1 Introduction
Blunt traumatic aortic injury (BTAI) is one of the fatal traumatic injuries of the chest. In the 1990s, prehospital mortality of emergency patients with BTAI reached 75%, and about one half of these patients alive at hospital arrival died within the following 24 hours.[1,2] [3] [4]
A number of previous studies revealed the usefulness of enhanced computed tomography (CT) scanning for the diagnosis of BTAI,[5–9] [10]
The Japanese Trauma Data Bank (JTDB) is a nationwide trauma registry in Japan that is managed by The Japanese Association for the Surgery of Trauma. Data registration in the JTDB was launched in 2003 and approximately 230,000 emergency patients with trauma were enrolled by 2015. The aim of this study was to assess the relationship between the timing of CT scanning and the prognosis of BTAI patients using this database.
2 Methods
2.1 Study design, population, and setting
This study was a retrospective observation using the JTDB database. The study period spanned 12 years from January 2004 to December 2015. We included emergency patients who had a BTAI in the chest and/or the abdomen among those who were transported to the JTDB-participating hospitals and were registered in the database. We excluded those who were in cardiopulmonary arrest on hospital arrival, received inter-hospital transport, had no records on the time interval from hospital arrival to CT scanning, had penetrating trauma, or had an inappropriate dataset. We extracted BTAI patients based on the following Abbreviated Injury Scale (AIS) codes: 420299.4, 420292.4, 420204.5, 420206.4, 420208.4, 420210.5, 420212.5, 420216.5, 420218.6, 520299.4, 520202.4, 520204.4, 520206.4, and 520208.5. To assess the relationship between the timing of CT scanning and prognosis in the BTAI patients, we also excluded patients in whom the first elective CT scanning was performed ≥72 hours after hospital arrival. This study was approved by the ethics committee of Osaka University Graduate school of Medicine. Personal identifiers were removed beforehand from the JTDB database, and the patients’ right to informed consent was waived.
2.2 Japanese Trauma Data Bank
The JTDB was launched in 2003 by the Japanese Association for the Surgery of Trauma (Trauma Surgery Committee) and the Japanese Association for Acute Medicine (Committee for Clinical Care Evaluation),[11,12] [13] [12] [13]
The JTDB captures trauma patients with data on age, gender, mechanism of injury, AIS code (version 1998), Injury Severity Score (ISS), Revised Trauma Score (RTS), vital signs on hospital arrival, date and time series from hospital arrival to discharge, medical treatment such as interventional radiology, surgical operation, and CT scanning, complications, and survival at discharge.[14]
From the JTDB database, we extracted age, gender, time of day and day of the week of hospital admission, maximum AIS score for each site, ISS, and severe complications such as prolonged shock and acute renal failure in accordance with regular forms with coding items. This study defined daytime as 09:00 to 17:59 and nighttime as 18:00 to 08:59 and also defined shock as a systolic blood pressure below 90 mm Hg on hospital arrival.[15]
2.3 Endpoints
The primary endpoint was death in the emergency department (ED), and the secondary endpoint was discharge to death.
2.4 Statistical analysis
Patient characteristics in the 3 groups were assessed by chi-square test for categorical variables and analysis of variance for continuous variables. To evaluate the factors associated with death in the ED, we calculated the adjusted odds ratio (AOR) and its 95% confidential interval (CI) with use of a multivariable logistic regression model. The potential factors were age, gender, falling from a high place, pedestrian injured by traffic accident, calendar year, time of the day (daytime/nighttime), day of the week (weekday/weekend and holiday), shock at hospital arrival, RTS, ISS, case volume (upper/middle/lower), and the timing of CT scanning (early/middle/late in the manner of tertile). It was previously reported that the prognosis of trauma patients and emergency patients at night-time or weekends was worse than that at daytime or weekdays,[16,17] timing of CT scanning by shock status. All tests were 2-tailed, and a P value of <.05 was considered statistically significant. Statistical analysis was performed by SPSS version 22.0J (IBM Corp., Armonk, NY). This manuscript was written based on the STROBE statement to assess the reporting of cohort and cross sectional studies.[18]
3 Results
Figure 1 shows the patient flow in this study. During the study period, 226,298 emergency patients were registered in the JTDB. Of them, 1541 patients suffered BTAI in the chest and/or the abdomen. After excluding 1120 patients for the reasons shown in Figure 1 , a total of 421 patients were eligible for our analysis. We divided these patients into tertile groups according to the time interval from hospital arrival to first CT scanning: early group (≤26 minutes, n = 142), middle group (27–40 minutes, n = 135), and late group (≥41 minutes, n = 144).
