No abstract

Objective: The initial treatment of a wounded patient with hypovolemia necessitates rapid infusions of fluid. In cold surroundings, the infusion sets can freeze very quickly. Preventing this is not enough, since rapid cold infusions cause physiological danger to the patient. The aim of this study was to develop an infusion set and method which, in cold field conditions, will allow rapid pressure infusions of warm (>20°C) fluids to the wounded. The further aim was to develop a protective sheet to prevent cooling of the wounded patient. Our objective was to find material and equipment which were simple, domestic, and inexpensive. Methods: A plastic infusion bag was used with a ready-made infusion tube without a drop chamber. Since infusion with this system necessitated the use of a pressure cuff, a simple transparent one was developed. Measurements were made of the drop in temperature of infusion fluids, which were placed in thermal boxes both in the laboratory (-40°C) and in the field. Two liters of fluid usually are sufficient for the initial treatment of shock. Results: Laboratory and field conditions indicated that the infusion liquid was kept warm most efficiently when the plastic infusion bag (+40°C) was placed inside the patient's field jacket and the infusion tube was taken to the patient's hand through his or her sleeve. In this way, the patient's own body warmth was utilized, and a separate active or passive shielding of the plastic bag or infusion set was not needed. Of the tested cover sheets, the best proved to be a combination of three blankets. During the tests, a drop in body temperature was found. This was measured from the back of the patients who were lying on iron mesh stretchers. Therefore, the bottom of such stretchers should be well-insulated. Conclusions: This equipment makes it possible to give warm fluid infusions in cold conditions and, at the same time, prevent the patient from cooling.