Ultrasound in Med. & Biol., Vol. -, No. -, pp. 1–7, 2014 Copyright Ó 2014 World Federation for Ultrasound in Medicine & Biology Printed in the USA. All rights reserved 0301-5629/$ - see front matter
http://dx.doi.org/10.1016/j.ultrasmedbio.2014.01.017
d
Original Contribution COMPARISON OF THE ACCURACY AND REPRODUCIBILITY OF FOCUSED ABDOMINAL SONOGRAPHY FOR TRAUMA PERFORMED BY EMERGENCY MEDICINE AND RADIOLOGY RESIDENTS ALI ARHAMI DOLATABADI,* AFSHIN AMINI,* HAMIDREZA HATAMABADI,y PARISA MOHAMMADI,z SARA FAGHIHI-KASHANI,x HOJJAT DERAKHSHANFAR,* SEYED MORTEZA TABATABAEE,x MEHRDAD MOGHIMI,k and ALI KABIR{# * Imam Hossein Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; y Safety Promotion & Injury Prevention Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; z Haft-e-Tir Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; x Department of Internal Medicine, Tehran University of Medical Sciences, Tehran, Iran; k Department of Surgery, Shahid Beheshti University of Medical Sciences, Tehran, Iran; { Department of Epidemiology, Faculty of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran; and # Gastrointestinal and Liver Disease Research Center, Iran University of Medical Sciences, Tehran, Iran (Received 11 May 2013; revised 13 January 2014; in final form 17 January 2014)
Abstract—We compared the diagnostic accuracy of emergency medicine residents (EMRs) and radiology residents (RRs) in performing focused abdominal sonography for trauma (FAST). The cohort in this prospective study comprised 200 unstable patients (163 males and 37 females; mean ± standard deviation of age, 34.3 ± 16.4 y) who presented with trauma. These patients were evaluated using FAST, first by EMRs and subsequently by RRs. Patients with positive FAST results underwent further diagnostic procedures such as computed tomography, diagnostic peritoneal lavage and laparotomy. Those with negative FAST results underwent clinical follow-up for 72 h until their condition deteriorated or they were discharged. Sensitivity, specificity, positive and negative predictive values and accuracy in evaluating free intraperitoneal fluid were 80%, 95%, 57%, 98% and 94% when FAST was performed by EMRs and 86%, 95%, 59%, 98% and 94% when FAST was performed by RRs. The level of agreement between EMRs and RRs was moderate (k 5 0.525). FAST is a useful screening tool for initial assessment of free abdominal fluid in patients with trauma. Our results indicate that EMRs can perform sonography on trauma patients as successfully as RRs. (E-mail: [email protected]) Ó 2014 World Federation for Ultrasound in Medicine & Biology. Key Words: Abdominal injuries, Ultrasonography, Computed tomography, Emergency medicine, Radiology.
INTRODUCTION
(1994). FAST is a non-invasive, readily available, timesaving procedure that is useful in detecting pericardial or intraperitoneal free fluid in trauma patients. It is a complement to primary or secondary survey assessment in hemodynamically unstable patients (Bode et al. 1999; Healey et al. 1996; Ma et al. 1995). There is growing evidence that using FAST in primary trauma workup improves diagnosis (Melniker et al. 2006; Ollerton et al. 2006). Although radiologists are educated and trained to perform ultrasound scans, emergency physicians and trauma surgeons use FAST to evaluate trauma patients in emergency departments (Viscomi et al. 1980). In teaching hospitals, emergency medicine residents (EMRs) are the first to meet trauma patients and are responsible for primary evaluations. Therefore, EMRs
After head and chest injuries, abdominal injuries are the third leading cause of death in trauma cases (Tsui et al. 2008). Abdominal injury, when recognized, can be a preventable cause of death. Abdominal involvement in trauma cases is still very difficult to diagnose and poses a significant challenge to emergency medical personnel (American College of Surgeons Committee on Trauma 1997). The use of ultrasound in the evaluation of abdominal trauma has a 30-y history, but ‘‘focused abdominal sonography for trauma,’’ or FAST, was first described by Rozicky et al.
Address correspondence to: Ali Kabir, Nikan Health Researchers Institute, Unit 9, No. 1, 3rd Floor, 3rd Bahar Alley, Ashrafi Isfahani Highway, Poonak Square, Tehran, Iran. E-mail: [email protected] 1
2
Ultrasound in Medicine and Biology
can save critical time by performing FAST, as compared with radiology residents (RRs), who may not be immediately accessible in emergency settings. Although other studies have measured the diagnostic accuracy of ultrasound performed by emergency physicians and residents (Brenchley et al. 2006; Brooks et al. 2004), none have measured the difference in diagnostic accuracy between FAST performed by EMRs and FAST performed by RRs. In other published studies, the sensitivity of FAST has been reported as between 60% and 100%, and specificity, between 88% and 100% (Patel and Riherd 2011; Rozycki et al. 1995). Most studies such as ours have used computed tomography (CT), diagnostic peritoneal lavage (DPL) and clinical follow-up as the gold standard. We performed a prospective study to compare the diagnostic accuracy of FAST performed by EMRs and RRs in trauma patients admitted to the emergency department. Unlike other studies, we used the k statistic to measure the level of agreement between FAST performed by EMRs and that performed by RRs. Moreover, this study presents descriptive information about trauma cases in a region with the highest mortality from road traffic injuries worldwide (Soori et al. 2011). METHODS This prospective observational study compared results of FAST performed by EMRs and RRs in trauma patients. We enrolled all patients who met the study’s eligible criteria. Trauma patients admitted with red tag triage to the emergency department of Imam Hossein Hospital, an inner-city teaching hospital in Tehran, the capital of Iran, between May 2009 and May 2010 were included in this study. All patients were in the cardiopulmonary resuscitation room in unstable condition. Unstable condition is defined as a systolic blood pressure ,100 mm Hg accompanied by a heart rate $100 beats/ min with clinical evidence of shock, such as cold, dry skin and pallor. The sources of trauma included falls, motorcycle or motor vehicle crashes, pedestrian accidents, assaults and stab wounds. Patients arriving when the radiology staff was not present, after regular hours, were excluded from the study. Patients for whom there was an urgent need for laparotomy or other procedures were excluded. The study design was approved by the institutional review board of Tehran University of Medical Science. Written informed consent was obtained from the person legally responsible for patients unable to sign. Trauma patients underwent primary assessment in the cardiopulmonary resuscitation room by an emergency physician who was not part of the research staff. A decision on whether to proceed immediately to the operating room was made by the attending surgeon. After a primary
Volume -, Number -, 2014
survey, all traumatic patients underwent FAST first by an EMR within 15 min of admission. Thereafter, RRs performed FAST using the same ultrasound machine (HS2000, Honda, Korea) within 30 min of the FAST performed by EMRs. A low-frequency curvilinear transducer for FAST and pericardium high-frequency inner transducer for the pleural space were used. Patients’ bladders were not filled in the cases of empty bladder. Pelvic FAST was repeated in these cases. All radiology residents were blinded to the results of the previous FAST and were not aware of any other diagnostic procedures. Patients were supine during FAST. The goal of FAST in trauma patients is to detect intraperitoneal fluid. The absence of fluid in an ultrasound scan is considered negative. A positive scan is defined as the presence of fluid regardless of volume and location. To consider the results of FAST as positive, the hemoperitoneum should be visualized; the presence of fluid alone in the pleural or pericardial space did not persuade us to consider the results of FAST positive. CT scans were obtained for 193 patients. CT scans revealing spleen or liver rupture without free fluid were also considered positive. The following views were scanned in ultrasound: Morrison’s pouch, splenorenal space, retrovesical space, pleural space and pericardial space. Ten EMRs and seven RRs participated in the study. Both EMRs and RRs were completely trained and underwent full didactic and hands-on training for FAST and detection of the presence of free fluid. These training courses were part of the residents’ curriculum. EMRs were in either the second or third year of their programs; RRs were in either the first or second year. All patients, regardless of negative or positive FAST, underwent further evaluation, including CT, laparotomy, DPL and clinical follow-up. Patients with positive FAST results underwent CT if they were hemodynamically stable. CT scans were obtained by radiology attending physicians after performing FAST. CT scans are the gold standard and are the most accurate of all diagnostic procedures (Brenchley et al. 2006). The presence of free fluid, such as hemoperitoneum, or parenchymal lesions, such as liver and spleen lacerations, on a CT scan is a sign of abdominal injury and considered positive. Patients with positive FAST results who were hemodynamically unstable underwent DPL earlier in their evaluation process. Patients with positive DPL results were transferred to the operating room. DPL and laparotomy was performed by an attending surgeon or surgery residents, and the results were used as a reference criterion for hemodynamically unstable patients with positive FAST results. DPL results were considered positive if the red blood cell count was .100,000/mm3 (Fischer et al. 1978). We performed DPL for all four cases with stab wounds, even if their FAST result was negative.
