From the Guidelines
Renal colic cramps are primarily caused by the obstruction of the urinary tract by kidney stones, leading to intense, wavelike pain as the ureter contracts to move the stone. This pain is a result of the ureteral spasm and inflammation caused by the stone. According to a study published in the BMJ in 2002 1, the management of acute renal colic involves a pathway of care that includes pain management and urological investigation.
Key Points to Consider
- The pain from renal colic can be severe and may require immediate medical attention if accompanied by fever, inability to urinate, or severe nausea and vomiting.
- The use of intramuscular diclofenac 75 mg is recommended as the first line of treatment for renal colic when the diagnosis is clear and there are no signs of complications 1.
- Patients with renal colic should be offered fast-track urological investigation with follow-up, regardless of whether they are managed at home or in the hospital.
- The pain from renal colic typically radiates from the flank to the groin and may be accompanied by other symptoms such as nausea, vomiting, and blood in the urine.
Management of Renal Colic
- Pain management is a crucial aspect of treating renal colic, and NSAIDs like diclofenac are preferred for their anti-inflammatory properties.
- Adequate hydration is essential for patients with renal colic, unless contraindicated, to help facilitate the passage of the stone.
- Application of heat to the affected area can provide additional comfort and help relieve pain.
From the Research
Causes of Cramps from Renal Colic
- Renal colic is generated by hyperperistalsis of the obstructed ureter 2
- Peristalsis is modulated by alpha-receptors (contraction), beta-receptors (relaxation) and prostaglandins (PG F2alpha: contraction, PG E1/E2: relaxation) 2
- The pain from renal colic is often severe and incapacitating, and is caused by an obstruction in the upper urinary tract 3, 4
- The obstruction can cause ureteric spasm, which can lead to severe pain 5
Mechanism of Pain
- The pain is caused by the obstruction of the ureter, which leads to an increase in ureteral pressure and a subsequent activation of nociceptors 4
- The activation of nociceptors leads to the transmission of pain signals to the brain, resulting in the sensation of pain 4
- Non-steroidal anti-inflammatory drugs (NSAIDs) are effective in relieving pain by reducing inflammation and inhibiting prostaglandin synthesis 2, 3, 4, 6
Treatment Options
- NSAIDs are highly effective in pain relief and should always be given in the absence of contraindications 2
- Opioids are indicated for most severe pain 2
- alpha-blockers and calcium channel blockers can dilate the distal ureter and increase the likelihood of spontaneous stone passage 2
- Non-opioid medications such as hyoscine and antispasmodics may not be as effective as NSAIDs in relieving pain 6