Lung heat transfer: author’s reply

Excerpt

We appreciate the interest of Drs. Schlimp and Wiedermann and welcome the opportunity to comment on the potential clinical utility of our observations. Heat exchange and the transfer of energy during respiration are governed by complex interactions of fluid mechanics, biophysics and heat transfer phenomena. Despite the simplicity of measuring the temperature, humidity and flow rate of exhaled gas, these values are the end result of complex interactions among multiple variables, at least a dozen of which are important and only a few of which can be estimated with reasonable accuracy. Critical variables include the architecture of the bronchial tree and the bronchial walls throughout the lungs, the blood supply to the bronchi and the parenchyma, the amount of tissue in the parenchyma, the presence of a free liquid layer on the airway surface, the pattern of ventilation and the instantaneous gas flow rates. …