Figure 1: Chart of patient flow in this study.
Table 1 shows the characteristics of the BTAI patients by tertile group according to the timing of CT scanning. There were no statistically significant differences in any of the variables between these groups. Mean age was 60 years, and the proportion of male sex was 73.2%. The proportion of patients with shock at hospital arrival was 32.5%, and the median ISS was 34. The overall proportion of open surgery in chest and/or abdomen was 19.5% (82/421). The proportions of patients with the complications of prolonged shock and acute renal failure were 4.5% and 3.6%, respectively. The median time interval from ambulance call to hospital arrival was 38 minutes.
Table 1: Patient characteristics among patients with blunt traumatic aortic injury by the timing of CT scanning.
Table 2 shows the factors associated with the death of BTAI patients in the ED by a multivariable logistic regression model. Nighttime (AOR: 2.409, 95% CI: 1.035–5.604), RTS (AOR for increment of one score: 0.681, 95% CI: 0.535–0.866), ISS (AOR for increment of one score: 1.054, 95% CI: 1.029–1.079), and later timing of CT scanning (AOR: 2.864, 95% CI: 1.017–8.064) were associated with the death of BTAI patients in the ED. The increment of one category in the timing of CT scanning was also associated with the death of BTAI patients in the ED (AOR: 1.663, 95% CI: 1.012–2.732). As for the secondary endpoint shown in Table 3 , compared with the early group, the late group tended to have a higher rate of discharge to death (AOR: 1.438, 95% CI: 0.735–2.813). The AOR for increment of one category in the timing of CT scanning was 1.207 (95% CI: 0.862–1.690).
Table 2: Factors associated with death in the ED among patients with blunt traumatic aortic injury.
Table 3: Timing of CT scanning and death to discharge among patients with blunt traumatic aortic injury.
Death in the ED of the BTAI patients with or without shock by the timing of CT scanning is shown in Table 4 . In the patients with shock, the AOR was 3.292 (95% CI: 0.495–21.902) in the middle group and 6.039 (95% CI: 0.990–36.837) in the late group compared with the early group. The AOR for the increment of one category in the timing of CT scanning was 2.294 (95% CI: 1.018–5.170). The patients without shock also showed similar results, and there was no significant interaction of death in the ED between the timing of CT scanning and shock status.
Table 4: Timing of CT scanning and death in the ED with or without shock among patients with blunt traumatic aortic injury.
4 Discussion
From the analysis of a nationwide trauma registry in Japan, this study revealed that later timing of the first CT scanning was associated with a higher incidence of death in the ED and at hospital discharge among emergency BTAI patients. In addition, these results were similar irrespective of shock status. Although the EAST guidelines recommend conducting enhanced CT scanning for BTAI patients, the influence of the timing of first CT scanning on the prognosis of BTAI patients was not sufficiently assessed. The JTDB nationwide large-scale trauma registry enabled us to assess the relationship between the timing of CT scanning and the prognosis of BTAI patients, and our findings suggest that quicker CT scanning would lead to earlier intervention with advanced procedures and improvement of the prognosis of these patients.
