Helicopter emergency medical services: their role in integrated trauma care

Can Helicopters Solve the Transport Dilemma for Patients With Symptoms of Large-Vessel Occlusion Stroke in Intermediate Density Areas? A Simulation Model Based on Real Life Data

Background

This modeling study aimed to determine if helicopters may optimize the transportation of patients with symptoms of large vessel stroke in “intermediate density” areas, such as Denmark, by bringing them directly to the comprehensive stroke center.

Methods

We estimated the time for the treatment of patients requiring endovascular therapy or intravenous thrombolysis under four configurations: “drip and ship” with and without helicopter and “bypass” with and without helicopter. Time delays, stroke numbers per municipality, and helicopter dispatches for four helicopter bases from 2019 were obtained from the Danish Stroke and Helicopter Registries. Discrete event simulation (DES) was used to estimate the capacity of the helicopter fleet to meet patient transport requests, given the number of stroke codes per municipality.

Results

The median onset-to-needle time at the comprehensive stroke center (CSC) for the bypass model with the helicopter was 115 min [interquartile range (IQR): 108, 124]; the median onset-to-groin time was 157 min (IQR: 150, 166). The median onset-to-needle time at the primary stroke center (PSC) by ground transport was 112 min (IQR: 101, 125) and the median onset-to-groin time when primary transport to the PSC was prioritized was 234 min (IQR: 209, 261).

A linear correlation between travel time by ground and the number of patients transported by helicopter (rho = 0.69, p < 0.001) indicated that helicopters are being used to transport more remote patients. DES demonstrated that an increase in helicopter capture zone by 20 min increased the number of rejected patients by only 5%.

Conclusions

Our model calculations suggest that using helicopters to transport patients with stroke directly to the CSC in intermediate density areas markedly reduce onset-to-groin time without affecting time to thrombolysis. In this setting, helicopter capacity is not challenged by increasing the capture zone.

Helicopter Emergency Medical Services in Buenos Aires: An Operational Overview

As part of the emergency medical care system, helicopter emergency medical services (HEMS) have a different crew composition from the traditional team. HEMS consist of a pilot, doctor, and firefighter with rescue skills and training in basic life support on board an air ambulance. This allows the adaptation to different environments and increases the varieties of air procedures normally performed. HEMS began operating relatively recently in Buenos Aires. Yet, in 3 years, its use grew to such an extent that in 2015 it tripled, and by 2016 the number of medical assists was 4 times greater than in 2014. Furthermore, over the 3-year study period, 92% to 95% of assisted victims were traffic accident casualties requiring primary care. The HEMS crew is informed about the availability of resources in the acute care general hospitals and can therefore transfer patients to the most appropriate trauma center in the shortest time. However, 75% to 85% of the time, the choice of destination is strongly influenced by the availability of a helipad and the operational safety that it provides.

Air Medical Service: a Review on its Cost-Effectiveness, the Role of in-Flight Physician and Safety

A literature review of recent articles on helicopter aeromedical services (HEMS) was carried out. The methods used included a Medline search using the key words ‘air ambulance’ and ‘helicopter EMS’. Other sources of information were also obtained from internet web-sites such as www.aams.org , www.info.gov.hk/gfs/performctx.htm and eMedicine.com free online textbook. The results show that HEMS is cost-effective with a good safety record, and it is also evident that in-flight physicians are particularly useful in improving the survival of severely injured patients. Strict criteria to select patients for HEMS operations must be publicised and followed by both callers and the HEMS dispatcher.

[Air rescue missions at night: Data analysis of primary and secondary missions by the DRF air rescue service in 2014]

The advantages that are inherent to the air ambulance service are shown in a reduction in mortality of critically ill or injured patients. The air ambulance service ensures quick and efficient medical care to a patient as well as the immediate transport of patients to a suitable hospital. In addition, primary air rescue has proved to be effective as a support for the standard ground-based ambulance services in some regions of Germany during the night. Under certain conditions, such as the strict adherence to established, practiced and coordinated procedures, air rescue at night does not have a significantly higher risk compared to operations in daytime. Particular requirements should be imposed for air rescue operations at night: a strict indication system for alerting, 4-man helicopter crews solely during the night as well as pilots (and copilots) with the correct qualifications and experience in dealing with night vision devices on a regular basis. Moreover, the helicopters need to be suitable and approved for night flying including cabin upgrades and the appropriate medical technology equipment. To increase the benefits of air rescue for specific diseases and injuries, a nationwide review of the processes is needed to further develop the primary air rescue service.

