Here's a HEMS study from Bryan Bledsoe and others..

[Ace844]

(Helicopter Scene Transport of Trauma Patients with Nonlife-Threatening Injuries: A Meta-Analysis

[Original Articles)

Bledsoe, Bryan E. DO, FACEP; Wesley, A Keith MD, FACEP; Eckstein, Marc MD, FACEP; Dunn, Thomas M. PhD; O’Keefe, Michael F. MS

From the The George Washington University Medical Center (B.B.), Washington, DC; Saint Johns Hospital (K.W.), Minneapolis, MN; University of Southern California (M.E.), Los Angeles, CA; University of Northern Colorado (T.D.), Greeley, CO; and Vermont Department of Health (M.O.), Burlington, VT.

Submittted for publication October 12, 2004.

Accepted for publication May 18, 2005.

Address for Reprints: Bryan Bledsoe, DO, 6420 Hayes Road, Midlothian, Texas 76065-5235; email: bbledsoe@earthlink.net.]

Abstract

Background: Helicopters have become a major part of the modern trauma care system and are frequently used to transport patients from the scene of their injury to a trauma center. While early studies reported decreased mortality for trauma patients transported by helicopters when compared with those transported by ground ambulances, more recent research has questioned the benefit of helicopter transport of trauma patients. The purpose of this study was to determine the percentage of patients transported by helicopter who have nonlife-threatening injuries.

Methods: A meta-analysis was performed on peer-review research on helicopter utilization. The inclusion criteria were all studies that evaluated trauma patients transported by helicopter from the scene of their injury to a trauma center with baseline parameters defined by Injury Severity Score (ISS), Trauma Score (TS), Revised Trauma Score (RTS), and the likelihood of survival as determined via Trauma Score-Injury Severity Score (TRISS) methodology.

Results: There were 22 studies comprising 37,350 patients that met the inclusion criteria. According to the ISS, 60.0% [99% confidence interval (CI): 54.5–64.8] of patients had minor injuries, According to the TS, 61.4% (99% CI: 60.8–62.0) of patients had minor injuries. According to TRISS methodology, 69.3% (99% CI: 58.5–80.2) of patients had a greater than 90% chance of survival and thus nonlife-threatening injuries. There were 25.8% (99% CI: -1.0–52.6) of patients discharged within 24 hours after arrival at the trauma center.

Conclusions: The majority of trauma patients transported from the scene by helicopter have nonlife-threatening injuries. Efforts to more accurately identify those patients who would benefit most from helicopter transport from the accident scene to the trauma center are needed to reduce helicopter overutilization.

--------------------------------------------------------------------------------

The use of helicopters to transport patients from the scene of their injury to a trauma center has become a major part of the modern trauma care system. Early studies reported decreased mortality for trauma patients transported by helicopters when compared with those transported by ground ambulances.1–4 However, more recent research has questioned the benefit of helicopter transport of trauma patients.5–7 Helicopter utilization criteria have been established by leading industry and professional organizations to aid prehospital personnel in determining when to summon a medical helicopter to a trauma scene.8–10 These criteria utilize both mechanism of injury (MOI) information and physiologic parameters to determine which patients may benefit from helicopter transport. Underutilzation of helicopter transport can result in some patients being denied the benefit of the speed and care helicopter transport affords while overutilization results in inappropriate use of this relatively expensive and potentially dangerous modality.11

Prehospital triage of trauma patients is an inexact science and some degree of overtriage (patients transported by helicopter who are later determined to have nonlife-threatening injuries) is generally accepted.12 This is to assure that the majority of trauma patients who are likely to benefit from helicopter transport have it available. Several studies have demonstrated that most helicopter transports adhere to established utilization criteria.13–16 However, utilization describes frequency of use rather than need. Need, when applied to health care technology, implies that the proposed technology provides a demonstrated patient benefit. Thus, to be considered beneficial, helicopter transport of trauma patients must show improved outcome, enhanced safety, and/or reduced overall health care cost when compared with ground transport.17

The purpose of this study was to determine the percentage of trauma patients transported from the scene by medical helicopter who have nonlife-threatening injuries.

METHODS

This study was an observational meta-analysis of peer-reviewed articles in the English language literature regarding helicopter transport of trauma patients.18 Each of the authors was independently polled to establish inclusion criteria for the study. The inclusion criteria called for studies that used validated and recognized trauma scoring systems to allow for comparison of outcomes and injury severity across different patient populations.

Studies were also limited to helicopter transports where trauma patients were retrieved from the scene of the injury and transported to a trauma center/hospital. Interfacility helicopter transport of trauma patients were excluded as these patients often received stabilization and definitive care at the referral hospital before transfer and thus their values on standardized trauma scoring systems might be artificially skewed because of the care provided.

After determination of selection criteria, an on-line search of Pub Med was carried out using the following keywords: “helicopter”, “helicopter + trauma” “helicopter + utilization criteria.” The keyword “helicopter” returned 5836 citations, “helicopter + trauma” revealed 977 citations, and “helicopter + utilization criteria” revealed 77 citations. These citations were independently reviewed by the authors. Forty-eight articles were identified as possibly relevant for inclusion. These were retrieved and evaluated independently by three of authors (BEB, AKW, ME) and 22 articles were determined to meet one or more of the inclusion criteria.

Standard scoring systems that quantify the severity of trauma include the Injury Severity Score (ISS), Trauma Score (TS), Revised Trauma Score (RTS), and Trauma Score-Injury Severity Score (TRISS). The ISS is an anatomic scoring system for patients with multiple injuries and does not include physiologic variables. The ISS ranges from 0 to 75 with the severity of injury and mortality increasing with the score. Patients with an ISS >15 are deemed to require specialized trauma care while patients with an ISS of 15 or less are considered to have nonlife-threatening injuries.19–21 The original TS included four physiologic parameters (respiratory rate, respiratory expansion, systolic blood pressure, capillary refill) and the Glasgow Coma Scale (GCS). It had a range from 1 to 16 points. Patients with a score of 12 or less were deemed to be seriously injured and required specialized trauma care.22 The TS was revised in 1989 and became the RTS. Two of the physiologic parameters (respiratory expansion and capillary refill) were dropped. The range of the RTS is 0 to 12. Patients with a score of 11 or less are deemed to require specialized trauma care. While the RTS is most commonly used in the prehospital setting, a weighted form of the scale is used to predict patient outcomes following trauma. With the weighted RTS, greater emphasis is placed on the GCS. The range for the weighted RTS is 0 to 7.8408. Higher scores are associated with a better prognosis.23 Patients with a weighted RTS score of <4 are felt to benefit from specialized trauma care while patients with a score of >=4 are generally considered to have minor injuries. The TRISS system combines the RTS, the ISS, the patient’s age, and the type of trauma sustained (blunt or penetrating) to determine a probability of survival (Ps).24

To determine which patients were unlikely to benefit from helicopter transport, we used the standard trauma scoring systems described above. Based upon validated criteria, patients having a TS >=13, a RTS >11, a weighted RTS >=4, and/or an ISS <=15 were deemed to have sustained nonlife-threatening injuries and therefore did not require helicopter transport. Likewise, a TRISS-derived probability of survival (Ps) of greater than 0.90 (a 90% or better chance of survival) also represents nonlife-threatening injuries and was included as one of the inclusion criteria.25 Finally, patients who were discharged from the emergency department or hospital within 24 hours of admission for trauma are generally considered to have nonlife-threatening injuries and were included in the inclusion selection criteria.26

Statistical analysis was completed by two of the authors (TMD and MFO). Ultimately, this study had four different variables (ISS, TS, TRISS, and Discharge within 24 hours of admission). A meta-analysis was conducted for each of the four variables by entering the percentages of patients with scores indicative of nonlife-threatening injuries into a statistical software package (Statistical Package for the Social Sciences, Version10.0, SPSS, Inc., Chicago, Ill.). The total number of patients was also entered to weight each percentage. A mean percentage was calculated and a confidence level around each mean was also computed.

