Background: CoolStick is a steel cylindrical device designed to be refrigerated and provide a sustainable, cost efficient alternative to vapo-coolant sprays when assessing cold sensation of neuraxial anaesthesia. We compared sensory block level testing with ethyl chloride and CoolSticks. We aimed to investigate the clinical efficacy, economic, environmental and practical considerations of CoolStick use. Methods: Assessments of sensory block height were made using ethyl chloride and CoolStick prior to caesarean delivery according to a standardised protocol. Block height to cold sensation was compared to light touch using cotton wool. Patient feedback was collected to determine ease of discrimination between testing methods. Statistical analysis of concordance were assessed using the Kappa test, and depicted using Bland-Altman plots. Results: 50 patients undergoing caesarean delivery were included. Block assessment using ethyl chloride and CoolStick showed good agreement bilaterally (x = 0.77, 0.63) and good concordance on Bland-Altman plot. Block level agreement with cotton wool was poor with both CoolStick (x = 0.086, x = 0.044) and ethyl chloride (x = 0.076, x = 0.035). Switching to routine CoolStick use in a hospital with 5500 deliveries may save 9,500 pound annually while preventing 229.32 kg of potentially unnecessary CO2 equivalent emissions in the first year, and 238.4 kg each year thereafter. Conclusions: CoolStick offers clinical equivalency to ethyl chloride for sensory block level assessment. Switching to using CoolStick may represent a positive economic and environmental movement.
