Transcript Acute Renal Failure/Acute Kidney Injury

ACUTE RENAL FAILURE/ACUTE
KIDNEY INJURY
Dr. Sudarshan Singh
INTRODUCTION
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Acute renal failure (ARF), or acute kidney injury
(AKI), [as it is now referred to in the literature],
is defined as
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An abrupt or rapid decline in renal filtration function
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Condition is usually marked by a rise in serum
creatinine concentration or by azotemia (a rise in
blood urea nitrogen [BUN] concentration)
CAUSES
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Acute kidney failure appears most frequently as
a complication of serious illness, like
Heart and/or liver failure, serious infection,
dehydration, severe burns, and excessive
bleeding (hemorrhage)
 May also be caused by an obstruction to the urinary
tract or as a direct result of kidney disease, injury, or
an adverse reaction to medicine
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These conditions divide AKF into 3 main categories:
 Prerenal
 Postrenal, and
 Intrinsic (inside) conditions
CAUSES
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Prerenal AKF
Does not damage the kidney, but can cause diminished kidney
function and significantly decreased renal (kidney) blood flow
 Most common type of acute renal failure, and is often the result of:
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Dehydration
Extracellular fluid (ECF) volume depletion (or other acute fluid
loss from the gastrointestinal tract, kidneys, or skin)
Drugs (NSAIDS, cyclosporine, radiopaque contrast materials,
or any substance toxic to the kidneys)
Hemorrhage
Septicemia, or sepsis
Congestive heart failure (CHF)
Liver failure
Burns
Decreased intravascular volume (referred to as third spacing, also found in
the presence of pancreatitis, post surgical patients, and patients with
a nephrotic syndrome)
CAUSES
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Postrenal AKF
Result of an obstruction of some kind somewhere in
the urinary tract, often in the bladder or ureters (the
tubes leading from the kidney to the bladder)
 The kidneys compensate to such a degree that one
kidney can be completely obstructed and the other
will maintain nearly normal kidney function for the
body
 The conditions that often cause postrenal AKF are:
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Inflammation of the prostate gland in men (prostatitis)
 Enlargement of the prostate gland (benign prostatic
hyperplasia - BPH)
 Bladder or pelvic tumors
 Kidney stones (calculi)
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CAUSES
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Intrinsic AKF
Involves a type of kidney disease or direct injury to the
kidneys.
 Accounts for 20-30% of AKF reported among hospitalized
patients
 Intrinsic AKF can result from:
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Lack of blood supply to the kidneys (ischemia)
Use of radiocontrast agents in patients with kidney problems
Drug abuse or overdose
Long-term use of nephrotoxic medications, like certain pain
medicines
Acute inflammation of the glomeruli, or filters, of the kidney
(glomerulonephritis)
Kidney infections (pyelitis or pyelonephritis)
Infiltration by lymphoma, leukemia, or sarcoid carcinomas
THE FOUR PHASES OF ACUTE RENAL
FAILURE
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Onset Phase – this period represents the time
from the onset of injury through the cell death
period. This phase can last from hours to days
and is characterized by:
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Renal flow at 25% of normal
Oxygenation to the tissue at 25% of normal
Urine output at 30 ml (or less) per hour
Urine sodium excretion greater than 40 mEq/L.
In this phase only 50% of the patients are noted to be
oliguric. With prompt treatment, irreversible damage
can be achieved during this pre renal failure onset
phase.
THE FOUR PHASES OF ACUTE RENAL
FAILURE
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Oliguric/Anuric Phase – this phase usually lasts
between 8-14 days and is characterized by
further damage to the renal tubular wall and
membranes. Other characteristics in the oliguricanuric phase include:
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Great reduction in the glomerular filtration rate
(GFR)
Increased BUN/Creatinine
Electrolyte abnormalities (hyperkalemia,
hyperphosphatemia and hypocalcemia)
Metabolic acidosis
THE FOUR PHASES OF ACUTE RENAL
FAILURE
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Diuretic Phase – this phase occurs when the
source of obstruction has been removed but the
residual scarring and edema of the renal tubules
remains. This phase usually lasts and additional
7-14 days and is characterized by:
Increase in glomerular filtration rate (GFR)
 Urine output as high as 2-4 L/day
 Urine that flows through renal tubules
 Renal cells that cannot concentrate urine
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Increased GFR in this phase contributes to the
passive loss of electrolytes which requires the
administration of IV crystalloids to maintain
hydration.
