The FAST D protocol: a simple method to rule out traumatic vascular injuries of the lower extremities

Abstract

BackgroundThe aim of this study is to assess the accuracy of a Fast Doppler protocol for the examination of an injured lower limb, namely 2-Point Fast Doppler (2PFD), in order to rapidly triage arterial lesions after penetrating trauma.MethodsThe presence of flow and the aspects of the Doppler waveform of the dorsalis pedis artery (DPA) and posterior tibial artery (PTA) of the injured lower limb (2PFD) were evaluated immediately before the execution of a standardized Color Duplex Doppler (SD) evaluation in 149 limbs of 140 patients with gunshot penetrating injuries. We considered 2PFD normal exams as the ones with triphasic patterns in both the DPA and PTA, and 2PFD pathologic exams as the ones with absent, biphasic, or monophasic flow patterns in the DPA and/or PTA. 2PFD data were then analyzed to assess accuracy variables, using SD results as matching test reference. According to the trauma center standard protocols, SD positive cases underwent also angiography and surgical exploration, whose findings were used to further match the 2PFD specificity.ResultsThe 2PFD protocol showed a sensitivity of 100%, and a specificity of 100% compared with the SD, in the diagnostic workup of arterial injuries of the lower limbs after penetrating trauma. Furthermore, all the pathologic cases that resulted in all true positives (TP), compared with SD, were confirmed as TP also when matched with the angiography evaluation results.ConclusionsThe 2PFD protocol can rapidly identify arterial flow and differentiate between normal and pathologic spectral Doppler analyses in distal arteries. The presence of the normal triphasic flows in DPA and PTA is as sensitive as the standardized Color Doppler Duplex assessment of the entire limb in ruling out arterial lesions in lower-limb penetrating trauma. The absence of flow or the presence of a biphasic or monophasic pathologic flow in DPA and PTA is pathologic and should be always followed by further investigation. 2PFD is faster and easier to perform compared with the SD approach. It could become a new first-line screening technique, both in pre-hospital and hospital critical scenarios, particularly in contexts where advanced diagnostic performance is limited by time concerns or scarce resources.

Overutilization of Cross-Sectional Imaging in the Lower Extremity Trauma Setting

“…10 Furthermore, the trauma population is young and we can save this patient group from the potential negative effects of radiation exposure at an early age. 11 Therefore, Montorfano et al 12 have explored options to spare patients from excessive radiation exposure by using duplex ultrasound in the same form as a FAST protocol for diagnosis of traumatic LEVIs. 12 The limitations of our retrospective study are twofold.…”

“…11 Therefore, Montorfano et al 12 have explored options to spare patients from excessive radiation exposure by using duplex ultrasound in the same form as a FAST protocol for diagnosis of traumatic LEVIs. 12 The limitations of our retrospective study are twofold. First, we have a small sample size that precludes generalization of our findings to all level I trauma centers, and second, there is a relative delay in the evaluation of patients with LEVI from the vascular surgery service standpoint, since this subspecialty is not in-house during overnight call.…”

Penetrating Extremity Trauma Endovascular versus Open Repair?

“…21 In a recent study by Montorfano et al, the authors assessed the accuracy of 2-point fast Doppler (2PFD) in triaging 149 limbs of 140 patients with gunshot penetrating injuries. 22 The 2PFD was considered normal when triphasic patterns were present in both the dorsalis pedis artery and posterior tibialis artery, and pathologic when absent, biphasic, or monophasic flow patterns in the dorsalis pedis artery and/or posterior tibialis artery were noted. The 2PFD data were compared with the standard Doppler while matching test reference.…”

New Perspectives for Modern Trauma Management – Lessons Learned from 25 Years FAST and 15 Years E-FAST

“…Of course, PoCUS can also be used in the secondary ATLS survey. For example, colleagues in Argentina suggested a simple two-point Doppler method to rule out vascular injury in patients with gunshot wounds to the lower extremities [60].…”