Ckd causes Prerenal

CKD
Causes

• 
  Prerenal
  

• 
  Failure of perfusion of kidneys with blood
  
• 
  Causes:
  

• 
  Hypovolaemia = hemorrhage, D, diuretics, pancreatitis, DKA, sepsis, burns
  
• 
  Decreased CO = MI, massive PE, CHF
  
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  Severe LF (hepatorenal syndrome)
  
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  Renal artery obstruction = stenosis, thrombosis, embolisation
  

• 
  Renal
  

• 
  Loses ability to conc urine and conserve Na+
  
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  Causes:
  

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  Acute tubular necrosis = ischaemia, exogenous nephrotoxins (gentamicin, IV contrast), endogenous nephrotoxins (Bence Jones protein, uric acid, Mb)
  
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  Acute tubulointerstitial nephritis = drug hypersensitivity, infections
  
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  Large renal vessels = renal artery/vein thrombosis
  
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  Small renal vessels = vasculitis, malignant HT, haemolytic uraemic syndrome, TTP
  
• 
  Acute glomerulonephritis
  
• 
  Congenital = PCKD
  

• 
  Postrenal
  

• 
  Total urinary outflow tract obstruction – intraluminal, intrinsic, extrinsic
  

Stages

1. 
   Stage 1: eGFR > 90 ml/min + some sign of kidney damage on other tests
   
2. 
   Stage 2: eGFR 60-90 ml/min + some sign of kidney damage on other tests
   
3. 
   Stage 3a: eGFR 45-59 ml/min + moderate reduction in kidney function
   
4. 
   Stage 3b: eGFR 30-44 ml/min + moderate reduction in kidney function
   
5. 
   Stage 4: eGFR 15-29 ml/min + severe reduction in kidney function
   
6. 
   Stage 5: eGFR < 15 ml/min + established KF  dialysis/transplant needed
   

History

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  General = anorexia, confusion, weakness, malaise, headaches
  
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  Anaemia = lethargy, SOBOE
  
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  Skin = bruising, pruritis, pigmentation, oedema
  
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  GI = N+V, D
  
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  Bone = pain, #
  
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  Urine = nocturia, polyuria
  

Examination

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  General = oedema, skin pigmentation, jaundice bruising, myopathy, cachexia
  
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  Arm = AV fistula (buzzes)
  
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  CV = HF, uraemic pericarditis, peripheral vascular disease
  
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  Abdo = kidneys not palpable, renal artery stenosis, transplanted kidney, scars
  

Investigations

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  Bedside = urine dipstick, ECG (hyperkalaemia)
  
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  Bloods = U+Es (raised urea + creatinine), eGFR, FBC (normocytic anaemia), Bone (low Ca, high PO4), ESR
  
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  Imaging = USS, CT KUB, CXR
  
• 
  Special tests = biopsy
  

Management

• 
  Conservative = Na and K dietary restriction
  
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  Medical = antihypertensives (ACEI/ARB, diuretics, CCB), Vit D and Ca supplements, PO4 binders, Epo  haemodialysis, peritoneal dialysis, haemofiltration (ITU)
  
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  Surgical = AV fistula, renal transplant
  
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  Psycho = screen for depression/anxiety (HADS)
  
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  Social = family support, transport for hospital appts, carers, finance
  

Complications

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  Anaemia
  
• 
  Renal osteodystrophy
  
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  Myopathy
  
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  Neuropathy
  
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  CVD
  
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  Infection (SBP, immunocompromise)
  

Differentiation between ARF and CRF

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  Hx
  
• 
  Duration of symptoms
  
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  Previous urinalysis/measure of renal function
  
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  Normocytic anaemia, small kidneys on US and renal osteodystrophy = CRF
  

Tips for finals

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  Investigations = bedside, bloods, imaging, special tests
  
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  Management = bio-psycho-social approach
  
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  Bio = conservative, medical, surgical
  
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  Explaining RRT/transplant to a pt