Flank Pain

Question 1

DDx of flank pain (12, in women 2 more, and 3 more abdominal pathologies)

Answer 1

Muscular sprain
Nephrolithiasis/ureteric colic
Leaking/ruptured abdominal aortic aneurysm (AAA)
Spinal pathology (fractures, metastases, disc prolapse) Testicular torsion (very unusual in an elderly person)
Pyelonephritis (unusual in a man)
Perforated peptic ulcer
Renal cancer
Abscess (perinephric, renal) Basal pneumonia

Ectopic pregnancy
Ovarian torsion

Pancreatitis
Diverticulitis
Appendicitis

Question 2

Site of kidney stone pain?

Answer 2

Unilateral

May radiate from loin to groin

Question 3

Character of ureteric stone pain?

Answer 3

Ureteric stones give a colicky (waxing and waning) pain because of periodic spasms of the ureteric smooth muscle walls trying to dislodge the blockage.

Question 4

How to differentiate ureteric vs kidney stones?

Answer 4

Constant = kidney
Colicky = ureteric

Question 5

What is an achey pain in the flank suggestive of?

Answer 5

Musculoskeletal

Question 6

What is a sharp shooting pain in the flank suggestive of?

Answer 6

Nerve impingement

Question 7

What pain typically radiates to the groin

Answer 7

Ureteric

Question 8

What pain typically radiates down the leg

Answer 8

Lumbar nerve root pain

Question 9

Typical radiation of ureteric pain

Answer 9

To the groin

Question 10

Typical radiation of lumbar nerve root pain

Answer 10

Down the leg

Question 11

If flank pain is said to be excruciatingly painful what is it suggestive of?

Answer 11

Kidney stones

Question 12

What questions should you ask in the when checking the history of the flank pain? (After socrates, 17)

Answer 12

Fevers, rigors, night sweats
Dehydration
Nausea and vomiting
Haematuria
Lower UTI symptoms (FUN HIIPS - frequency, urgency, nocturne, hesitancy, intermittency, )
Cloudy or offensive smelling urine
Leg weakness

Question 13

What does leg weakness suggest in flank pain?

Answer 13

Spinal pathology

Question 14

What does cloudy or offensive-smelling urine suggest in flank pain?

Answer 14

Infection

Question 15

What does nausea and vomiting suggest in flank pain? (3)

Answer 15

This is more typical of visceral organ pathology (e.g. ureteric stones, biliary colic, appendicitis)

Question 16

What dehydration indicate?

Answer 16

Concentrated urine and therefore kidney stones

Question 17

What do fevers, rigors and night sweats suggest in flank pain? (3)

Answer 17

A markedly raised fever indicates an inflammatory process, potentially pyelonephritis or sepsis. The fever of malignancies (e.g. renal cell carcinoma) is typically intermittent, unlike in infection.

Question 18

Difference between fever in inflammatory processes vs malignancy?

Answer 18

Malignancies is intermittent

Question 19

What PMHx should you inquire about in flank pain? (5)

Answer 19

Previous kidney stones
Recurrent cystitis
Atherosclerotic disease
Long-standing back pain
Kidney disease

Question 20

What type of stone does recurrent cystitis predispose to?

Answer 20

Struvite

Question 21

What drugs can lead to kidney stone formation? (3)

Answer 21

Indinavir, aciclovir, and acetazolamid

Question 22

What does FHx of kidney stones suggest in someone presenting with kidney stones?

Answer 22

This may indicate a (rare) inherited condition such as cystinuria.

Question 23

What do people with ureteric colic look like on examination?

Answer 23

Unable to sit still and thus tend to writhe in pain.

Question 24

What do people with peritonitis look like on examination?

Answer 24

Rigid and motionless, as any movement causes pain.

Question 25

What abdominal sign is seen in individuals with flank or loin tenderness

Answer 25

Tenderness in the flank or loin, particularly in the costovertebral angles

Question 26

What is the difference in testicular tenderness referred from renal stones and testicular pathology (e..g torsion)?

