Article Text
Abstract
Background: The helicopter emergency medical service (HEMS) has been working in Iran since 2000. The present study is the first prospective research to determine the epidemiological characteristics of injured patients transported by helicopter in Tehran.
Methods: All injured patients brought to three hospitals from the injury scene by HEMS were reviewed in a 4-month period.
Results: The mean transport time was 54 minutes. The most common mechanism of trauma was road traffic accidents (96.2%). The mean injury severity score was 8.6 (SD 8.6) and 9.6% of patients were sent to the intensive care unit; 10.2% of patients died.
Conclusion: This study shows that overtriage in HEMS (transportation of patients without severe injuries) and the long transportation time is mainly a result of not having a trauma system. The study has shown HEMS to be an effective and feasible option in countries with heavy traffic and no trauma system.
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Trauma is the main cause of mortality within the first four decades of life; it is also the fifth major cause of mortality at all ages. The major proportion of trauma mortalities occurs in developing countries and road traffic injuries constitute the greatest part of it.1 In other words, road traffic accidents are the eleventh cause of mortality in the world and 90% of the resulting mortalities occur in countries with average and low incomes.2
The resulting deaths and disabilities are reduced by 15–20% following the establishment of trauma centres.3 Administering and developing prehospital emergency medical services (EMS) and helicopter emergency medical services (HEMS) have played a major role in establishing these centres.3
The use of helicopters for transporting injured soldiers during the war in Vietnam and Korea was the basis and a turning point in forming aeromedical systems in industrialised countries. An aeromedical system was first established in the USA in 1972 and they were then funded in Europe and some Asian countries.4 Several studies have been conducted to evaluate the efficiency of aeromedical systems and the quality of their care. Some studies have demonstrated their efficiency by showing a significant decrease in mortality rates and improvements in outcome in trauma patients who are aeromedically transported; on the other hand, others claim this method does not really influence the outcome of this group of patients.4
HEMS was established in Iran in 2000. Since then, HEMS has been offering medical services in Tehran; however, on special occasions and during the new year and summer holidays, the services are available across the country. In Tehran, the majority of patients are transported to Imam Khomeini, Fayyaz Bakhsh and 7-Tir hospitals.
The present article is the first prospective cross-sectional study to describe the epidemiological characteristics of injuries and consequences of HEMS-transported patients in Tehran, aimed at evaluating the efficacy of HEMS, which is commonly considered a part of trauma coordination in a system lacking such coordination.
MATERIALS AND METHODS
Having been approved by the ethical board committee of Tehran University of Medical Sciences, the required correspondence was conducted with the authorities of the hospitals (Imam Khomeini, Fayyaz Bakhsh and 7-Tir) and the HEMS service in order to collect the necessary information.
The study was conducted over a 4-month period from May to August 2004, as more casualties are aeromedically transported to hospital during that time of the year due to better flight conditions, including a lower probability of rain and longer hours of daylight. It should be noted that according to Iranian EMS legislation, HEMS should be used for patients requiring EMS care but who are far from hospital or are in regions with heavy traffic.
In order to carry out the project, a questionnaire was designed based on the available literature and trauma specialists’ consensus; several general practitioners were trained to gather the necessary data. The questionnaire contained information about the accident (time, date and type of accident), demographic data on injured patients, primary Glasgow coma score (GCS) (evaluated by HEMS physicians), prehospital care performed, evaluations conducted in the emergency department, type of injury, mechanism of trauma based on the coding system of the International Classification of Diseases (ICD) 9th revision, care performed in hospitals according to the ICD10 scoring system, injury severity score (ISS), duration of hospitalisation, patients’ outcome and causes of death.
The questionnaires were then reviewed in Sina Trauma and Surgery Research Center; after applying the required amendments, they were entered into SPSS version 11.5 and analysed.
RESULTS
A total of 313 trauma patients was transported to the target hospitals via 138 helicopter flights during the study period; 239 (76.4%) of which were reported to be male (76.4%). The mean age of the patients was 31.1 years (SD 14.8).
Of the total patients aeromedically transported, 156 (49.8%), 105 (33.5%) and 52 (16.6%) patients were transported to Imam Khomeini, Fayyaz Bakhsh and 7-Tir Martyrs hospitals, respectively.
Table 1 outlines the mechanisms of trauma in the patients enrolled in the study. According to the findings, road traffic accidents were the most common mechanism.
Several organs were injured in the patients studied; head and face injuries (48.2%) followed by limb injuries (39.3%) comprised the main sites of injury (see table 2).
