American Journal of Emergency Medicine xxx (2014) xxx–xxx

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American Journal of Emergency Medicine journal homepage: www.elsevier.com/locate/ajem

Correspondence

Streamlined focused assessment with sonography for mass casualty prehospital triage of blunt torso trauma patients To the Editor,

Without prompt medical attention and often expedient emergency surgery, earthquake victims having blunt torso trauma will experience increased mortality [1]. Rapid identification of necessary emergent medical vs surgical interventions is critically important. Accurate triage is a necessity, particularly with limited medical resources in the chaos after a mass casualty event. The Simple Triage

and Rapid Treatment (START) triage method [2] sorts patients into 4 colored tag categories, dependent upon respiratory rate, perfusion (presence of radial pulse and capillary refill time), and mental status (response to commands): red (critically ill patients requiring immediate medical care), yellow (patients in urgent condition, which may receive delayed medical care), green (patients having minor injuries), and black (patients deceased or expectantly soon to be deceased) (Fig. 1). The START method typically requires 3 minutes to complete per patient after an earthquake [3]. However, the

Fig. 1. Simple Triage and Rapid Treatment protocol. Based on respiratory rate, perfusion (radial pulse presence and capillary refill time), and mental status (ability to obey command), the START procedure sorts patients into 4 triage categories, which include (1) Red tag: Victim requires immediate intervention and transport. Medical attention is required within (60) minutes for survival; (2) Yellow tag: Victim’s transport may be delayed. Serious and potentially life-threatening injuries are included in this strata, but patient status is not expected to deteriorate significantly over several hours; (3) Green tag: Victim had relatively minor injuries and may be able to assist in his/her own care. A proportion will require additional secondary triage; (4) Black tag: Victim is unlikely to survive given severity of injuries, level of available care, or both. Palliative care and pain relief should be provided. 0735-6757/© 2014 Elsevier Inc. All rights reserved.

Please cite this article as: Hu H, et al, Streamlined focused assessment with sonography for mass casualty prehospital triage of blunt torso trauma patients, Am J Emerg Med (2014), http://dx.doi.org/10.1016/j.ajem.2014.03.014

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Correspondence / American Journal of Emergency Medicine xxx (2014) xxx–xxx

accuracy of START has been estimated to be 81.6% to 84.2% for blunt torso trauma patients [4], leaving significant improvement to be desired. The injury severity score ([ISS], based upon the abbreviated injury scale, 1990) is an established, internationally adopted method for assessing the extent of patient injuries. However, due to its complexity, ISS is unfeasible and unrealistic to be used on-site [5]. In recent years, the Focused Assessment with Sonography for Trauma (FAST) examination has been a widely publicized, accurate, and swift patient evaluation (Fig. 2) assessing patient volume status, detecting abdominal free fluid, pericardium effusion, intrathoracic fluid, and pneumothorax. [6] Execution of the FAST scan theoretically requires 2 to 3 minutes [3], although real-world practice takes longer (N5 minutes) [6].

On April 20, 2013, 11 826 people were injured in the Richter 7.0 Lushan earthquake. As the members of National Medical Rescue Team, we were dispatched to the earthquake-stricken area to give first aid to the injured patients. Using a handheld, portable ultrasound machine (VScan GE Vingmed Ultrasound AS; GE Healthcare, Horten, Norway) (Fig. 3), we used a modified, streamlined FAST scan methodology (SFAST, Fig. 2) for prehospital triage of blunt torso trauma patients [7]. Here, we report our experiences in the utilization of SFAST in the 24 hours after a natural disaster mass casualty event, with hopes of improving future triage processes. Because of the bad weather, limited helicopters, and destroyed roads, only a few of the most seriously injured patients were transported to the rescue site within the first 24 hours after earthquake hit. Hence, there were only 45 nonambulatory blunt

Fig. 2. Streamlined FAST protocol. 1) Ambulatory status is determined first. Green tag is assigned to those able to ambulate independently. 2) FAST is performed. Any positive finding in any quadrant of the FAST obviates the need for completion of scan. A positive FAST assigns red tag status to the patient (suggestive of low volume status, abdominal free fluid, pericardium effusion, intrathoracic fluid, or pneumothorax). Focused Assessment with Sonography for Trauma negative patients were assigned yellow tag status.

Please cite this article as: Hu H, et al, Streamlined focused assessment with sonography for mass casualty prehospital triage of blunt torso trauma patients, Am J Emerg Med (2014), http://dx.doi.org/10.1016/j.ajem.2014.03.014

Correspondence / American Journal of Emergency Medicine xxx (2014) xxx–xxx

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Fig. 3. Technology used. In the aftermath of the Lushan earthquake, patients subjected to blunt abdominal trauma were scanned in the field via handheld portable ultrasound equipment (GE Healthcare). This machine had 2 components: a 5-MHz phase array probe and a 3.5-inch clamshell screen, akin to a flip cellular phone.

