Prehospital FAST reduces time to admission and operative treatment: a prospective, randomized, multicenter trial

Abstract

Background: The focused assessment with sonography in trauma (FAST) exam is an established trauma care diagnostic procedure. Ultrasound performed during prehospital care can improve early treatment and management of the patients. In this prospective randomized clinical trial, we wanted to assess whether a pre-hospital FAST (p-FAST) influences pre-hospital strategy and the time to operative treatment.

Methods: We studied 296 trauma victims in a prehospital setting. Inclusion criteria were potential abdominal injuries identified either by clinical examination or suggested by the mechanism of injury. Physician-staffed helicopters and emergency ambulances were equipped with portable ultrasound devices. According to a scheme related to calendar weeks, a clinical exam only (CEX) or a clinical exam together with a p-FAST (CEX-p-FAST) was conducted. Outcome variables were prehospital diagnosis and strategy, the time to admission to the trauma room and to operation theater. The study was approved by the university ethical committee (REB#: 46/06).

Results: CEX-p-FAST showed a high sensitivity (94.7%) and specificity (97.6%) in detection of free fluid compared to CEX-only (80.0%, 84.4%). The median time to admission was reduced significantly by 13 min and to operative treatment by 15 min after CEX-p-FAST. We observed a cross-over rate of 30.8% of p-FAST (n = 36) to CEX-p-FAST during the CEX-only weeks.

Conclusion: According to the experience of the principal investigators, CEX-p-FAST was superior to CEX-only. Despite the time needed for p-FAST, the relevant admission time was significantly shorter. Thus, p-FAST is recommended in addition to CEX if possible for decision-making in prehospital trauma care.

Trial registration: German Clinical Trials Register #DRKS00022117-Registered 10 July 2020-Retrospectively registered, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00022117 .

Keywords: Abdominal injury; FAST; Prehospital ultrasound; Time-to-surgery; Trauma room.

Fig.1

Consort flow diagram. CONSORT flow diagram of enrollment, allocation, and analysis

Fig. 2

Time from examination to admission in trauma room. No significant difference in the time from the examination of the abdomen to admission to trauma room can be observed between the CEX (median 33 min; IQR 16 min) and CEX-p-FAST (median 30 min; IQR 20 min) groups. However, there is a significant difference between the two groups in the preclinical positive patient subset. In the p-FAST group (median 25 min; IQR 18 min), the time to admission to the trauma bay is significantly shorter than the CEX group (median 38 min; IQR 22 min; Mann–Whitney-U-Test p = 0.001; **p < 0.01)

Fig. 3

Frequency of changes in strategy. In preclinical cases suspected of abdominal injuries, changes in strategy, and treatment can be observed. In the CEX-p-FAST group, changes (i) in therapy at the scene in 47.6%, (ii) in admitting hospital in 71.4%, (iii) in communication with the admitting team in 90.48% and (vi) in management of transfer in 85.7% of the patients can be observed. In the CEX group, changes in therapy are seen in 63.4%, in admitting hospital in 68.2%, in communication with admitting team in 77.3%, and in management of transfer in 77.3% of the patients

Fig. 4

Time from prehospital exam to operative treatment. A significant decrease in time from prehospital examination to operative treatment can be observed in the CEX-p-FAST group (median 135 min; IQR 53 min) compared to the CEX group (median 150 min; IQR 185 min) (Mann–Whitney-U-Test p = 0.037)