Acute renal failure

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Common Manifestations Associated with Acute and Chronic Renal
Failure
Acute Renal Failure:
Initiation Phase: Few manifestations
Maintenance Phase:
1) Urinary Changes:
a) Output less than 20cc/ hr.
b) Casts, RBCs, WBCs.
c) Specific gravity of 1.010 same as plasma. Kidney can
no longer concentrate urine.
2) Fluid Volume Excess:
a) Fluid retention
b) Distended neck veins
c) Bounding pulse
d) Edema
e) CHF and pulmonary edema
3) Metabolic Acidosis:
a) Kidney cannot excrete acid metabolites.
b) Bicarbonate level decreases because bicarbonate is
used to buffer hydrogen ions.
Also
there is defective reabsorption and regeneration.
c) Kussmaul respiration to blow off CO2.
4) Sodium Excess:
a) Sodium is retained
b) leading to excess fluid volume, hypertension, and CHF.
5) Potassium Excess:
a) Kidney cannot excrete K therefore high serum K levels.
b) If failure is associated with tissue injury higher K
levels may exist.
c) Acidosis enhances K movement from intracellular to
extracellular fluid.
d) K levels above 6 mEq/L must be treated immediately
to prevent cardiac dysthymias.
Earliest sign is high peaked T waves on EKG.
6) Calcium Deficit:
a) Decreased absorption from GI tract because of
increased phosphate levels and
increased excretion by the kidney.
b) Usually asymptomatic because acidosis keeps what
little calcium there is ionized.
c) Azotemia: BUN and serum creatinine elevated
7) Confusion, disorientation, agitation or lethargy, hyper
refexia, seizuresm anorexia, nausea,
vomiting,
absent bowel sounds and other manifesttions
associated with
azotemia and uremic syndrome.
Recovery Phase:
1) Diuresis
2) Serum creatinine, BUN, potassium, and phosphate levels
remain gigh and may continue to rise in spite of increasing
urine output. Recovery m ay take up to a year.
Chronic Renal Failure:
1) Diminished Renal Reserve: Absence of symptoms
2) Renal Insufficiency: Easy fatigue and weakness are
common symptoms. Headaches, nocturia and polyuria
occur.
3) Renal Failure: Increasing azotemia, edema metabolic
acidosis, hypercalcemia and uremia.
Oliguria
with proteinuria, casts, pyuria, and hematuria, then
anuria.
4) End Stage Renal Failure: kidney atrophy and fibrosis; overt
uremia
Physiological Effects of Azotemia and Uremia on Body
Systems:
Metabolic Disturbances:
Azotemia:
a) BUN and serum creatinine increase and creatinine
clearance decrease.
b) BUN influenced by protein intake, fever, and catabolic
rate.
c) Serum creatinine and creatinine clearance are better
indicators of renal function than BUN.
d) As BUN increases nausea, vomiting, diarrhea, and
headaches occur.
e) Uric acid levels increase leading to gouty arthritis. Actual
incidence of gout is low.
Carbohydrate Intolerance:
a) Cells become insensitive to insulin leading to
hyperinsulinism, hyperglycemia, and
abnormal glucose metabolism.
b) Insulin and glucose metabolism improve but do not
return to normal with dialysis.
c) Diabetics often require less insulin before.
Elevated Triglycerides:
a) Hyperinsulinemia stimulates hepatic pro- duction of
triglycerides.
b) Increase in triglycerides (type IV) leads to increased
atherosclerosis.
Electrolyte Imbalances:
Potassium Excess:
a) Kidneys cannot excrete.
b) Acidosis causes shift from intracellular to extracellular.
Metabolic Acidosis:
a) Kidney cannot excrete NH3 and reabsorb and regenerate
bicarbonate.
b) Plasma bicarb usually stabilizes around 16 to 20 mEq/L.
because of demineraization from the bone.
c) Kussmaul respirations may occur but less prevalent than
in acute.
Magnesium: Excreted by the kidneys and is usually not a
problem unless the client takes large amounts of milk of
magnesia or antacids containing magnesium.
Sodium Excess or Deficit: Excess usually develops in late
stages.
Hematological System:
Anemia:
a) Main cause is decreased erythropoietin by the kidney
resulting in decreased erythropoiesis by the bone marrow.
b) Additional causes are nutritional defi- ciencies,
hypersplenism, decreased RBC life span and GI bleeding.
c) Dialysis dialyzes folic acid, traumatizes RBCs, and blood
may be lost in the dialyzer.
Bleeding Tendencies: Uremia impair platelet aggregation and
impairs release of platelet factor.
Infection:
a) Uremia decreases cellular and humoral immunity causing
lymphopenia and lymphoid atrophy.
b) Uremia also decreases chemotaxis causing neutrophils and
monocytes to ignore an inflammation.
c) Limited protein intake causes limited WBC production.
Cardiovascular System:
Hypertension: Caused by fluid retention and sometimes increased
renin production may lead to atherosclerosis, intrarenal arterial
spasm, CHF, retinopathy, and encephalopathy.
Cardiac Arrhythmias: Caused by hyperkalemia, hypocalcemia, and
decreased coronary artery perfusion.
Pericarditis: Caused by edema may progress to hemorrhagic effusion
and cardiac tamponade.
M.I. and CVA are the leading cause of death for clients on dialysis.
Respiratory System: Uremic pneumonitis: Show up as interstitial edema
on X-ray. Thick tenacious sputum.
Gastrointestinal Tract:
Urea causes an inflammation of the mucosa.
Ulcerations throughout the tract are caused by the increased
ammonia produced by the bacterial breakdown of urea.
Urine odor on breath and metallic taste.
Constipation is a frequent complaint because of the aluminum
antacids taken to lower phosphate levels.
Neurological System: Cause unknown. Attributed to nitrogenous wastes.
General Depression of the CNS: Apathy, lethargy inability to
concentrate, convulsions and coma.
Peripheral Neuropathy: May describe as bugs crawling on legs,
burning sensations and eventually motor involvement such as foot
drop, weakness, atrophy, and paralysis.
Dialysis may or may not halt or reduce symptoms.
Musculoskeletal System: Renal Osteodystrophy
Phosphate is not excreted by the kidney. Calcium phosphate is
formed leading to a drop in the serum calcium levels. The low serum
calcium level stimulates a rise in parathyroid hormone
eventually leading to demineralization of the bone.
Normally the kidney metabolizes vitamin D which is either ingested or
formed in the skin. Vit. D is necessary for calcium absorption from the
GI tract. In failure the kidney does not metabolize Vit. D and calcium
absorption is impaired.
The above factors contribute to:
a. Osteomalacia: Lack of mineralization of newly formed bones.
b. Osteitis fibrosa: The calcium reabsorbed from the bone is replaced
with fibrous tissue.
c. Metastatic calcification: Calcium phosphate is deposited in soft
tissues such as blood vessels, joints, lungs, myocardium and eyes
(uremic red eye). Arterial calcification in the fingers and toes
may cause gangrene.
Integumentary System:
Yellow color of the skin is caused by the uremia..
Pallor is caused by anemia.
Dryness is caused by a decrease in oil gland activity.
Puritis is caused by a combination of dry skin, calcium phosphate
deposits on the skin, and sensory neuropathy. May also by caused
by urea crystals on the skin which is called uremic frost.
Petechiae and ecchymosis are due to clotting abnormalities.
Reproductive System:
Decrease in hormone levels cause decrease in libido and infertility.
Amenorrhea and anovulation in women and low sperm count and
loss of testicular consistency in men.
Usually improves with dialysis.
Endocrine System: Unexplained hypothyroidism.
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