ORIGINAL CONTRIBUTION advanced trauma life support, cardiac injury; prehospital care, trauma, chest

Prehospital Advanced Trauma Life Support for Penetrating Cardiac Wounds Prehospital advanced trauma life support (ATLS) is controversial because the risks, benefits, and time required to accomplish it remain unknown. We studied 70 consecutive patients with penetrating cardiac injuries to determine the relationships among prehospitai procedures, time consumed in the field, and ultimate patient outcome. Thirty-one patients sustained gunshot wounds, and 39 h a d stab wounds. The m e a n Revised Trauma Score was 2.8 + 0.5. Paramedics spent an average of lO.7 +- 0.5 minutes at the scene. Seventy-one percent of the patients underwent endotracheal intubation; 93% had at least one IV line inserted; and 57% had two IV lines inserted. Twenty-one (30%) survived. There was no correlation between on-scene time and either the total n u m b e r of procedures performed (r = .17, P - .17) or IV lines established (r = .06, P = .6). On-scene times did not differ regardless of whether endotracheal intubation or pneumatic antishock garment applications occurred. We conclude that well-trained urban paramedics can perform multiple life-support procedures with very short on-scene times and a high rate of patient survival and that prehospital trauma systems require a m i n i m u m obligatory on-scene time to locate patients and prepare t h e m for transport. [Honigman B, Rohweder K, Moore EE, Lowenstein SR, Ports PT." Prehospital advanced trauma life support for penetrating cardiac wounds. A n n Emerg M e d February 1990;19:145-150.]

INTRODUCTION The role of advanced trauma life support (ATLS) in the prehospital management of critically injured patients remains controversial. Some authors state that there should be m i n i m a l to no prehospital intervention, 1-s whereas others advocate aggressive ATLS for all seriously injured patients. 6-11 The proper scope of ATLS and the required time to accomplish it form the cornerstone in this debate. Ivatury et al's review of heart wounds and ATLS, which concluded that minimal prehospital intervention resulted in improved survival, has continued to fuel this debate. 4 Therefore, we analyzed our recent six and one-half year experience with patients with penetrating cardiac injuries to determine the relationships among prehospital procedures, time in the field, and ultimate patient out-

Benjamin Honigman, MD, FACEP* Kent Rohweder, MSt Ernest E Moore, MD, FACS* Steven R Lowenstein, MD, MPH, FACEP* Peter T Pons, MD, FACEP§ Denver, Colorado From the Section of Emergency Medicine and Trauma, Department of Surgery, Emergency Medicine Clinical Research Center, University of Colorado Health Sciences Center;* University of Colorado School of Medicine;t and Departments of Surgery* and Emergency Medicine,§ Denver General Hospital, Denver, Colorado. Received for publication February 9, 1989. Revision received June 27, 1989. Accepted for publication September 22, 1989. Address for reprints: Benjamin Honigman, MD, FACER Section of Emergency Medicine and Trauma, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, Colorado 80262.

come.

MATERIALS A N D M E T H O D S The prehospital m a n a g e m e n t of patients with penetrating cardiac wounds transported by the Denver Department of Health and Hospitals (DHH) paramedic ambulances to Denver General Hospital (DGH) from January 1980 through June 1987 was reviewed. DGH, a 350-bed teaching hospital, is a Level I trauma center for the city and county of Denver. The paramedic division is comprised of 92 full-time, state-certified paramedics (EMT-Ps) with a full-time physician director. On-line medical control is provided by telemetry radio by the attending staff and fourth-year emergency medicine residents in the D G H emergency department. Quality assurance and continuing education are rigorous and include on-scene evaluations, monthly morbidity and mortality conferences, didactic lectures, and frequent audits of paramedic performance. City ambulance coverage is based on a zone distribution concept in which ambulances are assigned to specific regions of the city. As ambu-

19:2 February 1990

Annals of Emergency Medicine

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CARDIAC WOUNDS H o n i g m a n et al

