Renal Colic



Background

  • The average lifetime risk of stone formation is 5-10%
  • Acute colic usually characteristic loin (to groin) pain ± vomiting ±fever
  • If fever >38.0°, beware superimpoised infection
  • Early anagesia and imaging will dictate management course
  • Most will have haematuria (micro- or macroscopic)
  • Beware missing an abdominal aortic aneurysm

Kidney Stone Disease

There are 4 major types of stones:

Calcium oxalate/phosphate

  • approx 85% of all

Uric acid

  • Radiolucent

Struvite

  • alkaline urine
  • secondary to infection

Cysteine

  • Rare
  • Only 1% of stone

Investigations

  • Dipstick urinalysis and microscopy. A high urinary pH points to struvite stones
  • A few WBC on microscopy is common and does not necessarily represent infection
  • U&E/Creat (renal function) and FBC (infection), serum Ca++ should be checked (hypercalcaemia)
  • INR/PTT only if instrumentation planned
  • Image with non-contrast CT (in preference to IVU) [BestBets]

Differential Dx


Management

  • Treat the pain with parenteral or rectal NSAIDs, ±IV lignocaine (1.5mg/kg infusion) [BestBets], ±opiates
  • Not all patients with stones need to be admitted to hospital. 80% of stones will pass spontaneously with conservative therapy
  • For patients with confirmed acute ureteric colic deemed suitable for medical expulsive therapy (MET), prescribe Tamsulosin (in preference to a Ca++ channel blocker to facilitate stone passage.(BMJ Meta-analysis 2016), [BestBets]) and ensure urology follow up has been arranged within the advised time-frame
  • Patients should not normally be prescribed antibiotics
  • Patients with calculi > 5mm or who present with proximal ureteric calculi are less likely to pass calculi spontaneously. Patients with ureteric obstruction and urinary infection are not suitable for MET
  • If surgery is needed may take form of Open, ESWL or Endoscopy
  • If the stone can be retrieved, it should be sent for analysis. If the patient has a second stone, the urologist will usually do a "metabolic work up". Although each type of stone can be treated differently, the easiest and often most effective treatment is to increase fluid intake significantly (8 -10 glasses a day)

Protocol for suspected renal colic in the ED at MUH.

Diagnosis

History, Physical examination, dipstick urinalysis, vital signs, FBC, U+E, Creatinine, Urine microscopy (only if dipstick equivocal), KUB, CT-KUB

Indications for Urology review ± admission – after the above, with a CT-confirmed stone (if CT KUB has been performed):

  • Pain not controlled by oral analgesia
  • Pyrexia or sepsis
  • Abnormal U&E
  • Obstruction
  • Solitary kidney. Decision regarding admission can then be made by Urology on-call
  • For patients presenting "out of hours" (i.e. when CT-KUB not available) with a suspected stone, who are well enough to be discharged, ED staff should arrange CT KUB. This can be done on PACS
  • The Radiology Department will accept referrals from ED staff, who should include the patient’s contact telephone number on the referral form
  • The patient will be issued with an appointment for a CT KUB within 48 hours, unless at weekends, when it will be done on the following Monday or Tuesday
  • The patient should proceed directly to the Radiology Department for the investigation and return to the ED immediately afterwards. 
  • If the scan is negative, they will be reviewed by the EM team
  • If the scan is "positive", and there are no complications (as listed under ‘Indications for Urology Review’ above), the patient can be referred to Urology OPD. If being discharged from the ED without Urology review, patients’ notes should be forwarded to the Urology secretaries for OPD follow-up to be arranged
  • If the scan is "positive" and there are complications, they must be referred to Urology who should review the patient promptly
  • Patients without diagnosis of renal stones will not be referred to the Urology OPD

Where a patient presents out of hours and a strong clinical suspicion of a stone exists but that patient is not fit for discharge, they should be admitted under the care of the Urology service, with a view to Urology arranging a CT-KUB at the next available opportunity.

Return attendances at the ED are for diagnostic reasons only, after the CT KUB has been performed. Once a stone is confirmed, their follow-up is exclusively with the Urology service, either as an inpatient or in the OPD.

Patients with confirmed stones will then be formally “discharged” from the Urology service, following either inpatient Urology admission or Urology OPD review.

* If patients with confirmed stones are being discharged from the ED, they should always be advised to return if they develop further pain, nausea and vomiting, fevers, rigors or diaphoresis (intense sweating).

  • For MUH patients with confirmed acute ureteric colic deemed suitable for medical expulsive therapy (MET), prescribe Tamsulosin or Silodosin (in preference to a Ca++ channel blocker to facilitate stone passage.[BestBets]) and ensure urology follow up has been arranged within the advised time-frame
  • Patients with calculi > 5mm or who present with proximal ureteric calculi are less likely to pass calculi spontaneously. Patients with ureteric obstruction and urinary infection are not suitable for MET

Renal colic in pregnancy

  • Incidence same as non-pregnant population
  • Like the non-pregnant person, 70-80% of the symptomatic stones pass spontaneously
  • Ultrasound is the initial investigation of choice
  • Further investigations after discussion with radiologists


Content by Dr Íomhar O' Sullivan. Reviewed by Mr. Ciarán Brady, Mr. Frank O' Brien, Dr ÍOS 05/05/2015. Last review Dr ÍOS 13/12/21.