Accuracy of focused abdominal sonography for trauma d A. ARHAMI DOLATABADI et al.
3
Laparotomy reports were considered positive if a macroscopic lesion on an abdominal organ or hemoperitoneum was detected. Patients with negative FAST results were monitored in the surgery ward or intensive care unit for at least 72 h. If their clinical symptoms deteriorated, they underwent CT or proceeded to the operating room. Ultrasonograms revealing small amounts of fluid in the pelvis of women of childbearing age were considered positive until CT ruled out organ damage or significant fluid. Research personnel collected each patient’s demographic data and source of traumatic injury after admission. The FAST results were collected and concealed from other members of the research staff. EMRs and RRs were unaware of the exam results. CT reports were written and confirmed by attending radiologists. Laparotomy and DPL reports were written by attending surgeon or surgery residents. Descriptive statistics are reported as the mean 6 standard deviation (SD). Test characteristics such as sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values and accuracy were calculated with SPSS Version 19 software (IBM, Armonk, NY, USA) and reported with 95% confidence intervals. The c2 test was used to determine the difference between results for the two groups. Accuracy was defined as the percentage of FAST results that were consistent with the reference criterion. The k statistic was used to represent the level of agreement between EMRs and RRs. RESULTS We prospectively enrolled all patients with trauma admitted to the emergency department of Imam Hossein Hospital over a 1-y period. Of 250 patients who met the inclusion criteria, 50 patients were excluded because of cardiac arrest in the cardiopulmonary resuscitation room or during transfer to the operating room (n 5 16), incomplete registry of surgery notes or CT report (n 5 19), laparotomy or DPL before FAST by radiology residents (n 5 12) and transfer to other hospitals (n 5 3). Two hundred patients completed the study. Of these 200 cases, 163 (81.5%) patients were male. Age ranged from 3 to 84 y (mean 6 SD: 34.3 6 16.4 y). Sources of trauma included motor vehicle crashes (56, 28%), motorcycle crashes (52, 26%), falls (43, 21.5%), pedestrian accidents (40, 20%), assaults (5, 2.5%) and stab wounds (4, 2%). Among the 200 patients who underwent FAST by EMRs, 21 had positive results (Fig. 1). Of these 21, there were 15 patients with one positive view (7 Morrison’s pouch, 4 splenorenal, 4 retrovesical space free fluid), 3 patients with two positive views (3 Morrison’s pouch
Fig. 1. Flowchart of patients with traumas referred to the emergency department of Imam Hossein Hospital between May 2009 and May 2010 and evaluated by emergency medicine residents.
and retrovesical space, 1 Morrison’s pouch and splenorenal space, 1 splenorenal and retrovesical space free fluid) and 1 patient with three positive views (Morrison’s pouch, splenorenal space and retrovesical space free fluid). Twenty-two of the FASTs performed by RRs were positive (Fig. 2). Of these 22, RRs reported 15 persons with one positive view (5 Morrison’s pouch, 6 splenorenal and 4 retrovesical space free fluid), 5 patients with two positive views (retrovesical recess and pericardial space), 1 patient with three positive views (Morrison’s pouch, retrovesical and splenorenal space free fluid) and 1 patient with five positive views. Additional procedures (laparotomy and CT) yielded 15 positive results among the 200 patients, including mesenteric tear (3 patients), small bowel perforation
4
Ultrasound in Medicine and Biology
Volume -, Number -, 2014
Table 1. Comparison of FAST results performed by emergency medicine residents and radiology residents
Sensitivity (%) Specificity (%) Positive likelihood ratio Negative likelihood ratio Positive predicted value (%) Negative predicted value (%) Accuracy (%)
EMR
RR
80 (57–100)* 95 (92–98) 16 (7.1–50) 0.21 (0–0.46) 57 (34–80) 98 (96–100) 94 (90–97)
86 (77–100) 95 (92–98) 17.2 (9.6–50) 0.04 (0–0.25) 59 (36–81) 98 (97–100) 94 (91–97)
EMR 5 emergency medicine resident; FAST 5 focused abdominal sonography for trauma; RR 5 radiology resident. * Mean (confidence interval).
EMRs and those performed by RRs (p 5 0.824). In addition, the k statistic between EMRs and RRs was 0.525. A k statistic between 0.4 and 0.75 represents intermediate reproducibility. Although female patients represented a minority in this study, with the exception of the positive predictive value, there was no difference between male and female patients in FAST results reported by EMRs (Table 2). In this group, the positive predictive value in males was higher than that in females (52 vs. 75). The results of FASTs performed by RRs were nearly equally sensitive in males and females (90 vs. 75); the positive predictive value (62 vs. 50) was higher (Table 3) in males. DISCUSSION
Fig. 2. Flowchart of patients with traumas referred to the emergency department of Imam Hossein hospital between May 2009 and May 2010 and evaluated by radiology residents.