FIGURE 1. O u t c o m e after penetrating cardiac wounds (all patients). Revised Trauma Score is as revised by Champion 12 (scale, 0 to 12); all pat i e n t s are r e p r e s e n t e d , i n c l u d i n g those with no in-field vital signs. lances are used, the remaining vehicles relocate to provide m a x i m u m citywide coverage with the shortest possible response times. The system is based on a modified two-tiered concept and has specific response protocols based on the nature of the emergency: the fire department {basic life support [BLS]} and DHH paramedics corespond to patients with medical problems and blunt trauma; paramedics with police protection respond to patients sustaining penetrating trauma. Calls for assistance (by telephoning 911} are received by a central dispatcher who is located at DGH and assigns the closest available ambulance. According to protocols, Denver paramedics may perform the ATLS interventions of IV line placement, crystalloid administration, and endotracheal intubation without base-station contact. Pneumatic antishock garment (PASG) usage was part of this protocol during the first five and one-half years of the study but is n o longer used for prehospital management of patients with penetrating chest injuries. It is routine for two paramedics to be used per ambulance, allowing simultaneous diagnostic and therapeutic interventions at the scene. Standard practice involves initiating the first IV line at the scene while subsequent lines are obtained in the ambulance en route using 14-gauge catheters. Patients were identified by a review of the trauma registry at DGH; all patients presenting with definite penetrating cardiac injuries, verified at ED or operating room thoracotomy, were included in our study. There were no exclusions, and no patients were pronounced dead in the field due to lack of vital signs. Data were analyzed by a retrospective review of ambulance records, ED charts, o p e r a t i v e notes, n u r s i n g notes, and other hospital records. Prehospital times (to-the-scene, o n scene, and from-the-scene) were determined by ambulance dispatch run cards. Data obtained included patient demographics, initial vital signs, and m e c h a n i s m of injury. In addition, 66/146

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Survival = 30% (21/70)

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prehospital ATLS procedures performed (eg, number of IV lines, total fluid administered, endotracheal intubation, application of PASG} were tabulated. Revised T r a u m a Scores (RTS) were calculated from data in the patients' prehospital records according to the m e t h o d of Champion. lz The location and size of the cardiac wound, operative procedures, and outcome were derived from the patients' medical records and autopsy reports. The on-scene time was defined as the time from paramedic arrival at the scene until departure; thus, onscene time includes the time required to ensure crew safety by assessing the on-scene environment, find the patient and perform a primary survey, establish an airway, initiate an IV line while drawing blood for typing, and extricate and load the patient into the ambulance. Statistical procedures were performed using the statistical analysis system (SAS).13 Categorical variables were analyzed using the X~ test (or Fisher's exact test for small sample sizes}. For continuous variables, Student's t test (two-tailed) was used to compare two means, whereas o n e Annals of Emergency Medicine

way analysis of variance (ANOVA) was used to examine the significance of differences among three or more group means. Values are given as mean ± SEM. RESULTS Patients

The average age of the 70 patients with penetrating cardiac wounds was 35 ± 1.8 years (range, 14 t o 7 4 years); 31 sustained gunshot wounds, and 39 had stab wounds. The mean RTS was 2.8 +- 0.5, corroborating the serious nature of these injuries. Fifty-five of the patients (78.6%} had an RTS of less than 6, and 43 patients (6i%) had no vital signs before paramedic arrival as indicated by an RTS of zero (Table 1). Thirty-two of the patients (46%) had cardiac tamponade confirmed at thoracotomy. Wounds were located in the right ventricle in 23 patients, left ventricle in 22, and atria in seven, and ll had biventricular injuries. Specific anatomic descriptions were lacking for seven patients. Paramedics spent an average of 10.7 +- 0.5 minutes at the scene. O n scene time was higher for gunshot wounds (12.4 +_ 0.8 minutes) com19:2 February 1990

