Transcript Acute Renal Failure

Objectives
 Anatomy
 Function
 Chronic Renal Failure (CRF)
 Causes
 Symptoms
 Dialysis
Anatomy and Physiology
 The Kidneys
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Hilum
Medulla
Pyramids
Papilla
Renal Pelvis
Anatomy
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2 Kidneys
2 Ureters
Bladder
Urethra
Kidney Function
 Detoxify blood
 Increase calcium absorption
 calcitriol
 Stimulate RBC production
 erythropoietin
 Regulate blood pressure and
electrolyte balance
 renin
 Formation of Urine
 Glomerular Filtration
 GFR
 Reabsorption and Secretion
 Simple diffusion and osmosis
 Facilitated diffusion
 Active transport
Azotemia: elevated blood
urea nitrogen not from an intrinsic
renal disease
Oliguria:
urine output less than
500cc/24hr.
Nonoliguria: urine output greater than
500cc/24hr.
Anuria: urine output less than
50cc/24hr.
Acute Versus Chronic
 Acute
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sudden onset
rapid reduction in urine output
Usually reversible
Tubular cell death and regeneration
 Chronic
 Progressive
 Not reversible
 Nephron loss
 75% of function can be lost before its
noticeable
ARF versus CRF
Neuropathy
Renal osteodystrophy
Small size Kidney
Past history of CKD
Broad cast
Chronic renal failure
 Chronic renal failure: slowly
progressive and non- reversible loss of
kidney function
 Uraemia: metabolic outcome of chronic
renal failure
 End-stage renal disease: requirement
for renal replacement therapy
ETIOLOGY
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Diabetes mellitus (28%)
Hypertension (25%)
Glomerulonephritis (21%)
Polycystic Kidney Diease (4%)
Other (23%): Obstruction, infection,
etc.
Progression of chronic renal failure
 Factors causing progression
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sustaining primary disease
systemic hypertension
Intraglomerular hypertension
Proteinuria
Nephrocalcinosis
Dyslipidaemia
Imbalance between renal energy demands
and supply
Slowing the Progression of
Chronic Renal Failure
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Control BP to <130 /80
Diet
Anaemia
Calcium and Phosphate
Dyslipidaemia
Obesity
Smoking Cessation
Old Chinese saying…….
Good doctor relieve disease
Better doctor cure disease
Superior doctor prevent disease
Symptoms of chronic renal failure
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Many are symptom free until 2/3 of
renal mass lost. Often no physical
examination findings or history.
Several common modes of
presentation:
progressive lethargy, anorexia, (and
later vomiting)
hypertension, and /or heart failure
unexplained anaemia
serendipitous findings on biochemistry
The Medical Burden Of
Chronic Renal Failure
 Prevention of ESRD may prevent
other co-morbid conditions from
developing
 In particular, there is a high
prevalence of Cardiovascular diseases
in patients with Chronic kidney
disease
CHRONIC RENAL FAILURE:
CLINICAL MANIFESTATIONS
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Sodium and water retention
Hyperkalemia
Metabolic Acidosis
Mineral and Bone metabolism
Cardiovascular and Pulmonary Disorders
Hematologic Abnormalities
Neuromuscular Abnormalities
Gastrointestinal Abnormalities
Endocrine Abnormalities
Dermatologic Abnormalities
Sodium and Volume Balance
 Sodium and water retention:
 CHF, Hypertension, ascites, edema
 Enhanced sensitivity to extra-renal sodium
and water loss
 vomiting, diarrhea, fever, sweating
 Symptoms: dry mouth, dizziness, tachycardia,
etc.
 Recommendations
 Avoid excess salt and water intake
 Diuretics or dialysis
Potassium Balance
 Hyperkalemia (GFR below 5 mL/min)
 GFRs >5 mL/min: compensatory
aldosterone-mediated K transport in the
DCT
 K-sparing diuretics, ACEis, beta-blockers
impair Aldosterone-mediated actions
 Exacerbation of hyperkalenia:
 Exogenous factors: K-rich diet, etc.
