Chronic Renal Failure Flashcards
(32 cards)
What is chronic renal failure?
Decreased GFR (<60mL/min/1.73m2) for > 3 months.
Mostly irreversible
What is the classification of chronic renal failure? Describe each stage.
What stage would you normally present with symptoms?
Each stage is determined by the GFR (mL/min)
Stage 1: >90 Stage 2: 60-89 Stage 3a: 45-69 Stage 3b: 30-44 Stage 4: 15-29 Stage 5: <15
Symptoms normally present at stage 4 (<30mL/min)
How is GFR calculated? What are the problems with this.
eGFR is a way of estimating GFR using an equation. The values you need to input are serum creatinine, age, race, and sex. This is the method currently advocated in the NHS. It is accurate it kidney disease, however, the method consistently underestimates the GRF of healthy people with a GFR of over 60ml/min.
Creatinine is a product of skeletal muscle metabolism that is produced at a constant rate and is proportional to body mass.
Serum creatinine has an exponential relationship to GFR, therefore is insensitive marker to earlier real impairment, and early small changes can indicate large drops in kidney function.
eGFR is an estimate and degree or error relating to extremes of muscle mass.
The GFR – normal GFR is about 125ml/minute.
Causes of CKD
- Diabetes (Diabetic nephropathy) Type 2 more than type 1.
- Glomerulonephritis: commonly IgA nephropathy also systemic disorders e.g. SLE, Vasculitis. Rare: mesangiocapillary GN
- Unknown: 20%
- Hypertension or renovascular disease
- Pyelonephritis and reflux nephropathy
Hereditary: polycystic kidney disease
Drugs: NSAIDs
Rare: Urianry tract obstruction (prostatic disease)
Aetiology
Common disease: 6-7% in England have CKD stage 3-5.
More common in older individuals who have other medical conditions e.g. diabetes and vascular disease.
Higher rates in Black people, hispanic people and Fhx or Hx of AKI.
How do CKD patients normally present?
- Often found incidentally during other investigation or monitoring of ‘at risk’ individuals.
- Symtoms of CKD (late)
- Crash landers: acute presentation of undiagnosed.
Symptoms of CKD
Anaemia (lack of EPO)
- Breathless
- Pallor
- Fatigue
Platelet abnormality:
- Bruising and Epitaxsis
Skin:
- Pigmentation and pruritus
GI tract:
- Anorexia, Nausea, Vomiting and Diarrhoea (toxins).
Renal:
- Nocturia, Polyuria, Oedema from salt and water retention.
CVS:
Hypertension, Peripheral vascular disease heart failure, uraemia pericarditis
Renal Osteodystrophy (decreased phosphate excretion, low activate of vitamin D3, high parathyroid) - Oesteomalacia, muscle weakness, bone bone, hyperparathyroid, osteosclerosis
CNS:
- Confusion, coma, fits (severe uraemia)
Endocrine:
- Amenorrhoea, erectile dysfunction, infertility.
What is uraemia? What problems can it cause?
High levels of urea in the blood. >60mmol/L causes severe ureamic symptoms involving the CNS.
Mental slowing, confusion, seizures, myoclonic twitching, encephalopathy, coma
Signs
Brown nails Yellow skin Pallor Purpura Brusing Excoriations High BP Cardiomegaly Pericardial friction rub Proximal myopathy
Signs of underlying disease:
DM: peripheral neuropathy and retinopathy
Indications for monitoring/screening?
How are they screened?
- Diabetes Mellitus
- Hypertension
- Cardiovascular disease (IHD, CCF, peripheral vascular disease, cerebrovascular disease)
- Nephrotoxic drugs (NSAIDs, Lithium)
- Structural renal disease (stones or BPH)
- Recurrent UTIs
- Multisystem illness
- Fhx of End Stage Kidney failure
- Opportunistic detection of haematuria
Bloods: eGFR
BP
Urinalysis: proteinuria/albuminuria
Allows for early intervention and slow/prevent progression to end-stage.
Questions in Hx
Pc: Ask ureamic: anorexia, vomiting, restless leg, fatigue weakness, itching, bone pain. Oliguria, dysponea, ankle swelling Women: amenorrhoea Men: impotence
To find cause:
- previous UTIs
- PMH hypertension, DM, IHD, systemic disorder, renal colic
Check drug Hx
Fhx
System review
Examination and Investigations
periphery: hypertension, arteriovenous fistula (thrill, bruit) signs of previous transplant- bruising from steroids,
Face: pallor (anaemia), yellow tinge (uraemia), gum hypertrophy from cyclosporine, cushingoid appearance from steroids
Neck: Current or previous tunnelled line insertion, scar form parathyroidectomy.
Cardiovascular exam
Abdomen: peritoneal dialysis catheter or sign of previous, signs of transplant, ballot able polycystic kidney +- liver.
Elsewhere: diabetic neuropathy, retinopathy, peripheral vascular disease
Investigations
Tests: Blood: FBC (normochromic, normocytic anaemia) ESR U&Es (raised) Glucose (raised if DM) Calcium (low) Phospahte (high) Alk Phos (high in renal otseodystrophy) PTH: high
Urine: Dipstick (haematuria and proteinuria) MC&S (Microscopy, Culture and Sensitivity) Albumin:Creatinine Ratio (Urine Microalbumin 30-300mg/day)
Imaging:
USS: check size/anatomy, presence of obstruction or hydronephrosis/stones
eGFR: <60mL/minute/1.73.2
Consider renal biopsy for histology (if rapidly progressive)
Who manages CKD?
Mild-Moderate= GPs
Refer to nephrologist if if:
- Stage 4/5 (eGFR <30)
- Significant Proteinuria
- Haematuria and proteinuria
- Rapidly falling eGFR
- Genetic cause
- Suspected renal artery stenosis
What are the aims of CKD management?
- Early Diagnosis
- Treat underlying cause
- Slow or prevent progression
- Prevent/Treat complications
- Timely education, planning and preparation for end-stage renal disease
- Reduce mortality
- Preserve quality of life
Treat underlying cause
Identify and treat:
relieve obstruction, stop nephrotoxic drugs, deal with high calcium and cardiovascular risk (stop smoking, weight) and tight glucose control
Limit progression, what are the 4 main factors to consider
Blood pressure, renal bone disease, cardiovascular modification and diet.
Describe management of BP
Even a small change in BP can have significant impact to BP.
CKD aim: 140/90
CKD + Diabetes aim: <130/80
Drug: local guidance but even with normal BP treat with ACEi or ARB.
Renal Bone Disease
- Treat if PTH raised
- Phosphate rises in CKD increasing PTH
- Restrict dietary phosphate (milk, cheese, eggs)
- Give binders e.g. calcichew
- Vit D analogues (alfacalcidol) and calcium supplements to decrease bone disease and hyperparathyroidism.
Cardiovascular Risk
- In stage 1/2 the risk of cardiovascular death is higher than risk of ESRF.
- Give statins (if raised lipids)
- Aspirin (low dose)
Diet
Multidisciplinary team: patient should be reviewed by a dietician for advice on healthy, moderate protein diet, K restricted if hyperkalaemic, and avoid high phosphate foods.
Name 4 main symtoms of CKD that can be controlled
Anaemia, Acidosis, Oedema and restless leg/cramps
Anaemia
- Check haemantics and replace iron/B12/folate if necessary.
- Consider EPO injections
- Keep Hb 100-120 g/L (above this increases risk of bleeding, increases BP and MI)
Acidosis
consider sodium carbonate supplements (caution if high BP as sodium load can increase BP)
