Case 1

Abdominal pain has an extensive differential diagnosis covering GIT, GUT, respiratory, cardiovascular and musculoskeletal causes. Diagnoses vary both with gender (males obviously don’t get PID or ovarian pathology) and age (for example AAA is rare in a 25 year old). Extra-abdominal causes such as cardiovascular disease (eg. cardiac ischaemia) and respiratory illness (such as lower lobe pneumonias) can also present with abdominal pain as their primary symptom.

(a) Most likely diagnoses

• renal colic
• biliary colic
• gastroenteritis
• bowel obstruction

 (b) Most serious diagnoses

• AAA
• small bowel obstruction
• bowel perforation
• ischaemic bowel

1. MSU – looking for

• RBC as evidence of renal colic
• Evidence of infection (an infected obstructed renal stone requires urgent treatment)

2. Electrolytes – looking for

• Renal impairment either secondary to obstruction or NSAID use
• Uric acid  and calcium – potentially treatable causes of renal stones

3. FBC – looking for

• High WCC might suggest an infective process, although a mildly elevated WCC is a common finding in patients with renal colic secondary to a stress response
• Anaemia –if Hb is low consider other causes of pain such as AAA with blood loss

4. KUB plain X-ray

• This may show a renal stone. Although uric acid stones are usually not seen. Even radio-opaque stones can be difficult to identify due to overlying bone and bowel shadows. A lot of departments now do not do KUB films, unless the patient is known to have visible radio-opaque stones.

5. CT KUB

• This is considered the first-line investigation for renal stones as it shows the size and position of the stone very well. If may also show other causes of pain if it is not renal colic.

Your initial treatment should be aimed at relieving his pain. He will then need treatment to aid the passage of stone.

(i) Analgesia

Renal colic is a severe pain. Most patients should receive IV opiates titrated to effect eg 2-5mg morphine every 5-10min. NSAIDs such as ibuprofen and diclofenac are very effective for renal colic. If the patient is unable to swallow tablets, usually due to vomiting, diclofenac can also be given rectally

(ii) Anti-emetics

The pain from renal colic is often nauseating, and vomiting is common. This may be made worse by the morphine given to the patient. Anti-emetics such as metoclopramide or ondanstron are often needed.

(iii) Helping the stone pass

Patients with renal stones are given a course of doxazosin for 1-2 weeks as a smooth muscle relaxant to hopefully encourage the stone to pass.

If you suspect that the stones is uric acid in composition (high serum urate, known gout, radiolucent), Ural sachets or other urinary alkalinising agents are used to try and dissolve the stone

(iv) Follow-up

A 4mm stone is likely to pass on its own and this patient does not need any specific follow-up. As a general rule, most stones <5mm will pass on their own, while stones >10mm usually do not.

On discharge (once his pain settles) he should be advised to return if he has more pain, develop fevers or urinary symptoms suggestive or a UTI

Indications for follow up in a urology clinic are:

• Stone s>5mm
• Recurrent stones
• High calcium or uric acid to allow treatment  to prevent further stones