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Contribution of air medical personnel to the airway management of injured patients
SCIENTIFIC CONTRIBUTION
Contribution of Air Medical Personnel to the Airway Management of Injured Patients • Robert J. O'Malley, RN, MS; and Kenneth J. Rhee, MD, MPH, University of California, Davis, Medical Center, Sacramento, Calif. Introduction: Air medical services are being pressured to demonstrate their way with endotracheal intubation" value. Airway management is the first priority of care when treating injured pa- and recommends that all injured patients in the prehospital setting. Injured patients with decreased Glasgow Coma tients with a Glasgow Coma Scale (GCS) <8 be intubated.2,13 Scale (GCS) are candidates for advanced airway procedures and air medical The purpose of this study was to transport. Research Question: The purpose of this study was to determine the extent of air determine to what extent air medmedical crews' contributions to the airway management of the injured patient in ical personnel contribute to the airthe prehospital setting. way management of injured patients Method: A study of adult (age >12 years) injured patients encountered in a field in the prehospital setting. setting, whose GCS on the arrival of the air medical crew was _<8,was conducted for 21 months (Feb. 1, 1991-Oct. 31, 1992). Results: During the study period, 174 patients who met the criteria were transported by the air medical crew. All but one received advanced airways including oral tracheal intubation, nasal tracheal intubation or cricothyrotomy. Of those, 68 (39%) of these procedures were completed by ground personnel (ground group), and 105 (61%) were completed by the air medical personnel (air group). The mean GCS for the ground group was 3.69 and for the air group was 4.69. The distributions were significantly different (Wilcoxon Rank Test p = 0.0002). Nineteen percent (13/68) of the patients whose airways were successfully managed by the ground personnel had a GCS of 5 to 8, as did 44% (46/105) of the air group's patients. The groups' patients were not significantly different in age or sex distribution. Conclusion: Properly trained air medical personnel positively contribute to the prehospital care of injured patients by establishing definitive airways in patients with higher GCSs. Key Words: Aeromedical transport, airway management
Introduction Thousands of injured patients are transported annually by air medical helicopter services directly from the scenes of accidents. 1 Yet in the current climate of cost control and health care reform, air medical services are being pressured, as are all medical resources, to demonstrate their value to the medical community and their sponsoring organizations.
Airway management is the first priority of care when treating the injured patient. 2-6 For patients whose airway is compromised, the use of the endotracheal tube has been est a b l i s h e d as the i n t e r v e n t i o n of choice in the p r e h o s p i t a l setting. 7-12 In fact, the A d v a n c e d Trauma Life Support (ATLS) course indicates that "altered consciousness represents the single most frequent indication to provide an air-
Setting Life Flight, based at the University of California, Davis, Medical Center, is a 24-hour, critical-care, air-transport program serving the greater Sacramento area with a population of approximately 1.5 million; the medical center is the only Level-I trauma center in California's central valley. Each air transport has a medical crew of two registered nurses, although one of the nurses is occasionally replaced by a staff or resident physician. The ground emergency medical system is primarily served by paramedics, although there are a small percentage of intermediate emergency medical technicians (EMTIIs) in the service area who use oral and nasal intubation but are not permitted to use needle cricothyrotomy. Life Flight is a second responder and, e x c e p t for very rare occasions, there is at least one advanced life support (ALS) person at all scenes to which Life Flight responds.
Address correspondence to: Robert J. O'Malley, RN, MS, University of Cafifornia, Davis, Medical Center, 2315 Stockton Blvd., Sacramento, CA 95817.
