Effects of Cold Exposure on Functionality of Fresh Whole Blood Transfusion Equipment in Austere Environments

Abstract

Abstract. Clinical observations from austere environments reveal operational failures in field whole blood transfusion equipment. These failures compromise patient care by impeding blood product delivery due to flow restriction and condensation accumulation within the delivery system. This research investigated the effects of cold exposure on the transfusion kit components, with a specific focus on intravenous (IV) tubing to address an important gap in the current literature regarding the quantitative assessment of cold-induced changes in medical equipment functionality. Fresh whole blood transfusion equipment was exposed to −40 °C in an environmental chamber for 24, 44, 84, and 96 h to simulate cold exposure during transportation in an austere environment. Postcold exposure testing was conducted at room temperature, simulating conditions in a heated field tent, and comprised of two phases: (1) structural deformation assessment using MicroVu camera imaging system and (2) volumetric flowrate measurement using ultrasonic flowrate sensor. Cold exposure induced significant structural alterations in the intravenous (IV) tubing, characterized by patterns of localized indentations and diameter variations. Deformation was most prominent at stress concentration points such as the tubing inlet near flow control valves and downstream of the filter. It was shown that volumetric flowrates decreased substantially from baseline measurements of 165 mL/min to 110–120 mL/min postcold exposure. Plastic, single-use medical equipment, particularly IV tubing, demonstrated poor tolerance to cold exposure of as little as 10 min, resulting in compromised functionality. However, it was demonstrated that increasing the temperature of the infused fluid promotes structural recovery of the tubing and improves functional performance. This recovery mechanism suggests potential interventional strategies: (1) development of prewarming protocols for cold-exposed equipment, (2) incorporation of cold-resistant polymer formulations in transfusion kit components, and (3) design modifications at identified stress concentration points.