Renal colic

What is it?

Renal colic is an acute pain syndrome usually caused by obstruction of the upper urinary tract, most commonly due to a ureteral stone.

The rise in pressure proximal to the obstruction and the distension of the urinary tract produce the characteristic pain.

Clinical presentation

The typical picture is characterized by:

• severe pain of sudden onset;
• lumbar or flank location;
• radiation to the lower abdomen, groin, or genitals;
• nausea and vomiting;
• restlessness: the patient often keeps changing position seeking relief;
• gross or microscopic hematuria, which may be absent.

When the stone is close to the bladder, urgency, frequency, and voiding discomfort may appear.

Initial evaluation

We need to determine:

• intensity and characteristics of the pain;
• temperature;
• history of stone disease;
• baseline renal function;
• presence of a solitary kidney;
• symptoms of infection;
• possibility of pregnancy;
• ability to tolerate fluids.

Tests may include:

• urinalysis;
• creatinine and renal function;
• complete blood count depending on the context;
• ultrasound;
• non-contrast CT when indicated.

Initial treatment

NSAIDs are usually the first analgesic option when there are no contraindications.

Other analgesics and antiemetics may be added as needed.

Many small ureteral stones can pass spontaneously, so not all require surgery.

When does it become a major urological emergency?

Especially in the presence of:

• fever or sepsis associated with obstruction;
• anuria;
• worsening renal function;
• obstruction of a solitary kidney;
• refractory pain;
• persistent vomiting.

The initial goal is to drain the urinary tract, using a ureteral stent or nephrostomy depending on the case. Definitive treatment of the stone is generally performed after the infection is controlled.