Air Medical Journal • November/December 1993
425
Using the GCS as an objective measure for the level of consciousness, Life Flight medical personnel function under an airway algorithm that indicates that any injured patient presenting with a GCS less than or equal to 8 have an advanced airway. The ground personnel functions in a variety of jurisdictions that have variable criteria for intubation. Method The data used in this report were collected primarily for a prospective, randomized study comparing neuromuscular-blockade-assisted intubation and nasal intubation. T h o s e results are reported elsewhere. 14 The inclusion criteria for the study included all injured adults (age >12 years), whose GCS on the arrival of the air medical crew was ___8,who had cardiac electrical activity and who were transported from scenes by the air medical program. The period of data collection was Feb. 1, 1991, through Oct. 31, 1992. The GCS, age, gender and type of medical crew (ground or air) completing the airway m a n a g e m e n t were a portion of the data recorded for the primary study. The information on intubations performed by the ground personnel was collected retrospectively and compared to that of air medical personnel. For the statistical comparison of the GCS distributions, the Wilcoxon Rank Test for non-parametric data was used. Chi-square was used to compare gender proportions and the "Student's" t-test was used to c o m p a r e the age distributions. Differences would be considered significant at a level of 0.05.15 The primary study was approved by the Human Subjects Review Committee of the U n i v e r s i t y of California, Davis. Results During the 21-month study period, 174 patients who met inclusion criteria were transported by air medical personnel. The groups were not significantly different with respect to
426
-igure 1
Distribution of Intubations to Glasgow Coma Scales
50--454009 t- 3 5 .o 3 0 ..O 2 5 -I (- 2 0 -
10a-
I
3
1t
l I
I
I
4 5 6 7 Glasgow Coma Scale []Ground
gender (X 2, p = 0.84) or age (t test, p = 0.81). The ground group was 79% male, and the average age was 36.1; the air group was 78% male, and the average age was 36.5. One hundred seventy-three patients received advanced airways including oral tracheal intubation, nasal tracheal intubation or cricothyrotomy (needle or surgical). One patient received no advanced airway. Sixty-eight (39%) of these advanced airways were completed by the g r o u n d p e r s o n n e l ( g r o u n d group), and 105 (61%) were completed by the air medical personnel (air group). The mean GCS for the ground group was 3.69 and for the air group was 4.69. Figure 1 displays the distribution of the GCSs of the patients m a n a g e d by b o t h groups. The distributions of the GCSs for the groups were significantly different (Wilcoxon Rank Test, p = 0.0002). Nineteen percent (13/68) of the patients whose airways were successfully managed by the ground personnel had a GCS of 5 to 8, compared to 44% (46/105) of the air g r o u p ' s patients in that range. The ground personnel performed needle cricothyrotomy on four patients. Two of these were converted to surgical cricothyrotomies by the air medical personnel, and one pa-
I
I
8
•Air
tient required neuromuscular blockade by the air medical personnel to effect oral intubation. One needle cricothyrotomy was maintained by the air medical personnel until arrival at the receiving hospital. Further examination of the final method employed to achieve airway control is summarized in Table 1. Oral intubation without neuromuscular blockade, nasal intubation, needle cricothyrotomy, and intubation methods within the paramedic scope of practice were the methods ultimately successful for 129 (75%) of the patients who had advanced airway intervention. For the remaining 44 (25%) of the patients, the air medical personnel relied on techniques not currently available to the ground personnel (neuromuscular blockade or surgical cricothyrotomy). Interestingly, 96% (64 of 67) of the oral intubations without the assistance of neuromuscular blockade were for patients whose GCS was 3 or 4 (see Table 2). Discussion Definitive prehospital airway management positively contributes to the care and outcomes of injured patients. 16-18 Altered consciousness has been identified as criteria for intubafion, t,t9, 20 The ATLS course in-
Air Medical Journal • N o v e m b e r / D e c e m b e r 1993
Fable
S u c c e s s f u l M e t h o d of I n t u b a t i o n by G r o u p
Type of Airway Management Oral tracheal intubation (without neuromuscular blockade) Nasal tracheal intubation Needle cricothyrotomy Neuromuscular-blockade-assisted oral tracheal intubation Surgical cricothyrotomy Total
Table 2
Ground
Air
43 24 1
24 37
67 61 1
39% 35% 1%
26 18 105
26 18 173
15% 10% 100%
68
Total Percentage
S u c c e s s f u l M e t h o d of I n t u b a t i o n by G l a s g o w C o m a S c a l e
Glasgow Coma Scale Oral tracheal intubation (without neuromuscular blockade) Nasal tracheal intubation Neuromuscular-blockade-assisted oral tracheal intubation Cricothyrotomy (needle or surgical) Total
