Intranasal ketamine for the treatment of patients with acute pain in the emergency department

Background: Pain in the emergency department (ED) is common but undertreated. The objective of this study was to examine the efficacy and safety of intranasal (IN) ketamine used as an analgesic for patients with acute injury with moderate to severe pain.

Methods: This study was a cross sectional, observational study of patients more than 8 years old experiencing moderate to severe pain [visual analog score (VAS) >50 mm]. The initial dose of IN ketamine was 0.7 mg/kg with an additional dose of 0.3 mg/kg if VAS was more than 50 mm after 15 minutes. Pain scores and vital signs were recorded at 0, 15, 30 and 60 minutes. Side-effects, sedation level and patient's satisfaction were also recorded. The primary outcome was the number of patients achieving ≥ 20 mm reductions in VAS at 15 minutes. Other secondary outcome measures were median reduction in VAS at 15, 30 and 60 minutes, changes of vital signs, adverse events, satisfaction of patients, and need for additional ketamine.

Results: Thirty-four patients with a median age of 29.5 years (IQR 17.5-38) were enrolled, and they had an initial median VAS of 80 mm (IQR 67-90). The VAS decreased more than 20 mm at 15 minutes in 27 (80%) patients. The reduction of VAS from baseline to 40 mm (IQR 20-40), 20 mm (IQR 14-20) and 20 mm (IQR 10-20) respectively at 15, 30 and 60 minutes (P<0.001). No critical changes of vital signs were noted and adverse effects were mild and transient.

Conclusion: This study showed that IN ketamine is an analgesic choice for patients with acute injury in moderate to severe pain in an overcrowded and resource limited ED.