Pulmonary mechanisms of the normal ferret

Pulmonary mechanics were measured in normal anesthetized male Fitch ferrets (200-360 g). In eight transorally intubated ferrets, pressure-volume (PV) curves for the lung and chest wall were obtained with an esophageal balloon and body plethysmograph. The lung volumes and capacities expressed as a percentage of the total lung capacity (mean, 49.8 ml) were: vital capacity, 84.7%; inspiratory capacity, 63.7%; inspiratory reserve volume, 58.2%; functional residual capacity, 33.8%; expiratory reserve volume, 16.8%; residual volume, 15.3%; and tidal volume, 8.0%. The compliance of the lung (2.93 ml . cmH2O-1), chest wall (22.42 ml . cmH2O-1) and respiratory system (2.55 ml . cmH2O-1) were determined from the PV curves. The dynamic compliance (1.6 ml . cmH2O-1), pulmonary resistance (0.024 cmH2O . ml-1 . s), frequency of breathing (43.5 breaths . min-1), and minute ventilation (195 ml . min-1) were measured during spontaneous breathing. In a second group of 10 ferrets the total airway resistance (0.116 cmH2O . ml-1 . s) and specific conductance (0.915 ml . s-1 . cmH2O . ml-1) were measured during spontaneous nasal breathing. In general the pulmonary mechanics of the ferret were similar to those of the rabbit and dog, when the data were normalized for lung volume.