3
4
5
6
7
8
Total
57 18
7 7
0 7
2 10
1 12
0 7
67 61
13
1
3
3
2
4
26
11 99
0 15
1 11
2 17
4 19
1 12
19 173
dicates that any injured patient presenting with a GCS <8 should have a definitive airway established. 1 In two separate studies, it was demonstrated that air medical transport positively contributed to the outcomes of trauma victims in spite of longer transport times when compared to patients transported by ground.21, 22 In both reports, it was suggested that the treatment interventions by a highly skilled team may have contributed to the improved outcomes. In other reports, methods for establishing definitive airways have been identified as key interventions performed by air medical personnel. 23,24 This report further clarifies this contribution by air medical personnel in the performance of advanced airway management. The fact that the air medical program had 11 crew m e m b e r s who were accustomed to working as a team and who were highly skilled in advanced airway procedures probably accounts for most of the differences between the two groups. In most situations, the arrival of the air transport service tripled the number of ALS providers at a scene, be-
cause most of the ground units had one paramedic. Second, it is significantly easier to train and maintain the skills of 11 people working under singular direction than it is to train and maintain the skills of the 250 to 400 paramedics who worked in a variety of different service jurisdictions with varying protocols for airway management. An additional part of the difference in the two groups of patients may be explained by the differences in the scopes of practice between the air medical p e r s o n n e l and ground paramedics. The scope of practice for the paramedics in the service area included oral intubation, nasal intubation and needle c r i c o t h y r o t o m y . In addition to these, the air medical personnel were permitted to use neuromuscular blockade to facilitate intubation and to perform surgical cricothyrotomies. Whether or not equivalent success securing definitive airways on more patients would occur if the scope of practice of the paramedics was expanded would require further study and significant policy change.
Air Medical Journal • November/December 1993
T h e r e are limitations to this study. First, the study population was a convenience sample based on patients who were treated by the air medical personnel. The intubations by ground personnel on patients who were not transported by the air medical service were not included because the service area covered by Life Flight includes several different emergency medical services jurisdictions, and there is no central collection point for data or information. Another limitation is that the GCS used to determine inclusion in the study was determined by and on arrival of the air medical personnel. The patients in the population were unstable, and some change in the GCS would be expected over time. In any case, coincidental with the time of the assumption of care by t h e air medical p e r s o n n e l , the ground personnel would have been responsible for airway management of the patient when the inclusion criteria was met. Conclusion
Properly prepared air medical personnel positively contribute to the prehospital care of injured patients by establishing definitive airways in patients with higher GCSs. Welltrained air medical personnel enhance emergency medical systems' ability to definitively manage an increased number of difficult airways in injured patients with altered consciousness and therefore improve outcomes. [] References 1. Annual transport statistics. ]AMT 1992; 11(3)27. 2. Subcommittee on Advanced Trauma Life Support Course: Advanced Trauma Life Support Program Instructor Manual. Chicago American College of Surgeons, 1989. 3. Hedges JR, Dronen SC, Feero S, et al: Succinytcholine-assisted intubations in prehospital care. Ann Emer Med 1988; 17 (5) :469-472. 4. Jacobs LM, Sinclair A, Beiser A, et aI: Prehospital advanced life support: Benefits in trauma. J Trauma 1984; 24(1):8-13.
427
5. Trunkey DD: Trauma: The first hour. Emer Med 1984; 15:93-107. 6. Vicario SJ, Coleman R, Cooper MA, et al: Ventilatory status early after head injury. Ann Emer Med 1983; 12(3):145-148. 7. Blaisdell FW. Trauma myths and magic: 1984 Fitts lecture. J Trauma 1985; 25 (9) :856-863. 8. Fortner GS, Oreskovich MR, Copass MK, et al: The effects of prehospital trauma care on survival from a 50-meter fall. J Trauma 1983; 23 (11) :976-981. 9. Gervin AS, Fischer, RP. The importance of prompt transport in salvage of patients with penetrating heart wounds. J Trauma 1982; 22 (6):443-448. 10. Ivatury RR, Nallathambi MN, Roberge RJ, et al: Penetrating thoracic injuries: In-field stabilization vs. prompt transport. J Trauma 1987; 27 (7) :1066-1073. ll. Pepe RE, Copass MK, Joyce TH: Prehospital endotracheal intubation: Rationale for training emergency medical personnel. Ann Emer Med 1985; 14(11):1085-1092.