Survival = 66.7% 1 O0

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TABLE 1. Description of patients and procedures performed

Injury Mechanism Stab wound Gunshot wound IV Lines One Two Three Tracheal Intubation PASG Inflated Revised Trauma Score (mean ± SEM) IV Volume Infused (mean ± SEM mL)

pared w i t h stab w o u n d s (9.4 ± 0.6 m i n u t e s ) (P = .002). F o r t y - n i n e patients (71%) u n d e r w e n t endotracheal i n t u b a t i o n , a n d 44 (63%} h a d t h e PASG applied. A t l e a s t one IV line w a s i n s e r t e d i n 63 of 68 p a t i e n t s (93%). Seventeen patients (25%) had one IV line, 39 (57%} h a d t w o IV lines, and seven (10%) had three IV 19:2 February 1990

No. of Patients

(%)

39 31

56 44

least one IV line and 30 (63%) had two or m o r e IV lines p l a c e d in the field. T w e n t y - o n e of 70 p a t i e n t s (30%) survived. Survival was higher for patients w i t h stab w o u n d s (19 of 39, or 49%} compared with gunshot w o u n d s (two of 31, or 6.5%) (P < .001). W h e n patients w h o had no vital signs at the scene (43) are eliminated, overall survival is 66.7% (18). Of the 43 p a t i e n t s w i t h no vital signs in t h e f i e l d , o n l y t h r e e s u r v i v e d (7.0%), all of w h o m had stab w o u n d s (Figures 1 and 2). There w a s no correlation b e t w e e n on-scene time and either the total n u m b e r of procedures performed (r = .17, P = .17) or IV lines established (r = .06, P = .6} (Table 2). Average on-scene t i m e s were 10.8, 9.6, 11.2, and 10.4 m i n u t e s for p a t i e n t s w i t h no, one, two, or three IV lines established, r e s p e c t i v e l y ( A N O V A F test = .49, P = .7). The on-scene times were the same regardless of w h e t h e r endotracheal intubations were (9.8 + 0.8 minutes) or were not performed (11.1 + 0.6 minutes, P = .3). The on-scene t i m e s also did not differ b e t w e e n patients w i t h and witho u t P A S G a p p l i c a t i o n (11.2 ± 0.6 c o m p a r e d w i t h i0.0 -+ 1.0 m i n u t e s , P = .3}. Average on-scene t i m e s did n o t correlate w i t h t r a u m a score (r --

-.09, 17 39 7 50 44 2.8 ± 0.5

25 57 10 71 63

1,300 ± 120

lines inserted. P a t i e n t s w h o h a d IV lines established received an average of 1,300 _ 120 mL fluid at the scene and during transport. Thirty-eight p e r c e n t of p a t i e n t s r e c e i v e d 2 L or m o r e [Table 1). A m o n g t h e 48 patients w i t h an RTS of 3 or less, ons c e n e t i m e a v e r a g e d 11 m i n u t e s ; a m o n g this group, 41 (85%) h a d at Annals of Emergency Medicine

e

=

.48).

W h e n p a t i e n t s were stratified by t r a u m a score, there were no differences a m o n g t h e groups in m e a n onscene t i m e s (P = .5} (Figure 3). Furt h e r m o r e , there were no differences in on-scene t i m e s b e t w e e n survivors a n d n o n s u r v i v o r s (9.8 + 0.9 c o m pared w i t h 11.2 +_ 0.6 minutes, P = .2). O v e r a l l , n o a s s o c i a t i o n s w e r e found a m o n g on-scene t i m e s and any c o m p o n e n t of ATLS. T h e l a c k of corr e l a t i o n for o n - s c e n e t i m e s h e l d for gunshot wounds and stab wounds a n d for p a t i e n t s w i t h and w i t h o u t pericardial tamponade. On-scene t i m e s for all patients were centered at about ten m i n u t e s ± 30 seconds (± SEM). DISCUSSION

