Temperature Measurement and Thermal Management

Abstract

Temperature measurement and thermal management in surgical patients are both challenging issues that depend on regulating the patient’s immediate thermal environment in the face of the nonphysiologic perturbations that routinely occur in the operation room. Recognizing the different mechanisms involved in the physics of heat transfer, such as radiation, convection, conduction, and evaporation is paramount. In addition, the patient’s comorbidities and prescribed medications combine with the agents used during general anesthesia to further alter thermoregulation. Correctly measuring and monitoring temperature is critical and is an expected part of the American Society of Anesthesiologists (ASA) basic standards for monitoring for all but the shortest or lightest anesthetics. Understanding the advantages and disadvantages of the different anatomic sites available to measure temperature is imperative to prevent erroneous temperature recordings. Correctly preventing inadvertent hypothermia and iatrogenic hyperthermia are critical prior to deciding to institute thermal management. Different mechanisms exist to treat heat loss, using both passive and active warming. Other unique environments within the hospital impose stress on thermoregulation systems such as cardiopulmonary bypass and MRI. This review is a summary of the scientific and medical literature necessary to understand the fundamentals of temperature measurement and thermal management. This review contains 3 figures, 3 tables, and 43 references. Key Words: forced air convection, general anesthetics, hyperthermia, temperature measurement, thermal management, thermoregulation, threshold