 Endogenous factors: infection, trauma, etc.
Hyperkalemia & EKG
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K > 5.5 -6
Tall, peaked T’s
Wide QRS
Prolong PR
Diminished P
Prolonged QT
QRS-T merge –
sine wave
Hyperkalemia Symptoms
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Weakness
Lethargy
Muscle cramps
Paresthesias
Hypoactive DTRs
Dysrhythmias
Metabolic Acidosis
Decreased acid excretion and ability to
maintain physiologic buffering
capacity:
 GFR < 20 mL/min: transient
moderate acidosis
 Treat with oral sodium bicarbonate
 Increased susceptibility to acidosis
Mineral and Bone
Bone disease (Figure 16-6) from:
 Decreased Ca absorption from the gut
 Over-production of PTH
 Altered Vitamin D metabolism
 Chronic metabolic acidosis
Cardiovascular and Pulmonary
Abnormalities
 Volume and salt overload
 CHF and pulmonary edema
 Hypertension
 Hyperreninemia: Hypertension
 Pericarditis: Remic toxin accumulation
 Accelerated atherosclerosis: linked to
factors above and metabolic
abnormalities (Ca alterations,
hyperlipidemia)
Hematological Abnormalities
 Anemia: lack of erythropoietin production
 Bone marrow suppression:
 uremic poisons: leukocyte suppression infection
 bone marrow fibrosis: elevated PTH an
aluminum toxicity from dialysis
 Increased bruising, blood loss (surgery)
and hemorrhage
 Lab Abnormalities: Prolonged bleeding
time, abnormal platelet aggregation
Neuromuscular Abnormalites
 CNS Abnormalities:
 Mild-Moderate: Sleep disorders, impaired
concentration and memory, irritability
 Severe: Asterixis, myoclonus, stupor,
seizures and coma
 Peripheral neuropathies:
 “restless legs” syndrome
 Hemodialysis-related neuropathies
Gastrointestinal Abnormalities
 Peptic Ulcer disease: Secondary
hyperparathyrodism?
 Uremic gastroenteritis: mucosal
alterations
 Uremic Fetor: bad breath (ammonia)
 Non-Specific abnormalities:
 anorexia, nausea, vomiting,
diverticulosis, hiccoughs
Endocrine Abnormalities
 Insulin: Prolonged half-life due to
reduced clearance (metabolism)
 Amenorrhea and pregnancy failure:
low estrogen levels
 Impotence, oligospermia and geminal
cell dysplasia: Low testosterone levels
Dermatologic Abnormalities
 Pallor: anemia
 Skin color changes: accumulation
of pigments
 Ecchymoses and hematomas:
clotting abnormalities
 Pruritus and Excoriations: Ca
deposits from secondary
hyperparathyroidism
Conclusion – chronic renal
failure
 Progressive chronic disease leading to end-state renal
failure
 Different primary disease can cause chronic renal
failure
 Diabetic nephropathy is a frequent cause for chronic
renal failure
 Symptoms can be very different and depend on
primary disease and stage of chronic renal failure
 Stages of renal failure can be associated with a
progressive decrease of GFR
 The consequences are complex according to the
different function of the kidney and involve many
organ systems
 Pre-Dialysis Treatment
1. Maintain normal electrolytes
a. Potassium, calcium, phosphate are major
electrolytes affected in CRF
b. ACE inhibitors may be acceptable in many
patients with creatinine >3.0mg/dL
c. ACE inhibitors may slow the progression of
diabetic and non-diabetic renal disease [13]
d. Reduce or discontinue other renal toxins
(including NSAIDS)
e. Diuretics (eg. furosemide) may help
maintain potassium in normal range
f. Renal diet including high calcium and low
phosphate
1. Reduce protein intake to <0.6gm/kg body
weight
a. Appears to slow progression of diabetic
and non-diabetic kideny disease
b. In type 1 diabetes mellitus, protein
restriction reduced levels of albuminuria
c. Low protein diet did not slow progression
in children with CRF
1. Underlying Disease
a. Diabetic nephropathy should be treated
with ACE inhibitors until creatinine >2.53mg/dL
b. Hypertension should be aggressively
treated (ACE inhibitors are preferred)
Dialysis
 ½ of patients with CRF eventually
require dialysis
 Diffuse harmful waste out of body
 Control BP
 Keep safe level of chemicals in body
 2 types
 Hemodialysis
 Peritoneal dialysis
Hemodialysis
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f.