(1 patient), hepatic laceration (7 patients) and splenic rupture (4 patients). Of the 179 negative FAST results reported by EMRs, 176 were true-negative and 3 were false-negative results. Of the 21 patients with positive FAST results, 9 had falsepositive results. The overall sensitivity, specificity and positive likelihood ratio for FAST performed by EMRs were 80%, 95% and 16, respectively. Nine of the 22 FAST results reported by RRs were false positive. Two of the 178 negative FAST results were false negative. The overall sensitivity, specificity and positive likelihood ratio for evaluating free intraperitoneal fluid in RR-performed FASTs were 86%, 95% and 17.2, respectively. Results of FASTs performed by EMRs and RRs are compared in Table 1. A c2 test revealed no significant difference between FASTs performed by
In the present study, RRs and EMRs had similar overall accuracy and equal specificity in performing FAST. However, the sensitivity of the FASTs performed by RRs was higher than that of FASTs performed by EMRs. RRs and EMRs had equal positive and negative predictive values. The level of agreement between the two groups was intermediate (Landis and Koch 1977). Disagreement between observers may be a result of factors other than practitioner errors, such as patient selection, setting and limitations of the examination (McCarter et al. 2000). Table 2. Comparison of FAST results performed by emergency medicine residents between males and females
Sensitivity (%) Specificity (%) Positive likelihood ratio Negative likelihood ratio Positive predicted value (%) Negative predicted value (%) Accuracy (%)
Male
Female
80 (50–100)* 92 (88–96) 10 (4.1–25) 0.21 (0–0.56) 42 (17–66) 98 (96–100) 91 (86–97)
75 (4–100) 97 (90–99) 25 (0.4–100) 0.26 (0–1.06) 75 (0–100) 97 (90–100) 94 (87–100)
FAST 5 focused abdominal sonography for trauma. * Mean (confidence interval).
Accuracy of focused abdominal sonography for trauma d A. ARHAMI DOLATABADI et al.
Table 3. Comparison of FAST results performed by radiology residents between males and females
Sensitivity (%) Specificity (%) Positive likelihood ratio Negative likelihood ratio Positive predicted value (%) Negative predicted value (%) Accuracy (%)
Male
Female
100 (100–100)* 97 (94–99) 33 (16–100) 0 (0–0) 71 (44–98) 100 (100–100) 97 (94–100)
75 (0–100) 90 (80–99) 7.5 (0–100) 0.27 (0–1.25) 50 (0–100) 96 (90–100) 89 (78–99)
FAST 5 focused abdominal sonography for trauma. * Mean (confidence interval).
A literature review reveals that FAST sensitivity in trauma ranges between 60% and 100%, and its specificity, between 88% and 100% (Brooks et al. 2004; Dolich et al. 2001; Nural et al. 2005; Rozycki et al. 1993). In a prospective study performed on 3264 patients, sensitivity, specificity and positive and negative predictive values for identification of intra-abdominal free fluid by FAST were 60%, 98%, 82% and 95%, respectively (Richards et al. 2002). In a retrospective study on 2693 patients, these values were 84%, 96%, 61% and 99%, respectively (Brown et al. 2001). The sensitivity of FAST performed by RRs in our study is higher than in these studies, although the specificities are equal. However, these other studies involved more patients. The aforementioned studies were mostly based on ultrasound performed by either radiologists or emergency physicians, but none of the studies clarified the difference between FAST performed by emergency medicine physicians and FAST performed by radiologists. Although other studies have reported that EMRs can achieve proficiency in FAST comparable to that of radiologists or RRs (Brenchley et al. 2006; Brooks et al. 2004; Ma et al. 1995), many radiologists suggest that their training and experience are necessary to perform ultrasound in trauma patients (Bode et al. 1999; Rozycki et al. 1993) and emergency physicians and surgeons are not sufficiently educated to perform such scans. The negative predictive value of FAST performed by EMRs in our study was 98%, indicating that it can be used as screening tool in trauma patients to exclude negative FAST results. As indicated by the low positive predictive value of FAST in the present study, patients with positive FAST results should undergo further diagnostic procedures. Although predictive value is dependent on the prevalence, the high prevalence of traffic road injuries in our region, 32.2 per 100,000 (Vafaee-Najar et al. 2011), is a good reason for us to use FAST as a screening tool in trauma patients in the emergency department. The sensitivity of FAST performed by emergency physicians in other studies ranges from 90 to 100% (Brooks et al. 2004; Tayal et al. 2004).
5
In the present study, the negative predictive value of FAST performed by RRs was 98%, similar to that for EMRs (98%). We think it is sufficient to follow patients with negative FAST results by clinical observation alone. Unlike other studies in which surgeons performed ultrasound (Soundappan et al. 2005; Thourani et al. 1998), we used both EMRs and RRs. Radiologists are formally educated to perform such scans, but EMRs require more didactic and hands-on training with FAST before performing these scans. A minimum 8-h training course with 4-h theoretical and 4-h practical periods is suggested (Scalea et al. 1999). We did not schedule training courses for EMRs, but further studies can assess the effect of education on the results of FAST performed by emergency physicians. Computed tomography can help us to obtain true results, but its disadvantages limit its use for all patients: it is more expensive than ultrasound, and the use of contrast materials can be harmful in trauma patients. DPL is invasive and relies on experienced staff. The cost and difficulty of CT and DPL prohibit our emergency departments from using them as routine procedures. Thus, clinical follow-up is standard for all patients with negative FAST results until clinical status deteriorates. Solid organ injuries such as hepatic lacerations are revealed by ultrasound, but can be ignored because clinical status can improve with time. As a result, clinical follow-up can misrepresent the results. Ultrasound, as a portable, noninvasive and bedside procedure, is desirable, but it has some limitations. FAST is operator dependent, cannot specify the origin of trauma and penetrates gases (bowel or percutaneous) poorly (Patel and Riherd 2011). The presence of free fluid, depending on volume, can increase false-positive results in women. The presence of fluid in the pelvis can be a normal physiologic condition in women, and it decreases the specificity of the ultrasound and increases the need for further evaluations. In our study, the specificity for women was higher in FAST performed by EMRs (97 vs. 92) than in FAST performed by RRs (90 vs. 97). This difference may arise from the greater experience (Gracias et al. 2002) and attention of RRs in performing FAST, resulting in more false-positive results. In our institution, emergency medicine physicians and residents, unlike radiologists or RRs, are available 24 h a day. The similarity in EMR and RR results in the present study indicates that using trained EMRs instead of radiologists or RRs to diagnose trauma patients can save critical time, decrease costs and increase efficiency. However, there is disagreement as to how many patients surgery or emergency residents need to see before being considered competent to perform FAST (Shackford et al. 1999; Smith et al. 1998).