THE FOUR PHASES OF ACUTE RENAL
FAILURE
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Recovery Period Phase – The recovery phase can
last from several months to over a year. During
this phase, edema decreases, the renal tubules
begin to function adequately and fluid and
electrolyte balance are restored (if damage was
significant, BUN and Creatinine may never
return to normal levels). At this point the GFR
has usually returned to 70% to 80% of normal.
SYMPTOMS AND SIGNS
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The signs and symptom that may be experienced
with ARF depend on
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Phase, degree of azotemia (abnormal levels of urea
and creatinine) and degree of metabolic acidosis
The following signs and symptoms are consistent
with ARF:
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Decreased urine output (urine may be pink or
reddish in color)
Edema (face, arms, legs, feet eyes)
Flank pain/Pelvic pain
Poor appetite (nausea, vomiting)
Bitter or metallic taste in mouth
SYMPTOMS AND SIGNS
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Symptoms and signs (Contd)
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Dry itchy skin
Easy bruising
Fatigue
Seizures/LOC
Shortness of breath
Arrhythmias
Sudden weight gain
DIAGNOSING ARF
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More about BUN and Creatinine
Although elevated levels BUN/Creatinine are
considered to be the “hallmarks” of acute renal
failure, the rate of rise is actually dependant on the
degree of renal ischemia and injury and in regards to
BUN; the rate of protein uptake.
 BUN may also be elevated in other conditions not
directly related to acute renal failure such as; GI or
mucosal bleeding, steroid treatment therapy or
protein loading.
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DIAGNOSING ARF
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Imaging Studies/Procedures/Tests
Creatinine Clearance Test
 Ultrasound
 Doppler studies
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MEDICAL MANAGEMENT OF ACUTE
RENAL FAILURE
Medical management of acute renal failure must
focus on first identifying and treating the cause
 Maintaining volume homeostasis and correcting
biochemical abnormalities remain the primary
goals of treatment.
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Gathering a detailed patient history (pre-hospital
and current)
Maintaining adequate intravascular volume
Maintaining mean arterial pressure
Discontinuing all nephrotoxic medications (NSAIDS,
Gentamycin)
Eliminating exposure to any other nephrotoxins
MEDICAL MANAGEMENT OF ACUTE
RENAL FAILURE
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Correcting acidosis (sodium bicarbonate for severe
acidosis)
Correcting hemolytic abnormalities (blood
transfusion may be required)
Correcting all electrolyte abnormalities
(Hyperkalemia is very common)
Strict monitoring on intake and output/daily weight
(Hydration for prerenal failure)
Serial monitoring of labs
(BUN/Creatinine/Osmolality [urine/blood], etc)
Diet and fluid restrictions/replacement (in a state of
oliguria or polyuria)
MEDICAL MANAGEMENT OF ACUTE
RENAL FAILURE
Dialysis: (a short term intervention when fluids
and electrolytes cannot be managed by other
means). This may involve the use of any of the
following three methods:
 Peritoneal Dialysis – peritoneal dialysis is not
commonly used as a treatment with acute renal
failure. Although efficient, it is slow process that
involves the transfer of fluid and solutes between
the peritoneal cavity and the peritoneal
capillaries. The clearance that occurs with
peritoneal dialysis is thought to be less effective
than other types of dialysis.