Answer 26

Renal stones is mild, otherwise its suggestive of a testicular cause

Question 27

What is a central, laterally expansive abdominal mass suggestive of?

Answer 27

A leaking AAA

Question 28

What does an easily felt popliteal pulse suggest?

Answer 28

Popliteal aneurysm

Question 29

What is a popliteal aneurysm associated with?

Answer 29

50% also have an AAA

Question 30

What is the pH of the urine of a patient with renal stones?

Answer 30

Usually acidic

Question 31

What is an alkaline pH suggestive of?

Answer 31

The presence of urease-producing bacteria (e.g. Proteus, Pseudomonas, Klebsiella) that can predispose to stone formation.

Question 32

What Ix should you carry out in a Px suggestive of urinary stones? (9)

Answer 32

Urinalysis (haematuria, WBC, leucocyte esterase, pH and nitrites) Urine microscopy, culture and sensitivity FBC and CRP (WCC) Urea, creatinine and electrolytes Serum calcium, phosphate and urate (looking for what type of stone) CTKUB

Question 33

What should you look for in urine microscopy, culture and sensitivity? (3)

Answer 33

Blood, evidence of infection (white cells, bacteria...) and crystals

Question 34

What do red cell casts indicate?

Answer 34

Red cell casts indicate glomerular damage

Question 35

What do white cell casts indicate?

Answer 35

White cell casts suggest pyelonephritis

Question 36

The presence of what indicates pyelonephritis?

Answer 36

White cell casts

Question 37

The presence of what indicates glomerular damage?

Answer 37

Red cell casts

Question 38

What Ix is key in pancreatitis?

Answer 38

Serum amylase

Question 39

What Ix is key for a perforated peptic ulcer?

Answer 39

Erect CXR looking for air under the diaphragm

Question 40

What Ix suggest renal failure? (3)

Answer 40

High creatinine, urea and K+

Question 41

When should you admit someone into hospital with renal stones? (5)

Answer 41

``` Signs of UTI Signs of renal failure Refractory pain despite analgesia Bilateral obstructing stones If the patient is elderly, a child or otherwise unwell (e.g. unable to tolerate oral fluids) for closer monitoring ```

Question 42

What is the Mx acutely for someone presenting with renal colic?

Answer 42

Paracetamol NSAIDs ^preferred to opiates Encourage fluid intake

Question 43

Why are opiates not first choice for renal colic?

Answer 43

Studies show they provide equally adequate analgesia in the context of kidney stones, may have some additional effect of decreasing ureteric smooth muscle tone, and lack some of the adverse effects of opiates, notably respiratory and central nervous system (CNS) depression, vomiting, and disorientation.

Question 44

What does the Mx of urinary stones depend upon

Answer 44

Whether big or smaller than 0.5cm in diameter, and whether or not it has passed within 4-6 weeks

Question 45

Mx of urinary stones less than 0.5cm in size

Answer 45

1) Stones <0.5 cm diameter − Start with a trial of conservative management (analgesia and encourage oral fluid intake). Ninety per cent of stones <0.5 cm pass spontaneously, although only 10% of larger stones do. Patients should be asked to strain their urine to recover the stone for analysis. − You may consider adding medication to relax the smooth muscle of the ureter, either an α-blocker (e.g. tamsulosin) or a calcium-channel blocker (e.g. nifedipine). Follow up patients after 2–3 weeks and request a plain KUB radiograph to minimize the radiation exposure of repeat CT-KUB.

Question 46

Mx of urinary stones more than 0.5cm in size (5)

Answer 46

− Lithotripsy, otherwise known as extracorporeal shock wave lithotripsy (ESWL) if small enough (renal stones <2 cm, ureteric stones <1 cm). − Ureterorenoscopic removal (using a fine telescope inserted via the ure- thra) 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. − Percutaneous nephrolithotomy (PCNL) is rarely used nowadays as it is invasive and thus there are risks of bleeding and damage to the collecting system and neighbouring structures. − Stenting (using a JJ stent) or percutaneous nephrostomy may be performed in order to prevent hydronephrosis, if the obstruction cannot be resolved surgically. − Antibiotic cover if an invasive procedure is employed.

Question 47

What should all Px with renal stones be advised?

Answer 47

To increase their fluid intake

Question 48

What is the most common causative organism in acute pyelonephritis?

Answer 48

E coli

Question 49

Why must pyelonephritis be dealt with swiftly?

Answer 49

Can proceed to septicaemia very quickly

Question 50

Mx of acute pyelonephritis (7)

Answer 50

