Evaluation of a thoracic focused assessment with sonography for trauma (TFAST) protocol to detect pneumothorax and concurrent thoracic injury in 145 traumatized dogs

Abstract

Objective: To estimate the relative accuracy of a thoracic focused assessment with sonography for trauma (TFAST) protocol for rapid diagnosis of pneumothorax (PTX) and other thoracic injury in traumatized dogs. Design: Prospective case series. Setting: Private veterinary emergency center. Animals: One hundred and forty-five client-owned dogs evaluated within 24-hours of injury. Interventions: Thoracic focused assessment with sonography for trauma protocol. Measurements and Main Results: Traumatized dogs were evaluated with a conventional ultrasound (US) machine using a standardized 4-point thoracic FAST protocol before thoracic radiography (CXR) and thoracocentesis. PTX was diagnosed by the absence of the 'glide sign,' defined as the lack of the normal dynamic interface between lung margins gliding along the thoracic wall during respiration. Concurrent thoracic trauma was diagnosed by the presence of pleural or pericardial fluid or the presence of a 'step sign,' defined as an abnormal glide sign. Accuracy of TFAST was calculated relative to CXR findings. Results: Overall sensitivity (Se), specificity (Sp), and accuracy of TFAST relative to CXR were 78.1% (95% CI; 61.5, 89.9), 93.4% (95% CI; 87.4, 97.1), and 90.0%, respectively. Se and Sp were higher in dogs with penetrating trauma (93.3%, 96.0%) and for the evaluator with the most clinical experience (95.2%, 96.0%); only Se between the most experienced compared with others was statistically significant (Po0.05). TFAST documented other concurrent thoracic injury. Median time for TFAST was 3 minutes. Conclusions and Clinical Relevance: TFAST has the potential to rapidly diagnose PTX and other thoracic injury and guide therapy, including potentially life-saving interventions, in traumatized dogs.

Use of ultrasonography by veterinary surgeons in small animal clinical emergencies

“…1 -7 One of the major advantages of FAST, in the veterinary clinical environment, is that the protocol can be performed in minutes 8 -11 with minimal patient restraint and simultaneously with other concurrent interventions/ tests by veterinary surgeons who are not radiologists or experienced in ultrasonography. 8,9,12 Abdominal-FAST Intra-abdominal injury is difficult to detect and can potentially be fatal such as in cases of uncontrollable haemorrhage. Computed tomography (CT) is becoming the imaging modality of choice for intra-abdominal injury in veterinary medicine.…”

“…This along with Fluid-filled uterine body (U) and uterine horns (uh) in a dog with pyometra similar findings in humans 3,4,16 -23 assisted in dispelling the impression that air did not allow evaluation of the thorax by ultrasound. 19,20,23,24 The thoracic-FAST (T-FAST) examination includes five views: the right and left chest tube site view (Figure 10), the right and left pericardial site view 9,15 (Figure 11) and the diaphragmatico-hepatic view (Figure 1). The chest tube site view allows evaluation of possible pneumothorax in realtime by observing the ribs and pleuro-pulmonary interface ( Figure 12) and the 'to and fro' motion of the lung (glide sign) in realtime, a lack of which indicates pneumothorax.…”

Thoracic and Abdominal Trauma

“…18 A suspected body wall rupture can be definitively diagnosed with an ultrasound examination, and the organs displaced through the rupture may be assessed. 21 In this study, the thoracic FAST (TFAST) procedure is described with the patient placed in right lateral or sternal recumbency. 19,20 The early description of the FAST technique was for the evaluation of the abdomen and involved quickly assessing four specific areas (just caudal to the xiphoid process, just cranial to the pelvis, and over the right and left flanks caudal to the ribs at the most gravity-dependent location of the abdomen) with two views (transverse and longitudinal).…”

“…An ultrasonographic modality that is now regularly used in veterinary medicine is the focused assessment with sonography for trauma (FAST) technique. 21 There are three main views obtained: bilateral chest tube site views, pericardial site views, and a diaphragmatico-hepatic view. 19 This technique was found to be useful at detecting intraabdominal fluid, even when used by veterinarians with minimal ultrasonographic experience.…”

Use of focus assessed transthoracic echocardiography (FATE) in the veterinary emergency room

“…In veterinary medicine this type of evaluation is still being developed as a preliminary diagnosis method and initial guide for the management of patients in the emergency room (TSE et al, 2013). Patient side ultrasonography has been described in animals for identification of free fluid in the abdominal cavity (BOYSEN et al, 2004) and the presence of pneumothorax, pleural effusion and pulmonary edema (LISCIANDRO et al, 2008).…”