RESULTS

There were 22 articles spanning 21 years (1983–2004) that met the inclusion criteria providing a study cohort of 37,350 patients (Table 1).2,3,5–7,26–42 Table 2 details the 26 studies excluded from the study group and the reason(s) for exclusion.16, 43–67

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 1 Descriptions of Studies Included in Final Meta-Analysis Sample

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 2 Description of Studies Excluded From Final Meta-Analysis Sample

--------------------------------------------------------------------------------

Analysis

Thirteen of the 22 studies meeting inclusion criteria utilized the ISS and provided score stratification sufficient to determine the number of patients who had an ISS <=15. There were a total of 31,244 patients in this subgroup of which 18,629 (60.0%) [99% confidence interval (CI): 54.5–64.8] had an ISS <=15 and thus nonlife-threatening injuries. This subgroup is detailed in Table 3.

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 3 Patients with ISS of <=15

--------------------------------------------------------------------------------

Two of the 22 studies utilized the TS and provided score stratification sufficient to determine the number of patients who had a TS >=13. There were a total of 2,110 patients in this subgroup of which 1296 (61.4%) (99%CI: 60.8–62.0) had a TS >=13 and thus nonlife-threatening injuries. This subgroup is detailed in Table 4.

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 4 Patients with a Trauma Score >=13

--------------------------------------------------------------------------------

Only 1 of the 22 studies (Eckstein 7) utilized the RTS. However, this study also utilized the ISS system. Because of this, the RTS scores were not included in the meta-analysis. Eleven of the 22 studies utilized TRISS methodology and provided a stratified listing of Ps values. There were a total of 6,328 patients in this subgroup of which 4,414 (69.3%) (99% CI: 58.5–80.2) had a TRISS Ps >= 0.90 and thus nonlife-threatening injuries. This subgroup is detailed in Table 5.

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 5 Patients with a TRISS p > 0.90

--------------------------------------------------------------------------------

Five of the 22 studies provided data detailing the number of patients discharged from the hospital within 24 hours of admission after helicopter transport from the scene of their injury. There were a total of 1,850 patients in this subgroup of which 446 (25.82%) (99% CI: -0.90–52.63) were discharged from the emergency department and not admitted to hospital. Thus, one out of every four trauma patients transported by helicopters in this subgroup had injuries so minor that they did not require admission to hospital. This subgroup is detailed in Table 6.

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 6 Patients Discharged From Hospital in Less Than 24 h

--------------------------------------------------------------------------------

The sub-group findings were consistent across the three trauma scoring systems utilized. Figure 1 details the relationship between the various subgroups described above.

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Fig. 1. Percentage of patients with minor injuries by scoring system.

--------------------------------------------------------------------------------

DISCUSSION

Our study demonstrated that the majority of trauma patients transported by medical helicopter from the scene had nonlife-threatening injuries. We believe there are two possible explanations for this phenomenon. First, there may be a significant degree of overutilization of helicopter scene flights for trauma by air-medical services despite quality assurance oversight that reveals these flights to be nonbeneficial. Second, and more probable, the apparent overutilization may be because of a significant degree of overtriage in the field by prehospital providers resulting in inappropriate requests for helicopter scene transport.

Our findings are similar to other studies that have documented that a significant number of trauma patients transported from the scene to a hospital by medical helicopter do not receive any added benefit from helicopter transport. The incidence of non beneficial helicopter transport of trauma patients identified by these authors is similar to what we have identified in our meta-analysis (see Table 7).

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 7 Incidence of Nonbeneficial Helicopter Transports for Trauma Patients

--------------------------------------------------------------------------------

This meta-analysis suggests that current helicopter utilization criteria may result in a significant degree of overutilization. There are several sets of helicopter usage criteria for trauma patients. The Association of Air Medical Services (AAMS) has published a set of criteria.8 In addition, the Association of Air Medical Physicians (AAMP) has also published criteria which were subsequently affirmed by the Air Medical Physicians Committee of the National Association of Emergency Medical Services Physicians (NAEMSP).10 These criteria are quite similar and largely-based on criteria established by the American College of Surgeons.69 These criteria tend to emphasize MOI and situational conditions.

Many helicopter services publish their own criteria that generally follow the national consensus criteria. However, these criteria tend to be overly broad. For example, based on commonly used criteria, two or more long bone fractures meets criteria for helicopter transport. However, such injuries are often minor such as an uncomplicated fracture of the tibia and fibula or an uncomplicated fracture of the radius and ulna. Table 8 is an example of current helicopter utilization criteria provided to prehospital personnel by medical helicopter programs.70

--------------------------------------------------------------------------------

[Help with image viewing]

[Email Jumpstart To Image] Table 8 Typical Criteria for Air Medical Dispatch for Trauma Scene Responses

--------------------------------------------------------------------------------

Several researchers have recently questioned the ability of current trauma triage criteria to identify which patients might benefit from specialized trauma care. The MOI has been found to correlate poorly with injury severity. In one study, the MOI criteria alone only identified 73% of patients with an ISS >15.71 Wuerz and colleagues compared physiologic criteria with MOI criteria in 333 trauma patients and found that physiologic criteria, when used alone, had a high specificity (85.7%) but low sensitivity (55.6%). MOI criteria alone had a high sensitivity (86.6%) yet low specificity (19.9%). In their study, use of physiologic criteria alone would miss 44% of patients with an ISS >15 and 16% of the fatalities. The MOI criteria would capture 87% of major trauma patients missed by the physiologic criteria but would also capture an additional 25 patients with minor injuries representing an overtriage rate of 37.5%.40 Cook and colleagues have suggested that eliminating MOI as a triage criterion will result in reduction of trauma patient overtriage, which improves resource allocation.72 Black and colleagues introduced an algorithm that emphasized simple physiologic variables to determine which trauma patients should be transported from the scene by helicopter in the United Kingdom. A fundamental component of their algorithm is the dictum that patients should always be transported by ground ambulance if the transport time is less than 45 minutes.73 Diaz and colleagues found that, unless the helicopter is dispatched simultaneously with the ground ambulance, helicopter transport times are slower when the distance is less than 45 miles from the hospital.74 Future studies should critically evaluate each MOI and physiologic criteria to determine the best predictors of helicopter usage.