428
12. Rhee KJ, O'Malley RJ, Turner JE, et al: Field airway management of the trauma patient: The efficacy of bag mask ventilation. AmJErnerMed 1988; 6(7):333-336. 13.Teasdale G, Jennett B: Assessment of coma and impaired consciousness: A practical scale. Lancet 1974; 2:81-84. 14. Rhee KJ, O'Malley RJ: Neuromuscular blockade assisted oral intubation vs. nasotracheal intubation in the prehospital management of injured patients. In press, 1993. 15. JMP version 2.0.5 software for statistical visualization. SAS Institute Inc., Cary, NC. 1992. 16. Copass MK, Oreskovich MR, Bladergroen MR, et al: Prehospital cardiopulmonary resuscitation of the critically injured patient. Am J Surg 1984; 148 (7) :20-26. 17. Miller JD, Sweet RC, Narayan R, et al: Early insults to the injured brain. JAMA 1978; 240 (5) :439-442. 18. Rivera FP, Maier RV, Mueller BA, et al: Evaluation of potentially preventable deaths among pedestrian and bicyclist fa-
talities..lAMA 1989; 261 (4) :566-570. 19. Lewis FR. Prehospital trauma care. In Trunkey DD, Lewis FR (eds): Current Therapy of Trauma 1984-1985. Philadelphia: B. C. Decker, 1984. 20. Frost EA, Arancibia CU, Shulman K: Pulmonary shunt as a prognostic indicator in head injury. J Neurosurgery 1979; 50(6):768-772. 21. Baxt WG, Moody P: The impact of a rotorcraft aeromedical emergency care service on trauma mortality. JAMA 1983; 249 (22) :3037-3051. 22. Baxt WG, Moody P, Cleveland HC, et al: Hospital-based rotorcraft aeromedical emergency care services and trauma mortality: A multicenter study. Ann Emer Med 1984; 14(9):859-864. 23.Anderson TE, Rose WD, Leicht MJ: Physician-staffed helicopter scene response from a rural trauma center. Ann EmerMed 1987; 16(1):58-61. 24. Fischer RP, Flynn TC, Miller RW, et al: Urban helicopter response to the scene of injury. J Trauma 1984; 24 (11):946-951.
Air Medical Journal • November/December 1993
Contribution of Air Medical Personnel to the Airway Management of Injured Patients • Robert J. O'Malley, RN, MS; and Kenneth J. Rhee, MD, MPH, University of California, Davis, Medical Center, Sacramento, Calif. Introduction: Air medical services are being pressured to demonstrate their way with endotracheal intubation" value. Airway management is the first priority of care when treating injured pa- and recommends that all injured patients in the prehospital setting. Injured patients with decreased Glasgow Coma tients with a Glasgow Coma Scale (GCS) <8 be intubated.2,13 Scale (GCS) are candidates for advanced airway procedures and air medical The purpose of this study was to transport. Research Question: The purpose of this study was to determine the extent of air determine to what extent air medmedical crews' contributions to the airway management of the injured patient in ical personnel contribute to the airthe prehospital setting. way management of injured patients Method: A study of adult (age >12 years) injured patients encountered in a field in the prehospital setting. setting, whose GCS on the arrival of the air medical crew was _<8,was conducted for 21 months (Feb. 1, 1991-Oct. 31, 1992). Results: During the study period, 174 patients who met the criteria were transported by the air medical crew. All but one received advanced airways including oral tracheal intubation, nasal tracheal intubation or cricothyrotomy. Of those, 68 (39%) of these procedures were completed by ground personnel (ground group), and 105 (61%) were completed by the air medical personnel (air group). The mean GCS for the ground group was 3.69 and for the air group was 4.69. The distributions were significantly different (Wilcoxon Rank Test p = 0.0002). Nineteen percent (13/68) of the patients whose airways were successfully managed by the ground personnel had a GCS of 5 to 8, as did 44% (46/105) of the air group's patients. The groups' patients were not significantly different in age or sex distribution. Conclusion: Properly trained air medical personnel positively contribute to the prehospital care of injured patients by establishing definitive airways in patients with higher GCSs. Key Words: Aeromedical transport, airway management
Introduction Thousands of injured patients are transported annually by air medical helicopter services directly from the scenes of accidents. 1 Yet in the current climate of cost control and health care reform, air medical services are being pressured, as are all medical resources, to demonstrate their value to the medical community and their sponsoring organizations.
