Researchers analyzed four clinical trials to compare two pain relief methods for patients with severe kidney stone pain in emergency departments. They looked at 454 patients total, with about half receiving pain medication through a nasal spray (intranasal ketamine) and the other half receiving it through an IV (intravenous morphine or fentanyl). The goal was to see if one method worked better or faster than the other.
The analysis measured pain levels at 5, 15, and 30 minutes after treatment. It found no significant difference in pain relief between the nasal spray and the IV medication at any of these times. There was also no difference in how often patients needed extra pain medication or in common side effects like nausea and dizziness.
The main reason to be careful with these results is that they come from only four studies involving 454 patients. The confidence intervals—a statistical measure of certainty—for the pain scores were wide, meaning the true effect could range from a small benefit to a small harm for either treatment. Readers should understand that this review does not prove the treatments are equal, but rather that current evidence from a small number of studies shows no clear difference in effectiveness or safety for this specific use in the emergency room.