Schiller et al. was among the first to recognize that helicopter transport of urban trauma patients may be nonbeneficial. In a retrospective study of patients in the Phoenix, AZ metropolitan area, they compared ground versus air transport of trauma patients and found that helicopter transport did not improve survival.61 Norton et al. found a high proportion of inappropriate scene flights in the Portland (Oregon) area. They suggested that utilization could be improved by using physiologic markers to determine which patients might benefit from helicopter transport.34 Cunningham et al. found that outcomes were not uniformly better among trauma patients transported by helicopter in North Carolina.5 Braithwaite et al. retrospectively evaluated 8 years of data in the Pennsylvania trauma registry and found that helicopter transport of trauma patients did not affect the estimated odds of survival.28 Kerr et al. was able to document improved survival in trauma patients transported by helicopter in Maryland when the patient had an ISS >31.31 Wills et al. had an independent panel retrospectively evaluate 179 trauma scene flights in northern New South Wales, Australia. The panel found that helicopter transport only benefited 17.3% of patients and possibly was harmful to 1.7%.39 Shatney et al. retrospectively studied all trauma patients transported to the Santa Clara Valley (California) trauma center by helicopter for a 10 year period (1990–2001) and found that only 22.8% of the study population possibly benefited from helicopter transport.6

Several studies have demonstrated a significant overutilization of helicopter transport for pediatric trauma patients. Moront et al. performed a retrospective assessment of triage criteria and utilization patterns for helicopter patients transported to the Children’s National Medical Center in Washington, DC. They were able to demonstrate that helicopter transport was associated with better survival rates among urban injured children. However, they found an overtriage rate of 85% and, based upon this, recommended that the use of physiologic criteria (GCS and heart rate) would improve helicopter resource utilization without compromising care.33 Eckstein et al. reported that 83% of urban injured children transported by helicopter in Los Angeles (California) had minor injuries. They found that pediatric trauma patients with a GCS <10 and/or RTS <=6.5 are those most likely to benefit from helicopter transport.7 Larson et al. compared outcomes of injured children transported by helicopter to those transported by ground ambulance in central Ohio. They found that 68% of children had minor injuries and, overall, were not able to verify any benefit for pediatric trauma patients transported by helicopter directly from the injury scene to a pediatric trauma center.32

Additionally, beyond the issue of overutilization, helicopters are costly to operate. The average helicopter charge is typically 10 to 15 times that of ground ambulance transportation. Hourly operational costs can exceed $5,000.00 per hour.28,38,75,76

Despite the cost, many operators enjoy significant downstream revenues from air medical operations. In FY 2001, the University of Michigan Health System’s Survival Flight program had operating costs of approximately $6.0 million but generated inpatient revenues of $62.0 million (excluding professional fees).77

There has been a marked increase in the number of medical helicopter accidents in the United States.78 In fact, half of all accidents in one 10-year study (1993–2002) occurred during the last 3 years of the study period.79 Because of the lack of a centralized database, it is impossible to determine whether this increase in accidents reflects a decline in operational safety or merely reflects the fact that there are more aircraft flying more missions. In January of 2005, in response to a sharp increase in fatal medical helicopter accidents, the NTSB and the Federal Aviation Administration (FAA) launched safety reviews of medical helicopters.80

It is curious that early studies demonstrated that helicopter transport decreased mortality from trauma while more recent studies have indicated little or no benefit from helicopter transport. The authors believe this reflects the tremendous improvements in ground prehospital care observed over the last 20 years including more widespread advanced life support units and markedly enhanced EMT and paramedic education. Other factors that may explain this difference include improved categorization of hospitals, the organization and implementation of regional trauma systems, trauma centers, and postgraduate educational programs that specialize in trauma care.

There are several limitations in this study. First, all of the studies included in our meta-analysis were uncontrolled. Second, the majority of the included studies were of a retrospective design and are thus at risk for selection bias. However, prospective studies of medical helicopter utilization are difficult as medical helicopters are widely perceived as beneficial and it would be difficult to secure IRB approval to conduct a randomized clinical trial where one subset of patients would not receive this modality. Also, as with all observational studies, there exists the possibility of publication bias.

Third, it is assumed that helicopter utilization is based on scientific criteria that accurately predict the likelihood of the presence of major trauma. Our meta-analysis did not undertake an evaluation of each specific criterion as the included studies did not stratify the specific criteria used to justify helicopter utilization.

Fourth, current helicopter utilization criteria are applied at the scene of trauma while the ISS is calculated retrospectively once the patient has received definitive care. The use of the ISS has been reported to not identify a subset of trauma patients who may benefit from definitive trauma care. However, the ISS is usually applied retrospectively following hospital admission and is not routinely used for prehospital trauma triage decision making. The ISS is the scoring system most commonly used in the studies referenced in this article.

The use of the TRISS system has both benefits and limitations. TRISS is widely used and validated. However, it is applied retrospectively and does not aid prehospital personnel in determining which patients may actually benefit from helicopter transport Furthermore, the TRISS has been reported to overestimate survival in patients who are severely injured.42 However, in our cohort we were interested in patient with minor injuries.

Finally, there are those patients who might benefit from the assessment and monitoring provided in a tertiary care trauma center based upon their MOI or field vital signs, even though they ultimately did not require surgical intervention. One example is a pediatric patient with a splenic hematoma who is closely monitored in an ICU setting, but ultimately does well with conservative management.

The incidence of patients transported from trauma scenes by helicopter and subsequently discharged from the emergency department or hospital in less than 24 hours has not been widely studied. However, review of the recent literature demonstrates a significant percentage of trauma patients transported by helicopter were discharged. The percentage of patients discharged from the hospital in less than 24 hours in our meta-analysis had a large CI and thus does not have the power to make any conclusions. Additional studies and a larger sample size are necessary to further define the significance of this finding. The data on discharges in less than 24 hours was presented as an incidental finding but worthy of further investigation.

The potential difference in prehospital care provided by helicopter transport is a potentially confounding variable. In some of the systems that were studied, helicopters were staffed with flight nurses, flight paramedics, or flight surgeons who may have a greatly expanded scope of practice compared to the ground-based EMS providers in their respective jurisdictions. Prehospital interventions such as definitive airway control with the use of paralytic induction agents (rapid sequence induction [RSI]) may be permitted by flight paramedics but not ground-based paramedics in the same system. It is possible that patients with closed head injury and a low GCS might have had airway compromise that was controlled via the use of RSI, even though the patient was ultimately determined to have a minor head injury or was intoxicated. But, despite low ISS values (reflecting nonlife-threatening injuries), such prehospital intervention may have been life-saving.81 Without prospective cohort-controlled studies, it is difficult to draw definitive conclusions.

Additional comparative studies are needed to determine the benefits of the various modes of transport (ground, helicopter, and fixed-wing). In addition, the implementation of statewide and national registries of helicopter utilization would provide an unbiased centralized repository of data that will help answer some of the questions raised in this study. Finally, given the costs and risks associated with their use, further research must refine the utilization criteria to better define and predict those patients who would benefit most from helicopter transport.

CONCLUSIONS

The majority of trauma patients transported from the scene by helicopter have nonlife-threatening injuries. Additional studies are required to clearly identify the subset of trauma patients who would benefit most from helicopter transport and revise utilization criteria to reflect these studies.