6
Ultrasound in Medicine and Biology
This study was performed in a region with the highest prevalence of traffic road injuries worldwide. Better diagnosis and management of trauma patients can decrease the mortality rate. Our results can be useful in decision making by physicians and in development of hospital policies. One study has reported that exposure to positive cases during training improves the proficiency of residents (Gracias et al. 2001). This should be considered when developing a training curriculum. Although this study was prospective, the sample size and lack of a certain gold standard represent its limitations. The results of this study would be more precise if we could use CT in all patients. Further studies with larger samples will allow us to better compare the results of FASTs performed by EMRs and RRs in trauma patients. CONCLUSIONS Focused abdominal sonography for trauma is a useful diagnostic procedure for primary assessment of trauma patients in emergency departments. FAST is a portable and non-invasive procedure, but is operator dependent. Although radiologists and radiology residents are sufficiently trained to perform such scans, emergency medicine residents can achieve the same proficiency when given training courses. The sensitivity and specificity of FAST performed by EMRs were 80% and 95%, and for RRs, 86% and 95%. The accuracy of both EMRs and RRs were 94%. On the basis of the high negative predictive values of FAST performed by both EMRs and RRs (98%), FAST is an effective screening tool in trauma patients. In addition, the level of reproducibility indicates that EMRs, who are available at all times, can perform FAST reliably. Acknowledgments—We appreciate the full cooperation of the patients and hospital personnel in all stages of the present study.
REFERENCES American College of Surgeons Committee on Trauma. Abdominal trauma. In: Advanced Trauma Life Support Program for Doctors. Chicago: American College of Surgeons Committee on Trauma; 1997. Bode PJ, Edwards MJ, Kruit MC, van Vugt AB. Sonography in a clinical algorithm for early evaluation of 1671 patients with blunt abdominal trauma. AJR Am J Roentgenol 1999;172:905–911. Brenchley J, Walker A, Sloan JP, Hassan TB, Venables H. Evaluation of focussed assessment with sonography in trauma (FAST) by UK emergency physicians. Emerg Med J 2006;23:446–448. Brooks A, Davies B, Smethhurst M, Connolly J. Prospective evaluation of non-radiologist performed emergency abdominal ultrasound for haemoperitoneum. Emerg Med J 2004;21:e5. Brown MA, Casola G, Sirlin CB, Patel NY, Hoyt DB. Blunt abdominal trauma: Screening us in 2,693 patients. Radiology 2001;218: 352–358. Dolich MO, McKenney MG, Varela JE, Compton RP, McKenney KL, Cohn SM. 2,576 ultrasounds for blunt abdominal trauma. J Trauma 2001;50:108–112.
Volume -, Number -, 2014 Fischer RP, Beverlin BC, Engrav LH, Benjamin CI, Perry JF Jr. Diagnostic peritoneal lavage: Fourteen years and 2,586 patients later. Am J Surg 1978;136:701–704. Gracias VH, Frankel HL, Gupta R, Malcynski J, Gandhi R, Collazzo L, Nisenbaum H, Schwab CW. Defining the learning curve for the focused abdominal sonogram for trauma (FAST) examination: Implications for credentialing. Am Surgr 2001;67:364–368. Gracias VH, Frankel H, Gupta R, Reilly PM, Gracias F, Klein W, Nisenbaum H, Schwab CW. The role of positive examinations in training for the focused assessment sonogram in trauma (FAST) examination. Am Surg 2002;68:1008–1011. Healey MA, Simons RK, Winchell RJ, Gosink BB, Casola G, Steele JT, Potenza BM, Hoyt DB. A prospective evaluation of abdominal ultrasound in blunt trauma: Is it useful? J Trauma 1996;40:875–883. discussion 83–85. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–174. Ma OJ, Mateer JR, Ogata M, Kefer MP, Wittmann D, Aprahamian C. Prospective analysis of a rapid trauma ultrasound examination performed by emergency physicians. J Trauma 1995;38:879–885. McCarter FD, Luchette FA, Molloy M, Hurst JM, Davis K Jr, Johannigman JA, Frame SB, Fischer JE. Institutional and individual learning curves for focused abdominal ultrasound for trauma: Cumulative sum analysis. Ann Surg 2000;231:689–700. Melniker LA, Leibner E, McKenney MG, Lopez P, Briggs WM, Mancuso CA. Randomized controlled clinical trial of point-ofcare, limited ultrasonography for trauma in the emergency department: The first sonography outcomes assessment program trial. Ann Emerg Med 2006;48:227–235. Nural MS, Yardan T, Guven H, Baydin A, Bayrak IK, Kati C. Diagnostic value of ultrasonography in the evaluation of blunt abdominal trauma. Diagn Interv Radiol 2005;11:41–44. Ollerton JE, Sugrue M, Balogh Z, D’Amours SK, Giles A, Wyllie P. Prospective study to evaluate the influence of FAST on trauma patient management. J Trauma 2006;60:785–791. Patel NY, Riherd JM. Focused assessment with sonography for trauma: Methods, accuracy, and indications. Surg Clin North Am 2011;91: 195–207. Richards JR, Schleper NH, Woo BD, Bohnen PA, McGahan JP. Sonographic assessment of blunt abdominal trauma: A 4-year prospective study. J Clin Ultrasound 2002;30:59–67. Rozycki GS, Ochsner MG, Jaffin JH, Champion HR. Prospective evaluation of surgeons’ use of ultrasound in the evaluation of trauma patients. J Trauma 1993;34:516–526. discussion 26–27. Rozycki GS, Ochsner MG, Schmidt JA, Frankel HL, Davis TP, Wang D, Champion HR. A prospective study of surgeon-performed ultrasound as the primary adjuvant modality for injured patient assessment. J Trauma 1995;39:492–498. discussion 498–500. Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K, McKenney MG, Nerlich ML, Ochsner MG, Yoshii H. Focused assessment with sonography for trauma (FAST): Results from an international consensus conference. J Trauma 1999;46: 466–472. Shackford SR, Rogers FB, Osler TM, Trabulsy ME, Clauss DW, Vane DW. Focused abdominal sonogram for trauma: The learning curve of nonradiologist clinicians in detecting hemoperitoneum. J Trauma 1999;46:553–562. Smith RS, Kern SJ, Fry WR, Helmer SD. Institutional learning curve of surgeon-performed trauma ultrasound. Arch Surg 1998;133: 530–535. Soori H, Hussain SJ, Razzak JA. Road safety in the Eastern Mediterranean Region—Findings from the Global Road Safety Status Report. East Mediterr Health J 2011;17:770–776. Soundappan SV, Holland AJ, Cass DT, Lam A. Diagnostic accuracy of surgeon-performed focused abdominal sonography (FAST) in blunt paediatric trauma. Injury 2005;36:970–975. Tayal VS, Beatty MA, Marx JA, Tomaszewski CA, Thomason MH. FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma. J Ultrasound Med 2004;23:467–472.
Accuracy of focused abdominal sonography for trauma d A. ARHAMI DOLATABADI et al. Thourani VH, Pettitt BJ, Schmidt JA, Cooper WA, Rozycki GS. Validation of surgeon-performed emergency abdominal ultrasonography in pediatric trauma patients. J Pediatr Surg 1998;33:322–328. Tsui CL, Fung HT, Chung KL, Kam CW. Focused abdominal sonography for trauma in the emergency department for blunt abdominal trauma. Int J Emerg Med 2008;1:183–187.
