Acute renal and ureteric colic

 

Renal colic is generally used to describe an acute and severe loin pain caused by the formation of urinary stones (urolithiasis).  Urinary stones are often asymptomatic but may cause pain when they move or obstruct the flow of urine.  However, a more clinically accurate term for the condition is ureteric colic as the pain usually arises from obstruction of the ureter.  Acute renal or ureteric colic is common with the annual incidence is 1–2 cases per 1000 people.  It is estimated that 12% of men and 6% of women will have one episode of renal colic at some stage in their life, with incidence peaking between 40–60 years for men and in the late 20s for women

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When to suspect renal or ureteric colic

Suspect acute renal or ureteric colic in people presenting with an abrupt onset of severe unilateral abdominal pain originating in the loin or flank and radiating to the labia in women or to the groin or testicle in men

  • The pain typically:
    • Lasts minutes to hours and occurs in spasms, with intervals of no pain or dull ache
    • Is often accompanied by nausea, vomiting, and haematuria
    • Is usually described as the most severe pain experienced by the person — many women describe the pain as more intense than that of childbirth
  • The person:
    • Is restless and cannot lie still (which helps to differentiate renal colic from peritonitis)
    • May have a history of previous episodes
    • May present with fever and sweats — if concomitant urinary infection is present
    • May complain of dysuria, urinary frequency, and straining — when the stone reaches the vesico-ureteric junction (due to the stone irritating the detrusor muscle)

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Diagnosis

  1. Where possible, perform urine dipstick testing to support the diagnosis and to look for evidence of a urinary tract infection (UTI)
    1. Check for haematuria — the presence of haematuria can support the diagnosis of renal or ureteric colic. However, specificity and positive predictive values are poor, and the absence of haematuria does not exclude a diagnosis but should prompt consideration for other causes of pain
    2. Check for nitrite and leucocyte esterase — the presence of nitrite (with or without leucocyte esterase) in the urine suggests infection
  2. Exclude other diagnoses that may cause acute flank pain, such as ruptured aortic aneurysm, appendicitis, and diverticulitis
  3. Look for signs which may indicate a complication, including:
    1. Fever and sweats — suggesting coexisting urinary tract infection, pyonephrosis, or pyelonephritis
    2. Hesitancy of micturition or an intermittent urinary stream — suggesting urinary tract obstruction

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Initial management and referral

  1. Treat symptoms of pain, nausea, and/or vomiting:
    1. Administer a parenteral analgesic (such as intramuscular diclofenac) for rapid relief of severe pain
    2. If necessary, administer a parenteral anti-emetic (such as intramuscular metoclopramide) for relief of severe nausea and/or vomiting
  2. Arrange urgent hospital admission if:
    1. The person is in shock or has fever or other signs of systemic infection
    2. The person is at increased risk of acute kidney injury, for example if there is a solitary or transplanted kidney, pre-existing chronic kidney disease, or bilateral obstructing stones are suspected
    3. The person is pregnant
    4. The person is dehydrated and cannot take oral fluids due to vomiting
    5. There is uncertainty about the diagnosis
    6. There is no response to symptomatic treatment within 1 hour (or sooner depending on clinical judgement), or there is a rapid recurrence of severe pain
  3. If hospital admission is not required:
    1. Prescribe oral or rectal analgesia (such as a nonsteroidal anti-inflammatory drug) and/or anti-emetic (such as metoclopramide) for ongoing symptom relief
    2. Advise a normal fluid intake to maintain colourless urine
    3. Explain that the stone may pass spontaneously.  Advise the person to, if possible, sieve the urine through a tea strainer, nylon stocking, or filter paper (such as a coffee filter) to capture the stone (this can be done directly as the urine is passed or urine can be collected into a container before sieving)
      1. If a stone is captured, send it to the laboratory for analysis
    4. Advise the person to seek urgent medical assistance if they develop fever or rigors, the pain worsens, or they have rapid recurrence of severe pain
    5. Arrange urgent referral to urology within 7 days of the onset of symptoms (if possible) so that diagnostic investigations can be done to confirm the diagnosis and to assess the likelihood of spontaneous stone passage

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Follow up

While awaiting specialist assessment:

  1. Check for urinary tract infection (if this has not already been done) by sending a urine sample for culture, or testing the urine with a dipstick and sending a urine sample for culture if the result is positive
  2. Assess renal function by checking serum creatinine, urea, and electrolytes
  3. Exclude common medical risk factors for urinary stones by checking calcium, phosphate, and urate levels.  If the serum calcium level is high (greater than 2.60 mmol/L), a diagnosis of suspected hyperparathyroidism should be investigated
  4. Send the stone for analysis (if possible)
  5. Give advice to prevent recurrence

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Advice to prevent recurrence

Advise the person to:

  1. Increase their fluid intake to produce 2–3 litres of urine each day
  2. Eat a balanced diet, including plenty of fruits and vegetables
  3. Reduce salt intake
  4. Maintain a healthy weight
  5. Avoid fructose-containing soft drinks due to their association with increased urate levels

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For people with calcium stones (responsible for up to 80% of urinary stones), advise that they should also avoid:

  • Excessive dietary intake of:
    • Oxalate-rich products, such as rhubarb, spinach, cocoa, tea leaves, nuts, soy products, strawberries, and wheat bran
    • Animal protein — limit intake to 0.8–1.0 g/kg body weight
    • Sodium — do not exceed 3 g daily
  • The use of calcium supplements, but they should not restrict dietary calcium intake

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For people with uric acid stones, advise that they should also avoid excessive dietary intake of:

  • Urate-rich products, such as liver, kidney, calf thymus, poultry skin, and certain fish (herring with skin, sardines, anchovies, and sprats)

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For people with mixed stones containing both uric acid and calcium oxalate ions (hyperuricosuric calcium oxalate stones), offer advice as for people with calcium or uric acid stones (see above)

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Blood tests / Phlebotomy

If your practice does not have a practice nurse who is trained to take bloods, you can refer a patient to the Pathology Department at East Kent Hospitals for a blood test (find details here)

Alternatively, Buckland Hospital (Dover) and the Royal Victoria Hospital (Folkestone) both operate a walk-in service where no appointment is necessary, except for if the patient requires a Glucose Tolerance Test (GTT).  In the event that a GTT is required, please call 01304 222552 (for Buckland) and 01303 854484 (for Royal Victoria) to arrange a suitable appointment

Please ensure that the patient remembers to take with them their blood test form to the walk-in centres

Advice and Guidance is being made available for all specialties, and is being provided by consultant specialists at East Kent Hospitals.  To make a request or to check to if a query has been answered, you will need to log in via the electronic Referral System (eRS)

Click here for the "how to access" e-Referral Advice and Guidance Manual for instructions on how to make a request and check responses

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