REFERENCES

1. Cowley RA, Hudson F, Scala E, et al. An economical and proved helicopter program for transporting the emergency critically-ill and injured patient in Maryland. J Trauma. 1973;13:1029–1038. Bibliographic Links [Context Link]

2. Baxt WG, Moody P. The impact of rotorcraft aeromedical emergency care service on trauma mortality. JAMA 1983;249:3047–3051. Bibliographic Links [Context Link]

3. Baxt WG, Moody P, Cleveland HC, et al. Hospital-based rotorcraft aeromedical emergency care services and trauma mortality: a multicenter study. Ann Emerg Med. 1985;14:859–864. Bibliographic Links [Context Link]

4. Baxt WG, Moody P. The impact of advanced prehospital emergency care on the mortality of severely brain-injured patients. J Trauma. 1987;27:365–369. Bibliographic Links [Context Link]

5. Cunningham P, Rutledge R, Baker CC, et al. A comparison of the association of helicopter and ground ambulance transport with the outcome of injury in trauma patients transported from the scene. J Trauma. 1997;43:940–946. Ovid Full Text Bibliographic Links [Context Link]

6. Shatney CH, Homan SJ, Sherck JP, Ho CC. The utility of helicopter transport of trauma patients from the injury scene in an urban trauma system. J Trauma. 2002;53:817–822. Ovid Full Text Bibliographic Links [Context Link]

7. Eckstein M, Jantos T, Kelly N, et al. Helicopter transport of pediatric trauma patients in an urban emergency medical services system: A critical analysis. J Trauma. 2002;53:340–344. Ovid Full Text Bibliographic Links [Context Link]

8. Association of Air Medical Services. Position paper on the appropriate use of emergency air medical services. Pasadena, CA. Association of Air Medical Services; 1990. [Context Link]

9. Thomson DP, Thomas SH, for the 2002–2003 Air Medical Services Committee of the National Association of EMS Physicians. Prehosp Emerg Care. 2003;7:265–271. Bibliographic Links [Context Link]

10. Air Medical Physicians Association. Medical condition list and appropriate use of air medical transport. Prehosp Emerg Care. 2002;6:464–470. [Context Link]

11. Rhee KJ, Holmes EM, Heinzpeter HP, Thomas FO. A comparison of emergency medical helicopter accident rates in the United States and the Federal Republic of Germany. Aviat. Space Environ Med. 1990;62:750–752. Bibliographic Links [Context Link]

12. Knopp R, Yanagi A, Kallsen G, Geide E, Doehring L. Mechanism of injury and anatomic injury as criteria for prehospital trauma triage. Ann Emerg Med. 1988;17:895–902. Bibliographic Links [Context Link]

13. Benson NH, Alson RL, Norton EG, Beauchamp AP, Weber R, Carreras JL. Air medical transport utilization review in North Carolina. Prehospital Disaster Med. 1993;8:133–137. Bibliographic Links [Context Link]

14. Stohler SA, Schwartz RJ, Sargent RK, Jacobs LM. Quality assurance in the Connecticut Helicopter Emergency Medical Service. J Air Med Transp. 1991;10:7–11. Bibliographic Links [Context Link]

15. Van Wijngaarden M, Kortbeek J, Lafreniere R, Cunningham R, Joughin E, Yim R. Air ambulance trauma transport: a quality review. J Trauma. 1996;41:26–31. Ovid Full Text Bibliographic Links [Context Link]

16. Bamoski A, Kovach B, Podmore M, Pastis E, Fulton WF Jr. Trauma triage: do AAMS transport guidelines do it effectively? Air Med J. 1998;17:19–23. Bibliographic Links [Context Link]

17. Thomas F. (Editorial Comment) in Benson NH, Alson RL, Norton EG, Beauchamp AP, Weber R, Carreras JL. Air medical transport utilization review in North Carolina. Prehospital Disaster Med. 1993;8:133–137. [Context Link]

18. Stroup DF, Berlin JA, Morton SC, et al. Meta-analysis of observation studies in epidemiology: a proposal for reporting. JAMA. 2000;283:2008–2012. Ovid Full Text Bibliographic Links [Context Link]

19. Baker SP, O’Neill B, Haddon W Jr, et al. The Injury Severity Score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma. 1974;14:187–196. Bibliographic Links [Context Link]

20. Baker SP, O’Neill B. The Injury Severity Score: an update. J Trauma. 1976;16:882–885. [Context Link]

21. Kane G, Englehardt R, Celentano J, et al. Empirical development and evaluation of pre-hospital trauma triage instruments. J Trauma. 1985;25:482–489. Bibliographic Links [Context Link]

22. Champion HR, Sacco WJ, Carnazzo AJ, et al. Trauma Score. Crit Care Med. 1981;9:672–676. Bibliographic Links [Context Link]

23. Champion HR, Sacco WJ, Copes WS, et al. A revision of the Trauma Score. J Trauma. 1989;29:623–629. Bibliographic Links [Context Link]

24. Champion HR, Sacco WJ, Hunt TK. Trauma severity scoring to predict mortality. World J Surg. 1983;7:4–11. Bibliographic Links [Context Link]

25. Rhodes M, Perline O, Aronson J, et al. Field triage for on-scene helicopter transport. J Trauma. 1986;26:963–969. Bibliographic Links [Context Link]

26. Amatangelo M, Thomas SH, Harrison T, Wedel SK. Analysis of patients discharged from receiving hospitals within 24 hours of air medical transport. Air Med J. 1997;16:44–46. Bibliographic Links [Context Link]

27. Bartolacci RA, Munford BJ, Lee A, McDougall PA. Air medical scene response to blunt trauma: effect on early survival. Med J Aust. 1998;169:612–616. Bibliographic Links [Context Link]

28. Brathwaite CE, Rosko M, McDowell R, et al. A critical analysis of on-scene helicopter transport on survival in a statewide trauma system. J Trauma. 1998;45:140–146. Ovid Full Text Bibliographic Links [Context Link]

29. Cameron PA, Flett K, Kaan E, et al. Helicopter retrieval of primary trauma victims by a paramedic helicopter service. Aust N Z J Surg. 1993;63:790–797. Bibliographic Links [Context Link]

30. Garner A, Rashford S, Lee A, Bartolacci R. Addition of physician to paramedic helicopter services decreases blunt trauma mortality. Aust N Z J Surg. 1999;69:697–701. Buy Now Bibliographic Links [Context Link]

31. Kerr WA, Kerns TJ, Bissell RA. Differences in mortality rates among trauma patients transported by helicopter and ambulance in Maryland. Prehosp Disaster Med. 1999;14:159–161. Bibliographic Links [Context Link]

32. Larson JT, Dietricj AM, Abdessalam SF, et al. Effective use of the air ambulance for pediatric trauma. J Trauma. 2004;56:89–93. Ovid Full Text Bibliographic Links [Context Link]

33. Moront ML, Gotschall CS, Eichelberger MR. Helicopter transport of injured children: system effectiveness and triage criteria. J Pediatr Surg. 1996;31:1183–1186. Bibliographic Links [Context Link]

34. Norton R, Wortman E, Eastes L, et al. Appropriate helicopter transport of urban trauma patients. J Trauma. 1996;41:886–891. Ovid Full Text Bibliographic Links [Context Link]

35. Phillips RT, Conway C, Mullarkey D, Owen JL. One year’s trauma mortality experience at Brooke Army Medical Center: is aeromedical transportation of trauma patients necessary? Mil Med. 1999;164: 361–365. Bibliographic Links [Context Link]

