Article, Emergency Medicine

Does the number of emergency medical technicians affect the neurological outcome of patients with out-of-hospital cardiac arrest?

a b s t r a c t

Background: It is unclear whether the number of paramedics in an ambulance improves the outcome of patients with out-of-hospital cardiac arrest (OHCA) or not.

Methods and Results: This study was a prospective, observational study conducted on patients with OHCA. Pa- tients were divided into the One-paramedic group (Group O) and the Two-or-more-paramedic group (Group T) and we analyzed the differences. Patients who were treated with only basic life support during transportation, and whose cause of cardiac arrest were extrinsic cause such as trauma and poisoning were excluded. Good neu- rological outcome was defined as Cerebral Performance Category 1 or 2.

In Group O, there were 1516 patients (male/female, 922/594). In Group T, there were 2932 patients (male/fe-

male, 1798/1134). Return of spontaneous circulation (ROSC) was obtained in 528 patients (34.8%) in Group O and 1058 patients (36.1%) in Group T (p = 0.589). 320 patients (21.1%) in Group O and 656 patients (22.4%) in Group T were admitted to hospital after ROSC (p = 0.461). At 90 days, there were 57 survivors (3.8%) in Group O and 114 survivors (3.9%) in Group T (p = 0.873). At 90 days, 14 patients (0.9%) in Group T had a CPC of 1 or 2, while 30 patients (1.0%) in Group T did so (p = 0.87). From the results of logistic regression analysis, age [odds ratio (OR): 0.983, 95% confidence interval (CI): 0.952-0.993], witnessed OHCA (OR: 4.583, 95% CI: 1.587-13.234), and shockable rhythm as first documented (OR: 19.67, 95% CI: 9.181-42.13) were associated with good outcome.

Conclusion: The number of paramedics in an ambulance did not affect the outcome in OHCA patients.

(C) 2016

Introduction

Out-of-hospital cardiac arrest (OHCA) is one of the greatest healthcare problems of community and public health. The correct and timely identi- fication of cardiac arrest is critical to ensuring [1] the appropriate dispatch of a high-priority response, [2] the provision of telephone cardiopulmo- nary resuscitation (CPR) instructions, and [3] activation of community First responders carrying automated external defibrillators (AEDs) [1]. Optimizing emergency medical service (EMS) dispatch is likely to be one of the most cost-effective solutions to improving the outcome of OHCA [1]. Before arriving at the hospital, the key persons who perform advanced life support are emergency medical technicians or paramedics; therefore, it is assumed that the procedures that EMTs per- form greatly influence the outcome of patients with OHCA.

* Corresponding author at: Department of Emergency Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.

E-mail address: [email protected] (S. Hagiwara).

The Fire and Disaster Management Agency in Japan recommends that EMTs receive off-the-job training in basic life support and this agency maintains the operational system of EMT services with the goal of ensuring that at least one EMT is regularly present in all emer- gency services (one EMT among 3 members) [2]. The Utstein Osaka Pro- ject reported that an ambulance with three EMTs was associated with good outcome of patients with OHCA [3]. However, the number of pa- tients included in that study was not large. The importance of the number of EMTs in the ambulance for patients with OHCA is still controversial.

The Survey of Survivors of OHCA in the Kanto district of Japan 2012 study (SOS-KANTO 2012 study) was performed by the Japanese Associ- ation for Acute Medicine in the Kanto district between January 2012 and March 2013, and included 67 emergency hospitals and emergency med- ical services units. The SOS-KANTO 2012 study was a prospective, mul- ticenter, observational study on patients with OHCA. We hypothesized that the number of EMTs in the ambulance affects the neurological out- come of patients with OHCA. In this study, we evaluated this hypothesis with the data of the SOS-KANTO 2012 study.

http://dx.doi.org/10.1016/j.ajem.2016.11.020

0735-6757/(C) 2016

Methods

The SOS-KANTO 2012 study was a prospective, observational study conducted on patients with OHCA who were transported to 67 emer- gency hospitals (36 academic centers) in Kanto district between January 2012 and March 2013. The emergency hospitals that participated in the SOS-KANTO 2012 study are listed in the Acknowledgments. The protocol of the SOS-KANTO 2012 study was approved without the need for in- formed consent by the research ethics board of Yokohama City Univer- sity Medical Center (Yokohama, Kanagawa, Japan; D1402005). The results of various aspects of the SOS-KANTO 2012 study have been pub- lished in several journals [4-8].

