Lung mechanics and pulmonary function testing in cetaceans.
We measured esophageal pressures, respiratory flow rates, and expired O2 and CO2 in six adult bottlenose dolphins (Tursiops truncatus) during voluntary breaths and maximal (chuff) respiratory efforts. The data were used to estimate the dynamic specific lung compliance (sCL), the O2 consumption rate (V̇O2 ) and CO2 production rates (V̇CO2 ) during rest. Our results indicate that bottlenose dolphins have the capacity to generate respiratory flow rates that exceed 130 l s(-1) and 30 l s(-1) during expiration and inspiration, respectively. The esophageal pressures indicated that expiration is passive during voluntary breaths, but active during maximal efforts, whereas inspiration is active for all breaths. The average sCL of dolphins was 0.31±0.04 cmH2O(-1), which is considerably higher than that of humans (0.08 cmH2O(-1)) and that previously measured in a pilot whale (0.13 cmH2O(-1)). The average estimated V̇O2  and V̇CO2  using our breath-by-breath respirometry system ranged from 0.857 to 1.185 l O2 min(-1) and 0.589 to 0.851 l CO2 min(-1), respectively, which is similar to previously published metabolic measurements from the same animals using conventional flow-through respirometry. In addition, our custom-made system allows us to approximate end tidal gas composition. Our measurements provide novel data for respiratory physiology in cetaceans, which may be important for clinical medicine and conservation efforts.
['Fahlman|Andreas|A|', 'Loring|Stephen H|SH|', 'Levine|Gregg|G|', 'Rocho-Levine|Julie|J|', 'Austin|Trevor|T|', 'Brodsky|Micah|M|']
D000818:Animals D050681:Bottle-Nosed Dolphin D002245:Carbon Dioxide D004947:Esophagus D008168:Lung D008297:Male D010101:Oxygen Consumption D012129:Respiratory Function Tests D015656:Respiratory Mechanics
Lung mechanics Diving physiology Excised lung Marine mammals Minimum air volume Total lung capacity