Flank Pain Flashcards
What are differentials for acute flank pain?
- Muscular spasm
- Nephrolithiasis/ureteric colic
- Spinal pathology (fractures, metastases, disc prolapse)
- Leaking/ruptured AA
- Testicular torsion (very unusual in elderly patients)
- Pyelonephritis (unusual in men)
- Perforated peptic ulcer
- Renal cancer
- Abscess (perinephric, renal)
What are gynae differentials for acute flank pain?
ectopic preg, ovarian torsion
What would unilateral flank pain radiating from loin to groin suggest?
kidney stones
What would trauma causing the onset of flank pain suggesting?
- musculoskeletal pain
2. internal bleeding
What would colicky (waxing and waning) flank pain suggest?
ureteric stones
What would constant flank pain suggest?
stones lodged in kidney or inflammatory cause
What would cause achey flank pain?
musculoskeletal pain
What would cause shooting flank pain?
nerve impingement
What would flank pain radiating to groin suggest?
ureteric pain
What would flank plain radiating down the leg suggest?
lumbar nerve root pain
What could be alleviating factors for flank pain?
posture/eating/drinking/medications etc
What would many weeks of flank pain suggest?
muscuskeletal cause
How would a leaking AAA go on with time?
not persist more 1 day without resolution
What are exacerbating factors for peritonitis e.g from perforated peptic ulcer?
movement
What would flank pain which is excruciating suggest?
kidney stones
What other questions must you ask about the history of presenting complaint?
- fevor, rigors, night sweats
- dehydration
- nausea and vomiting
- haematuria
- lower urinary tract symptoms
- cloudy or offensive smelling urine
- leg weakness
What would a raised fever with flank pains suggest?
- Inflammatory process e.g. pyelonephritis,
- Sepsis from e.g. psoas abscess
- Rare - malignancy e.g RCC
Why is dehydration important to ask about with flank pain?
persistent dehydration, predisposes to concentrated urine and therefore to kidney stones
What would nausea and vomiting with flank pain suggest?
visceral organ pathology e.g. ureteric stones, biliary colic, appendicitis
What would haematuria with flank pain suggest?
70-90% of patient with kidney/uteric stones have microscopic haematuria
What are lower urinary tract symptoms are common in UTI?
- urinary frequency
- urgency
- dysuria
What lower urinary tract symptoms are more common in uteric obstruction e.g. (enlarged prostate, stones, tumours)?
- hesitancy
- reduced flow
- dribbling
- incomplete voiding
What would cloudy or offensive-smelling urine suggest?
infection
What could flank pain with leg weakness suggest?
spinal pathology
What PMHx is important to ask about with flank pain?
- Previous kidney stones
- Recurrent cystitis
- Atherosclerotic disease
- Longstanding back pain
- Kidney disease
Why do you ask about previous kidney stones with flank pain?
nephrolithiasis associated with a 50% 10yr recurrence
Why do you ask about recurrent cystitis in flank pain?
recurrent episodes of UTI predisposes to stones of struvite type
Why do you ask about atheroscloertic disease in flank pain?
strong risk factor of AAA
Why do you ask about longstanding back pain with flank pain?
usually due to pathology affecting muscles, ligaments, and bones
Why do you ask about kidney disease in flank pain?
PCKD predisposes to pyelonephritis - need to know if only one kidney as obstruction of the only functional ureter is a medical emergency
Which medications do you ask about with flank pain?
- Aciclovir and Indinavir
2. Acetazolamide
What does aciclovir and indinavir do?
crystallize in urine
What can acetazolamide cause?
diuresis and potentially dehydration predisposing to kidney stone formation
What FHx do you check with flank pain and why?
- Kidney stones
- may indicate rare inherited conditions such as cystinuria
What signs do you look for on examination in flank pain?
- Position
- Tenderness
- Masses
- Spine
- Lower Limb
- Temperature
What would a restless patient unable to sit still suggest with flank pain?
ureteric colic
What would a motionless and rigid patient with flank pain suggest?
peritonitis e.g. from ruptured AAA are rigid and motionless
What would flank or loin tenderness (esp in costovertebral angles) suggest?
renal or ureteric stones
What would abdominal tenderness suggest?
suggests peritoneal cavity problem (e.g. appendicitis, pancreatitis)
What would a centrally laterally expansive mass suggest?
leaking AAA - physical examination does not exclude this esp if >55yo
How do you exclude spinal pathology in flank pain?
by testing range of movement (e.g. straight leg raise) + feel for tenderness along vertebrae
When do you conduct a neurological lower limb exam?
if spinal pathology is suspected from history and examination so far
When do you conduct a vascular exam of lower limbs?
- suspect AAA
- AAA can comprimise blood supply to the lower limb
What does it mean if you can easily feel the popliteal pulse?
uspect popliteal aneurysms (50% of patients with a pa also have a AAA)
Why do you check temperature with flank pain?
whether an inflammatory process e.g. polynephritis is ongoing
What urine tests do you do for flank pain?
- urinalysis
2. urine microscopy, culture and sensitivity (MCandS)
What presences are you looking for in urinalysis?