The flow diagram of the present study is shown in Fig. 1. First, we se- lected OHCA patients whose age was 18 years old or older. We excluded patients who were transferred by an ambulance with an unknown number of EMTs or no EMT, those who received only chest compression and rescue breathes, and those in whom advanced airway management or taking intravenous line was not performed during transportation because to reduce the selection bias. Patients whose etiology of cardiac arrest was trauma, burn, toxicosis, hypothermia, drowning, and neck hanging, were also excluded (detailed numbers of patients are shown in Fig. 1). We divided the patients into two groups according to the number of EMTs. Group O included patients with OHCA in which there was only one EMT in the ambulance when the patient was trans- ferred to the hospital, and Group T included OHCA patients in which there were two or more EMTs in the ambulance.

We analyzed the rate of return of spontaneous circulation (ROSC), admission after ROSC, and 90-day survival and neurological status, and compared these results between the two groups. Neurological sta- tus was described with the cerebral performance category : cate- gory 1, good cerebral performance; category 2, moderate cerebral disability; category 3, severe cerebral disability; category 4, coma or vegetative state; and category 5, death [9,10]. Good neurological out- come was defined as CPC1 and CPC2.

Finally, we conducted logistic regression analysis in which the de-

pendent variable was good neurological outcome or survival, and objec- tive variables were prehospital procedures and findings.

Statistical Analysis

Age and time are shown as the mean +- standard deviation. The sig- nificance of differences between the two groups was analyzed with

Student’s t-test and the ?2 test. survival curves were drawn by the Kaplan-Meier method and were compared with the log-rank test. Logis- tic regression analysis was performed to model the concurrent effects of age, sex, witnessed, bystander CPR, and other factors on the outcome.

IBM SPSS Statistics 22 (IBM Corporation; Endicott, NY, USA) and EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan) were used for statistical analyses. EZR is a graphical user interface for R (The R Foundation for Statistical Computing, Vienna, Austria). More precisely, it is a modified version of R commander designed to add statistical func- tions frequently used in biostatistics [11]. Statistical significance was as- sumed to be present at p b 0.05.

Results

During the study period, 16,452 patients with OHCA were enrolled in the SOS-KANTO 2012 study. Among them, 4448 patients with OHCA met the criteria of the present study. There were 1516 patients in Group O and 2932 patients in Group T (Fig. 1).

The patients’ characteristics are summarized in Table 1. There were 922 males (60.8%) in Group O and 1798 males (61.3%) in Group T (p = 0.892). The mean age was 73.4 +- 14.2 years in Group O, and

73.5 +- 14.3 years in Group T (p = 0.973). There were no significant dif- ferences in the male/female ratio and age between the two groups.

There were 792 patients (52.2%) whose cardiac arrest was witnessed in Group O, and 1585 patients (54.1%) in Group T (p = 0.543). Regard- ing by-stander CPR, 563 patients (37.1%) in Group O received by- stander CPR, while 1164 patients (39.7%) in Group T received by- stander CPR (p = 0.282). The percentage of witnessed patients was more than 50% in both groups, and by-stander CPR was performed in about 40% of patients with OHCA in both groups with no significant differences.

The number of patients whose initial electrocardiogram (ECG) waveform (i.e., ECG waveform monitored by EMTs in the ambulance) was ventricular fibrillation was 139 (9.2%) in Group O and 270 (9.2%) in Group T (p = 1). The number of patients whose initial ECG waveform was pulseless ventricular tachycardia was 2 (0.1%) in Group O and 1 (0.0%) in Group T (p = 0.561). The number of patients whose initial ECG waveform was pulseless electrical activity was 386 (25.5%) in Group O and 732 (25.0%) in Group T (p = 0.807). The number of pa- tients whose initial ECG waveform was asystole was 925 (61.0%) in Group O and 1805 (61.6%) in Group T (p = 0.882). There were 860 pa- tients (56.7%) whose etiology of cardiac arrest was cardiac in Group O,

SOS-KANTO 2012 Study N = 16,452

12,004 patients were excluded 288 were age <18 years old

434 in which the number of paramedics was unknown or no paramedic

4,106 received only basic life support

4,994 did not receive advanced airway management

1,631 did not try to keep intravenous line

551 were excluded because of the etiology of cardiac arrest 177 trauma

5 burn

20 toxicosis

20 hypothermia

162 drowning

167 hanging

Group O

One paramedic group 1,516

4,448 patients

Group T

Two or more-than-two paramedic group 2,932

Fig. 1. The study flow diagram that shows the patients with out-of-hospital cardiac arrest that were included in the present study.

