Criticism over the Intraosseus Route for Testudines: A Test with the Yellow-Footed Tortoise (Chelonoidis denticulata)
Fluid administration via the intraosseous route in Testudines at the carapacial bridge is advocated by some authors as an efficient method for replenishing fluids, whereas others advise against its use. The authors estimated the flow rates and distribution of fluids administered intraosseously to five adult male Chelonoidis denticulata with anatomically normal shells. The caudal aspect of the bridge of the carapace, immediately cranial to the rear limbs, was used as the site for catheter placement because it was considered the best candidate site to inject fluids and radiographic positive contrast. The technique was successful in two (40%) of the tortoises. Flow rates were more than sufficient to rehydrate the reptiles, with fluids entering the main circulation. The technique was ineffective in three (60%) of the tortoises, with fluids entering the coelomic cavity or not being able to be injected. Based on this pilot study, it was determined that this technique is highly prone to failure in the species of tortoises used in this study when they are >3 kg in weight because of the anatomical differences between individuals and the associated bridge bone drilling difficulties.Abstract
Image of a Chelonoidis denticulata sectioned through its frontal plane, over the bridge region. It may be seen that this region of the bone is thick, with no medullary space. The caudal aspect of the bridge shows a region with spongy bone (dotted circle); the site at which the intraosseus injection was performed. The arrow simulates the trajectory of the placement of the catheters.
Positive-contrast dorsoventral radiographic images of Chelonoidis denticulata. Contrast was injected through an intraosseous catheter set at the caudal portion of the carapacial bridge (Omnipaque 300, 300 mg/mL iohexol, Sanofi Laboratory, Suzano, SP, Brazil). (A) Radiographic image showing correctly placed catheter and intraosseous injection with fluid reaching the kidney and celiac vein. 55 kV, 100 mA, 5 mAs. (B) Radiographic image showing contrast material entering the coelomic space because of an incorrectly placed catheter. 60 kV, 100 mA, 5 mAs.
