Assessment and management of renal colic
BMJ 2013; 346 doi: https://doi.org/10.1136/bmj.f985 (Published 21 February 2013) Cite this as: BMJ 2013;346:f985
- Aditya Manjunath, ST4 trainee in urology 1,
- Richard Skinner, GP partner 2,
- John Probert, consultant urological surgeon 1
- 1Urology Department, Weston General Hospital, Urology, Weston-Super-Mare BS23 4TQ, UK
- 2West Street Health Centre, Bargoed, Mid Glamorgan, UK
- Correspondence to: A Manjunath aditya.m{at}doctors.org.uk
- Accepted 8 January 2013
A 34 year old man visits his general practitioner with a short history of intermittent severe pain radiating from his right loin to right groin. He is unable to get comfortable and is also complaining of urinary frequency and occasional urgency. His temperature is normal. A urine dipstick test shows only non-visible haematuria. The initial diagnosis is suspected renal/ureteric colic secondary to a stone.
What you should cover
Important features to explore in the history include:
Onset of pain—might be acute or insidious.
Duration of pain—longer duration indicates a stone in the kidney or could indicate another cause.
Location—predominantly loin, groin, or both (“loin to groin” pain).
Severity of pain—classically “worst pain ever,” patients are unable to get comfortable (unlike peritonism), but this is not always the case.
Urinary symptoms—distal ureteric stones often cause frequency, dysuria, and urgency and occasionally there is visible haematuria.
Associated symptoms—nausea and vomiting, fever/rigors, which indicate possible sepsis.
History of renal stones—lifetime risk of 50% for forming subsequent stones after first presentation.
Patient’s demographics—peak incidence of stone formation is in those aged 20-50, with a 3:1 male to female preponderance.
Family history of stone formation—stone formation is more common in white people and Asians, with about 20% having a positive family history.
Associated medical conditions—in general practice commonly seen conditions associated with increased risk of stone formation include recurrent urinary tract infections, gout, inflammatory bowel disease, hypercalcaemic disorders such as primary hyperparathyroidism, and anatomical abnormalities of the urinary tract such as polycystic kidney disease.
Environmental factors—“western” lifestyle, warmer temperature, and reduced water intake contribute to an increased risk of stone formation. A urine output of less than 1 L/day considerably increases this risk. In North America and northern Europe the peak incidence is in summer.
Important features of the examination include:
General examination. Look for signs of dehydration and infection. Is the patient flushed or clammy? Is there fever? Tachycardia might be present if there is severe pain, infection, or dehydration.
Occasionally renal angle tenderness can be identified, but this is not a sensitive sign. Testicular examination is essential in men as acute testicular pathology such as testicular torsion or epididymo-orchitis can present with referred pain to the loin or groin.
Urine dipstick. Non-visible haematuria is seen in about 80-85% of patients with urinary tract stones.1 Absence of blood does not rule out a stone but should prompt consideration of an alternative diagnosis. Presence of nitrites and/or leucocytes could indicate underlying urinary infection.
When taking a history and examining the patient keep in mind these possible differential diagnoses:
Appendicitis and other abdominal visceral infection—such as cholecystitis (fever and localised organ tenderness).
Abdominal aortic aneurysm (older age, cardiovascular disease)—check for a pulsatile expansile mass in all older patients.
Ovarian pathology/ectopic pregnancy (pelvic pain, younger women).
Testicular torsion (tender testis, younger men).
Musculoskeletal pain (triggered/exacerbated by movement).
What you should do
In terms of initial management there are three important aspects: pain management; the decision of whether to admit the patient urgently to hospital or to refer the patient for urgent outpatient assessment; and initial investigations to be done if the patient is not urgently admitted.
Pain management
The use of non-steroidal anti-inflammatory drugs (NSAIDs) is the treatment of choice in patients with acute renal colic. Diclofenac is the most commonly used and can be given orally (50-75 mg), intramuscularly (75 mg), or rectally (100 mg) as an immediate dose. Diclofenac as a 100 mg suppository is a good choice as the rectal route provides effective drug absorption and can be administered to a vomiting patient. Evidence shows less need for additional analgesia when non-steroidal anti-inflammatory drugs are used initially.2 Contraindications to use include coagulation defects, previous or active peptic ulceration, previous hypersensitivity to aspirin or any other non-steroidal anti-inflammatory drugs, severe heart failure, pregnancy, and breast feeding.
Opioids are an alternative if non-steroidal anti-inflammatory drugs are contraindicated, and these can be administered parenterally. For example, subcutaneous or intramuscular morphine at a dose of 5-10 mg can be used. Strong opioids should be used with care as they have a higher risk of adverse effects (such as respiratory depression), particularly pethidine, which has a higher rate of induced vomiting and should therefore be avoided.2
Antiemetic treatment should also be considered in tandem with analgesia— for example, with cyclizine, which is centrally acting and can be administered orally or parenterally at a dose of 50 mg. There is no evidence to support the use of one antiemetic over another.
Reasons to refer a patient immediately to hospital3
If they are systemically unwell or have a fever or have a history suggestive of fever/rigors.
Pain that does not settle or recurs after analgesia. Analgesia should take effect within 30-60 minutes so patients should be advised to re-contact for review if their symptoms have not settled after one hour. In 2009 a Cochrane review identified eight studies that allowed 30 minutes and two studies that allowed an hour to assess the efficacy of analgesia.2
Persistent nausea and vomiting, especially if dehydration occurs.
Solitary functioning kidney or transplanted kidney.
Suspected bilateral obstructing stones or other diagnostic uncertainty—for example, older patients with a suspected leaking abdominal aortic aneurysm.
Previous evidence of acute kidney injury on serum analysis or evidence of hydronephrosis on imaging. The common normal laboratory range for serum creatinine concentration is 60-120 µmol/L so a concentration higher than this with or without hydronephrosis should trigger urgent admission to hospital.
If the patient does not satisfy any of the above criteria they can be referred urgently as an outpatient to urology, ideally to a dedicated stone clinic having had appropriate imaging. The timing of the appointment depends largely on the results of imaging—for instance, patients with non-obstructing renal stones do not need to be seen as urgently as those with ureteric obstructing stones. Of those patients referred on an outpatient basis, the urologist will prioritise the referral depending on the results of the imaging, however consensus suggests that outpatient urology assessment should be within seven to 14 days.3
Initial investigations if patient is not admitted
If urgent radiology is accessible the best investigation would be to arrange imaging in the form of non-contrast computed tomography of the renal tract. This is the ideal investigation in patients with suspected urinary tract stones. Non-contrast computed tomography gives the highest degree of diagnostic accuracy, with a sensitivity and specificity of 92-100%. If computed tomography is not directly available, a plain radiograph of the kidneys, ureters, and bladder and renal ultrasonography or intravenous urography could be requested as alternatives. About 80% of renal stones are radio-opaque, although only around 60% are seen on radiography.
Blood tests in the acute setting should focus on identifying renal impairment, evidence of infection, and alternative causes of abdominal pain. Useful tests include full blood count, urea and electrolytes, serum creatinine, C reactive protein, liver function tests, and amylase.
Useful reading
European Association of Urology Guidelines. Urolithiasis. www.uroweb.org/guidelines/online-guidelines
American Urological Association. Clinical guidance. www.auanet.org/content/clinical-practice-guidelines
Engeler DS, Schmid S, Schmid HP. The ideal analgesic treatment for acute renal colic—theory and practice. Scand J Urol Nephrol 2008;42:137-42.
Notes
Cite this as: BMJ 2013;346:f985
Footnotes
This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Provenance and peer review: Not commissioned; externally peer reviewed.
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