Among the patients injured in road traffic accidents, there were 249 car passengers (82.7%), 44 motorcyclists (14.6%) and eight pedestrians (2.7%). By the position in the car of casualties, 63 were reported to be drivers (20.1%), 75 were sited on the front seat (24%), 111 passengers were on the back seat (35.5%) and the position of 64 (20.4%) casualties was not known.
The most common injury in head and neck traumas was open wounds (52.1%). Broken ribs (35.2%) and pneumothorax (27%) were the most prevalent injuries in cases of thoracic trauma. Splenic and liver injuries were found in 33.3% of cases of abdomen and pelvic trauma. Fracture was reported in 158 (54.7%) of cases transported as a result of limb injuries (see table 3); 28.8% of patients only had lacerations and abrasions.
From the seven (2.2%) patients injured in the workplace, only four (1.3%) cases were occupational accidents. Blunt trauma was considered to be the main reason in 99.7% of cases. Most patients were unintentionally injured and only one patient (0.3%) was injured in a fight.
A mean number of 2.3 patients was transported in each flight. The patients in the study were transported to hospital by 138 flights; 31 transport cases (22.5%) were evacuated from freeways, main streets or beltways. With reference to the roads in the surroundings of Tehran, statistics show that there were 38 (27.5), 34 (24.6%), 30 (21.7%) and five (3.6%) flights in the west, south, north-east and north of Tehran, respectively. The peak hours of HEMS postings were 12:00–14:00 hours and 18:00–19:00 hours (fig 1).
The mean time for transporting patients from the accident scene to the hospital was 54 minutes, ranging from 10 minutes to 7 h (fig 2).
With regard to patients’ GCS, HEMS personnel detected normal consciousness (GCS 13–15) in 255 patients (81.5%), a moderate loss of consciousness (GCS 9–13) in 16 patients (5.1%) and loss of consciousness with GCS lower than 9 in 42 casualties (13.4%). In the present study, the mean GCS was reported to be 13.3 (SD 3.1).
The mean ISS of the patients enrolled in the study was calculated to be 8.6 (SD 8.6). A total of 166 (53%) patients had a mild injury (ISS lower than 7), whereas 73 (23.3%) and 74 (23.6%) were reported to have moderate and severe injuries, with ISS of 7–15 and more than 15, respectively.
Thirty (9.6%) patients were hospitalised in the intensive care unit; road traffic accidents (27 patients) and multiple traumas comprised the majority of these cases.
From the total number of HEMS-transported patients, 32 (10.2%) patients died; 28 male and four female patients. The mean age of the patients who died was 34.3 years (SD 15.3). Road traffic accidents were the main mechanism of trauma in the patients who died; the majority of these cases were reported to have head injuries.
From among the total HEMS-transported patients, only 142 patients (45.4%) were hospitalised long term. The mean duration of hospitalisation was reported to be 12.4 days (SD 19.1). It should be noted that 124 cases (39.6%) left the hospital by personal consent, indicating that the patient preferred to transfer to a private centre or a centre with which they had an insurance contract. In addition, 15 (4.8%) of the cases were referred to other health centres for further management by the healthcare staff (fig 3).
DISCUSSION
In recent years, several studies have been conducted all over the world comparing the consequences of HEMS and EMS (ambulance) with regard to the mortality and disability rate and the imposed financial and time costs of HEMS. Many of those studies did not reveal any significant differences between the severity of injury, mortality rates and the outcomes following HEMS and EMS (ambulance) transportations.5–7 However, others have referred to higher levels of expertise and more comprehensive training of the EMS personnel compared with HEMS.4 8
The present study was conducted on 313 trauma patients transported to three hospitals by the Tehran HEMS during a 4-month period.
The results showed that 76.4% of the casualties were male, which was similar to the findings of Shatney et al.3 In a multicentric study conducted by Thomas et al,6 it was also revealed that 70% of HEMS-transported patients were male and 72% were reported to be between 14 and 55 years old. The study also reported that approximately 17.5% of cases were aged 55 years and older. Conversely, our study showed that the majority of cases were 20–40 years old and only 5.85% of the patients were above 60 years of age. The findings also showed that trauma mainly occurs among the active population in society.
