What is Renal Colic?

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Renal colic is one of the most frequent reasons for emergency department visits in the world (1% of the total number of patients attended), and accounts for 30-40% of urological consultations in the emergency department.

The most common cause of renal colic is urinary lithiasis (90%). In 5-10% of cases it may be due to other causes of obstruction of the urinary tract, such as pyeloureteral junction syndrome, clots in the urinary tract due to bleeding from a renal or ureteral tumour, ureteral obstruction due to intestinal, gynaecological, retroperitoneal, vascular or other processes, or oncological diseases. 

Signs and symptoms of Renal Colic

During the medical examination, hitting the lumbar area with the fist increases the pain (percussion). The patient is usually anxious, uncomfortable and restless when this exploration is carried out, and they often demand analgesic treatment to reduce this pain. It can be accompanied by nausea, vomiting, paleness, sweating, and a feeling of wanting to urinate.

Tests to Diagnose Renal Colic

Urine sample cup with bar code

Urinalysis. Red blood cells may be detected, making the urine red from the blood, but this is not always the case. There may also be crystals, leukocytes (white blood cells), and bacteria. 

Blood collection tube

Blood analysis. If the patient has a fever, it is advisable to carry out a blood test to find out the leukocyte (white blood cell) level, the leukocyte formula, as changes in this level are linked to infection. A urine culture is also recommended.

Ultrasound on a monitor

Image tests. These are essential in patients with fever or who have only one kidney, and when the diagnosis of lithiasis is dubious.

Treating Renal Colic

The most urgent therapy in the acute phase is analgesia. The drugs of choice are non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac sodium, dexketoprofen trometamol, ibuprofen, ketorolac, metamizole or paracetamol. 

Other possible medications include opiates, spasmolytics, antiemetics (metoclopramide helps control nausea and vomiting), or anxiolytics (benzodiazepines to control agitation and tachycardia caused by pain).

It is important to know that during the acute phase, fluid intake should be restricted

Once the symptoms have been properly controlled in the emergency department, home treatment should be followed.

A physical, effective and user-friendly way of relieving the pain is by applying local heat as a complementary treatment to pharmaceuticals

Generally, once the acute phase of the colic has passed, forced liquid intake is usually recommended to accelerate the passing of the kidney stone. However, further studies are needed to determine the effectiveness of this measure. Some drugs are used as a medical expulsion treatment to promote the passing of the stone, including alpha-blockers, calcium-antagonists and corticoids.

In most cases, the acute phase resolves favourably and then, together with maintenance treatment and home support measures, an outpatient urological study is indicated.

However, there are special situations in which the obstruction of the urinary tract by the stone causes infection, sepsis, anuria (absence of urine due to bilateral or unilateral obstruction in patients with only one kidney), and requires urgent and invasive measures such as ureteral catheterisation (placement of a catheter at the level of the ureter from the bladder to the kidney to drain the urine), or percutaneous nephrostomy (a catheter placed in the kidney via percutaneous lumbar puncture) to drain the obstructed urinary tract, together with antibiotic treatment. A complete blockage without drainage, from 4-6 weeks, can affect kidney function.

Substantiated information by:

Bárbara Romano Andrioni
Pilar Luque

Published: 16 November 2020
Updated: 16 November 2020

The donations that can be done through this webpage are exclusively for the benefit of Hospital Clínic of Barcelona through Fundació Clínic per a la Recerca Biomèdica and not for BBVA Foundation, entity that collaborates with the project of PortalClínic.


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