Technique for Ultrasound-Guided Arterial Catheter Placement in the Pectoral Flipper of the Bottlenose Dolphin (Tursiops truncatus)
A technique for minimally invasive ultrasound-guided arterial catheterization in Tursiops truncatus is described. Voluntary ultrasonography of the dorsal and palmar surfaces of an adult T. truncatus’s pectoral flippers was performed using a 13-6 MHz linear transducer (Sonosite Edge®, Bothell, WA). A vessel that measured ~ 2.0 mm in diameter was identified on the palmar aspect of the flipper. A comparable but more attenuated ~ 1.0 mm diameter vessel was seen on the dorsal aspect. Each vessel extended down the long axis of the flipper near the center, ~ 1 cm deep to the skin surface but superficial to the underlying bone. On pulsed wave Doppler, both vessels exhibited a pulsatile waveform suggestive of arterial interrogation. Under a general anesthetic event for an unrelated procedure, a 4.0-Fr 10-cm catheter was seated into the lumen of the palmar artery at approximately the level of the carpus (mid-flipper) in a retrograde fashion using ultrasound guidance and a 21-g 7-cm microintroducer set (Micropuncture® Introducer Set, Cook, Bloomington, IN). The arterial line was successfully maintained throughout the anesthetic event and subsequent recovery, allowing continuous assessment of arterial blood pressure and intermittent evaluation of arterial blood gases. References in the literature are limited;1-3 however, additional anatomical investigations are currently underway to confirm the appropriate nomenclature for the artery in question. This technique for cannulation of a peripheral artery may have important clinical applicability for cetacean anesthetic monitoring and critical care in the future.
The authors would like to thank Drs. Sam Ridgway, Cynthia Smith, Eric Jensen, and the veterinary, biotechnical, training, and management staff of the Navy Marine Mammal Program and the National Marine Mammal Foundation for their support in developing these techniques.
* Presenting author
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2. Cooper LN, Dawson SD, Reidenberg JS, Berta A. Neuromuscular anatomy and evolution of the cetacean forelimb. Anat Rec. 2007;290:1121-1137.
3. Elsner R, Pirie J, Kenney D, Schemmer S. Functional circulatory anatomy of cetacean appendages. In: Harrison RJ, ed. Functional Anatomy of Marine Mammals (Vol. 2). London, United Kingdom: Academic Press; 1974: 143–159.