Flank Pain Flashcards
Differentials for flank pain
Muscular sprain Nephrolithiasis/ureteric colic Spinal pathology (fractures, metastases, disc prolapse) Leaking/ruptured AAA Testicular torsion Pyelonephritis Perforated peptic ulcer Renal ulcer Abscess Basal pneumonia Ectopic pregnancy Ovarian torsion
What is the site of kidney stone pain
Almost always unilateral, but location may radiate from loin to groin
What can the character of flank pain suggest
Colicky pain - ureteric stone
Constant - stone lodged in the kidney or inflammatory cause
Ache - musculoskeletal
Shooting pain - nerve impingement
What does pain that radiates down the leg suggest
Lumbar nerve root pain
What associated symptoms should be asked for with flank pain
Fevers, rigors, night sweats Dehydration N+V Haematuria LRTI symptoms Cloudy or offensive smelling urine Leg weakness
What do the following symptoms (with flank pain) suggest: Fevers, rigors and night sweats Dehydration N+V Haematuria LRTI symptoms Cloudy or offensive smelling urine Leg weakness
Fevers, rigors and night sweats: pyelonephritis or malignancy e.g. Renal CC
Dehydration: predisposes kidney stones
N+V : ureteric stones, biliary colic, may be due to musc pain
Haematuria: microscopic - ureteric stones
LRTI symptoms: UTI or obstruction
Cloudy or offensive smelling urine: Infection
Leg weakness: Spinal pathology
What should be asked about in the past medical history for flank pain
Previous kidney stones (recurrence) Recurrent cystitis (struvite stones) Atherosclerotic disease (AAA) Long-standing back pain (musc, ligament, bone) Kidney disease (PKD -> pyelonephritis)
What drugs should be asked about specifically in a history for flank pain
Aciclovir and idinavir - may crystallise in the urine
Acetazolamide causes diuresis and potentially dehydration, predisposing to stone formation
What is being looked for on exam of a patient with flank pain
Position - colic (writhing in pain) or peritonitis (still)
Tendereness - flank/loin tenderness may be renal or ureteric stones
Masses - Look for expansale pulse - AAA
Spine and range of movement
Lowe limbs - spinal pathology or vascular pathology
Temperature - indicates whether it is inflammatory e.g. pyelonephritis is ongoing
What investigations should be done for suspected ureteric colic
Urinalysis and MC+S IF abnormal
FBC
CRP
U+Es - assess renal function
Calcium, phosphate and urate - aetiology of kidney stones
USS (Assess for AAA)
Non-contrast KUB - stones in the kidney or ureter or any obstructions or AAA
What imaging is used for stones in pregnant women
Magnetic resonance urogram (MRU)
What does pH of the urine suggest
Acidic - urate stone
Alkali - Urease-producing bacteria e.g. proteus, pseudomonas, klebsiella that predispose to stone formation
What indicates admission for a patient with a kidney stone
Evidence of URTI (cloudy urine, white cell clasts, high WCC, fever, high CRP)
Evidence of renal impairment/failure (Cr, Ur)
Refractory pain despite analgesia
Bilateral obstructing stones
Patient is elderly, a child, or otherwise unwell (unable to tolerate oral fluids)
What is the management for kidney stones
Regular multimodal analgesia e.g. paracetamol + NSAIDs
Encourage fluid intake
Tamsulosin (alpha-B) or nifedipine (CCB) to relax the ureter smooth muscle and increase chance of spontaneous passage, more useful in distal stones
Active stone removal if >5mm, if not ask to strain and follow up in 2-3 weeks + assessment if it shows up on radiograph
What is the determinant for active stone removal and how is it done
Stones >5mm
Lithotripsy (extracorpeal shock wave lithotripsy/ESWL) - renal <2, ureteric <1
Ureterorenoscopic removal with dormia basket, holmium laser, mechanical lithotripsy etc.
Percutaneous nephrolithotomy (rare as invasive)
Stenting (using JJ stent) to prevent hydronephrosis
Antibiotic cover for invasive procedures
What are the indications for further investigations of ureteric colic
Strong family history
Multiple stones at first diagnosis
Recurrent stone formation/passage
Patient with dull ache in the right flank with urinary frequency, dysuria and fever + vomiting
Urine dip shows haematuria, pyuria and nitrites
Acute pyelonephritis (often E.coli)
What should be looked out for in monitoring for an intrarenal or perinephric abscess
Persistently high fever Bacteraemia Very high initial WCC Severe tenderness on examination Failure to improve after the appropriate therapy
50M with high BMI who has right flank pain. Present for a week without specific trigger. Ache, worse in the morning or after a long day’s drive. Ibuprofen helps a bit, but only temporary fix. No associated symptoms. What is the diagnosis and how should it be managed
Musculoskeletal back pain (affects 80% of the population at some point)
Maintain activity and exercise Regular multimodal analgesia Build up core muscles Weight loss General back care Avoid surgery
What are the different types of kidney stones
Calcium (75-85%)
Struvite (10-20%)
Urate (5-10%)
Cystine (1%)
How are calcium stones treated
Hypercalciuria - investigate for hyperPTH, thiazides, low calcium diet
Hyperuricosuria - allopurinol
Hypocitraturia - potassium citrate
What medical conditions predispose to stone formation
Metabolic (hypercalciuria, uricosuria, citraturia, oxaluria, gout, cystinuria)
Primary hyperparathryoidism
Crohn’s (oxalate stones)
Chronic UTI due to urease-producing bacteria (struvite)
Medullary sponge or polycystic kidneys
Renal tubular acidosis
Sarcoidosis
What radiographic findings would be looked for in a patient with stones
The stone themselves
Hydronephrosis and/or hydroureter (dilated ureter) due to obstruction
Perinephric fluid
“soft-tissue rim sign” - stones surrounded by rim of soft tissue, differentiating ureter stones from a calcific pelvic vein (phlebolith)
“tail sign” - soft tissue opacity extends away from the stone like a tail, consistent with pelvic phlebolith - NOT a stone
What are the complications of kidney stones?
Ureteric stricture Acute or chronic pyelonephritis Renal failure Intrarenal or perinephric abscess Xanthogranulomatous pyelonephritis Urine extravasation
