Does "Freeze Spray" Work? Evaluating the Efficacy of Ethyl Chloride Usage Prior to Orthopaedic Injections

A procedure frequently performed by orthopaedic providers is the administration of corticosteroid injections for the management of various soft tissues and joint-related conditions, such as osteoarthritis, tendinitis, carpal tunnel syndrome, trigger finger, and de Quervain's tenosynovitis. While these injections have demonstrated effectiveness in alleviating symptoms, the discomfort associated with the procedure can be a source of anxiety and apprehension for patients. This discomfort arises from the sensation of the needle entering the affected area and the burning sensation induced by the corticosteroid solution.

In response to this concern, orthopaedic providers have turned to freeze sprays (Ethyl chloride), which are topical anesthetics that rapidly cool the skin and underlying tissues. By numbing the injection site superficially, freeze sprays offer the potential to mitigate patient discomfort during corticosteroid injections, thus improving the overall patient experience and potentially enhancing treatment compliance.

However, despite the popularity of freeze spray usage in orthopaedics, many orthopaedic providers have concerns about its efficacy when it comes to providing pain relief. There still needs to be comprehensive scientific evidence evaluating its efficacy and safety. A previous study evaluated the efficacy of freeze spray in hand surgery in a randomized study of 150 subjects without standardized outcomes measures. These investigators showed no difference between those receiving freeze spray vs no spray in pain or anxiety; another study of vapocoolant spray in IV start sites in the emergency department similarly showed no difference in pain or anxiety. Based on the literature, there is no definitive standard of care to use freeze spray with injections and this is the gap in knowledge we wish to answer with a rigorous, placebo-controlled study. This study will differ from the previous similar study in that the investigators will recruit double the number of patients and use standardized commonly accepted questionnaires. The use of a questionnaire based on standardized metrics will provide a more comprehensive assessment of patient perceptions and satisfaction with the use of freeze spray. Through a rigorous research approach, the investigators aim to provide valuable insights into the impact of freeze spray on patient comfort, injection success rates, and any potential complications associated with its use.

This study will contribute to the ongoing efforts of hand surgeons to refine their techniques, minimize patient discomfort, and optimize the delivery of corticosteroid injections. Ultimately, the investigators' findings may have significant implications for the broader field of musculoskeletal medicine, offering evidence-based guidance to improve the patient experience and outcomes in orthopaedic surgery.