Helicopter emergency medical service inTehran, Iran: a descriptive study

OBJECTIVE

The study provides descriptive information regarding missions performed by Tehran helicopter emergency medical services (HEMS) during a 1-year period.

METHODS

All patients transferred by Tehran HEMS between March 2006 and March 2007 were enrolled in this descriptive study. Based on HEMS records, information was gathered on flight time, the number of patients transferred in each flight, and mission outcomes.

RESULTS

During the 1-year study, a total of 353 patients were transported via 138 helicopter flights to 4 medical care centers in Tehran. The mean flight time, the time from the initial call until the patient was delivered to a medical facility, was 36.56 ± 18.44 minutes.

CONCLUSION

Tehran HEMS is still far from attaining optimal values, particularly regarding flight time. More efforts are needed to improve the timing as a component of care and the quality of care provided by this system.

Factors impacting on the activation and approach times of helicopter emergency medical services in four Alpine countries

Background

The outcome of severely injured or ill patients can be time dependent. Short activation and approach times for emergency medical service (EMS) units are widely recognized to be important quality indicators. The use of a helicopter emergency medical service (HEMS) can significantly shorten rescue missions especially in mountainous areas. We aimed to analyze the HEMS characteristics that influence the activation and approach times.

Methods

In a multi-centre retrospective study, we analyzed 6121 rescue missions from nine HEMS bases situated in mountainous regions of four European countries.

Results

We found large differences in mean activation and approach times among HEMS bases. The shortest mean activation time was 2.9 minutes; the longest 17.0 minutes. The shortest mean approach time was 10.4 minutes; the longest 45.0 minutes. Short times are linked (p < 0.001) to the following conditions: helicopter operator is not state owned; HEMS is integrated in EMS; all crew members are at the same location; doctors come from state or private health institutions; organization performing HEMS is privately owned; helicopters are only for HEMS; operation area is around 10.000 km2; HEMS activation is by a dispatching centre of regional government who is in charge of making decisions; there is only one intermediator in the emergency call; helicopter is equipped with hoist or fixed line; HEMS has more than one base with helicopters, and one team per base; closest neighboring base is 90 km away; HEMS is about 20 years old and has more than 650 missions per year; and modern helicopters are used.

Conclusions

An improvement in HEMS activation and approach times is possible. We found 17 factors associated with shorter times.

The top five research priorities in physician-provided pre-hospital critical care: a consensus report from a European research collaboration

Background

Physician-manned emergency medical teams supplement other emergency medical services in some countries. These teams are often selectively deployed to patients who are considered likely to require critical care treatment in the pre-hospital phase. The evidence base for guidelines for pre-hospital triage and immediate medical care is often poor. We used a recognised consensus methodology to define key priority areas for research within the subfield of physician-provided pre-hospital critical care.

Methods

A European expert panel participated in a consensus process based upon a four-stage modified nominal group technique that included a consensus meeting.

Results

The expert panel concluded that the five most important areas for further research in the field of physician-based pre-hospital critical care were the following: Appropriate staffing and training in pre-hospital critical care and the effect on outcomes, advanced airway management in pre-hospital care, definition of time windows for key critical interventions which are indicated in the pre-hospital phase of care, the role of pre-hospital ultrasound and dispatch criteria for pre-hospital critical care services.

Conclusion

A modified nominal group technique was successfully used by a European expert group to reach consensus on the most important research priorities in physician-provided pre-hospital critical care.

The experience of Teesside helicopter emergency services: doctors do not prolong prehospital on-scene times

BACKGROUND

The benefits of helicopter emergency medical services (HEMSs) attending the severely injured have been documented in the past. The benefits of doctors attending HEMS casualties have been demonstrated in particular in inner-urban and metropolitan areas. However, for UK regions with potentially less major trauma, concerns have been raised by ambulance services that a willingness of doctors to "stay and play" may lead to unnecessary delays on-scene without any additional benefit to the patient.

AIMS

To identify factors that do prolong on-scene time, establish whether doctors "stay and play" on-scene compared with paramedics and document how often advanced medical skills may have to be used by HEMS doctors working outside the London HEMS environment.

METHODS

Patient report form data were studied with regard to the number of and mean on-scene times of missions flown to (A) road-traffic collisions (RTCs), (B) other trauma calls (OTCs) and (C) medical emergencies. Trauma missions (categories A and B) were further subcategorised with regard to associated patient entrapment. Any advanced medical interventions (AMIs) performed by HEMS doctors were recorded and categorised. Finally, we looked at the difference in on-scene times for physician-paramedic partnerships (PPPs) and conventional paramedic crews (CPCs) for the above categories and subcategories.

