Chronic Renal Failure causes , clinical picture and complications

Chronic renal failure ( CRF)  will be discussed in this article concerning definition , Stages , Causes and clinical picture of the disease .CRF will be continued soon in another article which discusses the investigations and treatment methods of it .

It is a gradual slowly progressive (within years) irreversible deterioration of kidney function with development of the clinical syndrome of uremia
(Progressive course of ongoing loss of kidney function).
Finally it progresses to end stage renal failure.
DD from Acute renal Failure : here
chronic renal failure

End stage renal disease (ESRD) = GFR < 10-15 ml/m

It is a stage of C.R.F. at which kidney function cannot sustain life.So replacement therapy is indicated (dialysis or transplantation).

Stages of chronic Kidney disease :-

Stage 1 : Kidney damage (pathologic abnormalities or abnormalities in blood or urine tests or imaging studies) with normal GFR (GFR > 90 ml/m/1.732)
Stage 2 : Kidney damage with mild decrease in GFR (GFR 60-89)
Stage 3 : Moderate t GFR (GFR 30-59)
Stage 4 : Severe t GFR (GFR 15-29)
Stage 5 : Kidney failure (GFR < 15)

Causes of Chronic Renal Failure :

1- Diabetic nephropathy (longstanding history of D.M).
2- Systemic hypertension (long duration).
3- Chronic Glomerulu-nephritis (history of puffiness).
4- Chronic interstitial nephritis e.g chronic pyelonephritis (history of recurrent UTI), drug abuse.
5- Obstructive uropathy -> stones, bilharziasis.
6- Analgesic nephropathy (abuse of paracetamol + aspirin).
7- Lupus nephritis (young female + arthropathy).
8- Congenital polycystic Kidney (+ve family history).
9- Gout (History of arthropathy).
10- Undetermined etiology.

Clinical Picture      i.e. (Camplicatians af C.R.F)

a. GIT

1. Nausea & Vomiting 7 persistent & not responding to usual treatment.
2. Diarrhea.
3. Hepatitis (due to blood transfusion) (hepatitis C, B).
4. Hiccough (central effect).
5. Gastritis as uremic toxins are irritant to gastric mucosa with increased gastrin level.
6. GIT bleeding.
7. Decreased gastric emptying with increased risk of reflux oesophagitis.
8. Ammoniacal odour of mouth (urea excreted in saliva with splitting bybacteria 7 NH3). i.e uremic fetor.


-  Anemia  due to :
. Erythropoietin deficiency.
. Decrease intake with haematinic deficiency e.g. Iron, Vit. B12, Folate.
. Bleeding tendency.
. Decreased life span of RBCs and toxic B.M depression.
. Blood loss during hemodialysis or through GIT.
. B.M fibrosis due to hyperparathyroidism I?~
. ACE inhibitors may decrease erythropoietin release --> anemia.

- Bleeding tendency due to :
. Capillary fragility.
. Thromboasthenia due to the uraemic toxins.

c-  C.V.S

1. Pericarditis ;
 - uremic toxins are very irritant to pericardium. It is a feature of severe preterminal uraemia or inadequate dialysis. It usually resolves with intensive dialysis.
- Haemorrhagic pericardial effusion with the danger of pericardial tamponade may occur so, anticoagulants should be used with caution.

2. Systolic and diastolic dysfunctions are also common :
- Diastolic dysfunction is due to left ventricular hypertrophy
and contributes to hypotension during fluid removal and
- Systolic dysfunction is due to myocardial fibrosis, abnormal
myocyte function, myocardial calcification, carnitine and
selenium deficiency.
3. Arrhythmias due to electrolyte disturbances.
4. Hypertension due to salt and H2O retention and hyperreninism.

d- Endacrine & metabalism:

1. Insulin Resistance
- Impaired glucose tolerance and not D.M (uremic pseudodiabetes).
- Also insulin resistance may contribute to hypertension & lipid abnormalities.