Airway management is the first priority of care when treating the injured patient. 2-6 For patients whose airway is compromised, the use of the endotracheal tube has been est a b l i s h e d as the i n t e r v e n t i o n of choice in the p r e h o s p i t a l setting. 7-12 In fact, the A d v a n c e d Trauma Life Support (ATLS) course indicates that "altered consciousness represents the single most frequent indication to provide an air-
Setting Life Flight, based at the University of California, Davis, Medical Center, is a 24-hour, critical-care, air-transport program serving the greater Sacramento area with a population of approximately 1.5 million; the medical center is the only Level-I trauma center in California's central valley. Each air transport has a medical crew of two registered nurses, although one of the nurses is occasionally replaced by a staff or resident physician. The ground emergency medical system is primarily served by paramedics, although there are a small percentage of intermediate emergency medical technicians (EMTIIs) in the service area who use oral and nasal intubation but are not permitted to use needle cricothyrotomy. Life Flight is a second responder and, e x c e p t for very rare occasions, there is at least one advanced life support (ALS) person at all scenes to which Life Flight responds.
Address correspondence to: Robert J. O'Malley, RN, MS, University of Cafifornia, Davis, Medical Center, 2315 Stockton Blvd., Sacramento, CA 95817.
Air Medical Journal • November/December 1993
425
Using the GCS as an objective measure for the level of consciousness, Life Flight medical personnel function under an airway algorithm that indicates that any injured patient presenting with a GCS less than or equal to 8 have an advanced airway. The ground personnel functions in a variety of jurisdictions that have variable criteria for intubation. Method The data used in this report were collected primarily for a prospective, randomized study comparing neuromuscular-blockade-assisted intubation and nasal intubation. T h o s e results are reported elsewhere. 14 The inclusion criteria for the study included all injured adults (age >12 years), whose GCS on the arrival of the air medical crew was ___8,who had cardiac electrical activity and who were transported from scenes by the air medical program. The period of data collection was Feb. 1, 1991, through Oct. 31, 1992. The GCS, age, gender and type of medical crew (ground or air) completing the airway m a n a g e m e n t were a portion of the data recorded for the primary study. The information on intubations performed by the ground personnel was collected retrospectively and compared to that of air medical personnel. For the statistical comparison of the GCS distributions, the Wilcoxon Rank Test for non-parametric data was used. Chi-square was used to compare gender proportions and the "Student's" t-test was used to c o m p a r e the age distributions. Differences would be considered significant at a level of 0.05.15 The primary study was approved by the Human Subjects Review Committee of the U n i v e r s i t y of California, Davis. Results During the 21-month study period, 174 patients who met inclusion criteria were transported by air medical personnel. The groups were not significantly different with respect to
426
-igure 1
Distribution of Intubations to Glasgow Coma Scales
50--454009 t- 3 5 .o 3 0 ..O 2 5 -I (- 2 0 -
10a-
I
3
1t
l I
I
I
4 5 6 7 Glasgow Coma Scale []Ground
gender (X 2, p = 0.84) or age (t test, p = 0.81). The ground group was 79% male, and the average age was 36.1; the air group was 78% male, and the average age was 36.5. One hundred seventy-three patients received advanced airways including oral tracheal intubation, nasal tracheal intubation or cricothyrotomy (needle or surgical). One patient received no advanced airway. Sixty-eight (39%) of these advanced airways were completed by the g r o u n d p e r s o n n e l ( g r o u n d group), and 105 (61%) were completed by the air medical personnel (air group). The mean GCS for the ground group was 3.69 and for the air group was 4.69. Figure 1 displays the distribution of the GCSs of the patients m a n a g e d by b o t h groups. The distributions of the GCSs for the groups were significantly different (Wilcoxon Rank Test, p = 0.0002). Nineteen percent (13/68) of the patients whose airways were successfully managed by the ground personnel had a GCS of 5 to 8, compared to 44% (46/105) of the air g r o u p ' s patients in that range. The ground personnel performed needle cricothyrotomy on four patients. Two of these were converted to surgical cricothyrotomies by the air medical personnel, and one pa-