torso trauma cases included in our report. Traumatic brain injury cases or ambulatory cases were excluded. Each patient was triaged by both START and SFAST methods. Demographics, medical records, and the need for emergent surgery were recorded for each patient. With the goal of SFAST to differentiate between red and yellow tags of the START triage scenario, the green tag patients were excluded in our experiences. After determining ambulatory status (patients able to walk independently were assigned green tag status), the SFAST decision tree addressed used standard FAST to stratify all remaining patients. Patients were assigned red tag status if their FAST result indicated low volume status, abdominal free fluid, pericardium effusion, intrathoracic fluid, or pneumothorax. Yellow tag status was assigned to all remaining patients. Simple Triage and Rapid Treatment and SFAST were compared against each other in terms of assigned triage level compared with ISS standards and elapsed triage time. An ISS score equal to or exceeding 15 indicates a critical patient and should be assigned red flag status [4]. Triage accuracy rate, sensitivity, specificity, negative predictive values (NPV), and positive predictive values (PPV) for all patients assigned red or yellow tag status by either triage method were determined. Elapsed triage time was defined as the duration required for completion of each triage method [4] and were compared by the nonparametric Wilcoxon signed rank test. Statistical calculations were performed by SPSS Statistics version 17.0 (SPSS, Chicago, IL); P b .05 was considered to be significant. Of the 45 patients, 10 endured thoracoabdominal injuries, 29 endured abdominal traumas, and 9 had chest trauma. The male-tofemale patient ratio was 2:1 (30 males:15 females). The mean patient age was 43.5 ± 19.9 years. All 45 patients ultimately survived, and no patients were assigned an expectant black tag. Focused Assessment with Sonography for Trauma identified 22 patients (48.9%) with positive findings. Complete details concerning triage tag status assignment by START and SFAST are shown in Table 1. Table 1 Triage tag assignment by START vs SFAST ISS

Required emergent surgery

Against the benchmark, ISS score equal to or exceeding 15, the triage accuracy rate, sensitivity, specificity, PPV, and NPV of START were respectively 80.0%, 77.3%, 82.6%, 81.0%, and 79.2%. These same parameters of SFAST were 91.1%, 90.9%, 91.3%, 90.3%, and 91.9%, respectively (Table 2). The κ coefficient between START and ISS was 0.599 (P = .00). And that between SFAST and ISS was 0.822 (P = .00). Based on determining whether a patient required emergent surgery, the diagnostic accuracy rate, sensitivity, specificity, PPV, and NPV of START were respectively 55.6%, 51.9%, 61.1%, 66.7%, and 45.8%. These same parameters of SFAST were 62.2%, 59.3%, 66.7%, 72.7%, and 52.2%, respectively (Table 3). Median elapsed triage time of the START triage group was 2.3 minutes (range 0.5-4.0) and 2.9 minutes (range 1.4-4.7) in the SFAST group and were statistically different (P = .01). We demonstrate that FAST can be used to accurately evaluate blunt torso trauma after a mass casualty earthquake disaster. Multiple studies have reported FAST accuracy in blunt torso trauma patients ranging from 85% to 98% [8-10]. With technological advances, portable ultrasound has been used to perform FAST in the field, particularly the Haiti earthquake [11,12]. A study of the Wenchuan earthquake reported that ultrasound was an accurate triage tool assessing abdominal injuries (sensitivity 91.9%, specificity 96.9%) [13]. Real-time performance of FAST has been documented to take 5 to 8 minutes [6], which limits its advantage over START, the current international triage standard. Limitations: As with any ultrasound evaluation, SFAST is highly operator-dependent and requires training for mastery. It also has low sensitivity for identifying traumatic brain injury and detecting retroperitoneal injuries [14]. Moreover, the examiners, who made the SFAST, had access to vital information that was used for the standard triage, which might also affect the judgment. As a result, more works warrant to be done in our future studies to remedy these limitations. In our experiences, our hybrid methodology SFAST greatly reduced standalone FAST elapsed triage time. Our median elapsed triage time (2.9 minutes) meets the triage expectation of 3 total minutes postearthquake disaster. Although in our results, median triage SFAST time exceeded START by 0.6 minutes, the sensitivity and specificity of SFAST markedly exceeded START. The immense benefits

Red by ISS Yellow by ISS Red by ISS Yellow by ISS START Red by Yellow Total SFAST Red by Yellow Total

START 17 by START 5 22 SFAST 20 by SFAST 2 22

4 19 23 2 21 23

14 13 27 16 11 27

7 11 18 6 12 18

No patients in this study were assigned or met ISS criteria for black tag.

Table 2 Statistical comparison of START and SFAST against benchmark standard ISS scale

START SFAST

Accuracy rate (%)

Sensitivity (%)

Specificity (%)

PPV (%)

NPV (%)

80.0 91.1

77.3 90.9

82.6 91.3

81.0 90.9

79.2 91.3

Please cite this article as: Hu H, et al, Streamlined focused assessment with sonography for mass casualty prehospital triage of blunt torso trauma patients, Am J Emerg Med (2014), http://dx.doi.org/10.1016/j.ajem.2014.03.014

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Correspondence / American Journal of Emergency Medicine xxx (2014) xxx–xxx

Table 3 Statistical comparison of START and SFAST in determining whether patient needed emergent surgery

START SFAST

Accuracy rate (%)

Sensitivity (%)

Specificity (%)

PPV (%)

NPV (%)

55.6 62.2

51.9 59.3

61.1 66.7

66.7 72.7

45.8 52.2

of timely medical treatment of blunt torso trauma patients in a disaster scenario cannot be overemphasized. Streamlined FAST may increase triage accuracy of blunt torso trauma patients in mass casualty incidents with limited medical resources. We recommend the use of SFAST to decrease patient triage to treatment time in any unfortunate future disasters. Hai Hu, MD 1 Yarong He, MD Shu Zhang, MD Yu Cao, MD Emergency Department, West China Hospital, Sichuan University Chengdu 610041, PR China E-mail address: [email protected] 1

The Chinese National Emergency Rescue Team member.

http://dx.doi.org/10.1016/j.ajem.2014.03.014

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Please cite this article as: Hu H, et al, Streamlined focused assessment with sonography for mass casualty prehospital triage of blunt torso trauma patients, Am J Emerg Med (2014), http://dx.doi.org/10.1016/j.ajem.2014.03.014

Streamlined focused assessment with sonography for mass casualty prehospital triage of blunt torso trauma patients.

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