Table 1

Characteristics of patients with out-of-hospital cardiac arrest.

Group O

(N = 1516)

Group T

(N = 2932)

p-Value

Table 2 shows the rate of ROSC in the two groups. ROSC was obtain- ed in 528 patients (34.8%) in Group O and 1058 patients (36.1%) in Group T (p = 0.589). Three hundred twenty patients (21.1%) in Group O and 656 patients (22.4%) in Group T were admitted after ROSC

Male {N. (%)} 922 (60.8%) 1798 (61.3%) 0.892

Mean age (SD) (years old) 73.4 (14.2) 73.5 (14.3) 0.973

Witnessed {N. (%)} 792 (52.2%) 1585 (54.1%) 0.543

By-stander CPR {N. (%)} 563 (37.1%) 1164 (39.7%) 0.282

Initial ECG waveform

VF {N. (%)}

139 (9.2%)

270 (9.2%)

1

VT {N. (%)}

2 (0.1%)

1 (0.0%)

0.561

PEA {N. (%)}

386 (25.5%)

732 (25.0%)

0.807

Asystole {N. (%)}

925 (61.0%)

1805 (61.6%)

0.882

Other {N. (%)}

64 (4.2%)

124 (4.2%)

1

Etiology of cardiac arrest

Cardiac {N. (%)}

860 (56.7%)

1660 (56.6%)

0.991

90 days were almost the same in the two groups and there were no sig-

Aortic disease {N. (%)}

106 (7.0%)

185 (6.3%)

0.452

nificant differences.

pulmonary thromboembolism {N. (%)}

8 (0.5%)

23 (0.8%)

0.436

Fig. 2 shows the Kaplan-Meier survival curves of the two groups. The

(p = 0.461). Both the rates of ROSC and admission after ROSC tended to be higher in group T than in group O; however, there were no signif- icant differences between the two groups.

Table 3 shows the rates of Survival and neurological outcome after 90 days. At 90 days, there were 57 survivors (3.8%) in Group O and 114 survivors (3.9%) in Group T (p = 0.873). Also at 90 days, there were 14 patients (0.9%) whose CPC score was 1 or 2 in Group O and 30 patients (1.0%) whose CPC score was 1 or 2 in Group T (p = 0.87). Both the rates of 90-day survival and neurological outcome after

Subarachnoid hemorrhage {N. (%)} 51 (3.4%) 83 (2.8%) 0.388

Other {N. (%)} 491(32.4%) 981 (33.5%) 0.632

Mean time from the phone call to arrival 37.3 (10.3) 36.1 (10.6) b0.01 at the hospital (SD) (min.)

Airway management: intubation {N. (%)}

173 (11.4%)

416 (14.2%)

0.026 icant difference between the two groups (p = 0.638, log-rank test).

Success of establishing an intravenous

784 (51.7%)

1639 (55.9%)

0.155 The results of logistic regression analysis in which the dependent

estimated mean survival was 2.99 {standard error: 0.378, 95% confi- dence interval (CI): 2.253-3.726} days in Group O, and 2.83 (standard error: 0.257, 95% CI: 2.326-3333) days in Group T. There was no signif-

line before arrival {N. (%)}

Linkage with other emergency services before arrival {N. (%)}

Mean time from the phone call to drug injection (SD) (min.)

Mean time from the phone call to ROSC (SD) (min.)

1189 (78.4%) 2507 (85.5%) 0.072

35.0 (10.8)a 31.8 (11.6)b b0.01

41.0 (11.0)c 38.9 (11.6)d b0.01

variable was CPC 1 + 2 or survival, and objective variables were prehospital procedures and findings are shown in Table 4a. From the re- sults of logistic regression analysis for survival, age (odds ratio: OR 0.980, 95% CI 0.966-0.994), witnessed (OR: 3.066, 95% CI: 1.751-

5.369), and shockable rhythm as first documented by paramedics (OR: 10.88, 95% CI: 6.941-17.13) were associated with survival (Table 4a).

