MECHANICS OF VENTILATION IN PILOT WHALE

Pulmonary mechanics were measured in a pilot whale (using blowhole-esophageal pressure for transpulmonary pressure and ventilation at the blowhole for changes of lung volume). Absolute lung volumes were obtained by dilution of helium; alveolar gas concentrations were obtained from end-expired samples of gases. Conductance and compliance (as functions of lung volume) and maximal lung volume (as a function of body weight) have the same magnitudes in this whale as in man. In contrast to man this whale renews as much as 88% of lung air with a single breath and appears to have a more effective defense against aspiration of water. In response to an alveolar CO2 of 303 mm Hg and to inhaled carbachol, average pulmonary resistance increased 20% and 24% respectively (both changes not statistically significant). © 1969.