I
I
8
•Air
tient required neuromuscular blockade by the air medical personnel to effect oral intubation. One needle cricothyrotomy was maintained by the air medical personnel until arrival at the receiving hospital. Further examination of the final method employed to achieve airway control is summarized in Table 1. Oral intubation without neuromuscular blockade, nasal intubation, needle cricothyrotomy, and intubation methods within the paramedic scope of practice were the methods ultimately successful for 129 (75%) of the patients who had advanced airway intervention. For the remaining 44 (25%) of the patients, the air medical personnel relied on techniques not currently available to the ground personnel (neuromuscular blockade or surgical cricothyrotomy). Interestingly, 96% (64 of 67) of the oral intubations without the assistance of neuromuscular blockade were for patients whose GCS was 3 or 4 (see Table 2). Discussion Definitive prehospital airway management positively contributes to the care and outcomes of injured patients. 16-18 Altered consciousness has been identified as criteria for intubafion, t,t9, 20 The ATLS course in-
Air Medical Journal • N o v e m b e r / D e c e m b e r 1993
Fable
S u c c e s s f u l M e t h o d of I n t u b a t i o n by G r o u p
Type of Airway Management Oral tracheal intubation (without neuromuscular blockade) Nasal tracheal intubation Needle cricothyrotomy Neuromuscular-blockade-assisted oral tracheal intubation Surgical cricothyrotomy Total
Table 2
Ground
Air
43 24 1
24 37
67 61 1
39% 35% 1%
26 18 105
26 18 173
15% 10% 100%
68
Total Percentage
S u c c e s s f u l M e t h o d of I n t u b a t i o n by G l a s g o w C o m a S c a l e
Glasgow Coma Scale Oral tracheal intubation (without neuromuscular blockade) Nasal tracheal intubation Neuromuscular-blockade-assisted oral tracheal intubation Cricothyrotomy (needle or surgical) Total
3
4
5
6
7
8
Total
57 18
7 7
0 7
2 10
1 12
0 7
67 61
13
1
3
3
2
4
26
11 99
0 15
1 11
2 17
4 19
1 12
19 173
dicates that any injured patient presenting with a GCS <8 should have a definitive airway established. 1 In two separate studies, it was demonstrated that air medical transport positively contributed to the outcomes of trauma victims in spite of longer transport times when compared to patients transported by ground.21, 22 In both reports, it was suggested that the treatment interventions by a highly skilled team may have contributed to the improved outcomes. In other reports, methods for establishing definitive airways have been identified as key interventions performed by air medical personnel. 23,24 This report further clarifies this contribution by air medical personnel in the performance of advanced airway management. The fact that the air medical program had 11 crew m e m b e r s who were accustomed to working as a team and who were highly skilled in advanced airway procedures probably accounts for most of the differences between the two groups. In most situations, the arrival of the air transport service tripled the number of ALS providers at a scene, be-
cause most of the ground units had one paramedic. Second, it is significantly easier to train and maintain the skills of 11 people working under singular direction than it is to train and maintain the skills of the 250 to 400 paramedics who worked in a variety of different service jurisdictions with varying protocols for airway management. An additional part of the difference in the two groups of patients may be explained by the differences in the scopes of practice between the air medical p e r s o n n e l and ground paramedics. The scope of practice for the paramedics in the service area included oral intubation, nasal intubation and needle c r i c o t h y r o t o m y . In addition to these, the air medical personnel were permitted to use neuromuscular blockade to facilitate intubation and to perform surgical cricothyrotomies. Whether or not equivalent success securing definitive airways on more patients would occur if the scope of practice of the paramedics was expanded would require further study and significant policy change.