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MEDICAL MANAGEMENT OF ACUTE
RENAL FAILURE
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Hemodialysis – hemodialysis remains the
primary method of renal replacement therapy in
patients with acute renal failure
Provides ultrafiltration for rapid water removal and
diffusion for solute removal
 Indicated for uremia, electrolyte imbalances, fluid
overload and severe metabolic acidosis
 Recommended when there is a need for quick
removal of water and toxins
 One concern with using hemodialysis for critically ill
patients with acute renal failure is that the process
requires moving large amounts of fluid out of the
intravascular system which can lead to acute and
severe hypotension (secondary to hypovolemia).
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MEDICAL MANAGEMENT OF ACUTE
RENAL FAILURE
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Continuous Renal Replacement Therapy (CRRT)
– CRRT therapy works similarly to hemodialysis
except it is a continuous ongoing process that is
less likely to cause acute hypotension. Other
benefits to using CRRT as a method of dialysis
include:
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Hemodynamic stability
Correction of metabolic acidosis
Quicker kidney recovery time
Correction of malnutrition
Solute removal
PHARMACEUTICAL INTERVENTIONS
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Furosemide (Lasix) – a loop diuretic that can be
used to increase urinary flow with the intent of
flushing out cellular debris that may be causing
an obstruction.
Mannitol – an osmotic diuretic that can be used
to dilate renal arteries by increasing the
synthesis of prostaglandins (resulting in restored
renal flow).
PHARMACEUTICAL INTERVENTIONS
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Dopamine – at low doses (1-5 mcg/kg/min),
dopamine dilates renal arterioles and increases
renal blood flow and glomerular filtration.
Because dopamine (even at low doses) can cause
tachycardia, myocardial ischemia and
arrhythmias it use should be considered
carefully.
N-acetylcysteine – this medication can help
reverse acute renal failure when the cause is
thought to be from a nephrotoxic source.
NURSING CARE AND MANAGEMENT
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Because acute renal failure often progresses through
four phases, it is important for the nurse to detect
which phase of failure the patient is experiencing in
order to develop an appropriate plan of care
A detailed history should be obtained to help direct
nursing care; this history should include the following
information:
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History of chronic illness (hypertension, diabetes)
Recent infections (especially those that may have been
streptococcal in nature)
Recent episodes of hypotension (from surgery or bleeding)
Exposure to nephrotoxins or chemical agents
Recent blood transfusions
NURSING CARE AND MANAGEMENT
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Contd…
Recent urinary tract disorders
 Toxemia from pregnancy or abortion
 Recent severe muscle damage
 Recent burn trauma
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NURSING CARE AND MANAGEMENT
Nursing assessment and subsequent
interventions should focus around the following
physical findings (based on the phase of renal
failure):
 Onset Phase:
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Mild reduction in normal daily urine output
 Mild lethargy
 Mild malaise
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NURSING CARE AND MANAGEMENT
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Oliguric/Anuric Phase:
24 hour urine total 400 ml or less
Listlessness/fatigue
Confusion or altered LOC (from electrolyte imbalances)
ECG changes (elevated T waves, depressed ST segment,
prolonged PR interval, loss of P wave, wide QRS complex,
arrhythmias)
S3 or S4 gallop
Pericardial friction rub
Pulsus paradoxus
Fever
Chest pain
Crackles upon lung auscultation (due to fluid overload)
Shortness of breath (due to fluid overload)
NURSING CARE AND MANAGEMENT
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Oliguric/Anuric Phase:
Jugular vein distention (due to fluid overload)
Periorbital, peripheral or sacral edema (due to fluid overload)
Ascites (due to fluid overload)
Capillary fragility as evidenced by easy bruising
Metabolic acidosis
Anorexia, nausea, vomiting, diarrhea, constipation
Uremic frost (pale, yellow, dry or itchy skin)
Diuretic Phase:
Urine output of 3 to 5 liters in a 24 hour period
Lethargy or muscle weakness (due to hypokalemia)
Decreased blood pressure (due to fluid depletion)
Dry mucous membranes (due to fluid depletion)
Poor skin turgor and delayed capillary refill (due to fluid
depletion)
NURSING CARE AND MANAGEMENT
Recovery Phase:
 Urine output of 1500 to 1800 ml in a 24 hour
period
 Stabilization of serum potassium, bicarbonate,
BUN and creatinine
 Stabilization of cardiac rhythm and rate
 Reduction in lethargy and shortness of breath
 Reduction in adventitious breath sounds
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NURSING RESPONSIBILITIES FOR CRRT
Patient family teaching regarding the procedure
and equipment
 Monitoring of hemodynamic stability
 Frequent observation of the patients response to
fluid removal
 Continuous assessment of vital
signs/CVP/PAWP/PAP/Cardiac Output
 Monitoring changes in mental status
 Assessing breath sounds
 Assessing skin turgor/edema
 Monitoring for signs of bleeding/infection
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NURSING RESPONSIBILITIES FOR CRRT
Monitor specifically for hypotension in response
to hypovolemia (aggressive fluid replacement
with a crystalloid and/or alteration of the
ultrafiltration rate may be necessary).
