Kidney - Renal Colic and Urinary Retention

Renal Colic 

Diagnosis
85-90% present with haematuria

Uric acid stone formers have acidic urine, as to cystinurics
Calcium stones have alkaline urine

Imaging
Look carefully for stones at the points where they may get stuck:

    The pelviureteric junction where the large diameter of the renal pelvis decreases to that of the ureter (2-3 mm)
    The pelvic brim: as the ureters arch over the iliac vessels, they narrow to about 4 mm
    The vesicoureteric junction where the ureter narrows to 1-5 mm - this is the most common area
 
 Treatment
- Buscopan may be useful but no hard evidence. 

Physiology
- The most common types of stone are:

calcium-containing stones - 70%
    infection stones (struvite/ triple phosphate) - 15-20%
    uric acid stones - 5-10%    cystine stones - 1-3%
    xanthine stones - 1%

BMJ article
Acute Urinary Retention
 PSA: The serum PSA can be artificially elevated in acute urinary retention and after instrumentation of the urinary tract (catheterisation). It can also be artificially raised by infection (cystitis, prostatitis), prostatic biopsy itself, and after sexual intercourse but not by a gentle rectal examination. PSA should only be measured in the acute setting if there is a suspicious rectal examination or a concomitant history suggesting metastatic disease (bone pain, leg weakness).

Tamsulosin: less postural hypotension, more retrograde ejaculation (better in elderly men).

Alfusozin: more postural hypotension, less retrograde ejaculation (better in younger men).