Air Medical Journal • November/December 1993
T h e r e are limitations to this study. First, the study population was a convenience sample based on patients who were treated by the air medical personnel. The intubations by ground personnel on patients who were not transported by the air medical service were not included because the service area covered by Life Flight includes several different emergency medical services jurisdictions, and there is no central collection point for data or information. Another limitation is that the GCS used to determine inclusion in the study was determined by and on arrival of the air medical personnel. The patients in the population were unstable, and some change in the GCS would be expected over time. In any case, coincidental with the time of the assumption of care by t h e air medical p e r s o n n e l , the ground personnel would have been responsible for airway management of the patient when the inclusion criteria was met. Conclusion
Properly prepared air medical personnel positively contribute to the prehospital care of injured patients by establishing definitive airways in patients with higher GCSs. Welltrained air medical personnel enhance emergency medical systems' ability to definitively manage an increased number of difficult airways in injured patients with altered consciousness and therefore improve outcomes. [] References 1. Annual transport statistics. ]AMT 1992; 11(3)27. 2. Subcommittee on Advanced Trauma Life Support Course: Advanced Trauma Life Support Program Instructor Manual. Chicago American College of Surgeons, 1989. 3. Hedges JR, Dronen SC, Feero S, et al: Succinytcholine-assisted intubations in prehospital care. Ann Emer Med 1988; 17 (5) :469-472. 4. Jacobs LM, Sinclair A, Beiser A, et aI: Prehospital advanced life support: Benefits in trauma. J Trauma 1984; 24(1):8-13.
427
5. Trunkey DD: Trauma: The first hour. Emer Med 1984; 15:93-107. 6. Vicario SJ, Coleman R, Cooper MA, et al: Ventilatory status early after head injury. Ann Emer Med 1983; 12(3):145-148. 7. Blaisdell FW. Trauma myths and magic: 1984 Fitts lecture. J Trauma 1985; 25 (9) :856-863. 8. Fortner GS, Oreskovich MR, Copass MK, et al: The effects of prehospital trauma care on survival from a 50-meter fall. J Trauma 1983; 23 (11) :976-981. 9. Gervin AS, Fischer, RP. The importance of prompt transport in salvage of patients with penetrating heart wounds. J Trauma 1982; 22 (6):443-448. 10. Ivatury RR, Nallathambi MN, Roberge RJ, et al: Penetrating thoracic injuries: In-field stabilization vs. prompt transport. J Trauma 1987; 27 (7) :1066-1073. ll. Pepe RE, Copass MK, Joyce TH: Prehospital endotracheal intubation: Rationale for training emergency medical personnel. Ann Emer Med 1985; 14(11):1085-1092.
428
12. Rhee KJ, O'Malley RJ, Turner JE, et al: Field airway management of the trauma patient: The efficacy of bag mask ventilation. AmJErnerMed 1988; 6(7):333-336. 13.Teasdale G, Jennett B: Assessment of coma and impaired consciousness: A practical scale. Lancet 1974; 2:81-84. 14. Rhee KJ, O'Malley RJ: Neuromuscular blockade assisted oral intubation vs. nasotracheal intubation in the prehospital management of injured patients. In press, 1993. 15. JMP version 2.0.5 software for statistical visualization. SAS Institute Inc., Cary, NC. 1992. 16. Copass MK, Oreskovich MR, Bladergroen MR, et al: Prehospital cardiopulmonary resuscitation of the critically injured patient. Am J Surg 1984; 148 (7) :20-26. 17. Miller JD, Sweet RC, Narayan R, et al: Early insults to the injured brain. JAMA 1978; 240 (5) :439-442. 18. Rivera FP, Maier RV, Mueller BA, et al: Evaluation of potentially preventable deaths among pedestrian and bicyclist fa-
talities..lAMA 1989; 261 (4) :566-570. 19. Lewis FR. Prehospital trauma care. In Trunkey DD, Lewis FR (eds): Current Therapy of Trauma 1984-1985. Philadelphia: B. C. Decker, 1984. 20. Frost EA, Arancibia CU, Shulman K: Pulmonary shunt as a prognostic indicator in head injury. J Neurosurgery 1979; 50(6):768-772. 21. Baxt WG, Moody P: The impact of a rotorcraft aeromedical emergency care service on trauma mortality. JAMA 1983; 249 (22) :3037-3051. 22. Baxt WG, Moody P, Cleveland HC, et al: Hospital-based rotorcraft aeromedical emergency care services and trauma mortality: A multicenter study. Ann Emer Med 1984; 14(9):859-864. 23.Anderson TE, Rose WD, Leicht MJ: Physician-staffed helicopter scene response from a rural trauma center. Ann EmerMed 1987; 16(1):58-61. 24. Fischer RP, Flynn TC, Miller RW, et al: Urban helicopter response to the scene of injury. J Trauma 1984; 24 (11):946-951.
Air Medical Journal • November/December 1993