Indications
Uremia - azotemia with symptoms and/or signs
Severe Hyperkalemia
Volume Overload - usually with congestive heart
failure (pulmonary edema)
Toxin Removal - ethylene glycol poisoning,
theophylline overdose, etc.
An arterio-venous fistula in the arm is created
surgically
Catheters are inserted into the fistula for blood flow
to dialysis machine
Hemodialysis
 3-4 times a week
 Takes 2-4 hours
 Machine filters
blood and
returns it to
body
1. Procedure for Chronic Hemodialysis
a. Blood is run through a semi-permeable
filter membrane bathed in dialysate
b. Composition of the dialysate is altered to
adjust electrolyte parameters
c. Electrolytes and some toxins pass through
filter
d. By controlling flow rates (pressures),
patient's intravascular volume can be
reduced
e. Most chronic hemodialysis patients receive
3 hours dialysis 3 days per week
1. Efficacy
a. Some acids, BUN and creatinine are
reduced
b. Phosphate is dialyzed, but quickly
released from bone
c. Very effective at reducing
intravascular volume/potassium
d. Once dialysis is initiated, kidney
function is often reduced
e. Not all uremic toxins are removed
and patients generally do not feel
"normal"
f. Response of anemia to erythropoietin
is often suboptimal with hemodialysis
1. Chronic Hemodialysis Medications
a. Anti-hypertensives - labetolol, CCB, ACE
inhibitors
b. Eythropoietin (Epogen®) for anemia in
~80% dialysis pts
c. Vitamin D Analogs - calcitriol given
intravenously
d. Calcium carbonate or acetate to 
phosphate and PTH
e. RenaGel, a non-adsorbed phosphate
binder, is being developed for
hyperphosphatemia
f. DDAVP may be effective for patients with
symptomatic platelet problems
Types of Access
 Temporary site
 AV fistula
 Surgeon constructs by combining an
artery and a vein
 3 to 6 months to mature
 AV graft
 Man-made tube inserted by a surgeon to
connect artery and vein
 2 to 6 weeks to mature
Temporary Catheter
AV Fistula & Graft
Chronic Renal Failure
 Long-Term
Management
 Renal Dialysis
 Hemodialysis
 Common
complications
What This Means For You
 No BP on same arm as fistula
 Protect arm from injury
 Control obvious hemorrhage
 Bleeding will be arterial
 Maintain direct pressure
 No IV on same arm as fistula
 A thrill will be felt – this is normal
Access Problems
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AV graft thrombosis
AV fistula or graft bleeding
AV graft infection
Steal Phenomenon
 Early post-op
 Ischemic distally
 Apply small amount of pressure to
reverse symptoms
Peritoneal Dialysis
 Abdominal lining filters blood
 3 types
 Continuous ambulatory
 Continuous cyclical
 Intermittent
Considerations
 Make sure the dressing remains intact
 Do not push or pull on the catheter
 Do not disconnect any of the
catheters
 Always transport the patient and
bags/catheters as one piece
 Never inject anything into catheter
Dialysis Related Problems
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Lightheaded –give fluids
Hypotension
Dysrhythmias
Disequilibration Syndrome
 At end of early sessions
 Confusion, tremor, seizure
 Due to decrease concentration of blood
versus brain leading to cerebral edema