Vetnews | Februarie 2025 8 « BACK TO CONTENTS Cardiopulmonary adaptations of a diving marine mammal, the bottlenose dolphin: Physiology during anesthesia Abstract Diving marine mammals are a diverse group of semi-to completely aquatic species. Some species are targets of conservation and rehabilitation efforts; other populations are permanently housed under human care and may contribute to clinical and biomedical investigations. Veterinary medical care for species under human care, at times, may necessitate the use of general anesthesia for diagnostic and surgical indications. However, the unique physiologic and anatomic adaptations of one representative diving marine mammal, the bottlenose dolphin, present several challenges in providing ventilatory and cardiovascular support to maintain adequate organ perfusion under general anesthesia. The goal of this review is to highlight the unique cardiopulmonary adaptations of the completely aquatic bottlenose dolphin (Tursiops truncatus) and to identify knowledge gaps in our understanding of how those adaptations influence their physiology and pose potential challenges for sedation and anesthesia of these mammals. 1. INTRODUCTION Approximately 50–55 million years ago, a terrestrial artiodactyl similar to a small deer made the transition from land to water (Thewissen et al., 2009, 2007). Fossil records suggest that this ancestor of cetaceans became more amphibious over millennia until it became fully aquatic. Cetacea is the mammalian infraorder that includes whales, dolphins and porpoises. Carolina R. Le-Bert, Gordon S. Mitchell, Leah R. Reznikov Study objective(s) No Age(years) Weight range (kg) Pre-medication agent(s) Effect of halothane anesthesia on hepatic damage during auditory research 6 (F = 3, M = 3) N/A N/A N/A Bispectral index monitor to detect interhemispheric asymmetry 3 (F = 1, M = 2) N/A 212–263 Diazepam, 0.15 mg/kg, PO (n = 1) Anesthesia induction and maintenance with thiopental and halothane 10 5 N/A N/A N/A N/A N/A N/A Surgical approach to the dolphin ear 4 N/A N/A Atropine, 0.02 mg/kg, Hemodynamic and coronary angiographic studies in the dolphin 4 N/A 80 - 114 N/A Return of sound production following anesthetic recovery 10 (F = 4, M = 6) 8–46 (mean 32.4) N/A Midazolam, 0.08–0.1 mg/kg, IM Meperidine, 0.1–0.2 mg/kg, IM Apneustic anesthesia ventilation on pulmonary function 9 (F = 3, M = 6) 10–42 (mean 32) 141–292 Diazepam, 0.08–0.30 mg/kg, PO (n = 2) Midazolam, 0.08–0.1 mg/kg, IM Meperidine, 0.1–0.2 mg/kg, IM Plasma propofol concentrations in dolphins 6 12–27 (mean unk) N/A Diazepam, PO Midazolam, IM TABLE 1 Summary of general anesthesia performed during anatomic and physiologic studies of dolphins (Tursiops spp.)
RkJQdWJsaXNoZXIy OTc5MDU=