Urology Flashcards
Causes of transient non-visible haematuria
UTI
Menstruation
Vigorous exercise (settles after 3 days)
Sexual intercourse
Causes of persistent non-visible haematuria
Cancer (bladder, renal, prostate) Stones BPH Prostatitis Urethritis eg Chlamydia Renal causes - IgA nephropathy, thin BM disease
Spurious causes of haematuria
Foods - beetroot, rhubarb
Drugs - rifampicin, doxorubicin
Urgent referral criteria for haematuria
Age >=45 years AND - unexplained visible haematuria without UTI OR visible haematuria that persists or recurs after successful treatment of UTI
Age >=60 years AND have unexplained non-visible haematuria and either dysuria or raised WCC on blood test
What are the different types of renal stones? Features of each type of stone, including effect on urinary pH?
Calcium oxalate (85%)-
Major risk factor is hypercalciuria. Hypocitraturia increases risk because citrate forms complexes with calcium making it more soluble.
Stones are radio-opaque.
pH 6
Calcium phosphate (10%)-
May occur in renal tubular acidosis, high urinary pH increases supersaturation of urine with calcium and phosphate.
Radio-opaque stones.
pH >5.5
Struvite stones (2-20%) -
Formed from magnesium, ammonium and phosphate.
Occurs as result of urease producing bacteria (associated with chronic infections).
Slightly radio-opaque.
pH >7.2
Uric Acid stones (5-10%) -
May precipitate when urinary pH low. May be caused by disease with extensive tissue breakdown eg malignancy.
Radiolucent.
pH 5.5
Cystine stones (1%) -
Inherited recessive disorder of transmembrane cystine transport leading to decreased absorption of cystine from intestine and renal tubule.
Multiple stones may form
Relatively radiodense because they contain sulphur.
pH 6.5
3 common location of renal stones
Pelviureteric junction
Pelvic brim
Vesicoureteric junction
Risk factors for renal stones
Dehydration Hypercalciuria Hyperparathyroidism Hypercalcaemia Cystinuria High dietary oxalate Renal tubular acidosis Medullary sponge kidney, polycystic kidney disease Beryllium or cadmium exposure
Urate stones -
Gout
Ileostomy - loss of bicarbonate and fluid results in acidic urine, causing precipitation of uric acid.
Drug causes - loop diuretics, steroids, acetazolamide, theophylline
Thiazides can prevent calcium stones
What are staghorn calculi?
Forms shape of staghorn
Body sits in renal pelvis with horns extending into renal calyxes.
Usually composed of struvite.
In recent upper urinary tract infections, bacteria can hydrolyse the urea in urine to ammonia, creating solid struvite.
Symptoms and signs of renal stones?
Asymptomatic Renal colic - loin to groin pain Nausea and vomiting Restless/moving around Haematuria Dysuria Secondary infection may cause fever
Investigations for renal stones
Bloods - FBC, U&E, Calcium, phosphate, glucose, bicarbonate, urate
Urine dipstick - usually positive for blood.
MSU - MC&S
Urine pH
24 hour urine
Imaging -
Non-contrast CT scan KUB is gold standard.
AXR still used but not all stones are radio-opaque
USS - used in cases of known stone disease to assess for hydronephrosis.
Initial management of renal stones?
Adequate fluid resuscitation if required.
Diclofenac 75mg IV/IM or 100mg PR for analgesia.
Abx (tazocin or gent) if infection.
Stones in lower ureter <5mm will pass spontaneously in 95% of cases. Lithotripsy and nephrolithotomy may be used in severe cases.
Management of renal stones
Presence of ureteric obstruction, renal developmental abnormality such as horseshoe kidney and previous renal transplant - more intensive and urgent treatment is indicated.
Ureteric obstruction due to stones together with infection is surgical emergency and system must be decompressed - nephrostomy tube placement, insertion of ureteric catheters and ureteric stent placement.
Non-emergency setting - extracorporeal shock wave lithotripsy, percutaneous nephrolithotomy, ureteroscopy, open surgery.
Stone burden <2cm - lithotripsy
Stone burden <2cm pregnant - ureteroscopy
Complex renal calculi and staghorn calculi - percutaneous nephrolithotripsy
Ureteric calculi less than 5mm - manage expectantly
How to prevent renal stones?
Calcium stones - high fluid intake, low animal protein, low salt diet, thiazide diuretics
Oxalate stones - cholestyramine reduces urinary oxalate secretion
Pyridoxine reduces urinary oxalate secretion
Uric acid stones -
Allopurinol
Oral bicarbonate
Struvite stones - treat infection.
Criteria for urgent intervention of renal stones
Post-obstructive acute kidney injury
Uncontrollable pain from simple analgesics
Evidence of infected stones
Large stones >5mm
Cause of bladder stones?
Complications of bladder stones if not treated?