7
Vafaee-Najar A, Khabbazkhoob M, Alidadi-Soltangholi H, Asgari S, Ibrahimipour H. Investigating the relative risk factors of injuries caused by accidents on roads in the mashhad area in 2007. Iran Red Crescent Med J 2011;13:530–536. Viscomi GN, Gonzalez R, Taylor KJ, Crade M. Ultrasonic evaluation of hepatic and splenic trauma. Arch Surg 1980;115:320–321.
http://dx.doi.org/10.1016/j.ultrasmedbio.2014.01.017
d
Original Contribution COMPARISON OF THE ACCURACY AND REPRODUCIBILITY OF FOCUSED ABDOMINAL SONOGRAPHY FOR TRAUMA PERFORMED BY EMERGENCY MEDICINE AND RADIOLOGY RESIDENTS ALI ARHAMI DOLATABADI,* AFSHIN AMINI,* HAMIDREZA HATAMABADI,y PARISA MOHAMMADI,z SARA FAGHIHI-KASHANI,x HOJJAT DERAKHSHANFAR,* SEYED MORTEZA TABATABAEE,x MEHRDAD MOGHIMI,k and ALI KABIR{# * Imam Hossein Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; y Safety Promotion & Injury Prevention Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; z Haft-e-Tir Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran; x Department of Internal Medicine, Tehran University of Medical Sciences, Tehran, Iran; k Department of Surgery, Shahid Beheshti University of Medical Sciences, Tehran, Iran; { Department of Epidemiology, Faculty of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran; and # Gastrointestinal and Liver Disease Research Center, Iran University of Medical Sciences, Tehran, Iran (Received 11 May 2013; revised 13 January 2014; in final form 17 January 2014)
Abstract—We compared the diagnostic accuracy of emergency medicine residents (EMRs) and radiology residents (RRs) in performing focused abdominal sonography for trauma (FAST). The cohort in this prospective study comprised 200 unstable patients (163 males and 37 females; mean ± standard deviation of age, 34.3 ± 16.4 y) who presented with trauma. These patients were evaluated using FAST, first by EMRs and subsequently by RRs. Patients with positive FAST results underwent further diagnostic procedures such as computed tomography, diagnostic peritoneal lavage and laparotomy. Those with negative FAST results underwent clinical follow-up for 72 h until their condition deteriorated or they were discharged. Sensitivity, specificity, positive and negative predictive values and accuracy in evaluating free intraperitoneal fluid were 80%, 95%, 57%, 98% and 94% when FAST was performed by EMRs and 86%, 95%, 59%, 98% and 94% when FAST was performed by RRs. The level of agreement between EMRs and RRs was moderate (k 5 0.525). FAST is a useful screening tool for initial assessment of free abdominal fluid in patients with trauma. Our results indicate that EMRs can perform sonography on trauma patients as successfully as RRs. (E-mail: [email protected]) Ó 2014 World Federation for Ultrasound in Medicine & Biology. Key Words: Abdominal injuries, Ultrasonography, Computed tomography, Emergency medicine, Radiology.
INTRODUCTION
(1994). FAST is a non-invasive, readily available, timesaving procedure that is useful in detecting pericardial or intraperitoneal free fluid in trauma patients. It is a complement to primary or secondary survey assessment in hemodynamically unstable patients (Bode et al. 1999; Healey et al. 1996; Ma et al. 1995). There is growing evidence that using FAST in primary trauma workup improves diagnosis (Melniker et al. 2006; Ollerton et al. 2006). Although radiologists are educated and trained to perform ultrasound scans, emergency physicians and trauma surgeons use FAST to evaluate trauma patients in emergency departments (Viscomi et al. 1980). In teaching hospitals, emergency medicine residents (EMRs) are the first to meet trauma patients and are responsible for primary evaluations. Therefore, EMRs
After head and chest injuries, abdominal injuries are the third leading cause of death in trauma cases (Tsui et al. 2008). Abdominal injury, when recognized, can be a preventable cause of death. Abdominal involvement in trauma cases is still very difficult to diagnose and poses a significant challenge to emergency medical personnel (American College of Surgeons Committee on Trauma 1997). The use of ultrasound in the evaluation of abdominal trauma has a 30-y history, but ‘‘focused abdominal sonography for trauma,’’ or FAST, was first described by Rozicky et al.
Address correspondence to: Ali Kabir, Nikan Health Researchers Institute, Unit 9, No. 1, 3rd Floor, 3rd Bahar Alley, Ashrafi Isfahani Highway, Poonak Square, Tehran, Iran. E-mail: [email protected] 1
2
Ultrasound in Medicine and Biology
can save critical time by performing FAST, as compared with radiology residents (RRs), who may not be immediately accessible in emergency settings. Although other studies have measured the diagnostic accuracy of ultrasound performed by emergency physicians and residents (Brenchley et al. 2006; Brooks et al. 2004), none have measured the difference in diagnostic accuracy between FAST performed by EMRs and FAST performed by RRs. In other published studies, the sensitivity of FAST has been reported as between 60% and 100%, and specificity, between 88% and 100% (Patel and Riherd 2011; Rozycki et al. 1995). Most studies such as ours have used computed tomography (CT), diagnostic peritoneal lavage (DPL) and clinical follow-up as the gold standard. We performed a prospective study to compare the diagnostic accuracy of FAST performed by EMRs and RRs in trauma patients admitted to the emergency department. Unlike other studies, we used the k statistic to measure the level of agreement between FAST performed by EMRs and that performed by RRs. Moreover, this study presents descriptive information about trauma cases in a region with the highest mortality from road traffic injuries worldwide (Soori et al. 2011). METHODS This prospective observational study compared results of FAST performed by EMRs and RRs in trauma patients. We enrolled all patients who met the study’s eligible criteria. Trauma patients admitted with red tag triage to the emergency department of Imam Hossein Hospital, an inner-city teaching hospital in Tehran, the capital of Iran, between May 2009 and May 2010 were included in this study. All patients were in the cardiopulmonary resuscitation room in unstable condition. Unstable condition is defined as a systolic blood pressure ,100 mm Hg accompanied by a heart rate $100 beats/ min with clinical evidence of shock, such as cold, dry skin and pallor. The sources of trauma included falls, motorcycle or motor vehicle crashes, pedestrian accidents, assaults and stab wounds. Patients arriving when the radiology staff was not present, after regular hours, were excluded from the study. Patients for whom there was an urgent need for laparotomy or other procedures were excluded. The study design was approved by the institutional review board of Tehran University of Medical Science. Written informed consent was obtained from the person legally responsible for patients unable to sign. Trauma patients underwent primary assessment in the cardiopulmonary resuscitation room by an emergency physician who was not part of the research staff. A decision on whether to proceed immediately to the operating room was made by the attending surgeon. After a primary
Volume -, Number -, 2014
survey, all traumatic patients underwent FAST first by an EMR within 15 min of admission. Thereafter, RRs performed FAST using the same ultrasound machine (HS2000, Honda, Korea) within 30 min of the FAST performed by EMRs. A low-frequency curvilinear transducer for FAST and pericardium high-frequency inner transducer for the pleural space were used. Patients’ bladders were not filled in the cases of empty bladder. Pelvic FAST was repeated in these cases. All radiology residents were blinded to the results of the previous FAST and were not aware of any other diagnostic procedures. Patients were supine during FAST. The goal of FAST in trauma patients is to detect intraperitoneal fluid. The absence of fluid in an ultrasound scan is considered negative. A positive scan is defined as the presence of fluid regardless of volume and location. To consider the results of FAST as positive, the hemoperitoneum should be visualized; the presence of fluid alone in the pleural or pericardial space did not persuade us to consider the results of FAST positive. CT scans were obtained for 193 patients. CT scans revealing spleen or liver rupture without free fluid were also considered positive. The following views were scanned in ultrasound: Morrison’s pouch, splenorenal space, retrovesical space, pleural space and pericardial space. Ten EMRs and seven RRs participated in the study. Both EMRs and RRs were completely trained and underwent full didactic and hands-on training for FAST and detection of the presence of free fluid. These training courses were part of the residents’ curriculum. EMRs were in either the second or third year of their programs; RRs were in either the first or second year. All patients, regardless of negative or positive FAST, underwent further evaluation, including CT, laparotomy, DPL and clinical follow-up. Patients with positive FAST results underwent CT if they were hemodynamically stable. CT scans were obtained by radiology attending physicians after performing FAST. CT scans are the gold standard and are the most accurate of all diagnostic procedures (Brenchley et al. 2006). The presence of free fluid, such as hemoperitoneum, or parenchymal lesions, such as liver and spleen lacerations, on a CT scan is a sign of abdominal injury and considered positive. Patients with positive FAST results who were hemodynamically unstable underwent DPL earlier in their evaluation process. Patients with positive DPL results were transferred to the operating room. DPL and laparotomy was performed by an attending surgeon or surgery residents, and the results were used as a reference criterion for hemodynamically unstable patients with positive FAST results. DPL results were considered positive if the red blood cell count was .100,000/mm3 (Fischer et al. 1978). We performed DPL for all four cases with stab wounds, even if their FAST result was negative.