T h e risks and benefits of prehospi147/67

CARDIAC WOUNDS Honigman et al

TABLE 2. Prehospital ATLS after penetrating cardiac w o u n d s

Procedures

No. of Patients

On-Scene Time (mean _+ SEM)

P

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5 17 39 7

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19 48

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.3

42 25

11,2 +- 0,6 10.0 ± 1.0

.3

,7 (F = .49)

Intubation No Yes

PASG Inflated Yes No

Procedures were performed by prehospital personnel, and on-scene time is time spent at the scene of injury when various procedures were performed.

FIGURE 3. On-scene t i m e s after penetrating cardiac wounds. Revised Trauma Score is as revised by Champion 12 (scale, 0 to 12). Values are given as m e a n +- SEM minutes. tal ATLS are u n k n o w n . Advocates of t h e " s c o o p - a n d - r u n " p h i l o s o p h y l-s argue that critically injured patients should be transported to the hospital w i t h m i n i m a l or no p r e h o s p i t a l intervention. Others 641 argue that cert a i n ATLS p r o c e d u r e s are n e c e s s a r y to ensure safe transport of critically i n j u r e d p a t i e n t s to t h e h o s p i t a l and to enhance p a t i e n t salvage. In 1982, Gervin et al ~ studied the efficacy of p r e h o s p i t a l t r e a t m e n t in I3 patients w i t h penetrating cardiac i n j u r i e s ; all h a d v i t a l signs in t h e f i e l d and w e r e c o n s i d e r e d salvageable. Patients w h o received m i n i m a l or no in-field t r e a t m e n t had on-scene t i m e s of n i n e m i n u t e s . Five of six (83%) survived. P a t i e n t s w h o were s t a b i l i z e d in the field h a d on-scene t i m e s of m o r e than 25 minutes; none survived. T h e authors concluded that p a t i e n t s s h o u l d be t r a n s p o r t e d rapidly, w i t h o u t initiating resuscitation in t h e f i e l d . A n a l t e r n a t i v e i n t e r pretation m a y be that nine m i n u t e s is an o b l i g a t o r y o n - s c e n e t i m e for paramedics, even w h e n no interventions are performed. Of note, three of the six in the scoop-and-run group received fluid r e s u s c i t a t i o n and endotracheal i n t u b a t i o n en route. Clevenger et al 3 a n d S m i t h et al s also rep o r t e d h i g h e r m o r t a l i t i e s in t r a u m a 68/148

12

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i

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Revised Trauma Score

patients with excessive on-scene t i m e s and p r o l o n g e d t r a n s p o r t a t i o n times. I v a t u r y et al 4 r e c e n t l y r e v i e w e d I00 patients, 69 of w h o m had penet r a t i n g cardiac injuries. T h i r t y - t h r e e patients w i t h cardiac w o u n d s underw e n t in-field ATLS w i t h a m e a n onAnnals of Emergency Medicine

s c e n e t i m e of 12.2 m i n u t e s ; t h e r e was o n e (3%) s u r v i v o r . E l e v e n pat i e n t s w i t h s c o o p - a n d - r u n had average on-scene t i m e s of four minutes. There were three survivors (27%). T h r e e of the 11 scoop-and-run pat i e n t s h a d ATLS p r o c e d u r e s in the field IW line, PASG, intubation) b u t 19:2 February 1990