36. Rhodes M, Preline R, Aronson J, Rappe A. Field triage for on-scene helicopter transport. J Trauma. 1986;26:963–968. Bibliographic Links [Context Link]

37. Schmidt U, Frame SB, Nerlich ML, et al. On-scene helicopter transport of patients with multiple injuries: comparison of a German and an American System. J Trauma. 1992;33:548–555. Bibliographic Links [Context Link]

38. Snooks HA, Nicholl JP, Brazier JE, Lees-Mlanga S. The costs and benefits of helicopter emergency ambulance service in England and Wales. J Public Health Med. 1996;18:67–77. Bibliographic Links [Context Link]

39. Wills VL, Eno L, Walker C, et al. Use of an ambulance-based helicopter retrieval service. Aust N Z J Surg. 2000;70: 506–510. Buy Now Bibliographic Links [Context Link]

40. Wong TW, Lau CC. Profile and outcomes of patients transported to an accident and emergency department by helicopter: prospective case series. Hong Kong Med J. 2000;6:249–253. Bibliographic Links [Context Link]

41. Wuerz R, Taylor J, Smith JS. Accuracy of trauma triage in patients transported by helicopter. Air Med J. 1996;15:168–170. Bibliographic Links [Context Link]

42. Younge PA, Coats TJ, Gurney D, Kirk CJC. Interpretation of the Ws statistic: application to an integrated trauma system. J. Trauma. 1997;43:511–515. Ovid Full Text Bibliographic Links [Context Link]

43. Biewener A, Aschenbrenner U, Rammelt S, Grass R, Zwipp H. Impact of helicopter transport and hospital level on mortality of polytrauma patients. J Trauma. 2004;56:94–98. Ovid Full Text Bibliographic Links [Context Link]

44. Brazier J, Nicholl J, Snooks H. The cost and effectiveness of the London helicopter emergency medical service. J Health Serv Res Policy. 1996;1:232–237. Bibliographic Links [Context Link]

45. Buntman AJ, Yeomans KA. The effect of air medical transport on survival after trauma in Johannesburg, South Africa. S Afr Med J. 2002;92:807–811. Bibliographic Links [Context Link]

46. Burney RE, Passini L, Hubert D, Maio R. Comparison of aeromedical crew performance by patient severity and outcome. Ann Emerg Med. 1992;21:375–378. Bibliographic Links [Context Link]

47. Cummings G, O’Keefe G. Scene disposition and mode of transport following rural trauma: a prospective cohort study comparing patient costs. J Emerg Med. 2000;18:349–354. Bibliographic Links [Context Link]

48. Cocanour CS, Fischer RP, Ursie CM. Are scene flights for penetrating trauma justified? J Trauma. 1997;43:83–86. Ovid Full Text Bibliographic Links [Context Link]

49. Diler E, Vernon D, Dean JM, Suruda A. The epidemiology of pediatric air medical transports in Utah. Prehosp Emerg Care. 1999;3:217–224. Bibliographic Links [Context Link]

50. Falcone RE, Herron H, Werman H, Bonta M. Air medical transport of the injured patient: Scene versus referring hospital. Air Med J. 1998;17:161–165. Bibliographic Links [Context Link]

51. Fischer RP, Flynn TC, Miller PW, Duke JH. Urban helicopter response to the scene of injury. J Trauma. 1984;24:946–950. Bibliographic Links [Context Link]

52. Gerhardt RT, Stewart T, DeLorenzi RA, et al. U.S. Army air ambulance operations in El Paso, Texas: a descriptive study and system review. Prehosp Emerg Care. 2000;4:136–243. Bibliographic Links [Context Link]

53. Hamman BL, Cué JI, Miller FB, et al. Helicopter transport of trauma victims: does a physician make a difference? J Trauma. 1991;31:490–494. Bibliographic Links [Context Link]

54. Jacobs LM, Schwartz RJ, Jacobs BB, Gonsalves D, Gabram SGA. A three-year report of the medical helicopter transportation system of Connecticut. Conn Med. 1989;53:703–710. Bibliographic Links [Context Link]

55. Jacobs LM, Gabram SGA, Sztajnkrycer MD, Robinson KJ, Libby MCN. Helicopter air medical transport: ten-year outcomes for trauma patients in a New England program. Conn Med. 1999;63:677–682. Bibliographic Links [Context Link]

56. Kirk CJ, Earlam RJ, Wilson AW, Watkins ES. Helicopter emergency medical service operating from the Royal London Hospital: the first year. Br J Surg. 1993;80:218–221. Bibliographic Links [Context Link]

57. Kotch SJ, Burgess BE. Helicopter transport of pediatric versus adult trauma patients. Prehosp Emerg Care. 2002;6:306–308. Bibliographic Links [Context Link]

58. Mackenzie CF, Shin B, Fisher R, Cowley RA. Two-year mortality in 760 patients transported by helicopter directly from the road accident scene. Am Surg. 1979;45:101–108. Bibliographic Links [Context Link]

59. Nardi G, Massarutti D, Muzzie R, et al. Impact of emergency medical helicopter service on mortality in north-east Italy: a regional prospective audit. Eur J Emerg Med. 1994;1:69–70. Bibliographic Links [Context Link]

60. Rhee KJ, Baxt WG, Mackenzie JR, et al. Differences in air ambulance patient mix demonstrated by physiologic scoring. Ann Emerg Med. 1990;19:552–556. Bibliographic Links [Context Link]

61. Schiller WR, Knox R, Zinnecker H, et al. Effect of helicopter transport of trauma victims on survival in an urban trauma center. J Trauma. 1988;28:1127–1134. Bibliographic Links [Context Link]

62. Schoettker P, Ravussin P, Moeschler O. Ejection as a key word for the dispatch of a physician staffed helicopter: the Swiss experience. Resuscitation. 2001;49:169–173. Bibliographic Links [Context Link]

63. Schwartz RJ, Jacobs LM, Juda RJ. A comparison of ground paramedics and aeromedical treatment of severe blunt trauma patients. Conn Med. 1990;54:660–662. Bibliographic Links [Context Link]

64. Stohler SA, Schwartz RJ, Sargent RK, Jacobs LM. Quality assurance in the Connecticut helicopter emergency medical service. J Air Med Transp. 1991;10:7–11. Bibliographic Links [Context Link]

65. Thomas SH, Harrison TH, Buras WR, Ahmed W, Cheema F, Wedel SK. Helicopter transport and blunt trauma mortality: a multicenter trial. J Trauma. 2002;52:136–145. Ovid Full Text Bibliographic Links [Context Link]

66. Tortella BJ, Sambol J, Lavery RF, Cudihy K, Nadzam G. A comparison of pediatric and adult trauma patients transported by helicopter and ground EMS: managed care considerations. Air Med J. 1996;15:24–28. Bibliographic Links [Context Link]

67. Urdaneta LF, Miller BK, Ringenberg BJ, Cram AE, Scott DH. Role of an emergency helicopter transport service in rural trauma. Arch Surg. 1987;122:992–996. Bibliographic Links [Context Link]

68. Nicholl JP, Brazier JE, Snooks HA. Effects of London helicopter emergency services on survival after trauma. BMJ. 1995;311:217–222. Ovid Full Text Bibliographic Links