Accuracy of focused abdominal sonography for trauma d A. ARHAMI DOLATABADI et al.
3
Laparotomy reports were considered positive if a macroscopic lesion on an abdominal organ or hemoperitoneum was detected. Patients with negative FAST results were monitored in the surgery ward or intensive care unit for at least 72 h. If their clinical symptoms deteriorated, they underwent CT or proceeded to the operating room. Ultrasonograms revealing small amounts of fluid in the pelvis of women of childbearing age were considered positive until CT ruled out organ damage or significant fluid. Research personnel collected each patient’s demographic data and source of traumatic injury after admission. The FAST results were collected and concealed from other members of the research staff. EMRs and RRs were unaware of the exam results. CT reports were written and confirmed by attending radiologists. Laparotomy and DPL reports were written by attending surgeon or surgery residents. Descriptive statistics are reported as the mean 6 standard deviation (SD). Test characteristics such as sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values and accuracy were calculated with SPSS Version 19 software (IBM, Armonk, NY, USA) and reported with 95% confidence intervals. The c2 test was used to determine the difference between results for the two groups. Accuracy was defined as the percentage of FAST results that were consistent with the reference criterion. The k statistic was used to represent the level of agreement between EMRs and RRs. RESULTS We prospectively enrolled all patients with trauma admitted to the emergency department of Imam Hossein Hospital over a 1-y period. Of 250 patients who met the inclusion criteria, 50 patients were excluded because of cardiac arrest in the cardiopulmonary resuscitation room or during transfer to the operating room (n 5 16), incomplete registry of surgery notes or CT report (n 5 19), laparotomy or DPL before FAST by radiology residents (n 5 12) and transfer to other hospitals (n 5 3). Two hundred patients completed the study. Of these 200 cases, 163 (81.5%) patients were male. Age ranged from 3 to 84 y (mean 6 SD: 34.3 6 16.4 y). Sources of trauma included motor vehicle crashes (56, 28%), motorcycle crashes (52, 26%), falls (43, 21.5%), pedestrian accidents (40, 20%), assaults (5, 2.5%) and stab wounds (4, 2%). Among the 200 patients who underwent FAST by EMRs, 21 had positive results (Fig. 1). Of these 21, there were 15 patients with one positive view (7 Morrison’s pouch, 4 splenorenal, 4 retrovesical space free fluid), 3 patients with two positive views (3 Morrison’s pouch
Fig. 1. Flowchart of patients with traumas referred to the emergency department of Imam Hossein Hospital between May 2009 and May 2010 and evaluated by emergency medicine residents.
and retrovesical space, 1 Morrison’s pouch and splenorenal space, 1 splenorenal and retrovesical space free fluid) and 1 patient with three positive views (Morrison’s pouch, splenorenal space and retrovesical space free fluid). Twenty-two of the FASTs performed by RRs were positive (Fig. 2). Of these 22, RRs reported 15 persons with one positive view (5 Morrison’s pouch, 6 splenorenal and 4 retrovesical space free fluid), 5 patients with two positive views (retrovesical recess and pericardial space), 1 patient with three positive views (Morrison’s pouch, retrovesical and splenorenal space free fluid) and 1 patient with five positive views. Additional procedures (laparotomy and CT) yielded 15 positive results among the 200 patients, including mesenteric tear (3 patients), small bowel perforation
4
Ultrasound in Medicine and Biology
Volume -, Number -, 2014
Table 1. Comparison of FAST results performed by emergency medicine residents and radiology residents
Sensitivity (%) Specificity (%) Positive likelihood ratio Negative likelihood ratio Positive predicted value (%) Negative predicted value (%) Accuracy (%)
EMR
RR
80 (57–100)* 95 (92–98) 16 (7.1–50) 0.21 (0–0.46) 57 (34–80) 98 (96–100) 94 (90–97)
86 (77–100) 95 (92–98) 17.2 (9.6–50) 0.04 (0–0.25) 59 (36–81) 98 (97–100) 94 (91–97)
EMR 5 emergency medicine resident; FAST 5 focused abdominal sonography for trauma; RR 5 radiology resident. * Mean (confidence interval).
EMRs and those performed by RRs (p 5 0.824). In addition, the k statistic between EMRs and RRs was 0.525. A k statistic between 0.4 and 0.75 represents intermediate reproducibility. Although female patients represented a minority in this study, with the exception of the positive predictive value, there was no difference between male and female patients in FAST results reported by EMRs (Table 2). In this group, the positive predictive value in males was higher than that in females (52 vs. 75). The results of FASTs performed by RRs were nearly equally sensitive in males and females (90 vs. 75); the positive predictive value (62 vs. 50) was higher (Table 3) in males. DISCUSSION
Fig. 2. Flowchart of patients with traumas referred to the emergency department of Imam Hossein hospital between May 2009 and May 2010 and evaluated by radiology residents.