The time interval from hospital arrival to diagnosis and definitive treatment of trauma patients influences their prognosis. Clarke et al in the United States demonstrated that among hypotensive trauma patients at ED arrival or those with severe abdominal aortic injuries requiring emergency operation, the probability of death increased with the increasing length of time spent in the ED.[19] [20] [5]
Based on the severity of vascular injury, BTAI was classified into grade 1, intimal tear; grade 2, intramural hematoma; grade 3, aortic pseudoaneurysm; and grade 4, free rupture.[21] [21–27] [28] [29] [3] [10]
Although this study divided BTAI patients into those with and without shock and assessed the relationship between the timing of first CT scanning and patient prognosis, the prognosis of BTAI patients tended to worsen irrespective of shock status when the first CT scanning was delayed. Among BTAI patients with shock, delayed CT scanning could lead to delayed open repair or EVAR and subsequent worse prognosis. In contrast, BTAI patients without shock might have poor outcome due to concomitant injuries such as severe brain injury, but the definitive reason remains unclear in this study. For example, Rabin et al reported that severe patients with BTAI of grade 3 and pseudocoarctation, mediastinal hematoma, and large left hemothorax should be urgently repaired.[23]
In this registry, the time interval between hospital arrival and first CT scanning in the early group was ≤26 minutes and that in the late group was ≥41 minutes. In the REACT-2 study assessing the effect of total-body CT scanning compared with the standard work-up on in-hospital mortality among trauma patients, the time interval between arrival in the trauma room and completion of CT scanning was about 30 minutes for whole-body CT and 37 minutes for the standard work-up.[30] [20] [31,32]
Recently, several studies revealed that routine CT scanning improved the mortality of trauma patients.[33–35] [36] [37] [38]
4.1 Limitations
There are several limitations in this study. First, although we analyzed the JTDB database in which major critical care centers in Japan participated, there were some sorts of selection biases because exhaustive research was not performed. Second, although we assessed the time interval from hospital arrival to first CT scanning, we did not obtain information on whether enhanced CT scanning was performed for BTAI patients. Third, we did not obtain detailed information on surgical operation such as aortic repair with artificial vessel as well as medication such as inotropes, and data on the implementation of EVAR and subsequent complications of BTAI or EVAR such as stroke and paraplegia are not also included in the JTDB database. Fourth, although the grade of BTAI and the time to definite care were important confounding factors associated with the prognosis of BTAI, we did not obtain information on the BTAI grade and did not incorporate the time in our analysis model because of the insufficient number. Last, as this was retrospective observational study, there might be some unmeasured confounding factors that affected our results. Considering these limitations, our findings showing the effectiveness of early CT scanning for BTAI patients should also be confirmed in other large-scale cohorts.
5 Conclusions
We showed in a retrospective review of a nationwide hospital-based trauma registry in Japan that the prognosis of BTAI patients in the ED worsened as the time to first CT scanning was delayed.
5.1 Ethics approval and consent to participate
This study was approved by the ethics committees of the Osaka Graduate School of Medicine (No. 16260), and the requirement to obtain patients’ consent to participate was waived because the data were anonymous.
5.2 Consent for publication
Not applicable
5.3 Availability of data and material
The data that support the findings of this study are available from the JTDB, but the availability of these data is restricted.
Acknowledgments
The authors thank the emergency medical service personnel, nurses, and emergency physicians who participated in the JTDB.
Author contributions
YK analyzed the data and wrote the first draft of this manuscript. JS and KK did data-cleaning and supported to analyze the data. TK reviewed all statistical analyses and critically revised this manuscript. TH, TK, TM, JI, JT, TE, and YN interpreted the data and critically revised this manuscript. TS supervised the interpretation of data and critically revised this manuscript. All the authors read and approved the final manuscript.
Conceptualization: Yusuke Katayama, Tomoya Hirose.
Data curation: Yusuke Katayama, Tasuku Matsuyama, Junya Sado, Kosuke Kiyohara.
Formal analysis: Yusuke Katayama, Junya Sado, Kosuke Kiyohara.
Funding acquisition: Takeshi Shimazu.
Methodology: Yusuke Katayama, Takeyuki Kiguchi, Jotaro Tachino, Takeshi Ebihara.
Project administration: Yusuke Katayama.
Resources: Yuko Nakagawa.
Software: Yusuke Katayama, Kazuhisa Yoshiya.
Supervision: Yusuke Katayama, Tetsuhisa Kitamura.
