XyloFUNS: Xylocaine to freeze during unpleasant nasopharyngeal swabs in children—a randomized controlled trial

OBJECTIVES: To evaluate the efficacy of intranasal vaporized lidocaine in reducing pain for children undergoing a nasopharyngeal (NP) swab in the Emergency Department (ED). STUDY DESIGN: A randomized blinded clinical trial was conducted in a paediatric ED. Both participants and the researcher evaluating the primary outcome were blinded. Children aged 6 to 17 years old requiring a NP swab were eligible. Participants were randomly allocated to receive intranasal lidocaine or a sham treatment prior to their NP swab. The primary outcome measure was pain during the swab as assessed by the visual analog scale. Secondary outcome measures were pain using the verbal numeric rating scale, fear using the children fear scale, and adverse effects of the intervention. RESULTS: Eighty-eight participants were enrolled—45 in the lidocaine group and 43 controls. The mean visual analog scale scores for pain were 46 mm in the lidocaine group and 53 mm in the control group (mean difference 7 mm; 95% CI: −5 to 19 mm). No serious adverse events were observed. CONCLUSIONS: Intranasal lidocaine administered prior to NP swabs in the ED failed to show an improvement in pain scores for school-aged children and youth.