69. Committee on Trauma, American College of Surgeons: Resources for Optimal Care of the Injured Patient. 1992, American College of Surgeons. [Context Link]

70. Theda Clark Medical Center, ThedaStar. Air Medical Dispatch for Trauma Scene Responses. Neena, WI, 2003. [Context Link]

71. Esposito TJ, Offner PJ, Jurkovich GJ, Griffith J, Maier RV. Do prehospital TC triage criteria identify major trauma victims? Arch Surg. 1995;130:171–176. Ovid Full Text Bibliographic Links [Context Link]

72. Cook CH, Muscarella P, Praba AC, Melvin WS, Martic LC. Reducing overtriage without compromising outcomes in trauma patients. Arch Surg. 2001;136:752–756. Ovid Full Text Bibliographic Links [Context Link]

73. Black JJM, Ward ME, Lackey DJ. Appropriate use of helicopters to transport trauma patients from incident scene to hospital in the United Kingdom: an algorithm. Emerg Med J. 2004;21:355–361. Buy Now Bibliographic Links [Context Link]

74. Diaz MA, Hendey GW, Bivens HG. When is Helicopter Faster? A Comparison of Helicopter and Ground Ambulance Transport Times. J Trauma. 2005;58:148–153. Ovid Full Text Bibliographic Links [Context Link]

75. Nicholl JP, Beeby NR, Brazier JE. A comparison of the costs and performance of an emergency helicopter and land ambulance in a rural area. Injury. 119;28:145–153. [Context Link]

76. Kurola J, Wangel M, Uusaro A, Ruoken E. Paramedic helicopter service in rural Finland: do benefits justify the cost? Acta Anaesthesiol Scand. 2002;46:779–784. Buy Now Bibliographic Links [Context Link]

77. Rosenberg BL, Butz DA, Comstock MC, Taheri PA. Aeromedical service: how does it actually contribute to the mission? J Trauma. 2003;54:681–688. Ovid Full Text Bibliographic Links [Context Link]

78. Bledsoe BE. Air-medical helicopter accidents in the United States: a five-year review. Prehosp Emerg Care. 2003;7:94–98. Bibliographic Links [Context Link]

79. Bledsoe BE, Smith MG. Medical helicopter accidents in the United States: a ten-year review. J Trauma. 2004;56:1325–1329. Ovid Full Text Bibliographic Links [Context Link]

80. Levin A. Johnson K. Air Ambulance Crashes Spurs Reviews. USA Today. January 14, 2005 [available online at http://www.usatoday.com/news/washington/20...vacs-usat_x.htm ] [Context Link]

81. Davis DP, Ochs M, Hoyt DB, Bailey D, Marshall LK, Rosen P. Paramedic-administered neuromuscular blockade improves prehospital intubation in severely head-injured patients. J Trauma. 2003;55:713–719. Ovid Full Text Bibliographic Links [Context Link]

EDITORIAL COMMENT

The authors of this manuscript are to be commended for addressing an extraordinarily difficult topic: the provision of clinically optimal and responsible emergency transport. It is noteworthy to mention that this analysis reveals, the majority of scene call patients transported by helicopter did not have life-threatening injuries necessitating aeromedical care (ISS <=15). This manuscript provides a summary of the complexities surrounding prehospital triage and an examination of two substantive issues: the validity of the field triage criteria in determining need for aeromedical intervention and the growing use of commercial transport services.

Most trauma physicians are sympathetic to the difficulties inherent in obtaining reliable field information. Current nonanatomic and nonphysiologic field triage criteria are largely based upon indicators such as mechanism of injury, amount of vehicle deformation, initial vehicle speed, and extrication time. There are few or no data supporting the validity of the current criteria in determining need for aeromedical intervention. Empirically based criteria would improve the triage process; further analysis of currently accepted criteria is indicated.

Regions with multiple aeromedical services typically have excess flight capacity. The authors examined the disturbingly common incidence of multiple helicopter services vying for a single patient at a given scene. While market regulation is often unpopular, most would agree that the convergence of competing aeromedical services at a given location is irresponsible for clinical, economic and safety reasons. Likewise, launching an aircraft with little clinical data (often referred to as auto-launch) is excessive, expensive, and a poor use of resources. If allowed to continue, inefficient practices such as these will jeopardize the economic health of the entire EMS system.

As in any industry, aeromedical service providers must generate an acceptable rate of return to maintain their operation. To maximize efficiency and strengthen the response system, aeromedical coverage should be based upon geographic reach and clinical volume instead of predicted per flight reimbursement. Continued analysis of both clinical demand and the aeromedical triage process will improve industry efficiency and insure long term viability.

Paul Taheri, MD, MBA

Division Chief, Trauma Burn Critical Care

Ann Arbor, Michigan

[AZCEP]

I can think of a couple of questions regarding this study.

If the occasional "overtriage" of a patient that doesn't need air transport is okay, then how often would "undertriage" be acceptable?

When helicopters are used, is it solely based on the level of injury, or are there other factors involved?

In my own experience, any time a helicopter is requested it is a mix of both factors. The area I work in is 40+ minutes from a receiving facility by ground, and there is one ALS unit for the response area. If we didn't use air resources when they were needed, we would be extremely limited in our ability to provide service, just based on turn around times.

When we respond to reported trauma, we launch the aircraft, which will get them to us in 20-25 minutes. Just long enough to, maybe, arrive on scene and do a quick assessment. If we do in fact need them, we will land them, and turn the patient over. If we don't, we cancel them before they get too close. We've never had any problems with the 4 different air providers cancelling without landing.

I will admit that we are probably very guilty of the "overtriage", but at the same time, much can change in 40 minutes worth of transport time, so it will probably continue.

[paramedicmike]

Agreed, AZCEP.

It's only going to take that one "undertriaged" patient who didn't get a helicopter ride when s/he really needed it to bring this crashing down (no pun intended) in a massive, flaming civil suit.

I think another possibility that was not mentioned as to why so many patients are flown goes back to ER docs themselves. Speaking only for my current area of employment, many of the local ER docs "refuse" patients who might otherwise be appropriate for a local community hospital. Local medics and EMTs have gotten into the habit of calling the local doc, presenting a scenario only to have the local doc say they can't handle the patient and to refer to a trauma center. That brings in the helicopter. (I use the term "refuse" very loosely. The docs aren't saying "no" per se. They always fall back to the "this patient needs a trauma center" line and thereby wash their hands of further care.)

Now, if, in most of these cases, the medics didn't cater to the local ER docs and just showed up with the patient, the patient would be cleared and sent home. If it turned out the patient really needed a trauma center, stabilization of injuries by the local ER could be completed then the patient could be transferred out.

I realize and have seen first hand how HEMS has been overused and abused. But until they give us X-ray eyes I think it may be better to err on the side of caution on behalf of the patient. I'd rather fly someone who turns out not to have needed it than not fly someone only to have them die from unseen injuries.

-be safe.

[flight-lp]

Too many people are taking this like gospel. This study proves nothing and clearly acknowledges the failure to identify a true determinant of the original hypothesis. It even goes as far to state that the scope of practice and level of care actually increases when a critical care flight crew is used. Yet so many are now saying this article proves that helicopters should not be utilized in trauma cases which was not at all Brian's point. This, along with many other "research" studies in EMS provides a one sided view of an opinion of physicians, not a factual realization of truth. Err on the side of caution I say, if they are discharged within 24 hours then great, happy for them. But the one time we decide the other way.................................