RESULTS

A total of 203 patient report forms were identified and examined. In all, 44.3% of missions were flown to RTCs with a further 44.3% for OTCs and 11.4% to medical emergencies. AMIs were performed by HEMS doctors in 34.1% of PPP missions, with a prehospital rapid sequence induction rate of 3.8%. Overall mean on-scene time was 25 min, with no difference for PPP and CPC missions. The mean on-scene time was prolonged by 6 min for RTCs (p = 0.006) and by 23 min for patient entrapment (p<0.001). No significant differences were found for the comparison between PPPs and CPCs in any of the subgroups A-C. However, there seemed to be a trend towards reduced on-scene times of PPPs for medical emergencies and patient entrapments.

DISCUSSION

This study did not show any significant prolongation of mean on-scene times for PPP missions either overall or for any of the subgroups A-C. The fact that AMIs were performed in a large number of missions attended by HEMS doctors seems to further justify their current role in providing improved care at the roadside without leading to any delays in transfer to definitive care.

Resources for managing trauma in rural New South Wales, Australia

BACKGROUND

Trauma bypass is not always appropriate in the management of rural trauma because of the large distances and travel times. Rural hospitals in New South Wales, Australia are an essential component of the statewide integrated trauma system. The present study profiles the trauma resources of base hospitals in rural New South Wales.

METHODS

A structured questionnaire, addressed to the 'Director, Emergency Department' was distributed to all rural base hospitals in New South Wales. Follow-up telephone interviews were administered to complete data collection.

RESULTS

Fourteen hospitals were identified. General and orthopaedic surgeons provided trauma care in all hospitals. Forty-three per cent of hospitals had resident subspecialty surgeons. Fifty per cent of hospitals had a formal hospital trauma team. In the remaining hospitals, the most common reason (86%) stated for the absence of a formal trauma team was a lack of personnel to provide 24 h immediate response to all trauma presentations. Seventy-one per cent of hospitals are staffed by a single doctor after hours. All hospitals had 24 h access to plain radiography and blood products. 86% had 24 h access to ultrasound and computed tomography, although always on an 'on-call' basis after hours. All hospitals had the capability to maintain ventilated patients, averaging two ventilated beds per hospital. An average of two trauma patients per hospital per month is transferred to a larger institution. Sixty-four per cent of hospitals participated in a trauma retrievals for their surrounding areas. Seventy-one per cent of hospitals engaged in quality assurance activities regarding trauma outcomes.

CONCLUSIONS

Formal responses to major trauma in rural base hospitals in New South Wales are often restricted by a lack of specialist medical personnel. Nevertheless, the majority of hospitals have the resources to manage major trauma.

The effects of air ambulance admissions on orthopaedic trauma services in a single hospital

Emergency air ambulance admissions to the authors' hospital have increased five-fold from 18 in 1992-1993 to 92 in 1998-1999. The service implications for hospitals receiving air ambulance admissions is unknown.

AIM

An audit/analysis of all emergency air ambulance admissions to the authors' hospital between August 1998-July 1999.

METHOD

Admissions identified from computer records. The case notes were then retrospectively analysed. Data was collected on accident location, admitting specialty, number of orthopaedic procedures and their operative time, and length of inpatient stay.

RESULTS

There were 92 patients brought in by air ambulance. Hospital notes were available for 82 and a further 8 had A&E case notes only available for analysis. A total of 34 (38%) were admitted under the orthopaedic surgeons, 28 (31%) under the neurosurgeons, 10 (11%) under the plastic surgeons, 2 (2%) under the general surgeons and 2 (2%) under the physicians. Nine patients were discharged home from the A&E department, two died in A&E and five were transferred to other hospitals. Four of the neurosurgical patients needed orthopaedic input. The admitted patients required 122 orthopaedic procedures taking 120 h of theatre time. The total orthopaedic inpatient stay was 628 days, of which 145 days were in the intensive care or high dependency units. A total of 28 (80%) of the orthopaedic patients came from outside the hospital's catchment area.

CONCLUSIONS

Admissions by air ambulance place a high demand on orthopaedic services and often originate from outside the hospital's catchment area. Additional resources may be required by hospitals receiving trauma patients by this route.

