title: Lung mechanics and pulmonary function testing in cetaceans.
abstract: 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.
authors.affiliation: Department of Life Science, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA andreas.fahlman@tamucc.edu.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fahlman
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Loring
authors.affiliation: Dolphin Quest, Oahu, 5000 Kahala Ave, Honolulu, HI 96816, USA.
authors.forename: Gregg
authors.initials: G
authors.lastname: Levine
authors.affiliation: Dolphin Quest, Oahu, 5000 Kahala Ave, Honolulu, HI 96816, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Rocho-Levine
authors.affiliation: PaxArms, Ltd, Timaru 7910, New Zealand.
authors.forename: Trevor
authors.initials: T
authors.lastname: Austin
authors.affiliation: V.M.D. Consulting, Miami, FL 33138, USA.
authors.forename: Micah
authors.initials: M
authors.lastname: Brodsky
mesh_terms: D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000502:physiology*; D002245:Carbon Dioxide / Q000378:metabolism; D004947:Esophagus / Q000502:physiology; D008168:Lung / Q000502:physiology*; D008297:Male; D010101:Oxygen Consumption; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics
chemical_list: D002245:Carbon Dioxide
keywords: Diving physiology; Excised lung; Lung mechanics; Marine mammals; Minimum air volume; Total lung capacity