Renal Failure Flashcards
What is polyuria
The frequent passage of large volumes of urine
What is dysuria
Discomfort or burning with urination
What is haematuria
The presence of blood in urine
What is proteinuria
Protein in urine
What is uraemia
Kidneys cannot remove urea from the body so waste from urine accumulates in the blood
How can renal function be measured
Serum urea
Serum creatinine
eGFR - estimated glomerular filtration rate
24 hour urine collection - best measure
Describe eGFR
Modern quick way of looking at renal function calculated from U&Es measurement
What happens during renal failure
Loss of renal excretory function
Loss of water and electrolyte balance
Loss of acid base balance
Loss of renal endocrine function
What is controlled by renal endocrine function
Erythropoietin
Calcium metabolism
Renin secretion
Describe the different types of renal failure
Acute renal failure - rapid loss of renal function usually over hours or days
Chronic renal failure - gradual loss of renal function usually over many years
What are the types of causes of renal failure
Pre-renal
Renal
Post-renal
What are the pre-renal causes of renal failure
Hypoperfusion of the kidney
Shock
Renal artery or aorta disease
Caused by sudden and severe drop in blood pressure or interruption of blood flow to the kidneys from severe injury or illness
What are the renal causes of renal disease
Chronic disease Drug damage Trauma Rhabdomyolysis Caused by direct damage to the kidneys by inflammation, toxins, drugs, infection or reduced blood supply
What are the post-renal causes of renal failure
Renal outflow obstruction
Caused by sudden obstruction of urine flow due to enlarged prostate, kidney stones, bladder tumour or injury
What are the signs of acute renal failure
Rapid loss of renal function - creatinine >200umol/L Anuric initially with volume overload Ankle oedema or sacral oedema if bed bound Pulmonary oedema and breathlessness Raised jugular venous pressure (JVP) Weight gain Gradually progresses to polyuria Development of hypekalaemia (high K+) Development of uraemia and acidosis
What causes acute renal failure and how is it treated
Usually a pre-renal cause
Usually reversible with time
Renal support until recovery - dialysis and nutrition
What are the causes of primary renal failure
(Rare)
Glomerulonephritis
Polycistic kidney disease
What are the causes of secondary renal failure
Diabetes (30%) Hypertension (20%) Drug therapy Vasculitis Renal artery disease/aorta disease
What are the signs of glomerulonephritis
Haematuria/proteinuria - otherwise healthy individual
Gradual progression to hypertension and chronic renal failure
What is nephrotic syndrome and what are the signs
A complication of glomerulonephritis
Excessive loss of protein in the urine - >3g in 24 hours
Loss of plasma oncotic pressure
Oedema
Hypercoagulable state - loss of clotting factors - AT3 deficiency
Dehydration raises other coagulation factor concentrations
Which drugs should be avoided in patients with renal disease
NSAIDs - inhibit glomerular blood flow and cause interstitial nephritis
Nephrotoxic drugs - cyclosporin
How may renal vascular disease present
Reduced blood flow to the kidney - atheroma of renal arter/aorta or hypertension of the renal artery
Microangiopathy - immune reaction causing small blood vessel damage, RBC damage and thrombosis - E.Coli 0157
What are causes of immune mediated renal damage
Multiple myeloma - plasma cell tumour, excess light chain production clogs kidneys - tubular nephritis results
Good pasture’s syndrome - Anti-glomerular basement membrane antibody (anti-gbm)
Vasculitis - SLE and variants
What is polycistic disease and what does it cause
Gene mutation (PFD1, 2 or 3) Can be inherited or spontaneous Causes multiple cysts in the renal parenchyma Enlarged kidney Progressive destruction of normal kidney Gradual renal failure
When is end stage renal disease diagnosed
eGFR <15ml/min
Creatinine 800-1000umol/L
What is the normal GFR
90+ml/min
How is chronic renal failure managed
Reduce the rate of decline:
Eliminate nephrotoxic drugs
Control hypertension
Control diabetes
Control vasculitis disease
Use of steroids/other immune suppressant drugs
Correct fluid balance - restrict fluid intake, restrict salt, potassium, protein
Correct deficiencies - anaemia (erythropoietin), calcium (Vit D)
Remove outflow obstruction - renal stones or prostate enlargement
Treat infection - chronic renal system infection
What are the signs of chronic renal failure
Anaemia Hypertension Renal bone disease: Low Ca, high PO4 Hyperthyroidism Osteomalacia
What are the symptoms of chronic renal failure
Insidious - may be few Polyuria Nocturnia Tired and weak Nausea
What is renal replacement therapy
Replaces the functions of the kidney
Not a cure
What are common renal malignancies
Renal cell carcinoma
Transitional cell carcinoma
Describe a renal cell carcinoma
Renal tubular cell tumour
Abdominal mass and haematuria
Commoner in men and smokers
Hypertension (renin) and polycythaemia (EPO)
Describe a transitional cell carcinoma
Usually bladder - ureter/kidney possible
Haematuria - often asymptomatic
What is important in dentistry and renal disease
Check all drugs with renal physician - avoid NSAIDS and some tetracyclines, reduce dose of most others
Growth may be slow in children - tooth eruption may be delayed
Secondary effects of anaemia - oral ulceration, dyaesthesias - painful mucosa and tongue
White patches - uraemia stomatitis
Oral opportunistic infections
Dry mouth and taste disturbance
Bleeding tendencies - platelet dysfunction
Renal osteoid Ts trophy