 Monitoring for fluid volume overload (requiring a
decrease or temporary discontinuation of
replacement fluid).
 Monitor that all equipment connections are
secure (due to the risk for vast hemorrhage if a
break in the system occurs).
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NURSING RESPONSIBILITIES FOR CRRT
Close monitoring of electrolyte and acid-base
imbalances (prompt replacement is required).
 Adjusting care based on the mobility restrictions
that occur with CRRT equipment.
 Close monitoring of extremity distal to catheter
placement (pulses/perfusion).
 Assessment of catheter insertion site/dressing
changes as per policy.
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APPROPRIATE NURSING DIAGNOSIS FOR
CONSIDERATION
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Alteration in urinary elimination
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Fluid volume deficit
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(the goal is that the patient is euvolemic; with urine output
that is approximately 30 ml/hr and has no symptoms
suggestive of fluid deficit i.e. dry mouth, hypotension, poor
skin turgor, delayed capillary refill).
Fluid volume overload
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(the goal is that the patient is euvolemic and has no
symptoms suggestive of fluid deficit or overload).
(the goal is that the patient is euvolemic and has no
symptoms suggestive of fluid overload such i.e. edema, wt.
gain, JVD).
Altered nutrition
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(less than bodily requirement) - (the goal is that the
patient will have balanced nutrition and fluid balance with
weight within normal limits).
APPROPRIATE NURSING DIAGNOSIS FOR
CONSIDERATION
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Potential for impaired skin integrity
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Knowledge deficit
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(the goal is that the patient/family has a better
understanding of the disease process and understand the
need for follow up care).
Decreased cardiac output
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(the goal is that the patient remains free from pressure
ulcers and dry itchy skin).
(the goal for the patient is to have improved clinical
findings based on adequate cardiac output i.e. normal vital
signs, adequate capillary refill, absence of hypotension)
Fear (anxiety)
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(the goal for the patient will have a low level of anxiety and
be able to effectively express concerns and questions
regarding care. The patient will also be able to verbalize
symptoms of anxiety and mechanisms for dealing with
these symptoms).
APPROPRIATE NURSING DIAGNOSIS FOR
CONSIDERATION
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Potential for impaired skin integrity
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Ineffective individual/family coping
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(the goal is that Activity intolerance - (the goal for the
patient is to participate in activities of daily living without
become exhausted).
the goal of the patient/family is to be able to participate in
care without becoming overwhelmed. The goal is also to be
able to verbalize where counseling/support can be found i.e.
American Association of Kidney Patients or the National
Kidney Foundation for example).
Body image disturbance
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(the goal of the patient who may require a shunt for
hemodialysis is to state or demonstrate acceptance of this
change).
APPROPRIATE NURSING DIAGNOSIS FOR
CONSIDERATION
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Altered thought processes
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Potential for injury
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(the goal of the patient is to demonstrate improved
cognitive function and be able to participate in
activities of daily living).
(the goal for the patient is to remain injury free and
be able to verbalize and explain methods to prevent
injuries and/or falls).
Risk of infection
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(the goal for the patient is to remain free from
symptoms of infection (WBC’s within normal limits)
and to be able to state what symptoms of infection
are).