were not evaluated as a separate group. However, neither transport times nor physiologic indices were available on 25 other scoop-and-run patients. Because 21 of these 25 s c o o p - a n d - r u n p a t i e n t s (five survivors) were brought in by private vehicle or police cars, their in-field times were either not reported or not known. The apparent inequality of the groups, the lack of data comparing severity in all patients, and the lack of a u n i f i e d t r a n s p o r t a t i o n mechanism make these data difficult to interpret. Other authors support initiation of resuscitation in the field. Copass et aDo reviewed 131 patients requiring CPR after blunt or penetrating injuries. On-scene and t r a n s p o r t a t i o n time of survivors and nonsurvivors were nearly identical (22 vs 20 minutes). Procedures done during this time included endotracheal intubation and placement of two IV lines. These authors estimated the procedures added six to seven minutes to the total field time. Jacobs et al 8 and Aprahamian et al 9 also found that prehospital ATLS interventions improved patient outcome. We previously analyzed 203 consecutive patients who had critical penetrating wounds of the thorax or abdomen and were treated on-scene by paramedics. 6 Seventy-one of 100 patients (71%) with gunshot wounds survived, and 95 of 103 p a t i e n t s {92%) with stab wounds survived. The average on-scene times for these patients were 10.1 and 9.5 minutes, respectively. These data suggest that ATLS, w h e n p e r f o r m e d by welltrained paramedics operating under strict medical control, can be accomplished rapidly and yield an outcome comparable to those being reported by advocates of scoop-and-run. The data from the current study indicate that welbtrained paramedics can perform airway management and IV cannulation in 10.7 minutes. Even in those patients who had no interventions performed in the field, onscene times were not statistically different. This average on-scene time in an ATLS system compares favorably to the times reported for the scoopa n d - r u n s y s t e m s of G e r v i n and Fischer (nine minutes) l and Clevenger et al (8.3 minutes) 3 as well as those reported in ATLS systems by Copass et al (ten m i n u t e s ) m and Jaeobs et al (12 minutes). 8 Our own 19:2 February 1990

data in prior studies also report a tenminute on-scene time. 6 Our data and those of others 7"H suggest that in all prehospital care systems there is an evident minim u m "obligatory" time that must be spent at the scene. This fixed time is necessary to leave the ambulance, find the patient, assess the clinical and environmental situations, load the patient, and return to the ambulance. Our data and those from other studies strongly support the concept that ATLS procedures add minimally to the total on-scene time. The patients in our study had a critical anatomic injury accompanied by severe physiologic impairment; their average RTS was less than 3. Our results indicate that multiple ATLS procedures, including IV line placement, fluid resuscitation, airway management, and PASG application, can be performed in a time frame that compares with prehospital systems that use scoop-and-run. We have previously documented that i n i t i a t i o n of a single IV line in trauma patients requires 1.5 minutes in the D e n v e r s y s t e m . ~4 O t h e r studies have d o c u m e n t e d similar times in comparable systems.15,16 Airway management has an associated time cost, but this has never been studied. In those systems where two or more paramedics are at the scene, airway management and IV cannulation are usually performed simultaneously, thus minimizing the time spent. In the Denver system, there is no significant increase in on-scene time regardless of whether a patient has one or more IV lines started, is intubated, or has PASG applied. Patient survival rates in this study 30% for all penetrating cardiac injuries, 49% for p a t i e n t s w i t h stab w o u n d s to the heart, and 66.7% when patients with no vital signs in the field are eliminated - are comparable to those of other published reports, regardless of whether scoopand-run or ATLS interventions are performed. Our retrospective chart review cannot control for all potential confounding variables and cannot prove unequivocally that ATLS procedures performed in the field lead to greater survival. Only a randomized clinical trial will address that issue. T h e literature, however, supports the concept that airway m a n a g e m e n t imAnnals of Emergency Medicine