2. Insulin is catabolized by and to some extent excreted by the kidney so insulin requirements in diabetic patient with renal impairment will be decreased.

3. Thyroid dysfunction with sluggish TSH release !?
. ++ TRH -->  release of prolactin (also there is decrease in prolactin clearance) --> Amenorrhea, glactorrhea & Impotence .

4. Calcium decrease -->  2ry hyperparathyroidism.
5. Impaired clearance of triglycerides and hypercholesterolaemia may occur in advanced renal failure.
6. Decreased serum testosterone level with impotence and decreased spermatogenesis.
7. Disturbance of the cyclical changes in female sex hormones --> oligomenorrhea or amenorrhea.

e- Bone disease      (renal asteadystraphy)

1. Decreased renal production of 1-hydroxylase enzyme -->  decreased production of active vitamin D. this leads to increased parathyroid hormone release (2ry hyperparathyroidism).
2. Active vitamin D deficiency also results in calcium malabsorption --> 2ry hyperparathyroidism.
3. Phosphorus retention occurs due to reduced excretion by the kidneys .This results in 2ry hyperparathyroidism.
4. Secondary hyperparathyroidism leads to increased oseoclastic activity with cyst formation and bone marrow fibrosis (osteitis fibrosa cystica).
5. Active vitamin D deficiency and decreased Ca will result in impaired bone mineralization (Osteomalacia).
6. Long standing parathyroid hormone excess may cause increased bone density (osteosclerosis) particularly in the spine where alternating band of sclerotic and porotic give rise to rugger Jersey appearance.

7. Impaired mineralization also occurs with aluminium toxicity due to phosphorus binders containing aluminium or as a result of exposure to aluminium in water source used to make up dialysate fluids for hemodialysis.

f - Chest

1. Pneumonia (low immunity).
2. Acidotic breathing.
3. Non cardiogenic pulmonary edema.

g- Neuaralagical

1. Neuropathy
• Motor --> Weakness.
• Sensory --> Glove & Stock hypothesia.
• Autonomic neuropathy
- Impotence.    - GastroParesis
- Diarrhea & Constipation.    - Orthostatic hypotension .

2. Uraemic myopathy.

3. Uraemic myoclonic jerk. (myoclonus).
4. Convulsions.
5. Dysequilibruim syndrome : due to rapid drop of blood urea by intensive dialysis -->  (Brain edema).
6. Uraemic encephalopathy.
7. Strokes e.g. cerebral hge, due to hypertension and bleeding tendency.
8. Carpal tunnel syndrome : due to amyloidosis (B2 microglobulin).
9. Restless legs syndrome (irresistible need to move legs, often interfering with sleep).
10. Dialysis Dementia (Al related), it may be associated with aluminum bone disease and microcytic anemia.

h- Skin.

1. Itching due to:
- Hyperparathyroidism.
- Hyperphosphatemia.
- Hypercalcemia (due to Ca containing P binders + vit D).
- Elevated calcium and phosphate product.

2. Color (earthy look), it is a mixture of 3 colors :
- Yellow : due to urochrome pigment retention.
- Pallor : due to anemia.
- Increased melatonin.

3. Recurrent pyogenic infections.
4. Urea frost : whitish powder on the skin surface (another cause of itching)
5. Bronze color due to naornostdrosis.

i- Acid base & electrolytes
1. Ca decrease , p increase and AI increase  (excreted through the kidney).
2. Hyperkalemia (excreted through the kidney).
3. PH drop  (metabolic acidosis due to H+ retention).
4. Na and water retention with normal sodium level, hyponatremia may occur due to excessive ingestion of water,
- hypernatremia is infrequent in chronic renal failure.

j-  Urinary manifestalions

1. Manifestations of the cause as UTI, renal stones.
2. Early polyurea and nocturia due to irn aired concentrating ability .

Chronic Renal Failure causes , clinical picture and complications
Dr.Tamer Mobarak


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