(1 patient), hepatic laceration (7 patients) and splenic rupture (4 patients). Of the 179 negative FAST results reported by EMRs, 176 were true-negative and 3 were false-negative results. Of the 21 patients with positive FAST results, 9 had falsepositive results. The overall sensitivity, specificity and positive likelihood ratio for FAST performed by EMRs were 80%, 95% and 16, respectively. Nine of the 22 FAST results reported by RRs were false positive. Two of the 178 negative FAST results were false negative. The overall sensitivity, specificity and positive likelihood ratio for evaluating free intraperitoneal fluid in RR-performed FASTs were 86%, 95% and 17.2, respectively. Results of FASTs performed by EMRs and RRs are compared in Table 1. A c2 test revealed no significant difference between FASTs performed by
In the present study, RRs and EMRs had similar overall accuracy and equal specificity in performing FAST. However, the sensitivity of the FASTs performed by RRs was higher than that of FASTs performed by EMRs. RRs and EMRs had equal positive and negative predictive values. The level of agreement between the two groups was intermediate (Landis and Koch 1977). Disagreement between observers may be a result of factors other than practitioner errors, such as patient selection, setting and limitations of the examination (McCarter et al. 2000). Table 2. Comparison of FAST results performed by emergency medicine residents between males and females
Sensitivity (%) Specificity (%) Positive likelihood ratio Negative likelihood ratio Positive predicted value (%) Negative predicted value (%) Accuracy (%)
Male
Female
80 (50–100)* 92 (88–96) 10 (4.1–25) 0.21 (0–0.56) 42 (17–66) 98 (96–100) 91 (86–97)
75 (4–100) 97 (90–99) 25 (0.4–100) 0.26 (0–1.06) 75 (0–100) 97 (90–100) 94 (87–100)
FAST 5 focused abdominal sonography for trauma. * Mean (confidence interval).
Accuracy of focused abdominal sonography for trauma d A. ARHAMI DOLATABADI et al.
Table 3. Comparison of FAST results performed by radiology residents between males and females
Sensitivity (%) Specificity (%) Positive likelihood ratio Negative likelihood ratio Positive predicted value (%) Negative predicted value (%) Accuracy (%)
Male
Female
100 (100–100)* 97 (94–99) 33 (16–100) 0 (0–0) 71 (44–98) 100 (100–100) 97 (94–100)
75 (0–100) 90 (80–99) 7.5 (0–100) 0.27 (0–1.25) 50 (0–100) 96 (90–100) 89 (78–99)
FAST 5 focused abdominal sonography for trauma. * Mean (confidence interval).
A literature review reveals that FAST sensitivity in trauma ranges between 60% and 100%, and its specificity, between 88% and 100% (Brooks et al. 2004; Dolich et al. 2001; Nural et al. 2005; Rozycki et al. 1993). In a prospective study performed on 3264 patients, sensitivity, specificity and positive and negative predictive values for identification of intra-abdominal free fluid by FAST were 60%, 98%, 82% and 95%, respectively (Richards et al. 2002). In a retrospective study on 2693 patients, these values were 84%, 96%, 61% and 99%, respectively (Brown et al. 2001). The sensitivity of FAST performed by RRs in our study is higher than in these studies, although the specificities are equal. However, these other studies involved more patients. The aforementioned studies were mostly based on ultrasound performed by either radiologists or emergency physicians, but none of the studies clarified the difference between FAST performed by emergency medicine physicians and FAST performed by radiologists. Although other studies have reported that EMRs can achieve proficiency in FAST comparable to that of radiologists or RRs (Brenchley et al. 2006; Brooks et al. 2004; Ma et al. 1995), many radiologists suggest that their training and experience are necessary to perform ultrasound in trauma patients (Bode et al. 1999; Rozycki et al. 1993) and emergency physicians and surgeons are not sufficiently educated to perform such scans. The negative predictive value of FAST performed by EMRs in our study was 98%, indicating that it can be used as screening tool in trauma patients to exclude negative FAST results. As indicated by the low positive predictive value of FAST in the present study, patients with positive FAST results should undergo further diagnostic procedures. Although predictive value is dependent on the prevalence, the high prevalence of traffic road injuries in our region, 32.2 per 100,000 (Vafaee-Najar et al. 2011), is a good reason for us to use FAST as a screening tool in trauma patients in the emergency department. The sensitivity of FAST performed by emergency physicians in other studies ranges from 90 to 100% (Brooks et al. 2004; Tayal et al. 2004).
5
In the present study, the negative predictive value of FAST performed by RRs was 98%, similar to that for EMRs (98%). We think it is sufficient to follow patients with negative FAST results by clinical observation alone. Unlike other studies in which surgeons performed ultrasound (Soundappan et al. 2005; Thourani et al. 1998), we used both EMRs and RRs. Radiologists are formally educated to perform such scans, but EMRs require more didactic and hands-on training with FAST before performing these scans. A minimum 8-h training course with 4-h theoretical and 4-h practical periods is suggested (Scalea et al. 1999). We did not schedule training courses for EMRs, but further studies can assess the effect of education on the results of FAST performed by emergency physicians. Computed tomography can help us to obtain true results, but its disadvantages limit its use for all patients: it is more expensive than ultrasound, and the use of contrast materials can be harmful in trauma patients. DPL is invasive and relies on experienced staff. The cost and difficulty of CT and DPL prohibit our emergency departments from using them as routine procedures. Thus, clinical follow-up is standard for all patients with negative FAST results until clinical status deteriorates. Solid organ injuries such as hepatic lacerations are revealed by ultrasound, but can be ignored because clinical status can improve with time. As a result, clinical follow-up can misrepresent the results. Ultrasound, as a portable, noninvasive and bedside procedure, is desirable, but it has some limitations. FAST is operator dependent, cannot specify the origin of trauma and penetrates gases (bowel or percutaneous) poorly (Patel and Riherd 2011). The presence of free fluid, depending on volume, can increase false-positive results in women. The presence of fluid in the pelvis can be a normal physiologic condition in women, and it decreases the specificity of the ultrasound and increases the need for further evaluations. In our study, the specificity for women was higher in FAST performed by EMRs (97 vs. 92) than in FAST performed by RRs (90 vs. 97). This difference may arise from the greater experience (Gracias et al. 2002) and attention of RRs in performing FAST, resulting in more false-positive results. In our institution, emergency medicine physicians and residents, unlike radiologists or RRs, are available 24 h a day. The similarity in EMR and RR results in the present study indicates that using trained EMRs instead of radiologists or RRs to diagnose trauma patients can save critical time, decrease costs and increase efficiency. However, there is disagreement as to how many patients surgery or emergency residents need to see before being considered competent to perform FAST (Shackford et al. 1999; Smith et al. 1998).
6
Ultrasound in Medicine and Biology
This study was performed in a region with the highest prevalence of traffic road injuries worldwide. Better diagnosis and management of trauma patients can decrease the mortality rate. Our results can be useful in decision making by physicians and in development of hospital policies. One study has reported that exposure to positive cases during training improves the proficiency of residents (Gracias et al. 2001). This should be considered when developing a training curriculum. Although this study was prospective, the sample size and lack of a certain gold standard represent its limitations. The results of this study would be more precise if we could use CT in all patients. Further studies with larger samples will allow us to better compare the results of FASTs performed by EMRs and RRs in trauma patients. CONCLUSIONS Focused abdominal sonography for trauma is a useful diagnostic procedure for primary assessment of trauma patients in emergency departments. FAST is a portable and non-invasive procedure, but is operator dependent. Although radiologists and radiology residents are sufficiently trained to perform such scans, emergency medicine residents can achieve the same proficiency when given training courses. The sensitivity and specificity of FAST performed by EMRs were 80% and 95%, and for RRs, 86% and 95%. The accuracy of both EMRs and RRs were 94%. On the basis of the high negative predictive values of FAST performed by both EMRs and RRs (98%), FAST is an effective screening tool in trauma patients. In addition, the level of reproducibility indicates that EMRs, who are available at all times, can perform FAST reliably. Acknowledgments—We appreciate the full cooperation of the patients and hospital personnel in all stages of the present study.