proves p a t i e n t outcome.2, 4-6 The benefits of IV line access and the infusion of 0.9% sodium crystalloid are unknown, but recent reports of improved h e m o d y n a m i c status with 7.5% s o d i u m - d e x t r a n fluid m a y make the ability to rapidly initiate IV lines even more compelling. 17 In our opinion, a system-specific approach to in-field IV line placement for trauma patients is suggested for urban prehospital care systems. If IV lines can be initiated in one to two minutes, they should be inserted routinely; if it takes more than five minutes, then they should not be attempted. If it takes between two and five minutes, the IV line insertion should be selective based on transport time, paramedic skill, and patient physiologic status. CONCLUSION From our study, we conclude that well-trained urban paramedics can perform multiple life-support procedures w i t h very short on-scene times and a high rate of patient survival and that prehospital trauma systems require a minimum, obligatory on-scene time to locate patients and prepare them for transport. This fixed on-scene time m u s t be acc o u n t e d for in the p l a n n i n g and studying of prehospital care. Given this obligatory on-scene time and the fact that well-trained paramedics can achieve multiple procedures in rapid sequence with excellent patient salvage, the issue of excess time in the debate of scoop-and-run versus i n field stabilization appears to be moot until a prospective, randomized trial that evaluates procedures, time in the field, and the effect on outcome can be a c c o m p l i s h e d . U n t i l that study is performed, emphasis on prohospital care should consist of close medical supervision and advanced training and education of paramedics~

REFERENCES 1. Gervin AS, Fischer RP: The importance ol prompt transport in salvage of patients with p e n e t r a t i n g heart wounds. J Tr~uma 1982; 22:443-448. 2. Trunkey DD: Is ALS necessary for prehospi tal trauma care? J Trauma 1984;24:86 87. 3. Clevenger FW, Yarbrough DR, Reines lil): Resuscitative thoracotomy: The effect of field time on outcome. J Trauma 1988;28:441-445. 4. Ivatury RR, Nallatharnbi NN, Roberg~ RJ, ct ah Penetrating thoracic injuries: in-field stabiJi zation vs prompt transport. / Tr~um~ 1988; 27:1066-1073.

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CARDIAC WOUNDS Honigman et al

14. Pons PT, Moore EE, Cusick JM, et ah Prehospital venous access in an urban paramedic system: A prospective on-scene analysis, f Trauma 1988~28:1460-1463.

5. Smith JP, Bodai BI, Hill AS, et ah Prehospital stabilization of critically injured patients: A failed concept. J Trauma 1985;25:65-70.

et ah The effect of a paramedic system on mortality of major open intra-abdominal vascular trauma. J Trauma 1983;23:635-690.

6. Pons PT, Honigman B, Moore EE, et ah Prehospital advanced trauma life support for critical penetrating wounds to the thorax and abdomen. J Trauma 1985;25:828-832.

10. Copass MK, Oreskovich MR, Bladergroen MR, et ah Prehospital cardiopulmonary resuscitation of the critically injured patient. A m l Surg 1984;148:20-26.

7. Cwinn AA, Pons PT, Moore EE, et ah Prehospital advanced trauma life support for critical blunt trauma victims. Ann Emerg Med 1987; 16:399-407.

11. Fortner GS, Oreskovich MR, Copass MK, et al: The effects of prehospital care on survival from a 50-meter fall. J Trauma 1982;23:443-448.

16. Gorman M, Trabulsy P, Pitcher DB: Zerotime prehospital IV~ [ Trauma 1989;29:84-86.

8. Jacobs LM, Sinclair A, Beiser JS, et al: Prehospital advanced life support: Benefits in trauma. J Trauma 1984;24:8-13.

12. Champion H: Trauma Scoring in Trauma. Norwalk, Connecticut, Appleton-Lange, 1988.

17. Maningas PA, Deguzman LR, Tillman PJ, et ah Small volume infusion of 7.5% NaC1/6% dextran 70 for the treatment of severe hemorrhagic shock in swine. Ann Emerg Med 1986; 15:1131-1137.

9. Aprahamian CA, Thompson BM, Towne JB,

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13. SAS Institute: Statistical Analysis System. Cary, North Carolina, SAS Institute.

Annals of Emergency Medicine

15. Jones SE, Nester TP, Alcouloumre E: Prehospital intravenous line placement: A prospective study. Ann Emerg Med 1989~18:244-246,

19:2 February 1990