Urological Disorders Flashcards
What are the 5 functions of the kidneys?
- Filtration - Removal of waste substance and keeping the essential substance within the blood: e.g. blood cells, large protein including albumin
- Control salt and water balance
- Control of acid/base balance
- Hormone: erythropoietin (EPO) production: essential for synthesis of Haemoglobin (Hb)
- Vitamin D: 1-α-hydroxylation of vitamin D
What occurs when the kidney dysfunctions?
- Filtration failure - Unwell with accumulation of waste substance: haematuria and proteinuria, low serum protein, including albumin, in blood
- Hypertension, water retention (sometimes dehydration because unable to make concentrated urine)
- Metabolic acidosis
- Anaemia
- Vitamin D deficiency and secondary hyperparathyroidism
What are the 4 categories of kidney pathologies?
- Inflammatory (infection including cystitis or non-infective causes like metabolic (diabetic nephropathy) or immunological (nephritic and nephrotic syndrome))
- Obstructive (stones, benign prostatic hypertrophy)
- Neoplastic (Kidney, bladder, prostatic, testicular cancer)
- Developmental/Genetic (Polycystic kidneys, horseshoe kidney)
What are common locations and infectious agents?
Cystitis when occurs in bladder or pyelonephritis when occurs in kidneys. Most common pathogen is bacteria but virus and fungi possible in immunocompromised patients.
What are hallmarks of UTI?
Raised temperature, lower blood pressure, raised pulse and softeness over suprapubic area. Urine dipstick will indicate 2+ leucocytes, +nitrite and trace of blood.
What are the treatments for an UTI?
Antibiotics depending on severity of illness, most common bacteria in local area and modified once sensitivity determined from urine culture. Some patients may be very ill and need to be treated as inpatient. Pain control and supportive treatment such as hydration. Consider imaging if other factors or differential diagnosis.
What are immunological causes of kidney damage?
Can be caused by antibodies or other inflammatory cells. Clinical presentation is nephritic syndrome, nephrotic syndrome or proteinuria. Glomerulonephritis: Inflammation of the microscopic filtering units of the kidney.
What is the pattern of organ involvement for kidney damage?
Can be kidney only, kidney and lung or multiple organs/tissues.
What is the diagnostic approach for immunological causes?
History and physical examination Urine test Blood test: including immunology tests Imaging: start with ultrasound Kidney biopsy
What are symptoms of nephritic syndrome?
Haematuria
Variable amount of proteinuria
May have hypertension, reduced urine output, increased urea and creatinine.
Urine dipstick would show 3+ for blood, 2+ for protein
Raised urine:creatinine ratio
Kidney biopsy would show IgA nephropathy
Describe features of IgA nephropathy
The most common primary glomerulonephritis world-wide and very high prevalence in Far East. Deposition of IgA antibody in the kidney (detected by immunohistochemistry). Inflammation and scarring. About 30% progress to kidney failure.
What is supportive treatment for IgA nephropathy?
- Reduce hypertension and treat proteinuria - First line treatment: angiotensin receptor inhibitor (ARB) (e.g. irbesartan) or angiotensin converting enzyme inhibitor (ACEI) (e.g. ramipril)
- Reduce sodium intake
What immunotherapy is available for IgA nephropathy?
Renal replacement therapy: when reaching late stage kidney disease. Options are kidney replacement and dialysis.
What are common organ specific immunological causes?
Anti-glomerular basement membrane (GBM) antibody mediated: Goodpasture’s disease.
Shared common antigen between lung and kidney: α3chain of type IV collagen.
What are common systemic immunological causes?
Systemic lupus erythematosus (SLE): autoantibodies: antinuclear factor, anti-dsDNA.
Vasculitis: antineutrophil cytoplasm antibody (ANCA).
What are risk factors and clinical features of diabetic nephropathy?
Risk factors are hypertension, poor diabetic control and smoking.
Clinical features are microalbuminuria, proteinuria and associations with other complications of diabetes mellitus like diabetic retinopathy and neuropathy.
What is the treatment for diabetic nephropathy?
- Optimised diabetic control
- Optimised treatment of hypertension
- Reduce proteinuria using ARB or ACEI
- Stop smoking
- New clinical trials: SGLT2 inhibitor
- Transplantation (including combined pancreas and kidney transplantation
- Dialysis
What are the features of nephrotic syndrome?
Peripheral oedema
Severe proteinuria - frothy urine
Low serum albumin
Variable amount of microscopic haematuria
Associated with hyperlipidaemia
Urine dipstick shows no blood, 4+ protein
Very high urine protein : creatinine ratio
What are causes of nephrotic syndrome?
Minimal change glomerulopathy Membranous nephropathy Focal segmental glomerulosclerosis Lupus nephritis Others
What are key features of minimal change glomerulopathy?
Most common in children, also affect other age groups
Normal light microscopy
Electron microscopy: podocyte effacement- abnormal flatten appearance (figure below)
Complication: high risk of thrombosis
What is the treatment for nephrotic syndrome?
Immunotherapy
Traditionally: corticosteroid, cyclophosphamide.
Recent development: tacrolimus, antibody therapy targeting B cell pathway.
Diuretics: to reduce the peripheral oedema.
Prevention of thrombosis: anticoagulation
What are the possible locations and clinical presentation of kidney stones?
Kidney, ureter, bladder. Clinical features include:
abdominal/back pain, blood in urine, associated with urine infection, 90% of kidney stones are radio-opaque. Urine dipstick may show some blood in urine and evidence of infection.
What is the treatment for stones?
Supportive treatment includes pain control and hydration. Specific treatment depends on: size and location of stones, availability of local expertise, fitness of the patient for general anaesthetics.
What are the 3 options for stones treatment?
Shockwave Lithotripsy: High energy sound waves to break up large kidney stones into smaller one.
Ureteroscopy: Through urethra, bladder and ureter.
Percutaneous nephrolithotomy: Small percutaneous incision. Insertion of nephroscope. Stone is removed (may need to broken in smaller pieces).
What are benign and malignant tumours of the kidney?
Benign prostatic hypertrophy Kidney: Renal cell carcinoma Ureter and bladder: Transitional cell carcinoma Prostatic cancer Testicular cancer
What would clinical findings and investigations be for tumours?
Clinical presentation may be asymptomatic (incidental finding during other investigations), haematuria or pain. Imaging, urine cytology, PSA marker in urine, kidney function tests, biopsy/excised tumour and staging studies for metastasis may be done.
What is tumour treatment?
To release any obstruction of the urinary tract: nephrostomy, bladder catheter or/and surgery.
Chemotherapy
Radiotherapy
Hormonal therapy for hormone sensitive cancer (e.g. prostatic cancer).
Surgery
What are the different sorts of polycystic kidneys?
Neonatal: autosomal recessive
Adult onset: autosomal dominant
Some patients without family history
What are the consequences of polycystic kidneys?
Loss of kidney function Pain Bleeding into the renal cysts Infection of renal cysts Asymptomatic in some patient
What is the treatment for polycystic kidneys?
New medication: Tolvaptan (a vasopressin receptor 2 antagonist) to slow down the cysts formation.
Treat hypertension, infection.
Pain control.
Renal replacement therapy (transplantation, dialysis).
How is horseshoe kidney identified and what are the consequences?
Identified through imaging. Increased risk of obstruction, stone and infection.
