Flank pain Flashcards
Differentiate fever in malignancy vs that in infection
The fever of malignancies
(e.g. renal cell carcinoma) is typically intermittent, unlike in infection.
Differentiate UTI vs urinary obstruction symptoms
UTI= frequency, urgency and dysuria
Obstruction= hesitancy, reduced flow, dribbling and incomplete voiding
Obstruction of urine outflow might be due to?
Stones of tumours
Repeated bladder infections put you at risk of what type of stones
Recurrent episodes of urinary tract infection predispose
to stones of the struvite type.
What is important to ask in a PMH of flank pain?
Kidney disease? Polycystic kidney disease predisposes to pyelonephritis. If
the patient only has one kidney, you need to know as obstruction of the only
functional ureter is a medical emergency
Which drugs can lead to kidney stone formation
Indinavir, aciclovir, and acetazolamide can lead to kidney stone formation.
Why should you feel the popliteal pulse in somebody who has flank pain?
Also conduct a vascular examination of the lower limbs, as an AAA can compromise blood supply to the lower limbs. If you can easily feel the popliteal
pulse, you should suspect a popliteal aneurysm and remember that about 50%
of patients with popliteal aneurysms also have AAAs.
Why would you look at the pH of the urine when suspecting renal stones
You may also want to note the urine
pH, as patients with urate stones usually have acidic urine; an alkali pH suggests the presence of urease-producing bacteria (e.g. Proteus, Pseudomonas,
Klebsiella) that can predispose to stone formation
What do presence of red and white cell casts indicate
The presence of red cell casts or white
cell casts indicates that the red or white cells are coming from the kidney,
rather than the ureters or bladder. Thus red cell casts indicate glomerular damage and white cell casts suggest pyelonephritis (although these are
rarely found).
When to admit someone with renal stones
• there is evidence of upper urinary tract infection (cloudy urine ± white
cell casts, high WCC in blood, high CRP, fever) … infection proximal to an
obstruction is a surgical emergency, requiring drainage;
• there is evidence of renal failure (high creatinine, high urea, high K+);
• there is refractory pain (despite analgesia);
• there are bilateral obstructing stones (or a single obstructing stone if only one
kidney present);
• the patient is elderly, a child, or otherwise unwell (e.g. unable to tolerate oral
fl uids), for closer monitoring.
Management of renal stones
ABC
Admit according to above criteria.
If no admission:
-Analgesia (paracetemol+NSAIDS)
Why are paracetemol and NSAIDs given in preference to opioids in renal stones
NSAIDs and paracetamol are preferred to opiates as studies show they provide equally adequate analgesia in the context of kidney stones (see viva question), may have
some additional eff ect of decreasing ureteric smooth muscle tone, and lack some of
the adverse eff ects of opiates, notably respiratory and central nervous system (CNS)
depression, vomiting, and disorientation
Briefly outline how we classify and treat kidney stones
If stones <0.5cm, trial conservative management (analgesia and fluid intake)- 90% of small stones pass in the urine (they should filter it so the composition of stone can be assessed).
Could give CCB or a-blocker to relax smooth muscle of ureter. Follow up after 2-3 weeks to request plain KUB radiograph
If stone >0.5cm OR not passed after 4-6 weeks and continuing discomfort:
-Lithotripsy= ESWL (extracorpeal shock wave lithotripsy, if small enough. Renal stones <2cm, uteric stones <1cm)
-Ureterorenoscopic removal (using a fi ne telescope inserted via the urethra) with a dormia basket, holmium laser, mechanical lithotripsy etc., if
too large for ESWL. Note that this commonly requires a post-operative
ureteric stent as it can cause ureteric stricture.
- Stenting to prevent hydronephrosis
- Abx cover
