Welcome to Facts on the Ground a series brought to you by Natan Cramer from the University of Pittsburgh. Facts on the Ground is designed to be a concise literature review that helps answer common clinical questions.

The Article

Effect of Intranasal Ketamine vs Fentanyl on Pain Reduction
for Extremity Injuries in Children: The PRIME Randomized Clinical Trial

Frey et al.
JAMA Pediatrics, 2018


To investigate if intranasal ketamine was not inferior to intranasal fentanyl for treating pain in acute long bone fractures in children.

Study Design

This was a block randomized, double blinded non-inferiority trial of patients (8-17 years) with extremity fractures and a visual analog pain scale (VAS) score > 35mm. The study excluded those who had received opioids prior to arrival, who had distracting injuries, and patients with a GCS <15.

Patients were randomized to either receive 1.5mg/kg of ketamine or 2µg/kg of fentanyl. A non-inferiority margin of 10 on the VAS was chosen. A sample size of 78 was estimated to detect difference. 

The primary outcome was pain reduction difference between the groups at 30 minutes post-administration. Secondary outcomes were differences in sedation level using a validated sedation scale, capnometry, rescue medications needed, vital sign changes, and incidence of adverse events in each arm. 


Ultimately 45 patients were randomized to each group. There was no significant difference in the primary outcome (pain reduction at 30 minutes). Both groups continued to have effective pain reduction 60 minutes from treatment. A little more than half, 54.7% of all patients, suffered minor, brief, adverse events. The ketamine arm experienced a significantly higher proportion of adverse events (77%). More common adverse events included: dizziness, unpleasant taste, drowsiness, and nausea/vomiting.

There was no difference seen in the need for rescue medication. Ketamine had higher, but not clinically relevant sedation scores. the ketamine arm experienced higher rates of decreased capnometry values but this did not precede desaturation and all changes were brief.


Intention to treat analysis, though specified in the original protocol, was unable tube performed as four patients are withdrawn because they didn’t receive any medications. Additionally, the authors did not specify if there were differences between the intervention groups with respect to type of fracture, medication received beforehand etc,. Though single center, there are two other trails (see References) that have drawn a similar conclusion.

The Bottom Line

Intranasal ketamine appears to be just as good (not inferior) to intranasal fentanyl for the acute management of pain in long been fractures in children.


Frey et al. Effect of Intranasal Ketamine vs Fentanyl on Pain Reduction for Extremity Injuries in Children: The PRIME Randomized Clinical Trial. JAMA Pediatrics, 2018.

Graudins et al. The PICHFORK (Pain in Children Fentanyl or Ketamine) Trial: A Randomized Controlled Trial Comparing Intranasal Ketamine and Fentanyl for the Relief of Moderate to Severe Pain in Children With Limb Injuries. Annals of emergency medicine. 2015;65(3):248-254.e241.

Reynolds et al. Randomized Controlled Feasibility Trial of Intranasal Ketamine Compared to Intranasal Fentanyl for Analgesia in Children with Suspected Extremity Fractures. Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 2017.

Yeaman et al. Sub-dissociative dose intranasal ketamine for limb injury pain in children in the emergency department: a pilot study. Emergency medicine Australasia : EMA. 2013;25(2):161-167.

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