Experimental evaluation of infusion methods and administration speeds in confined spaces during urban search and rescue operations

Introduction Confined space (CS) medicine is required for urban search and rescue operations, particularly for victims with crush syndrome. Adaptable infusion techniques are sometimes required for each rescue setting. However, the knowledge of infusion methods and speeds in CS is limited. Aim To evaluate infusion speeds of various methods using an infusion model based on in vivo data, aiming to inform rescue planning and training. Methods Peripheral venous pressure and infusion rates were measured in healthy male participants, aged 20–29 years ( n = 20). An infusion model was established using a simulator arm based on these measurements. Seven infusion methods were tested, including spontaneous drip, manually pressurized bag + re-pressure, tube extension + pumping, and automated pressure devices (continuous or temporary by spring-loaded trays or batteries). Results Mean venous pressure of the participants was 19.8 cm H 2 O, and 500 ml was infused over 16 min 25 s. An infusion model replicated this pressure gradient. Infusion speed varied among different methods. Compared with spontaneous drip, the time required for a 1 L infusion was significantly shorter when using tube extension + pumping ( P < 0.0001), pressurized bag + re-pressurization ( P < 0.001), and automated devices (continuous battery, P < 0.001 and temporary battery, P < 0.05). Conclusions A CS infusion model was developed based on in vivo experiments. Manual pressure with re-pressurization after 10 min may be the most reasonable. Although each method has its advantages and disadvantages, selection should prioritize efficacy and safety. Further research is required to confirm the findings.