Pneumotórax fechado em tamanduá mirim (Tamandua tetradactyla)

Abstract

Background: Pneumothorax is characterized by the accumulation of air in the pleural space, either due to trauma or secondary to other conditions. Typically, pneumothorax is correlated with blunt trauma of the pulmonary parenchyma or penetrating trauma of the thoracic cavity, such as on being trampled upon or bitten, respectively. The therapeutic approach of this condition is rarely described in wild animals; therefore, the present study aims to describe the clinical manifestations, diagnostic method, and therapeutic aproach in a specimen of Tamandua tetradactyla with closed pneumothorax received for emergency care after being hit by a vehicle.

Case: A southern tamandua (T. tetradactyla) was received in our hospital after being hit by a vehicle. The patient presented with a state of stupor, nystagmus, a restrictive respiratory pattern, and muffling on auscultation of respiratory and cardiac sounds in the left antimer. Simultaneously with the physical examination, venous access was established, pain control was intravenously performed and oxygen therapy was started. After stabilization, the patient underwent abdominal ultrasound (abdominal-focused assessment with sonography for trauma) and thoracic radiographs. The abdominal ultrasound confirmed the presence of a small amount of free fluid in the evaluated recesses, i.e., hepatodiaphragmatic, splenorenal, cystocholic, and hepatorenal, suggesting the need for periodic ultrasonographic monitoring associated with the clinical evaluation of the patient because of suspicion of active hemorrhage. The thoracic radiographic image (ventrodorsal recumbency) revealed increased pulmonary opacity due to lobar retraction, marked by an enlarged gap between the pulmonary lobes and thoracic wall, and the formation of a radiolucent area between both structures. The lateral recumbency evidenced the dorsal displacement of the cardiac apex in relation to the sternum. In addition to the thoracic alterations, a transverse fracture in the middle third of the diaphysis of the left fibula was identified by radiographic examination. After extensive hair clipping and skin antisepsis of the left hemithorax, thoracentesis (an adapted technique from that used in domestic animals) was performed with access via the 8th intercostal space in its most dorsal presentation using a 21-gauge Butterfly needle attached to a three-way medical valve and 20-mL syringe. The procedure allowed 100 mL air to be drained until the negative pressure of the cavity was restored. At the end of the drainage, the patient showed a remarkable improvement in the respiratory pattern, and follow control radiographs showed full pulmonary expansion and no recurrence. The possibility of active abdominal hemorrhage was disregarded because ultrasound monitoring after 6 h revealed no change in the amount of free fluid in the suppressed recess.

Discussion: Pneumothorax is an important condition that can be detected in injured domestic and wild animals that are run over. The association between a detailed clinical evaluation and radiographic examination was essential for the diagnosis and initiation of the appropriate therapy, contributing to the prognosis of the patient. The adaptation of the thoracocentesis technique used in domestic animals proved to be suitable for the treatment of this Tamandua tetradactyla.