SD: standard deviation, CPR: cardiopulmonary resuscitation, ECG: electrocardiogram, VT: ventricular fibrillation, VT: pulseless ventricular tachycardia, PEA: pulseless electrical ac- tivity, ROSC: return of spontaneous circulation.

a N = 1172.

b N = 2298.

c N= 420.

d N= 821.

and 1660 patients (56.6%) whose etiology of cardiac arrest was cardiac in Group T (p = 0.991). There were 106 patients (7.0%) in Group O and 185 patients (6.3%) in Group T whose etiology of cardiac arrest was aor- tic disease (p = 0.452). There were 8 patients (0.5%) in Group O and 23 patients (0.8%) in Group T whose etiology of cardiac arrest was pulmo- nary thromboembolism (p = 0.436). There were 51 patients (3.4%) in Group O and 83 patients (2.8%) in Group T whose etiology of cardiac ar- rest was subarachnoid hemorrhage (p = 0.388). And only 5 patients were conducted autopsy (Group O:1 patient, Group T: 4 patients, p = 0.847). There were no significant differences in the initial ECG wave- form and the etiology of cardiac arrest between the two groups.

The mean time from the emergency call to arrival at the hospital was significantly shorter in group T than in group O (36.1 +- 10.6 min vs. 37.3 +- 10.3 min, p b 0.01). In addition, the percentage of intubated pa- tients before arrival at the hospital was significantly higher in group T

{Group T: N = 416 (14.2%) vs. Group O: N = 173 (11.4%)} (p =

0.026). There were no significant differences in the percentages of cases with success of establishing an intravenous line {Group O: N = 784 (51.7%) vs. Group T: N = 1639 (55.9%)} and linkage with other emergency services before arrival at the hospital {Group O: N = 1189(78.4%) vs. Group T: N = 2507(85.5%)} between the two groups. Regarding the time from the emergency call to drug injection, we could analyze only 3470 patients; the time from the emergency call to drug injection was significantly shorter in Group T (Group T: 31.8 +- 11.6 min vs. Group O: 35.0 +- 10.8 min). Regarding the time from emer-

From the results of logistic regression analysis for good neurological outcome, age (OR 0.983, 95% CI 0.952-0.993), witnessed (OR: 4.583, 95% CI: 1.587-13.234), and shockable rhythm as first documented by paramedics (OR: 19.67, 95% CI: 9.181-42.13) were associated with good neurological outcome (Table 4b).

Discussion

OHCA is one of the greatest problems of public health. Therefore, the International Liaison Committee on Resuscitation published guidelines of the Consensus on Science with Treatment Recommenda- tion (CoSTR) in 2000, and the CoSTR guidelines are followed widely throughout the world with some modifications based on each local sit- uation such as modifications made by the American Heart Association [12], European Resuscitation Council [13], and Japan Resuscitation Council (JRC) [14].

In the past decade, the prognosis of patients with OHCA has im- proved in Japan [4,15]. This improvement is due to the following factors: allowing citizens to use AED since 2004 [16,17], increasing use of chest- compression-only CPR [17,18], therapeutic hypothermia after ROSC [19, 20], emergent coronary angiography for OHCA patients [21,22], dissem- ination of doctor car and/or helicopter, and prehospital paramedic actions.

The Japanese law for EMTs was enacted in 1991, and it is recom- mended that at least one EMT is regularly present in all emergency ser- vices (basically, one EMT out of 3 members including the driver) [2]. The law has been gradually revised to allow EMTs to perform advanced life support in out-of-hospital situations under the instruction of a physi- cian, for example, advanced airway management (from 2004), keeping an intravenous line (from 2006), and injecting adrenaline (from 2006) in patients with OHCA. However, whether or not each prehospital

Table 2

Return of spontaneous circulation and admission in Groups O and T.