[AZCEP]

Well said by someone doing the flights.

I have a hard time buying the "helicopter EMS is a higher level of care" mantra, simply due to the experiences that I've had with several flight services. Knuckleheads in all groups, I guess.

Get them off my scene and to definitive care faster.

[Ace844]

Hello Everyone,

Since this has turned into an interesting debate, here's another study with a similar view point to throw in the mix...

(Air Medical Journal

Volume 25 @ Issue 4 , July-August 2006, Pages 165-169

doi:10.1016/j.amj.2006.04.002

Copyright © 2006 Air Medical Journal Associates Published by Mosby, Inc.

Original Research

Disagreement between transport team and ED staff regarding the prehospital assessment of air medically evacuated scene patients

John P. Benner NREMT-Pa, b, Genevieve Brauning MDa, Mike Green RNc, Wendy Caldwell RNc, Matthew P. Borloz EMT-Ia, b and William J. Brady MDa, b, ,

aDepartment of Emergency Medicine, University of Virginia Health System, Charlottesville, VA

bCharlottesville-Albemarle Rescue Squad, Charlottesville, VA

cPegasus Aeromedical Flight Operations, Department of Emergency Medicine, University of Virginia Health System, Charlottesville, VA

Available online 1 July 2006.)

Original Research

Disagreement between transport team and ED staff regarding the prehospital assessment of air medically evacuated scene patients

John P. Benner NREMT-Pa, b, Genevieve Brauning MDa, Mike Green RNc, Wendy Caldwell RNc, Matthew P. Borloz EMT-Ia, b and William J. Brady MDa, b, ,

aDepartment of Emergency Medicine, University of Virginia Health System, Charlottesville, VA

bCharlottesville-Albemarle Rescue Squad, Charlottesville, VA

cPegasus Aeromedical Flight Operations, Department of Emergency Medicine, University of Virginia Health System, Charlottesville, VA

Available online 1 July 2006.

Abstract

Study objective

To determine the rate of disagreement in assessment of significant illness or injury between air medical transport team assessment and emergency department (ED) diagnosis in patients transferred from the scene of an incident to the ED.

Methods

Retrospective analysis was performed on 84 patients transported by medical flight teams from an accident scene to an ED.

Results

Results show transport team assessment concurred with ED diagnosis 96.7% of the time; most of the differences in assessment were overassessments by the transport team. Assessment differences occurred most often for abdominal injuries and least often for head injuries. Underassessment occurred most often for spinal cord injuries.

Conclusions

Despite the numerous difficulties involved in patient assessment, data show that the transport teams accurately evaluated patients in most instances. Disagreements in assessment of injury/illness most often were overassessments.

Article Outline

Introduction

Methods

Head

Spine

Chest/airway

Abdomen

Musculoskeletal

Cardiovascular

Discussion

Conclusion

References

Introduction

In 1967, the use of emergency air medical transport was extended from the Asian battlefields of Vietnam to the streets of the United States.1 Over the past 30 years, emergency air transport has evolved extensively from its military beginnings. Undeniably, the rotor- and fixed-wing aircraft have increasingly been supplied with advanced medical equipment and specialized personnel.2 and 3 These specialized practitioners, who are typically trained in critical care, have extensive experience in emergency medicine and operate under advanced medical protocols. Depending on the flight program, some of these protocols include such skills as rapid sequence intubation, pericardiocentesis, and thrombolysis of suspected acute myocardial infarction.

Because of the advanced nature of these treatment options, use depends heavily on early recognition and accurate prehospital patient assessment. Accurate assessment by the transport team is vital in determining injuries/illness type and expediting treatment. Thus, patient assessment remains an integral yet challenging function of the medical transport team. Unfortunately, the circumstances of an emergency incident often limit time, space, light, and other factors needed for accurate evaluation.4 The absence of a controlled environment can hinder the accuracy of prehospital patient assessment and result in a diagnosis that disagrees with that of the emergency department (ED) staff.

Only two previous studies have been published addressing the agreement of the flight team's patient assessment with the diagnosis of the ED staff; these studies rate the accuracy of the prehospital assessment at 89.4% and 75.2%.2 and 4 By comparing the transport team's assessment with that of the ED, we hope to gain insight into the areas in which flight personnel may benefit from additional education and clinical training.

Methods

The medical records of 84 patients transported from an incident location by medical helicopter to the University of Virginia Emergency Department were reviewed retrospectively. Patients transported by flight from another hospital were not included in the study. The University of Virginia ED is a Level 1 Trauma Center that serves approximately 60,000 patients a year. Transport team members consisted of either two flight nurses or a flight nurse and a flight paramedic. The average patient age was 38 years; 18 of the 84 patients (27.6%) were transported for medical problems, whereas 65 (72.4%) were transported for traumatic injury.

Patient medical records were evaluated, noting the transport teams' assessment and the final ED diagnosis. Injuries were categorized into head, spine, chest/airway, abdomen, musculoskeletal system, and cardiovascular system (Figure 1). Any disagreement between the transport team's assessment and that of the ED was categorized as a difference. If the transport team indicated an actual or potential injury or illness that was not found by the ED, this difference was marked “overassessment,” whereas any injury/illness found by the ED and not noted by the transport team was marked “underassessment.”

(12K)

Figure 1. Data collection sheet for injury/illness classification by body system

Eighty-four patients met entry criteria for air medical transport from an incident scene to the ED. The transport team's assessment agreed with the ED diagnosis in 96.7% of instances and differed 3.3% of the time (Table 1). Four injury/illness types were classified as head, two as chest/airway, and three as cardiovascular. Four injury/illness types were classified as musculoskeletal, one injury/illness was classified as spinal, and one as abdomen.

Table 1.

Frequency and Percentage of Overassessments and Underassessments by the Transport Team

Head

The flight crew assessed 336 potential injuries (84 for each of the potential head injuries in Figure 1): 311 injuries were noted as not present, and 25 were noted as present. ED final diagnosis confirmed the transport team's assessment in 331 occurrences (98.5%) and disagreed with assessment in five (1.5%). Of these five differences, one was an underassessment (0.3% of total occurrences) by the transport team and four were overassessments (1.2% of total occurrences). See Figure 2.

(33K)

Figure 2.

Spine

The transport team assessed 84 potential spinal cord injuries: 81 injuries were noted as not present, and three were noted as present. The ED's final diagnosis confirmed the crew's assessment in 81 occurrences (96.4%) and disagreed with assessment in three occurrences (3.6%). Of the three differences, all were underassessment by the transport team (Figure 3).

(28K)

Figure 3.

Chest/airway

The transport team assessed 168 potential chest/airway injuries: 124 injuries were noted as not present, and 44 were noted as present. ED diagnosis confirmed these assessments in 162 occurrences (96.4%) and disagreed in 6 (3.6%). Of the six differences, two were underassessments (1.5% of total occurrences) and four were overassessments (1.8% of total occurrences). See Figure 4.

(30K)

Figure 4.

