The effect of spray topical anesthesia on pain caused by obtaining blood gas from the radial artery

Background and Aim: Arterial blood gas is a frequently used laboratory test in the diagnosis and treatment of patients in emergency departments. However, this procedure is known to be more painful than other vascular procedures. In this study, we aimed to investigate the effect of 10% lidocaine topical spraylocal anesthesia on pain when obtaining arterial blood gas from the radial artery. Material and Method: A single-center prospective, randomized, controlled, double-blind study was performed between December 2018 and September 2019 in a tertiary emergency department in patients with arterial blood gas indication. The demographic information (patient number, age, gender), complaints, comorbidities and whether arterial blood gas was previously taken were recorded. Randomization was accomplished by a patient-specific withdrawal of paper written in envelopes kept by another emergency medical assistant, and solution bottles were delivered to the practitioner. The application was made by one person. In the treatment group, 10% lidocaine topical spray anesthesia was applied to the radial artery region 6 times in 5 cm distance. Ethanol containing spray was applied to the placebo group in the same way. After the application, it was waited for 5 minutes and arterial blood gas was obtained. Visual analog scale (VAS0) during the procedure and visual analog scale (VAS5) 5 minutes after the procedure were marked by the patient. The difference of 13 mm was accepted as significant Results: Seventy patients were included in the study. Three patients were excluded from the study because blood gas could not be taken at once. 34 patients received treatment and 33 patients received placebo. The mean age of the patients was 57 ± 17 years in the placebo group whereas 56 ± 17 years in the treatment group (p = 0.831). The mean value of VAS0 in the placebo group was 41 mm. The mean VAS0 value was 28 mm in the treatment group. The difference in the mean VAS0 level between the two groups was 13 mm. A significant difference was found between the VAS at the time of intervention in the placebo and treatment groups (p=0.011). The mean VAS5 value of the placebo group was 11 mm and the mean VAS5 value of the lidocaine applied group was 9 mm. There was a significant difference in VAS levels at 5 minutes in placebo and treatment groups (p = 0.117). The question of 'Would you like the process to be applied to you again next time' were asked the patients. Patients in the placebo group answered yes to 33.3% (n = 11) and 76.5% (n = 26) in the lidocaine group. Conclusion: It was observed that the use of spray topical anesthesia during obtaining arterial blood gas significantly reduced pain during the procedure. There was no significant difference between placebo and lidocaine in pain 5 minutes after the procedure. The majority of the patients who underwent spray topical anesthesia stated that they wanted the same procedure to be repeated in the next radial artery blood gas procedure. Usage of spray topical anesthesia prior to arterial blood gas uptake can be used to reduce pain during the procedure.