Group O Group T p-Value

gency call to ROSC, we could analyze 1241 patients; the mean time from

ROSC {N (%)}

528 (34.8%)

1058 (36.1%)

0.589

the emergency call to ROSC was significantly shorter in Group T than in

Admission after ROSC {N (%)}

320 (21.1%)

656 (22.4%)

0.461

Group O (38.9 +- 11.6 min vs. 41.0 +- 11.0 min).

ROSC: return of spontaneous circulation.

CPC: cerebral performance category.

procedure improves the outcome of OHCA patients is still controversial [23-26]. The SOS-KANTO 2012 study group reported that it should be

Sex

Male

Female

Reference

1.481

0.923-2.376

0.104

Witnessed

3.066

1.751-5.369

b 0.001

With by-stander CPR

0.930

0.604-1.431

0.742

Shockable rhythm as first documented 10.88 6.914-17.13 b 0.001

Table 3

Table 4a

Outcome at 90 days

Logistic regression analysis (survival).

Group O

Group T

p-Value

Odds

95% CI

p-Value

CPC 1 or 2 {N (%)}

14 (0.9%)

30 (1.0%)

0.873

ratio

(lower-upper)

Survival {N (%)}

57 (3.8%)

114 (3.9%)

0.87

Age

0.980

0.966-0.994

0.005

thought that these prehospital procedures performed by EMTs were the main reason for improvement of the outcome of OHCA patients in the past decade [4]. On the other hand, it is still unknown which kind of treatment leads to a good outcome and whether the number of EMTs influences the prognosis of OHCA patients.

In this study, the time from the emergency call to arrival at the hos-

pital, time from the emergency call to drug injection, and time from the

Success of establish an intravenous line before arrival

Airway management: intubation group

O T

Linkage with other emergency services before arrival

1.442 0.928-2.240 0.104

0.546

0.246-1.213

0.137

Reference 0.866

0.558-1.345

0.522

0.657

0.395-1.094

0.106

emergency call to ROSC were significantly shorter in Group T than in Group O, and the percentage of intubated patients before arrival at the hospital was significantly higher in Group T. Komatsu et al. [27]. report- ed that shorter time until ROSC was the only independent factor for a good neurological outcome in patients with cardiac arrest from their small series (n = 227). However, there were no significant differences in the rate of ROSC and rate of admission after ROSC between the two groups in the present study. In addition, there were no significant differ- ences in both 90-day survival and the neurological outcome after 90 days between the two groups. Logistic regression analysis showed that the number of EMTs in the ambulance did not influence the neuro- logical outcome (CPC 1 or 2) and survival.

Image of Fig. 2The present study demonstrated that whether the number of EMTs in the ambulance was one or more did not influence survival and the neurological outcome after 90 days in patients with OHCA. Our hypoth- esis that the number of EMTs affects the outcome of patients with OHCA was not true. We could not find that the presence of two or more EMTs in the ambulance significantly improves the outcome of OHCA patients in this large prospective study. On the other hand, Kajino et al. [3] re- ported that the presence of a group of three on-scene EMTs was associ- ated with improved one-month survival with favorable neurological outcome from OHCA compared with one on-scene EMT in Osaka City (three EMT group: n = 412, one EMT group: n = 639). The present study also showed that the presence of two or more EMTs in an ambu- lance could transfer OHCA patients to the hospital faster (although this analysis included only 1241 patients); therefore, there is a possibility that the presence of three or more EMTs in an ambulance improves

CI: confidence interval, CPR: cardio pulmonary resuscitation.

the neurological outcome of patients with OHCA. The procedures that Japanese EMTs can perform on site are restricted and instructions from a physician are necessary. There is a possibility of obtaining a good outcome in patients with OHCA if advanced life support could be started as soon as possible on site by EMTs in Japan or by giving physi- cians the opportunity to go to the setting with the ambulance and/or he- licopter emergency medical service. Unfortunately, the use of ambulance and helicopter emergency medical service cannot be in- creased drastically considering the costs and the number of medical staff. Therefore, expanding the number of procedures that Japanese EMTs can perform is more realistic.

Limitations

The SOS-KANTO study 2012 was a large, prospective cohort study on OHCA. This study did not include all hospitals with an emergency center in the KANTO area in Japan. Therefore, a randomized double-blind trial would be necessary in the future. And we were not able to discuss about the Quality of CPR, neither.

