understanding of the treatment plan for this client? Prevent fluid overload. Prevent loss of electrolytes. Promote the excretion of wastes. Reduce the urine specific gravity.
Prevent loss of electrolytes.
What is typically ordered with Kayexalate
Sorbitol to draw water to the bowel, inducing diarrhea and excretion of K
ECG findings with hyperkalemia
Tall, tented or peaked T waves absent P waves widened QRS bradydysrhythmia
Cause of Postrenal ARF
Urinary tract obstructions: calculi tumors BPH strictures blood clots
What is ARF
abrupt loss of kidney function and GFR over a period of hours to days
Intrarenal ARF is the result of
actual parenchymal damage to the glomeruli or kidney tubules this is damage to the kidney itself
infectious processes
acute pyelonephritis acute glomerulonephritis
What nebulized med can lower K by 0.5 to 1.5 mEq/L
albuterol sulfate (Ventolin HFA)
Reduced erythropoietin production, uremic GI lesions, reduced RBC lifespan and blood loss cause....
anemia
Common drugs with renal excretions that require dosage adjustments with ARF
antibiotics (esp aminoglycosides) digoxin ACE inhibitors maganesium containing agents
Minimum daily urine output needed to excrete body's waste products through the kidneys
approx 400ml amt lower indicated a decreased GFR
What foods are high in K
bananas, citrus, tomatoes, melons potatoes green, leafy vegetables
Deposits of uremic toxins in tissues can cause the skin to
become excoriated and itch
What is done to reduce exertion and decreased the metabolic rate
bedrest during the most acute stage
To decrease absorption of phosphate from intestinal tract, what is given
calcium acetate (PhosLo) or aluminum hydroxide gel (short term only)
Which of the following medications are usually administered to control seizures, which may occur as azotemia worsens?
Diazepam (Valium) Phenytoin (Dilantin) Lorazepam (Ativan)
Fluid restrictions become important to prevent....
fluid overload and pulmonary edema
The client should retain a Kayexalate enema for....
30 to 45 minutes rectal cath with balloon may be needed to facilitate retention
Mortality rate
as high as 60%
What is essential with care of invasive lines and catheters
asepsis
Prerenal azotemia occurs where in relation to the kidneys
before the kidneys something is causing hypoperfusion to the kidneys
pigment nephropathy
breakdown of blood cells containing pigments that occlude kidney structure
What increases with glomerular damage and is more sensitive of an indicator of renal function
creatinine used to monitor kidney function and disease progression
What foods are high in Phosphorus
dairy products beans, nuts, legumes carbonated beverages
During the diuretic phase, clients are at risk for
dehydration which can further damage the kidney
What may be prescribed to initiate diuresis and maintain renal perfusion
diuretics
The skin with ARF may be dry or susceptible to breakdown as a result of...
edema
Kayexalate works by
exchanging sodium ions for potassium ions in the intestinal tract
What may increase the fluid requirement
fever increases insensible loss by about 13% for each degree of C elevation
A small percentage develop nonoliguric renal failure, usually associated with...
nephrotoxic agents burns, traumatic injury, halogenated anesthetic agents
hemoglobinuria
transfusion reaction, hemolytic anemia (hgb released from hemolysis becomes concentrated in tubules)
What is done to prevent atelectasis and resp tract infection
turn, cough and deep breathe frequently
What skin care should be provided with ARF
turning frequently bathing with cool water keeping skin clean and well moisturized fingernails kept trimmed
Fluid replacement in renal dse may be based on...
urine output any GI losses insensible losses
Lab & urine findings with prerenal azotemia
BUN increased Creat normal or slightly increased Ration > 20:1 urine output - decreased urine sodium - decreased urine osmolality - increased to 500 mOsm urine SG - increased MAP < 60 mmHg
Hyperkalemia is treated with
sodium polystyrene (Kayexalate) PO, NG, retention enema
As ARF resolves, chemistry tests are used to determine the amts of .........
sodium, potassium and water for replacement
What factors contribute to an older client's failure to consume adequate fluid
suppression of thirst decreased mobility to access fluids confusion
The nurse tests the urine of a client with acute kidney injury (AKI) with a multitest reagent strip. The strip tests highly positive for proteinuria. The nurse plans care, knowing that this result is consistent with which type of AKI?
With intrinsic failure, there is a fixed specific gravity and the urine tests positive for proteinuria. In prerenal failure, the specific gravity is high and there is very little or no proteinuria. In postrenal failure, there is a fixed specific gravity and little or no proteinuria
What are some nephrotoxic agents
aminoglycosides (gent, tobra, vanc, neomycin) contrast, heavy metals (cisplatin or bismuth) solvents & chemicals, NSAIDS, ACE inhibitors (interfere with normal autoregulatory mechanisms and may cause hypoperfusion and eventual ischemia) amphotericin B cyclosporine
Postrenal ARF is a result of
an obstruction that develops anywhere from the collecting ducts of kidney to urethra pressure rises in kidney tubules and hydronephrosis (stretching of the renal pelvis) occurs, compressing normal renal tissue and resulting in a decreased GFR
BUN increases steadily at a rate dependent on....
the degree of protein catabolism renal perfusion fluid & protein intake N/V, lethary, headache, muscle twitching, seizures may occur
Diuretic phase is marked by
gradual increase in urine output output may be normal or large amts of dilute urine
How is the caloric need met with ARF
high carb meals (protein sparing effect)
After the diuretic phase, what diet is used
high carb with sufficient protein to promote nitrogen balance
If prerenal azotemia is caused by hypovolemia secondary to hypoproteinuria, what may be prescribed
infusion of albumin
Initiation begins with .......... and ends when ..........
initial insult oliguria occurs
What worsens hyperkalemia
protein catabolism and acidosis
Accurate intake and output are an essential part of the nursing management for ARF. A part of fluid assessment is estimating insensible fluid loss. The nurse knows that a patient with a temperature of 100.6°F would have a maximum insensible fluid loss of __________ mL/day. 800 875 950 1,008
1008mL Normal insensible loss is 500 to 800 mL/day. Fever increases this loss by 13%/degree of Celsius temperature elevation. An increase of 2 degrees (from 37 to 39) would result in a minimum increase in fluid loss of 630 mL (500 mL × 26%) and a maximum loss of 1.008 mL (800 mL × 26%).
What is restricted from diet for ARF
proteins potassium caffeine phosphorus
Treatment of postrenal ARF
relieving the obstruction (prostatectomy, nephrostomy tubes, indwelling caths)
If there is residual damage to the glomerular basement membrane after the recovery phase....
residual renal impairment may result
Fluids administered (IV or PO) must replace both
sensible and insensible losses
Acidosis may require tx with
sodium bicarbonate if serum bicarbonate concentration is < 15 mmmol/L or arterial pH is < 7.2 OR dialysis
Causes of prerenal azotemia
volume-depletion states (dehydration, hemorrhage, GI losses decreased CO (MI, heart failure, dysrhythmias, cardiogenic shock) vasodilated states (sepsis, anaphylaxis, antihypertensives or other meds that cause vasodilation)