Validation: Yusuke Katayama, Tasuku Matsuyama, Jinichi Izawa.
Visualization: Jinichi Izawa.
Writing – original draft: Yusuke Katayama.
Writing – review & editing: Tetsuhisa Kitamura.
References
[1]. Fabian TC, Richardson JD, Croce MA, et al. Prospective study of blunt aortic injury: Multicenter Trial of the American Association for the Surgery of Trauma. J Trauma 1997;42:374–80. discussion: 380–383.
[2]. Jamieson WR, Janusz MT, Gudas VM, et al. Traumatic rupture of the thoracic aorta: third decade of experience. Am J Surg 2002;183:571–5.
[3]. Estrera AL, Gochnour DC, Azizzadeh A, et al. Progress in the treatment of blunt traumatic aortic injury: 12-year single-institution experience. Ann Thorac Surg 2010;90:64–71.
[4]. Parmley LF, Mattingly TW, Manion TW, et al. Nonpenetrating traumatic injury of the aorta. Circulation 1958;17:1086–101.
[5]. Fabian TC, Davis KA, Gavant ML, et al. Prospective study of blunt aortic injury: helical CT is diagnostic and antihypertensive therapy reduces rupture. Ann Surg 1998;227:666–76.
[6]. Melton SM, Kerby JD, McGiffin D, et al. The evolution of chest computed tomography for the definitive diagnosis of blunt aortic injury: a single-center experience. J Trauma 2004;56:243–50.
[7]. Parker MS, Matheson TL, Rao AV, et al. Making the transition: the role of helical CT in the evaluation of potentially acute thoracic aortic injuries. AJR Am J Roentgenol 2001;176:1267–72.
[8]. Dyer DS, Moore EE, Ilke DN, et al. Thoracic aortic injury: how predictive is mechanism and is chest computed tomography a reliable screening tool? A prospective study of 1,561 patients. J Trauma 2000;48:673–82.
[9]. Bruckner BA, DiBardino DJ, Cumbie TC, et al. Critical evaluation of chest computed tomography scans for blunt descending thoracic aortic injury. Ann Thorac Sur 2006;81:1339–46.
[10]. Fox N, Schwartz D, Salazar JH, et al. Evaluation and management of blunt traumatic aortic injury: a practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg 2015;78:136–46.
[11]. Yumoto T, Mitsuhashi T, Yamakawa Y, et al. Impact of Cushing's sign in the prehospital setting on predicting the need for immediate neurosurgical intervention in trauma patients: a nationwide retrospective observational study. Scand J Trauma Resusc Emerg Med 2016;24:147.
[12]. Japan Trauma Care and Research. Japan Trauma Data Bank Annual Report 2011–2015.
https://www.jtcr-jatec.org/traumabank/dataroom/data/JTDB2016.pdf . [Accessed August 21, 2017].
[13]. Shoko T, Shiraishi A, Kaji M, et al. Effect of pre-existing medical conditions on in-hospital mortality: analysis of 20,257 trauma patients in Japan. J Am Coll Surg 2010;211:338–46.
[14]. Nakada TA, Nakao S, Mizushima Y, et al. Association between male sex and increased mortality after falls. Acad Emerg Med 2015;22:708–13.
[15]. Sasser SM, Hunt RC, Faul M, et al. Guidelines for field triage of injured patients: recommendations of the National Expert Panel on Field Triage, 2011. MMWR Recomm Rep 2012;61:1–20.
[16]. Stefano DB, Massimiliano M, Chiara V, et al. A population based study on the night-time effect in trauma care. Emerg Med J 2014;31:808–12.
[17]. Walker AS, Mason A, Quan TP, et al. Mortality risks associated with emergency admissions during weekends and public holidays: an analysis of electronic health records. Lancet 2017;390:62–72.
[18]. Von Elm E, Altman DG, Egger M, et al. STROBE Initiative: The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol 2008;61:344–9.
[19]. Clarke JR, Trooskin SZ, Doshi PJ, et al. Time to laparotomy for intra-abdominal bleeding from trauma does affect survival for delays up to 90 minutes. J Trauma 2002;52:420–5.
