Comprasion of ultrasound guidance and the conventional approach for radial arterial blood gas sampling in emergency department shock patients

Introduction and Aim: In the emergency department, arterial blood gas analysis is among the fundamental initial tests for evaluating patients and guiding treatment. Obtaining arterial blood gas is particularly challenging in hypotensive patients. In this study, we aimed to compare US (ultrasound) guidance and the conventional (palpation) method for obtaining blood gas from the radial artery in all shock patients presenting to the emergency department. Materials and Methods: The study was planned as a single-center, prospective, randomized study. Shock patients who presented to the emergency department for any reason or were brought by ambulance were included in the study. When the treating physician ordered an arterial blood gas, arterial blood gas was obtained from the radial artery from the patients by the investigator physician. Prior to the procedure, randomization was performed into an ultrasonography (USG) group and a palpation (non-USG) group. Age, sex, type of shock, vital signs, procedural success, procedure time, use of rescue methods, and patient outcome were compared between the groups. Results: A total of 106 patients diagnosed with shock were included in the study. Two of these patients were excluded because consent could not be obtained, and four were excluded due to missing data. There were 50 patients in the Palpation group and 50 patients in the USG group. No difference was found between the groups in terms of shock types (p<0.779). Septic shock was the most common (48%) among the patients included in the study. First-attempt success was higher in the USG group compared with the Palpation group (p<0.01). In the Palpation group, arterial blood gas could be obtained on the second attempt in 12 patients (40%) and on the third attempt in 8 patients (40%). In the USG group, there were 3 patients (6%) in whom blood gas could not be obtained on the first attempt. The number of attempts was higher in the Palpation group (p<0.001). Procedure time was much shorter in the USG group (median: 17.5 s) compared with the Palpation group (median: 35 s) (p<0.001). Conclusion: In shock patients, the use of ultrasound for obtaining arterial blood gas samples shortens procedure time and increases procedural success. Therefore, the use of ultrasonography during arterial blood gas sampling is beneficial in all shock patients. Keywords: Emergency department, Arterial blood gas, Ultrasound, Shock, Radial artery puncture.