As in many other studies, the majority of Tehran HEMS-transported patients were injured due to penetrating trauma, particularly in road traffic accidents.9 10
Road traffic accidents were the most common mechanism of trauma among patients transported directly to the trauma centre. However, accidents secondary to sport, falls and fights comprised the main mechanisms of trauma in referred patients.11
Bartolacci et al9 have reported that head injury, particularly open wounds at the site, was the most common injury in HEMS-transported patients. According to that study, spinal cord trauma was found in 23% of patients, 7% had head trauma and 30% had head trauma associated with other injuries. Extremity injuries and fractures were the next most frequent injuries reported in the study.9 Another study also reported extremity injuries as the most common injuries.12
Several studies have indicated that the main reason for using HEMS is to reduce transport time when there is a long distance between the scene of the accident and the urban hospital.13 According to a study performed in 2002,3 it was shown that 54.7% of patients were transported faster via HEMS compared with EMS ambulances. The present study also reported that in more than two-thirds of flights, transported patients were transferred to hospital from outside the city (highways, expressways and suburbs), especially the southern and western regions; noting that it would require more time if ground ambulances were responsible for transporting patients. That fact is quite probable considering the heavy traffic in the areas mentioned (Tehran—Karaj Highway; Tehran—Qom Highway, Varamin Road, Islamshahr, …).
Deciding between HEMS or EMS is usually based on the place of the accident and the estimated transportation time. As mentioned before, the reason for using HEMS in trauma systems is to reduce the transportation time in rural and even urban areas. There is a golden time of 20 minutes for trauma patients to be transported to trauma centres.13 If the patient is transported in a maximum of 20 minutes, requisite treatments necessary for stabilising the patient’s haemodynamic status can be performed in less than an hour. Therefore, HEMS is used in areas where the EMS transportation time of patients is more than 20 minutes.5 The mean HEMS transportation time is reported to be less than 34 minutes in Los Angeles, USA.5 According to the study conducted by Shatney et al,3 the mean transportation time was estimated to be 17.1 minutes; which exceeded the golden 20 minutes in only 14.8% of flights. The study reported that the time required for removing the casualty from the vehicle was the reason for the excessive time.3 In the present study, most of the cases transported by Tehran HEMS were injured in accidents that took place outside the city (highways of Azadegan, Qom, Tehran, Karaj, Varamin, …).
The mean time for transporting patients to hospital in our study was 54 minutes; 13.1% of the flight postings were performed within 20 minutes or less. The transportation time was reported to be as high as 5–7 h in several cases, especially when the patient was transferred to a second health centre. As there is no trauma system in Iran, 39% of the casualties studied were first transported to a centre that did not have the required facilities, and therefore the paramedics were forced to take the patient to a second centre.
In a retrospective study,11 reviewing the charts of paediatric HEMS-transported casualties, 69% of the children were reported to be transferred to a child trauma centre following the stabilisation of their vital signs, whereas the other 31% were transported directly to the centre.
In our study, the mean ISS score of HEMS-transported patients was 8.6 and more than half of the patients had mild injuries. In a similar study,5 82% of the HEMS-transported patients were reported to have an ISS of less than 15; the score was reported to be higher than 30 in only 2% of patients. Similarly, Larson et al11 reported a mean ISS of 14.1 and 12.9 in patients directly transported to hospital and those transferred to other medical centres, respectively. Conversely, the mean ISS of HEMS-transported patients was calculated to be 19 in the study by Nicholl et al.10 Schwab et al14 also reported the mean ISS of these patients to be 36. These findings show that the severity of the injury is an acceptable reason for selecting patients who need to be transported via HEMS.
Using HEMS for faster transportation and the lack of sufficient skills among helicopter rescue personnel compared with EMS in industrial countries has resulted in the emergence of overtriage.8 The findings of the present study revealed excessively long transport time, overtriage in more than 55% of patients, and most worrisome, almost half of the patients were first transported to a hospital that had no trauma care capability. The high rate of mild to moderate injuries among HEMS-transported patients is due to overtriage, resulting from overestimation of the severity of the injury. These all show an urgent need for the development of a trauma system in Tehran, Iran.
CONCLUSION
The present study shows that HEMS is an effective and feasible option in countries with heavy traffic and no trauma system. The absence of a trauma system, however, contributes to overtriage in HEMS (transportation of patients without severe injuries) and long transportation times.
Acknowledgments
The authors of this article are indebted to the Trauma Research Center and the Research and Development Center of Sina Hospital for their cooperation.
REFERENCES
Footnotes
Competing interests: None.
Ethics approval: Ethics approval was obtained from ethical board committee of Tehran University of Medical Sciences.
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- Primary survey