- haematuria
- white blood cells (pyuria)
- leucoyte esterase
- nitrates
Why is it important to check urine pH?
- urate stones - acidic urine
2. alkali pH - presence of urease-producing bacteria that can predispose to stone formation
When do you do urine MCandS?
if urinanalysis is abnormal and shows blood, leukocytes or nitrates
What do you look for in urine MCandS?
- red cells
- evidence of infection (WC, bacteria)
- crystals
Why is knowing the type of crystal important?
helps to know cause + secondary prevention of future stones
What does the presence of red cell casts or white cell casts suggest?
red or white cells coming from kidney rather than ureters or bladder
What condition would red cell casts suggest?
glomerular damage
What damage would white cell casts indicate?
pyelonephritis
What bloods do you order for flank pain?
- FBC and CRO
- Urea, creatinine, electrolytes
- Serum calcium, phosphate and urate
What would a rasied WCC and CRP show?
infection or sepsis
Why do you measure urea, creatinine, electrolytes?
asses renal function, as obstruction by renal stone can lead to renal damage - renal failure a medical emergency
Why do you measure serum calcium, phosphate and urate?
provide clues to cause of kidney stone
What imaging is used in flank pain?
- Bedside US
2. Non-contrast CT-KUB (gold)
Why is bedside US useful?
look for AAA >3cm
Why is bedside US not that good?
- Not say if aneurysm is bleeding as will bleed into retroperitoneal space hard to visualise on US
- Hard if large body habitus or unfasted and have lots of air and peristalsis in transverse colon
- So if flank/back/abdominal pain and AAA on US need contrast CT abdo if haemodynamically stable
Why is a non-contrast CT-KUB great?
- shows any stones in kidney or ureter
- shows any rare causes of ureter obstruction causing renal colic e.g. a retroperitoneal tumour
- IMPORTANT AS DECTECTS AAA
When is KUB radiographs used?
following progression of confirmed stones with less exposure to ionizing radiation
What imaging is used if pregnant?
MRU
What other tests may be considered?
- If pancreatitis suspected order serum lipase or amylase
2. If perforated peptic ulcer concern request CXR to look for air under diaphragm
When is a patient with a kidney stone with no hydronephrosis admitted?
- evidence of upper UTI
- evidence of renal impairment/failure
- refractory pain (despite analgesia)
- bilateral obstructing stone (or one if one kidney)
- patient elderly, a child or otherwise unwell (e.g. unable to tolerate oral fluids) for closer monitoring
What would the evidence of an upper UTI be?
- cloudy urine ±
- white cell casts
- high WCC in blood
- high CRP
- fever
- infection proximal to an obstruction is surgical emergency and need drainage
What would evidence of renal impairment/failure be?
- high creatinine
- high urea
- high K+
What is the acute management of kidney stone?
- Regular multimodal analgesia (paracetamol + NSAIDs)
- Encourage fluid intake: oral if possible or IV fluids if admitted
- Tamsulosin (alpha blocker) or nifedipine (CCB)
- Active stone removal
Why do you use NSAIDs and paracetamol over opiates?
- additional effect of decreasing ureteric smooth muscle tone
- lack some of the adverse effects of opiate (respiratory and CNS depression vomiting and disorientation)
Why do you prescribe Tamsulosin (alpha blocker) or nifedipine (CCB) for kidney stones?
- both relax smooth muscle in ureters
2, increase chances of spontaneous passage of a renal tract stone with T being superior to N - mainly beneficial in distal ureteric stones <10mm
If a kidney stone is <5mm what is the chance it passes spontaneously?
50%
What is the treatment for a kidney stone <5mm?
- if no reason for admission patients discharged and asked to strain their urine to recover stone for analysis
- follow up in 2-3 weeks
- plain KUB radiograph before discharge to compare to one at follow up - to see if stone moved (better than repeat CT-KUB as less dose of radiation)
How is stones >5mm treated?
- less likely to pass spontaneously esp if >7mm
- should be discussed with urologist for consideration of removal
What are the options for treatment for renal Tract stones >5mm or smaller ones that haven’t passed spontaneously after 4-6 weeks?
- Lithotripsy
- Ureterorenoscopic removal
- PCNL
- Stenting
- Antibiotic cover
What is Lithotripsy?
- ESWL if small enough (renal stones <2cm and ureteric stones <1cm)
- . Uses shock waves to break down stone into smaller fragments that more likely to pass spontaneously
What is ureterorenoscopic removal (using a fine telescope inserted via the urethra)?
- with a dormia basket, holmium laster, mechanical lithotripsy etc
- if too large for ESWL
- usually requires post-operative ureteric stent as it can cause ureteric stricture
What is PCNL?
percutaneous nephrolithotomy (PCNL) - rarely used nowadays as invasive
What is stenting?
- (using a JJ stent) or percutaneous nephrostomy
2. performed to prevent hydronephrosis - if obstruction cannot be resolved surgically
When is antibiotic cover used?
if invasive procedure
What is the LT management of stones post removal?
- Increase fluid intake
- Further testing for cause to avoid recurrence if:
- Strong FHx
- Multiple stones at first diagnosis
- Recurrent stone formation / passage