Conclusion

We could not find evidence that reaffirmed our hypothesis that the presence of two or more EMTs in the ambulance leads to a better out- come for patients with OHCA than one EMT. The number of EMTs in an ambulance did not affect the rates of ROSC, survival and neurological outcome in patients with OHCA.

Table 4b

Logistic regression analysis (good neurological outcome).

Fig. 2. Kaplan-Meier survival curves of Groups O a in survival between the two groups (log-rank test).

Odds ratio

95% CI

(lower-upper)

p-Value

Age

0.983

0.952-0.993

0.008

Sex

Male

Reference

Female

0.983

0.444-2.176

0.966

Witnessed

4.583

1.587-13.234

0.005

With by-stander CPR

1.740

0.913-3.315

0.098

Shockable rhythm as first documented

19.67

9.181-42.126

b 0.001

Success of establish an intravenous line

1.477

0.761-2.864

0.248

before arrival

Airway management: intubation

0.167

0.022-1.253

0.082

Group

O

Reference

Log-rank test P = .638

T

1.078

0.548-2.118

0.828

Linkage with other emergency services

1.393

0.556-3.486

0.479

nd T. There was no significant difference

before arrival

CI: confidence interval, CPR: cardio pulmonary resuscitation.

Disclosures

The SOS-KANTO 2012 Study Group declares no conflicts of interest.

Acknowledgments

Contributors

Shuichi Hagiwara MD, Kiyohiro Oshima MD, Makoto Aoki MD, Minoru Kaneko MD, Dai Miyazaki MD, Atsushi Sakurai MD, Yoshio Tahara MD, Ken Nagao MD, Naohiro Yonemoto, MD, Arino Yaguchi MD, and Naoto Morimura MD.

SOS-KANTO 2012 Steering Council:

Yokohama City University Medical Center, Kanagawa (President, Naoto Morimura, MD); Nihon University School of Medicine, Tokyo (Di- rector, Atsushi Sakurai, MD); National Cerebral and Cardiovascular Cen- ter Hospital, Osaka (Director, Yoshio Tahara, MD); Tokyo Women’s Medical university hospital, Tokyo (Arino Yaguchi, MD); Nihon Univer- sity Surugadai Hospital, Tokyo (Ken Nagao, MD); Nippon Medical School Hospital, Tokyo (Tagami Takashi, MD); Japanese Red Cross Maebashi Hospital, Gunma (Dai Miyazaki, MD); National Disaster Med- ical Center, Tokyo (Tomoko Ogasawara, MD); Keio University Hospital, Tokyo (Kei Hayashida, MD, Masaru Suzuki, MD); Tokai University School of Medicine, Kanagawa (Mari Amino, MD); Kimitsu Chuo Hospi- tal, Chiba (Nobuya Kitamura, MD); Juntendo University Nerima Hospi- tal, Tokyo (Tomohisa Nomura, MD); Tokyo Metropolitan Children’s Medical Centre, Tokyo (Naoki Shimizu, MD); Tokyo Metropolitan Bokutoh Hospital, Tokyo (Akiko Akashi, MD), National Center of Neurol- ogy and Psychiatry, Tokyo, Japan (Naohiro Yonemoto, DPH).

SOS-KANTO 2012 Study Group:

