10 - Obstruction Flashcards
(23 cards)
What can cause a false positive for haematuria on a dipstick?
Myoglobin (rhabdomyolysis), bacterial peroxidases, bleach
What can cause a false negative for haematuria on a dipstick?
Vitamin C
What types of cancer cause haematuria?
Bladder cancer
Upper tract transitional cell carcinoma
Renal cell carcinoma
Prostate carcinoma (BURP)
What causes black urine?
Anti-malarials
Blackwater fever (Malaria leading to haemolysis)
Haemolysis
What causes orange urine?
Excess vitamin B and C
Rifampicin and Sulfasalazine (TB medication)
What causes red urine?
Beetroot and rhubarb
Phenolphthalein
Rifampicin (TB medication)
What causes dark urine? (also pale stools)
Obstructive jaundice (gallstones/pancreatic tumour)
What causes green/blue urine?
Pseudomonas
What causes cloudy urine?
Fistula
What are the differences between acute and chronic urinary retention?
Acute is painful, chronic isn’t
Acute will have a reduced eGFR
Acute can’t void, chronic can but is incomplete
When is a catheter needed for urinary retention?
Painful acute retention
High pressure chronic retention
Why is high pressure chronic retention a problem?
Can cause hydronephrosis (kidneys swell due to build up of urine) and impair renal function
Name acute causes of urinary retention in men
BPH, prostate cancer, urethral stricture, prostatic infection
Name acute causes of urinary retention in women
Prolapses, masses, post botox for stress incontinence
Name acute causes of urinary retention in both sexes
Blood clots
Drugs: Anticholinergics, sympathomimetics
UTIs
Neurological: Spinal cord compression due to metastases, supra-sacral: detrusor-sphincter dysynergia
How are kidney stones characterised?
Staghorn - Filling major and minor calices
Non-staghorn - Calyceal or pelvic in location
Urethral - Located in the proximal, middle or distal
What causes renal colic?
A kidney stone starting to travel down the urinary tract, causing loin to groin pain
What composes the majority of kidney stones?
Calcium oxalate and calcium phosphate
What causes struvite kidney stones to form?
Infection from bacteria that produce urease, creates alkaline conditions that promote stone formation
What causes calcium oxalate stones to form?
Hypercalcaemia
High uric acid - metabolic acidosis, H+ stays in tubule so urine not acidic, allows calcium compounds to precipitate
Low citrate
What causes uric acid stones to form?
Supersaturation of uric acid (common with gout)
What causes cysteine stones to form?
Autosomal recessive genes
Define pyonephrosis
A blocked renal tract causing a standing column of septic urine in upper urinary tract, including the kidney
