• concentration;
  • fentanyl;
  • intranasal


Objective: Intranasal fentanyl's (INF) effectiveness is established using highly concentrated INF (HINF). Standard concentration INF (SINF) is more widely available. We aimed to illustrate the equivalence of SINF to HINF.

Methods: Double-blinded randomized controlled trial was used within a children's hospital ED. Children aged 3–15 years with fractures were randomized to SINF or HINF. Outcome measures included pain scores at time zero and every 10 min until 30 min. Additional analgesic agents were noted.

Results: Data in 189 children (91 HINF, 98 SINF) were obtained. Pre-analgesia median VAS was 80.0 mm (interquartile range [IQR] 60.0–95.5) in SINF, 77.5 mm (IQR 60.0–100) in HINF. At 10 min median VAS was 49.5 mm (IQR 26.5–68.5) and 43.0 mm (IQR 15.2–66.0), respectively, at 20 min 27.5 mm (IQR 18.5–56.5) and 35.0 mm (IQR 9.0–57.0) and at 30 min 20.0 mm (IQR 10.0–46.0) and 21.5 mm (IQR 4.75–51.0). Each agent demonstrated significant decrease in pain scores (median decrease 40 mm, P = 0.000). Additional analgesia was given in 67 (42 SINF, 25 HINF) (P = 0.028). The decrease in pain scores between children < and ≥50 kg in SINF was significant both overall (P = 0.005) and between 10 and 20 min (P = 0.003). There was no difference in HINF at any time by weight.

Conclusions: The two concentrations of INF were equivalent in reducing pain, with a trend to increased oral additional agents in the more dilute solution. The widespread use of this readily available analgesic in the standard concentration can be supported, particularly in patients <50 kg.