Iatrogenic gas embolism in a juvenile loggerhead sea turtle (Caretta caretta)

Abstract

A mild pneumocoelom was diagnosed by computed tomography in a stranded juvenile loggerhead sea turtle (Caretta caretta). After gas extraction by ultrasound-guided puncture, the animal did not improve and was subjected to hyperbaric oxygen therapy (HBOT). After HBOT, the turtle developed marked subcutaneous emphysema and was found dead the following morning. Gross lesions included a distended right atrium with numerous gas bubbles within the epicardium, gas bubbles in the hepatic, gastric and mesenteric veins, a small gas-filled bulla in the left lung and diffuse haemorrhages in the encephalon. Histological lesions included gas-like emboli in the lumen of the right atrium with myocardial necrosis, gas-like emboli in the lumina of intestinal, pulmonary and renal blood vessels and severe meningeal haemorrhages. From a forensic pathology perspective, the subcutaneous emphysema of immediate onset after HBOT and the greater severity of the histological lesions in blood vessels, heart, lung and brain differentiate this case from other cases of gas embolism in turtles due to incidental capture. Two factors contributed to this outcome: the existence of a probably unresolved pneumocoelom and the application of HBOT without an initial diagnosis that accurately indicated its use. Therefore, as in human medicine, the use of HBOT in sea turtles with lung lesions and pneumocoelom is discouraged. This is the first description of an iatrogenic gas embolism in a sea turtle.

Keywords: Caretta caretta; gas embolism; hyperbaric oxygen therapy; loggerhead turtle; pneumocoelom.