Renal colic will affect one in 10 men before the age of 60 years and is three times more common in men than in women.1 It costs the economy of the US more than $5bn a year.2
The condition classically presents with sudden-onset loin to groin pain that is colicky in nature. Patients often complain of a sensation of not being comfortable in any position.
It is associated with haematuria (more commonly non-visible) in more than 90% of cases.3
Despite the extreme discomfort, examination of the patient is frequently unremarkable. Differential diagnoses are listed in box 1.
Availability of CT scans
Investigations that can be performed in primary care include urine dipstick testing, for the presence of Hb and to rule out an infective cause, and basic observations to determine the presence of pyrexia.
The gold standard investigation is non-contrast CT scan of the renal tract, which has a sensitivity of 90-97% and a specificity of 86-100% for detecting renal and ureteric calculi.4
There is nationwide variation in the availability to primary care doctors of CT scanning for the investigation of suspected renal colic.
In Berkshire, GPs have access to a dedicated CT time slot each day to investigate suspected renal colic and we have found this enables many more patients to be investigated and managed in the community by their GP.
It should be noted that in more than a third of patients who have a history consistent with renal calculi and microscopic haematuria, there will be no evidence of calculi on imaging,5 particularly in young female patients.
When to refer
When faced with a patient who has renal colic and is in extreme pain, it can be daunting to refrain from immediate referral to secondary care, but most patients will be comfortable with oral or PR analgesia and medical expulsive therapy. Not all require a same-day referral.
It is easier to divide patients into those who need to be seen as an emergency by the on-call team the same day (those with red flag symptoms who may warrant emergency treatment), patients who need urgent referral and should ideally be seen within a couple of weeks, and those who require routine referral.
We recommend following the guidance outlined in box 2 when deciding whether to refer patients for secondary care investigations and treatment.
Medical expulsive therapy
Spontaneous passage of kidney stones less than 5mm in diameter will occur 97% of patients when prescribed medical expulsive therapy. 6
Stones 5-10mm in diameter have a spontaneous passage rate of 76% with medical expulsive therapy and stones >10mm are unlikely to pass without non-pharmacological intervention.
Medical expulsive therapy consists of alpha-blockers or calcium- channel blockers, with evidence suggesting both are effective.7
The therapy offered in our institution is tamsulosin 400 microgram once daily. It should be noted that using the drug for this purpose is not licensed and this should be explained to the patient. It is not advised for pregnant patients.
Shock wave lithotripsy
Shock wave treatment is suitable for calculi >5mm in diameter in the renal pelvis, upper third of the ureter and occasionally, the lower third of the ureter. Contraindications include anticoagulants and pregnancy.
This treatment can be uncomfortable, although most patients tolerate the procedure. Availability of this treatment nationwide is variable.
Ureteric stents are inserted cystoscopically under general anaesthetic for obstructing stones as an emergency, to drain infection from the kidney, to preserve renal function or to manage uncontrolled pain.
A further procedure is needed to remove the stent and the calculus.
Most patients tolerate ureteric stents, although most report 'stent symptoms' to a varying degree, including frequency, dysuria, loin pain and haematuria.
It can be tempting to treat this as a UTI, because the urine dip is nearly always positive for blood and leucocytes, but this rarely improves symptoms. It should be noted that in a minority of patients, these 'stent symptoms' can be debilitating.
Percutaneous nephrostomy is a surgical procedure usually reserved for patients with an infected obstructed upper urinary tract.
Performed under local anaesthetic, usually by radiologists, a needle puncture is made into the affected kidney under ultrasound and fluoroscopic guidance, and the infected urine drained.
This has been demonstrated to have similar outcomes to cystoscopic ureteric stenting,8 but avoids the requirement for general anaesthetic.
Ureteric stents can be passed via the nephrostomy under local anaesthetic, in order to be able to remove the nephrostomy drain while ensuring the kidney is not obstructed.
Ureteroscopy involves a ureteroscope being passed up the ureter via the bladder to the calculus, under general anaesthetic. The calculus is either removed in its entirety or fragmented and removed, usually by laser. A temporary ureteric stent may be left in after this procedure.
Percutaneous nephrolithotomy is reserved for large stones in the renal pelvis. This involves inserting a nephrostomy into the kidney under general anaesthetic and fragmenting then removing the stone.
It should be noted that practice and availability of treatment and investigations varies across the country and this article is intended to be used as a rough guide and to try to provide clarity on some areas where there is more than one treatment or referral option available.
There is, however, no substitute for clinical assessment and experience in managing these patients.
If there is concern about a patient or the most appropriate treatment option or pathway, the local urology department can normally address these queries.
- Mr Gill and Mr Britnell are SpRs in urology and Mr Kumar is a consultant urologist at Royal Berkshire NHS Foundation Trust
- Curhan GC, Willett WC, Rimm EB et al. J Am Soc Nephrol 1997; 8(10): 1568-73.
- Saigal CS, Joyce G, Timilsina AR. Kidney Int 2005; 68(4): 1808-14.
- Perez JA, Palmes Mde L, Ferrer JF et al. Arch Esp Urol 2010; 63(3): 173-87.
- Drake T, Jain N, Bryant T et al. Indian J Urol 2014; 30(2): 137-43.
- Nadeem M, Ather MH, Jamshaid A et al. Int J Surg 2012; 10(10): 634-7.
- Preminger GM, Tiselius HG, Assimos DG et al. J Urol 2007; 178(6): 2418-34.
- Seitz C, Liatsikos E, Porpiglia F et al. Eur Urol 2009; 56(3): 455-71.
- Goldsmith ZG, Oredein-McCoy O, Gerber L et al. BJU Int 2013; 112(2): 122-8.