Aims and Objectives This project was supported by the RCEM Dragon’s Den event in 2014, the inaugural Young Investigator’s Award in 2015, and extensive input from college academics. It was funded by the NIHR RfPB.

Renal colic is pain experienced when a renal calculus causes partial or complete obstruction of the renal outflow tract; pain results from ureteric spasm, increased peristalsis, increased pressure at the renal pelvis, and prostaglandin release with inflammation. Lifetime incidence is approximately 12% in males and 6% in females, with recurrence rates approaching 50%.

The standard analgesic regimes for renal colic are often ineffective and associated with significant side effects; in some studies less than half of patients achieve complete pain relief, a large proportion of patients require rescue analgesia within four hours, and nausea, vomiting and drowsiness are frequently reported.

Salbutamol is a beta agonist in widespread use across healthcare services. It has been hypothesised that beta agonists may reduce the pain of renal colic by promoting ureteral relaxation, reducing the frequency of ureteral contractions, and reducing renal pelvic pressure. Salbutamol has the benefits of parenteral administration, rapid onset of action, and the ability to be used as an outpatient in inhaled form.

Method and Design This randomised, placebo-controlled, double-blind Phase II study provides the first evidence concerning the analgesic effects of salbutamol when added to the standard regime for emergency department patients with renal colic. Participants received conventional analgesia at clinicians’ discretion; they were randomised to receive either 250mcg intravenous salbutamol or placebo. Pain scores were collected using a VAS at baseline, 15, 30, 60, and 120 minutes, and then 4-hourly thereafter.