Urology Flashcards
Main functions of the kidneys?
- To eliminate waste material
- To regulate volume and composition of body fluid
- Endocrine function - EPO, renin, vit D in active form
- Autocrine function - endothelin, prostaglandins, renal natriuretic peptide
Why can’t hypotensive or hypovolaemic patients excrete hydrogen and potassium ions?
If renal perfusion or glomerular filtration fall, reabsorption of water and sodium by the proximal tubules increases so minimum fluid reaches the distal tubule- which is where potassium and hydrogen are excreted.
Define dysuria
Pain on micturition
Define polyuria
Excessive urine output of greater than 2.5-3L in 24 hours. Must be differentiated from urinary frequency and nocturia.
Define nocturia
Night-time urination
Define oliguria- what are the causes?
Low urine output
Caused by AKI or urinary tract obstruction
What are the most common causes of polyuria?
- Drink too much (polydipsia)
- Poorly controlled diabetes mellitus (solute diuresis)
- CKD
- Diabetes insipidus
Why and how does diabetes insipidus cause polyuria?
There is a lack of vasopressin produced by the hypothalamus (stored in pituitary), meaning kidneys fail to concentrate urine and a lot of fluid is lost.
What are the most common causes of nocturia?
- Drinking too much (polydipsia) especially before bed
- Prostatic enlargement (in men over 50)
- Congestive cardiac failure - lying down
- Sleep apnoea
How can congestive cardiac failure cause nocturia?
Oedema around legs and ankles when lie down there is lack of gravity and can go to heart and expand atria. This causes the release of ANP which in turn increases production of urine.
If man has benign prostatic enlargement, what 3 symptoms are they most likely to complain of?
- Nocturia
- Hesistancy
- Weak stream
What are the 3 classes of lower urinary tract symptoms and give examples of each
- Storage e.g. urgency, nocturia
- Voiding e.g. weak stream, hesistancy, intermittency
- Post-micturition e.g. dribbling
What 3 factors when taking a urology history would be red flags?
- Haematuria
- Pain
- Neurological deficit
What four things would you look out for in examination of 55 yo male with BOO?
- Bladder palpable? - Chronic urinary retention
- Urethral meatus stenosis?
- Phimosis
- Size of prostate and malignant feel?
How would an oliguric patient be managed (in 3 steps)?
- Exclude obstruction - pass catheter into bladder and large volume of urine released. If patient already catheterised, flush with saline to remove potential blockage
- Assess for hypovolaemia - if obstruction is excluded measure blood pressure, pulse, JVP, urinary electrolytes - urine output in response to fluid challenge is measured if hypovolaemic
- Management of established AKI - once above causes excluded
What measurement is the best indicator of kidney function and how it is measured?
GFR (worked out by creatinine clearance)
What tests can be done in urology to find or investigate underlying pathologies?
- Urinary tests - dipstick testing, urinary flow rate, post-void bladder residual
- Blood tests - U&E’s for creatinine and PSA
What can a urinary dipstick test detect?
- Proteinuria
- Haematuria
- Glucose
- Ketones
- Bilirubin
- pH
- Nitrites and leucocytes - UTI
Haematuria in different sections of the stream is indicative of different things. What are these?
Blood at start of micturition- urethral disease
Blood at end of micturition- bleeding from prostate or bladder base
Blood seen evenly throughout- bleeding from bladder or above
Most common cause of glucosuria?
Diabetes mellitus
Red cell casts in urine are pathognomonic for what?
Glomerulonephritis
White cell casts in urine may be seen in what?
Acute pyelonephritis
How are renal, bladder and prostate tumours staged?
CT
How is polycystic kidney disease diagnosed?
Ultrasonography