[20]. Bernhard M, Becker TK, Nowe T, et al. Introduction of a treatment algorithm can improve the early management of emergency patients in the resuscitation room. Resuscitation 2007;73:362–73.
[21]. Azizzadeh A, Keyhani K, Miller CC 3rd, et al. Blunt traumatic aortic injury: initial experience with endovascular repair. J Vasc Surg 2009;49:1403–8.
[22]. Chen SW, Wang SY, Liao CH, et al.
Timing of intervention in blunt traumatic aortic injury patients: open surgical versus endovascular repair. Ann Vasc Surg 2015;29:1559–66.
[23]. Rabin J, DuBose J, Sliker CW, et al. Parameters for successful nonoperative management of traumatic aortic injury. J Thorac Cardiovasc Surg 2014;147:143–9.
[24]. Spencer SM, Safcsak K, Smith CP, et al. Nonoperative management rather than endovascular repair may be safe for grade II blunt traumatic aortic injuries: an 11-year retrospective analysis. J Trauma Acute Care Surg 2018;84:133–8.
[25]. Osgood MJ, Heck JM, Rellinger EJ, et al. Natural history of grade I-II blunt traumatic aortic injury. J Vasc Surg 2014;59:334–41.
[26]. Rousseau H, Elaassar O, Marcheix B, et al. The role of stent-grafts in the management of aortic trauma. Cardiovasc Intervent Radiol 2012;35:2–14.
[27]. Durham CA, McNally MM, Parker FM, et al. A contemporary rural trauma center experience in blunt traumatic aortic injury. J Vasc Surg 2010;52:884–9. discussion 889–90.
[28]. Lee WA, Matsumura JS, Mitchell RS, et al. Endovascular repair of traumatic thoracic aortic injury: clinical practice guidelines of the Society for Vascular Surgery. J Vasc Surg 2011;53:187–92.
[29]. Di Eusanio M, Folesani G, Berretta P, et al. Delayed management of blunt traumatic aortic injury: open surgical versus endovascular repair. Ann Thorac Surg 2013;95:1591–7.
[30]. Sierink JC, Treskes K, Edwards MJ, et al. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial. Lancet 2016;388:673–83.
[31]. Wada D, Nakamori Y, Yamakawa K, et al. Impact on survival of whole-body computed tomography before emergency bleeding control in patients with severe blunt trauma. Crit Care 2013;17:R178.
[32]. Kinoshita T, Yamakawa K, Matsuda H, et al. The survival benefit of a novel trauma workflow that includes immediate whole-body computed tomography, surgery and interventional radiology, all in one trauma resuscitation room: a retrospective historical control study. Ann Surg 2017;doi: 10.1097/SLA.0000000000002527. (in press).
[33]. Huber-Wagner S, Lefering R, Qvick LM, et al. Effect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study. Lancet 2009;373:1455–61.
[34]. Wurmb TE, Frühwald P, Hopfner W, et al. Whole-body multislice computed tomography as the first line diagnostic tool in patients with multiple injuries: the focus on time. J Trauma 2009;66:658–65.
[35]. Hutter M, Woltmann A, Hierholzer C, et al. Association between a single-pass whole-body computed tomography policy and survival after blunt major trauma: a retrospective cohort study. Scand J Trauma Resusc Emerg Med 2011;19:73.
[36]. Meltzer JA, Stone ME, Reddy SH, et al. Association of whole-body computed tomography with mortality risk in children with blunt trauma. JAMA Pediatrics 2018;doi: 10.1001/jamapediatrics.2018.0109. (in press).
[37]. Holscher CM, Faulk LW, Moore EE, et al. Chest computed tomography imaging for blunt pediatric trauma: not worth the radiation risk. J Surg Res 2013;184:352–7.
[38]. Gupta M, Schriger DL, Hiatt JR, et al. Selective use of computed tomography compared with routine whole body imaging in patients with blunt trauma. Ann Emerg Med 2011;58:407–16.