``` IV fluids if hypotensive ABx for 2 weeks Analgesia Monitor renal function and urine output Maintain a high suspicion for intrarenal or perinephric abscess ```

Question 51

Medical conditions that can predisposed stones (12)

Answer 51

• Metabolic: − Hypercalciuria − Hyperuricosuria − Hypocitraturia − Hyperoxaluria − Gout and other hyperuricaemic states e.g. malignancy, glucose-6-phosphate dehydrogenase (G6PDH) deficiency (urate stones) − Cystinuria • Primary hyperparathyroidism • Crohn’s disease (often oxalate stones, although the exact mechanism for this remains unclear) • Chronic UTI due to urease-producing bacteria (struvite stones) • Medullary sponge or polycystic kidneys (resulting in static collections in which stones form) • Renal tubular acidosis (stones result from hypercalciuria, alkalinization of the urine causing precipita- tion of calcium phosphate, and low urinary citrate) • Sarcoidosis (causes a hypercalcaemia that can lead to stone formation

Question 52

What radiographical findings would you look for in a patient with suspected kidney stones? (3)

Answer 52

* The stones themselves * Hydronephrosis and/or hydroureter (dilated ureters) due to obstruction * Perinephric fluid

Question 53

What are the complications of kidney stones? (6)

Answer 53

``` Ureteric stricture Acute or chronic pyelonephritis Renal failure Intrarenal or perinephric abscess Xanthogranulomatous pyelonephritis Urine extravasation ```

Question 54

Contraindications of NSAIDs (4)

Answer 54

* Asthma * History of anaphylaxis with any NSAID * Previous or active peptic ulcers * Severe heart failure

Question 55

Contraindications of COX-2 selective inhibitors - form of NSAID (3)

Answer 55

Should not be used in ischaemic heart disease, cerebro- vascular disease, or peripheral arterial disease as they are associated with an increased risk of throm- botic events

Question 56

When should NSAID's be used with caution (7)

Answer 56

* Coagulation defects: may be exacerbated due to antiplatelet effects. * Renal, cardiac, or hepatic impairment: NSAIDs may impair renal function and cause fluid retention, lead- ing to pulmonary oedema in patients with cardiac failure. This is more likely to occur if the patient has poor liver function (hepatic impairment) or pre-existing kidney disease (renal impairment). * During pregnancy and breast-feeding: closure of the ductus arteriosus can occur in response to NSAIDs and this is a problem if it occurs in utero. There may also be delayed onset and increased duration of labour. NSAIDs are sometimes found in breast milk but there is little information on the risks presented. Nonetheless most manufacturers advise avoiding them if breast-feeding. * The elderly: as the risk of bleeding is more common and is more likely to have a serious outcome.

Question 57

What are the red flag symptoms of back pain? (2 immediate referral, 5 within 1 week, 4 ASAP)

Answer 57

Sphincter problems Patient unable to self-care or walk ``` Weight loss Fever Back tenderness to palpation Thoracic spinal pain Violent trauma ``` Age <20 years or >50 years Severe morning stiffness Structural deformity (e.g. scoliosis) Nerve root pain not resolving >6 weeks