Form from urine stasis within bladder - seen in chronic urinary retention.
Secondary to infections or passed ureteric stones.
Chronic irritation of bladder epithelium can predispose to development of TCC bladder cancer.
Presentation of upper and lower urinary tract obstruction
Upper - Loin to groin pain Reduced/no urine output Non-specific symptoms (eg vomiting) Reduced renal function on bloods
Lower -
Acute urinary retention
Lower urinary tract symptoms - poor flow, terminal dribbling, difficulty initiating urination
Reduced renal function on bloods.
Causes of obstructive uropathy
Upper - Kidney stones Local cancer masses pressing on ureters Ureteric strictures - scar tissue Anti-cholinergics
Lower - BPH Prostate cancer Ureter or urethral strictures Neurogenic bladder
Investigations of obstructive uropathy
Bloods - U&Es, creatinine, FBC and PSA
Urine - dipstick and MC&S
USS - modality of choice
If evidence of hydronephrosis or hydrometer - CT scan
Treatment of obstructive uropathy
Upper -
Nephrostomy or ureteric stent - also give alpha-blocker (tamsulosin) to reduce ureteric spasms.
Pyeloplasty to widen PUJ
Lower -
Insert urethral or suprapubic catheter to relieve acute retention.
Treat underlying cause.
Risk factors for BPH
Age - 50% of 50 year old men will have evidence of BPH and 30% will have symptoms.
Black > White > Asian
Clinical Features of BPH
Voiding symptoms - weak or intermittent urinary flow, straining, hesitancy, terminal dribbling and incomplete emptying
Storage symptoms - urgency, urgency incontinence, nocturia
Post-micturition - dribbling
Complications - UTI, retention, obstructive uropathy.
DRE - firm, smooth symmetrical prostate is reassuring sign - more rounded prostate of greater than 2 finger widths may indicate enlargement.
Investigations of BPH
Urinary frequency and volume chart Urinalysis Post-void bladder scan PSA Ultrasound scan of renal tract - calculates volume of prostate and looks for urinary retention or hydronephrosis. Any prostate >30ml is enlarged. Urodynamic studies
Management of BPH - lifestyle, medication, surgery
Lifestyle - avoid caffeine, alcohol, relax when voiding, void twice in a row to aid emptying, bladder training for urgency.
Medical -
If symptomatic, trial alpha adrenoreceptor antagonist such as tamsulosin. They relax prostatic smooth muscle. SE - drowsiness, postural hypotension, dry mouth, depression.
5alpha-reductase inhibitors (finasteride) if still symptomatic. Prevents conversion of testosterone to DHT, reducing prostatic volume. SE - erectile dysfunction, reduced libido, ejaculation problems, gynaecomastia.
Surgery -
TURP - aims to create wider space for urine to flow through, thereby improving symptoms. Complications - bleeding, infection, incontinence, retrograde ejaculation, urethral strictures, failure to resolve symptoms, erectile dysfunction.
Transurethral incision of prostate (TUIP) - less destruction than TURP, less risk to sexual function. Better for patients with a small gland <30g.
Retropubic prostatectomy - open surgery
Transurethral laser-induced prostatectomy (TULIP)
Robotic prostatectomy - less traumatic and minimally invasive treatment option.
What is TURP syndrome?
Life-threatening complication of TURP.
Caused by irrigation with large volumes of glycine, which is hypo-osmolar, and is systemically absorbed when prostatic venous sinuses are opened during prostate resection.
Results in hyponatraemia, and when glycine is broken down by the liver into ammonia, hyper-ammonia and visual disturbances.
CNS, respiratory and systemic symptoms.
Risk factors for developing TURP syndrome: Surgical time >1hr Height of bag >70cm Resected >60g Large blood loss Perforation Large amount of fluid used Poorly controlled CHF
What is the most common renal cancer? What are other types of renal cancers?
Renal cell carcinoma (85%)
Transitional cell carcinoma (urothelial tumours)
Nephroblastoma in children (Wilm’s tumour)
Squamous cell carcinomas (secondary to renal calculi, infection, schistosomiasis)
Risk factors for renal cell carcinoma
Smoking Industrial exposure to carcinogens - cadmium, lead, aromatic hydrocarbons Dialysis Hypertension Obesity Anatomical abnormalities such as PCKD von Hippel-Lindau disease BAP1 mutant disease Birthings-Hogg-Dube syndrome
Features of RCC
Classical triad - haematuria, loin pain, abdominal mass
Pyrexia
Left varicocele - due to occlusion of left testicular vein
Endocrine effects - may secrete erythropoietin (polycythaemia), parathyroid hormone (hypercalcaemia), renin, ACTH
25% have mets
Paraneoplastic hepatic dysfunction syndrome - Stauffer syndrome - cholestasis/hepatosplenomegaly