The prognostic importance of trauma scoring systems for morbidity in children with penetrating abdominal wounds: 17 years of experience

BACKGROUND/PURPOSE

Risk factors that may independently predict morbidity in children with penetrating abdominal wounds (PAW) have not been elucidated fully. The aim of this study was to identify not only correlated risk factors for morbidity in children with PAW, but also to evaluate the independent predictive value of 3 different trauma scoring systems: the Injury Severity Score (ISS), the Penetrating Abdominal Trauma Index (PATI), and the Pediatric Trauma Score (PTS).

METHODS

Between January 1983 and November 2000, 119 children (99 boys, 20 girls) presenting with PAW were reevaluated by an analysis of the relationship between overall morbidity and potential risk factors.

RESULTS

Wounds were caused by firearm trauma in 85 children and stabbing in 34. Univariate analysis found that age greater than 10 years, trauma mechanism, number of intraabdominal organs injured (NOI) greater than 2, presence of penetrating injury, and ISS and PATI score were associated with greater than 3-fold increased incidence of morbidity (P <.05). The relative risk of a postoperative septic complication was higher than 2 for the following risk factors: age greater than 10 years, shotgun injury, number of organs injured greater than 2, presence of colon injury, ISS greater than 15, and PATI score greater than 15. Multivariate analysis showed that only ISS (P =.02), and PATI score (P =.03) were independently significant in predicting morbidity.

CONCLUSION

ISS and PATI score were the most important indicators found to be independently associated with morbidity.

Use of an ambulance-based helicopter retrieval service

BACKGROUND

John Hunter Hospital is the major trauma centre for a region covering more than 25,000 square kilometres. The helicopter primary retrieval service for trauma is paramedic staffed and protocol driven. The aim of the present study was to assess the overtriage rate created by such protocols, and to assess the benefit to patient outcomes that may be attributable to the service.

METHODS

The John Hunter Hospital trauma database was used to identify all cases arriving by helicopter in 1996, as well as their demographic details, injury severity score, details of the accident and outcome. An expert panel reviewed the medical records for the 184 primary retrievals. Using a consensus model, estimates of time delay or saving were calculated and likelihood of benefit, no benefit or harm was assessed.

RESULTS

A total of 3087 trauma patients were assessed at John Hunter Hospital in 1996, of which 8% arrived by helicopter. Of the primary retrievals, 67.6% had an injury severity score of 9 or less, with only 17.9% having a score of 16 or greater. Twelve patients were discharged from Emergency and 36% were discharged within 48 h. The overall mortality was 5.0%. Twenty-five per cent of patients were retrieved within 35 km of John Hunter Hospital with minimal attributable benefit. Overall 1.7% of patients were felt to have been potentially harmed, 17.3% to have benefited and 81.0% to have had no attributable benefit related to the helicopter use.

CONCLUSIONS

Although the majority of retrievals are for minor injuries, the service provides benefit for the region. There is potential for harm, however, where base hospitals are overflown in situations where patients have airway compromise, and where patient transfer is delayed due to helicopter activation. Primary helicopter tasking to trauma cases within 35 km of the major trauma centre is seldom beneficial.

Factors affecting mortality and morbidity in patients with abdominal gunshot wounds

Risk factors that may independently predict mortality and morbidity in patients with abdominal gunshot wounds have not been fully elucidated. We prospectively studied the effects of 12 potential risk factors on mortality and morbidity in 82 patients with abdominal gunshot wounds who required laparotomy. Univariate analysis of these factors revealed that shock on admission, presence of penetrating colon injury and number of intra-abdominal organs injured (NOI)>2 were associated with greater than threefold increased incidence of death (p<0.05). Penetrating abdominal trauma index (PATI) score>15 was associated with twentyfold increased incidence of death (P<0.0001). Multivariate analysis showed that only PATI (P=0.001), number of postoperative complications per patient (N(comp)) (P=0.023) and presence of shock on admission (P=0. 028) were independently significant in predicting mortality. PATI was the only risk factor that independently predicted the development of postoperative infectious complications and N(comp) (P<0.0001). The type of gun used was not a significant risk factor (P>0.05). The 15 (18.3%) non-survivors were significantly older than survivors (P=0.02), had longer operations (P=0.004) and their NOI, PATI and N(comp) were significantly higher (P<0.001). The uniformly prolonged injury to surgery time in all patients contributed to the high incidence of infectious complications (62.2%) and mortality. PATI score was the most important factor found to be independently associated with mortality and morbidity in our subset of patients with prolonged injury to surgery time and high rate of colon injury.