REFERENCES American College of Surgeons Committee on Trauma. Abdominal trauma. In: Advanced Trauma Life Support Program for Doctors. Chicago: American College of Surgeons Committee on Trauma; 1997. Bode PJ, Edwards MJ, Kruit MC, van Vugt AB. Sonography in a clinical algorithm for early evaluation of 1671 patients with blunt abdominal trauma. AJR Am J Roentgenol 1999;172:905–911. Brenchley J, Walker A, Sloan JP, Hassan TB, Venables H. Evaluation of focussed assessment with sonography in trauma (FAST) by UK emergency physicians. Emerg Med J 2006;23:446–448. Brooks A, Davies B, Smethhurst M, Connolly J. Prospective evaluation of non-radiologist performed emergency abdominal ultrasound for haemoperitoneum. Emerg Med J 2004;21:e5. Brown MA, Casola G, Sirlin CB, Patel NY, Hoyt DB. Blunt abdominal trauma: Screening us in 2,693 patients. Radiology 2001;218: 352–358. Dolich MO, McKenney MG, Varela JE, Compton RP, McKenney KL, Cohn SM. 2,576 ultrasounds for blunt abdominal trauma. J Trauma 2001;50:108–112.
Volume -, Number -, 2014 Fischer RP, Beverlin BC, Engrav LH, Benjamin CI, Perry JF Jr. Diagnostic peritoneal lavage: Fourteen years and 2,586 patients later. Am J Surg 1978;136:701–704. Gracias VH, Frankel HL, Gupta R, Malcynski J, Gandhi R, Collazzo L, Nisenbaum H, Schwab CW. Defining the learning curve for the focused abdominal sonogram for trauma (FAST) examination: Implications for credentialing. Am Surgr 2001;67:364–368. Gracias VH, Frankel H, Gupta R, Reilly PM, Gracias F, Klein W, Nisenbaum H, Schwab CW. The role of positive examinations in training for the focused assessment sonogram in trauma (FAST) examination. Am Surg 2002;68:1008–1011. Healey MA, Simons RK, Winchell RJ, Gosink BB, Casola G, Steele JT, Potenza BM, Hoyt DB. A prospective evaluation of abdominal ultrasound in blunt trauma: Is it useful? J Trauma 1996;40:875–883. discussion 83–85. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–174. Ma OJ, Mateer JR, Ogata M, Kefer MP, Wittmann D, Aprahamian C. Prospective analysis of a rapid trauma ultrasound examination performed by emergency physicians. J Trauma 1995;38:879–885. McCarter FD, Luchette FA, Molloy M, Hurst JM, Davis K Jr, Johannigman JA, Frame SB, Fischer JE. Institutional and individual learning curves for focused abdominal ultrasound for trauma: Cumulative sum analysis. Ann Surg 2000;231:689–700. Melniker LA, Leibner E, McKenney MG, Lopez P, Briggs WM, Mancuso CA. Randomized controlled clinical trial of point-ofcare, limited ultrasonography for trauma in the emergency department: The first sonography outcomes assessment program trial. Ann Emerg Med 2006;48:227–235. Nural MS, Yardan T, Guven H, Baydin A, Bayrak IK, Kati C. Diagnostic value of ultrasonography in the evaluation of blunt abdominal trauma. Diagn Interv Radiol 2005;11:41–44. Ollerton JE, Sugrue M, Balogh Z, D’Amours SK, Giles A, Wyllie P. Prospective study to evaluate the influence of FAST on trauma patient management. J Trauma 2006;60:785–791. Patel NY, Riherd JM. Focused assessment with sonography for trauma: Methods, accuracy, and indications. Surg Clin North Am 2011;91: 195–207. Richards JR, Schleper NH, Woo BD, Bohnen PA, McGahan JP. Sonographic assessment of blunt abdominal trauma: A 4-year prospective study. J Clin Ultrasound 2002;30:59–67. Rozycki GS, Ochsner MG, Jaffin JH, Champion HR. Prospective evaluation of surgeons’ use of ultrasound in the evaluation of trauma patients. J Trauma 1993;34:516–526. discussion 26–27. Rozycki GS, Ochsner MG, Schmidt JA, Frankel HL, Davis TP, Wang D, Champion HR. A prospective study of surgeon-performed ultrasound as the primary adjuvant modality for injured patient assessment. J Trauma 1995;39:492–498. discussion 498–500. Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K, McKenney MG, Nerlich ML, Ochsner MG, Yoshii H. Focused assessment with sonography for trauma (FAST): Results from an international consensus conference. J Trauma 1999;46: 466–472. Shackford SR, Rogers FB, Osler TM, Trabulsy ME, Clauss DW, Vane DW. Focused abdominal sonogram for trauma: The learning curve of nonradiologist clinicians in detecting hemoperitoneum. J Trauma 1999;46:553–562. Smith RS, Kern SJ, Fry WR, Helmer SD. Institutional learning curve of surgeon-performed trauma ultrasound. Arch Surg 1998;133: 530–535. Soori H, Hussain SJ, Razzak JA. Road safety in the Eastern Mediterranean Region—Findings from the Global Road Safety Status Report. East Mediterr Health J 2011;17:770–776. Soundappan SV, Holland AJ, Cass DT, Lam A. Diagnostic accuracy of surgeon-performed focused abdominal sonography (FAST) in blunt paediatric trauma. Injury 2005;36:970–975. Tayal VS, Beatty MA, Marx JA, Tomaszewski CA, Thomason MH. FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma. J Ultrasound Med 2004;23:467–472.
Accuracy of focused abdominal sonography for trauma d A. ARHAMI DOLATABADI et al. Thourani VH, Pettitt BJ, Schmidt JA, Cooper WA, Rozycki GS. Validation of surgeon-performed emergency abdominal ultrasonography in pediatric trauma patients. J Pediatr Surg 1998;33:322–328. Tsui CL, Fung HT, Chung KL, Kam CW. Focused abdominal sonography for trauma in the emergency department for blunt abdominal trauma. Int J Emerg Med 2008;1:183–187.
7
Vafaee-Najar A, Khabbazkhoob M, Alidadi-Soltangholi H, Asgari S, Ibrahimipour H. Investigating the relative risk factors of injuries caused by accidents on roads in the mashhad area in 2007. Iran Red Crescent Med J 2011;13:530–536. Viscomi GN, Gonzalez R, Taylor KJ, Crade M. Ultrasonic evaluation of hepatic and splenic trauma. Arch Surg 1980;115:320–321.