Tokai University School of Medicine (Sadaki Inokuchi, MD); St. Marianna University School of Medicine, Yokohama Seibu Hospital (Yoshihiro Masui, MD); Koto Hospital (Kunihisa Miura, MD); Saitama Medical Center Advanced Tertiary medical center (Haruhiko Tsutsumi, MD); Kawasaki Municipal Hospital Emergency and Critical Care Center (Kiyotsugu Takuma, MD); Yokohama Municipal Citizen’s Hospital (Ishihara Atsushi, MD); Japanese Red Cross Maebashi Hospital (Minoru Nakano, MD); Juntendo University Urayasu Hospital (Hiroshi Tanaka, MD); Dokkyo Medical University Koshigaya Hospital (Keiichi Ikegami, MD); Hachioji Medical Center of Tokyo Medical University (Takao Arai, MD); Tokyo Women’s Medical University Hospital (Arino Yaguchi, MD); Kimitsu Chuo Hospital (Nobuya Kitamura, MD); Chiba University Graduate School of Medicine (Shigeto Oda, MD); Saiseikai Utsunomiya Hospital (Kenji Kobayashi, MD); Mito Saiseikai General Hospital (Takayuki Suda, MD); Dokkyo Medical University (Kazuyuki Ono, MD); Yokohama City University Medical Center (Naoto Morimura, MD); National Hospital Organization Yokohama Medical Center (Ryosuke Furuya, MD); National Disaster Medical Center (Yuichi Koido, MD); Yamanashi Prefectural Central Hospital (Fumiaki Iwase, MD); Surugadai Nihon University Hospital (Ken Nagao, MD); Yokohama Rosai Hospital (Shigeru Kanesaka, MD); Showa General Hospital (Yasusei Okada, MD); Nippon Medical School Tamanagayama Hospital (Kyoko Unemoto, MD); Tokyo Women’s Medical University Yachiyo Medical Center (Tomohito Sadahiro, MD); Awa Regional Medical Center (Masayuki Iyanaga, MD); Todachuo General Hospital (Asaki Muraoka, MD); Japanese Red Cross Medical Center (Munehiro Hayashi, MD); St. Luke’s International Hospital (Shinichi Ishimatsu, MD); Showa Universi- ty School of Medicine (Yasufumi Miyake, MD); Totsuka Kyoritsu Hospi- tal (Hideo Yokokawa, MD); St. Marianna University School of Medicine (Yasuaki Koyama, MD); National Hospital Organization Mito Medical Center (Asuka Tsuchiya, MD); Tokyo Metropolitan Tama Medical Center (Tetsuya Kashiyama, MD); Showa University Fujigaoka Hospital (Munetaka Hayashi, MD); Gunma University Graduate School of Medi- cine (Kiyohiro Oshima, MD); Saitama Red Cross Hospital (Kazuya Kiyota, MD); Tokyo Metropolitan Bokutoh Hospital (Yuichi Hamabe, MD); Nippon Medical School Hospital (Hiroyuki Yokota, MD); Keio Uni- versity Hospital (Shingo Hori, MD); Chiba emergency medical center

(Shin Inaba, MD); Teikyo University School of Medicine (Tetsuya Sakamoto, MD); Japanese Red Cross Musashino Hospital (Naoshige Harada, MD); National Center for Global Health and Medicine Hospital (Akio Kimura, MD); Tokyo Metropolitan Police Hospital (Masayuki Kanai, MD); Medical Hospital of Tokyo Medical and Dental University (Yasuhiro Otomo, MD); Juntendo University Nerima Hospital (Manabu Sugita, MD); Nihon University School of Medicine (Kosaku Kinoshita, MD); Toho University Ohashi Medical Center (Takatoshi Sakurai, MD); Saiseikai Yokohamashi Tobu Hospital (Mitsuhide Kitano, MD); Nippon Medical School Musashikosugi Hospital (Kiyoshi Matsuda, MD); Tokyo Rosai Hospital (Kotaro Tanaka, MD); Toho University Omori Medical Center (Katsunori Yoshihara, MD); Hiratsuka City Hospital (Kikuo Yoh, MD); Yokosuka Kyosai Hospital (Junichi Suzuki, MD); Saiseikai Yokohamashi Nambu Hospital (Hiroshi Toyoda, MD); Nippon Medical School Chiba Hokusoh Hospital (Kunihiro Mashiko, MD); Tokyo Metro- politan Children’s Medical Centre (Naoki Shimizu, MD); National Med- ical Center for Children and Mothers (Takashi Muguruma, MD); Chiba Aoba Municipal Hospital (Tadanaga Shimada, MD); Kuki General Hospi- tal (Yoshiro Kobe, MD); Matsudo City Hospital (Tomohisa Shoko, MD); Japanese Red Cross Narita Hospital (Kazuya Nakanishi, MD); Tokyo Bay Urayasu/Ichikawa Medical Center (Takashi Shiga, MD); NTT Medical Center Tokyo (Takefumi Yamamoto, MD); Tokyo Saiseikai Central Hos- pital (Kazuhiko Sekine, MD); Fuji Heavy Industries Health Insurance So- ciety OTA Memorial Hopital (Shinichi Izuka, MD). (http://www.jaam- kanto.jp/sos_kanto/sos_kanto2012_contributors.html).

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