Comprendre la technologie et les principes physiques des matelas à air pulsé

Perioperative hypothermia still shows a high incidence in high-risk patients of about 35-75% and is associated with numerous adverse outcomes. There are a large number of forced-air warming devices available on the market to prevent perioperative hypothermia. However, there is a paucity of data about the physical background of these devices. Heat flow produced by the power units is depending on the air temperature at the nozzle and the airflow. Heat transfer from the blanket to the body surface is depending on the heat exchange coefficient, the temperature gradient between the blanket and the body surface, the area of the body surface that is covered and homogeneity of heat distribution inside the blanket. The design of the blankets mainly determines the efficacy of a forced-air warming system. To achieve the best effect patients must be prewarmed for 30 to 60 min. During the operation, the largest blanket that is possible for the operation should be used. If large amounts of fluids are applied during the procedure, forced-air warming should be combined with fluid warming because forced-air warming alone is not powerful enough to compensate for the heat losses occurring by the infusion of large amounts of cold fluids.