15. The Urinary System and the Male Genital Tract Flashcards
Overview
Urinary tract infections Kidneys Bladder Prostate Testis
Urinary Tract Infections (1)
Very common disorder of the urinary tract
Risk factors include: Females>males Sexual intercourse Pregnancy Diabetes Urinary tract obstructions e.g. stones or catheters
Urinary Tract Infections (2)
Bacteruria: bacteria in the urine, may be asymptomatic or symptomatic.
Urinary Tract Infection (UTI): the presence of pure growth of >10^5 organisms in fresh urine.
E.coli is the most common causative organism (>70% of community UTIs).
Other organisms include: Staphylococcus, Proteus and Klebsiella
Cystitis
frequency, dysuria, urgency, haematuria, suprapubic pain
Pyelonephritis
high fever, rigors, vomiting, loin pain and tenderness
prostatitis
flu-like symptoms, few urinary symptoms, swollen tender prostate
Management
Drink plenty of fluids.
Urinate often (double voiding).
Antibiotics (trimethoprim usually first line treatment in uncomplicated UTIs).
Imaging – US in non-resolving UTIs, children, men and pyelonephritis.
Severe cases may require hospital admission specially pyelonephritis and in the elderly
Kidney Function (1)
Maintinance of water, electrolyte and acid-base homeostasis.
Excretion of many toxic metabolic waste products (urea and creatinine).
Hormonal function
Renin – help control blood pressure
Erythropoietin- stimulates production of RBCs in the bone marrow and helps in the production of vitamin D.
Kidney Function (2)
The functional unit is the nephron (consisting of a glomerulus and a renal tubule).
Filtration of most small molecules from the blood in the glomerulus.
Selective reabsorption in the renal tubule of most of the water and some molecules.
Maintenance of the acid-base balance.
Acute Renal Failure
over hours or days
There is a low urine volume (
Causes
Pre-renal
Hypoperfusion, sepsis
Renal
ATN damage to tubules due to ischaemia or nephrotoxins
Post-renal
Renal tract obstruction (eg stones, tumours)
Management
Treat exacerbating factors ( hypovolaemia, sepsis.. etc).
Stop nephrotoxic drugs ( NSAIDs, ACE-I, gentamycin and Vancomycin)
May need renal replacement therapy (haemofiltration/dialysis)
Chronic Renal Failure
depending on the glomerular filtration rate (GFR)
GFR is the volume of fluid filtered from the glomerular capillaries into the Bowman’s capsule per unit time
Symptoms usually occur by stage 4
Chronic Renal Failure stage
1 = >90 2 = 60-89 3 = 30-59 4 = 15-29 5 =
Chronic Renal Failure Common Causes
Glomerulonephritis Diabetes Renovascular disease Hypertension Polycystic disease
Managed under nephrology team. Treat reversible causes. Avoid exacerbating factors, avoid nephrotoxic drugs.
May progress to renal replacement therapy
Glomerulonephritis
A group of disorders where there is damage to the glomerular filtration apparatus. This may cause a leak of protein or blood into the urine.
Usually there is a deposition of immune complexes in one part of the nephron
Stones
Crystal aggregates that form in the collecting ducts of the kidneys and can deposit anywhere in the renal tract.
Life time incidence 15%
Peak age 20-40 years.
Male: female = 3:1
Risk Factors (1)
Dehydration
Dietary factors ( increase chocolates, tea and rhubarb)
Drugs ( loop diuretics, antacids, corticosteroids, theophylline and aspirin)
Renal tract abnormalities
Recurrent UTIs
Metabolic abnormalities (hyperparathyroidism, hyperthyroidism and cancer)
Risk Factors (2)
Patient may be asymptomatic (found accidently on x-ray or blood on dipstick ).
Pain. Kidney stones causes loin pain. Ureteric stones case renal colic (from loin to groin). Bladder and urethral stones cause pain on micturition with interrupted flow. Patients often can’t lie still from the pain.
Management
Imaging options: KUB-xray (80% of stones are visible). CT scan (99% of stones visible).
Prompt pain relief
Stones 5mm or causing obstruction may need intervention
Renal Cancer
Renal cell carcinoma
85% of all renal cancers.
Usually presents between the ages of 50 and 70 years.
2:1 male predominance .
Smoking an important risk factor along with obesity, hypertension, exposure to asbestos and certain hereditary conditions.
Presentation
50% incidental findings on abdominal imaging.
Haematuria.
Loin pain.
Abdominal mass.
Para neoplastic syndromes: e.g. polycythaemia, hypercalcaemia and hypertension.
Treatment
Radical nephrectomy +/- chemotherapy
Bladder
Cystitis is the commonest benign condition
Transitional cell carcinomas are the most common malignant condition in the bladder