Abdomen

The transport team assessed 84 potential abdominal injuries: 70 injuries were noted as not present, and 14 were noted as present. ED diagnosis confirmed the crew's assessment in 78 occurrences (92.9%) and disagreed with the assessment in six occurrences (7.1%). Of the six differences, two were underassessments (2.4% of total occurrences) and four were overassessments (4.7% of total occurrences). See Figure 5.

(29K)

Figure 5.

Musculoskeletal

The transport team assessed 336 potential musculoskeletal injuries: 312 were noted as not present, and 24 were noted as present. ED diagnosis confirmed the crew's assessment in 317 occurrences (94.4%) and disagreed with 19 (5.6%). Of the 19 differences, seven were underassessment (2.1% of total occurrences) and 12 were overassessment (3.5% of total occurrences). See Figure 6.

(30K)

Figure 6.

Cardiovascular

The transport team assessed 252 potential cardiovascular problems: 143 were noted as not present, and 109 were noted as present. ED diagnosis confirmed the crew's assessment in 247 occurrences (98.2%) and disagreed with the assessment in five occurrences (1.8%). Of the five differences, one was an underassessment (0.4% of total occurrences) and four were overassessments (1.6% of total occurrences). See Figure 7.

(30K)

Figure 7.

Discussion

These data indicate that flight personnel's assessment agreed with that of the ED staff 96.7% of the time. The existing previous studies showed that transport team assessments concurred with the ED diagnosis 75.2% and 89.4% of the time.2 and 4

Overassessment of the patient by the transport team occurred in 27 cases (1.9%), and underassessment occurred in 18 cases (1.3%). Because it is the responsibility of the transport team to determine potential or possible injuries without confirmation, overassessments by the transport team are expected.

Though disagreement between the transport team and ED is never desired, in most cases it is better that the transport team overassess the patient, ensuring that more precautions are taken than necessary. However, overassessments could result in an unnecessary therapy (medical or procedural), leading to higher costs. In the instance of underassessment, overlooked injuries will go untreated throughout transport and in the hospital until recognized by ED staff. Furthermore, underassessment denies forewarning to the ED staff, who prepare for a patient based on the transport team's pre-arrival radio report.

One previous study indicated that disagreement between assessments was most frequent in abdominal injuries and least frequent for head injuries.4 Our study shows the same results but with different divisions between overassessment and underassessment. Abdominal injuries showed the greatest percentage of disagreements (7.1%): four of the six disagreements were overassessments. This may be caused by the transport team's tendency to base assessment of possible injuries on the mechanism of injury. Underassessments may be attributed to the delayed presentation of certain symptoms such as abdominal distension.

Musculoskeletal injuries accounted for the second greatest percentage of disagreements (5.6%). A disproportionate number of overassessments occurred in musculoskeletal injuries, 9 of 27 total overassessments were attributed to musculoskeletal injuries. These overassessments may simply be precautionary; that is, because the transport team did not have the help of x-ray equipment, they indicated potential injuries without confirmation of their presence. Most overassessed musculoskeletal injuries were closed long bone fractures.

Spinal cord injuries were the third greatest cause of disagreements in assessment. This statistic is surprising because flight personnel, by protocol, use spinal precautions and immobilization for all trauma patients. Perhaps these precautions were always taken but the transport team thought spinal injuries were not present. Another possibility could arise from poor neurological assessment or a patient's altered mental status before the use of paralytics to secure a patient's airway; after the administration of these drugs, a complete neurological examination is impossible. If the severity of a patient's condition necessitated definitive airway intervention immediately on transport team arrival, any further examinations might be considered underassessments if deficits were present.

The remaining areas (head, cardiovascular, and chest/airway) show the lowest occurrences of disagreements, though all have some instances in both underassessments and overassessments. The conditions under which transport teams operate may account for the differences between their assessment and that of the ED. The transport team is subject to the constraints of limited time, minimal space, poor scene lighting, few diagnostic tools, and many other practical concerns that prevent a complete survey. Though quick arrival time may benefit the patient, it does not always support the complete assessment. Often, indications of injury may not be apparent early in the presentation because they have not yet had sufficient time to develop (eg, abdominal distension). An important diagnostic tool is often the patient's complaint of pain; however, for patients with multiple and major injuries, such as a fractured bone, the pain may be overshadowed by more severe injuries. This is also true for patients with an altered mental status; it is quite possible for injuries to be overlooked because of the patient's inability to complain.

Conclusion

Despite the apparent difficulties involved in accurately assessing the patient, data show that the transport teams overcame these obstacles and performed accurate assessments in most instances. Furthermore, the transport teams reviewed for this study were significantly more accurate in patient assessment than those reviewed in previous studies. Though their accuracy was high, areas of possible improvement exist.

Because spinal cord injuries had the highest incidence of underassessment, it may be beneficial for the transport team to be more cautious in evaluating mechanism of injury and possible spinal cord damage. In addition, a quick and accurate determination of a patient's baseline neurological status can be helpful for secondary assessments later in the flight. Because of the nature of and the potential for severe outcomes, the greatest precautions must be taken for these injuries.

Certainly, the most successful plan for improving the care and accuracy of assessment by the transport team will include continued evaluation and increased training in problem areas.

References

1 S Roberts, C Bailey and JR Vandermade et al., Medicopter: an airborne intensive care unit, Ann Surg 172 (1970), pp. 325–333. Abstract-MEDLINE

2 HC Cleveland and JA Miller, An air emergency service: the extension of the emergency department, Top Emerg Med 1 (1980), pp. 47–54. Abstract-MEDLINE | Abstract-EMBASE

3 HC Cleveland, DB Bigelow, D Dracon and F Dusty, A civilian air emergency service: A report of its development, technical aspects, and experience, J Trauma 16 (1976), pp. 452–463. Abstract-MEDLINE | Abstract-EMBASE

4 P Campbell, Comparison of flight nurses' prehospital assessments and emergency physicians' ED assessments of trauma patients, J Emerg Nurs 13 (1987), pp. 219–222. Abstract-MEDLINE

Address for correspondence: William J. Brady, MD, PO Box 800699, Department of Emergency Medicine, University of Virginia Health System, Charlottesville, VA 22908

[flight-lp]

"Get them off my scene and to definitive care faster."

The sole reason for our existance! Speed............

A lot of people dog some air services because they don't fly the "cool looking" helicopters or that they don't carry the "cool equipment". What they do not realize is that neither is of much benefit to a trauma patient. Flight crews don't save trauma patients, trauma centers do! The sole reason for the existance of HEMS is to haul ass, period. The nicer helicopters and nicer equipment materialized mainly from hospital based systems who wished to increase their urban based funding by performing specialty transports. Don't believe me...........Tell me the last time you saw an EC-145 sitting in the middle of farmer Joe's field in rural america? Or a worn out Bell 206-L1 sitting on top of a prestigious hospital based system's pad? It just doesn't happen that way.

Yea, there are some knuckleheads out there, even have a few in Texas.............

[paramedicmike]

Tell me the last time you saw an EC-145 sitting in the middle of farmer Joe's field in rural america? Or a worn out Bell 206-L1 sitting on top of a prestigious hospital based system's pad? It just doesn't happen that way.

Can't say that I have...but we've got a couple of almost 20 year old BKs and a 10 year old (I think...it might be older) S-76. And we're the latter of the two!

They do move fast, though.

-fly safe