Traumatic cardiac arrest: Scope of paramedic services

ORIGINAL CONTRIBUTION emergency medical services, cardiac arrest, trauma; trauma, cardiac arrest, emergency medical services

Traumatic Cardiac Arrest: Scope of Paramedic Services The challenge of the I960s to ambulance care provision was the stimulus for the emergence of prehospital advanced life support (ALS) being provided by paramedic personnel. While services for cardiac disease have been accepted, paramedic activities for the trauma victim continue to be a concern for many trauma surgeons. The capability and success rate of treatment, and the time spent at the scene and during transport to the hospital have raised questions about the overall need for paramedic services. Our study period was from January 1, 1981, to December 3I, 1982, and it covered 95 clinically dead trauma victims who were first seen and subsequently treated by paramedics working in a medically controlled emergency medical services system. Endotracheul intubation was successful in 81 of the patients (85%). Esophageal obturator airway use was viewed as unsuccessful intubation. Intravenous (IV) access utilizing 16-gauge angiocaths was placed successfully by a peripheral or jugular vein in 70 patients (74%). Thirty-three patients averaged 860 mL volume infusion (30 to 3,000 mL). Average scene time was 22 minutes. Scene time of patients with unsuccessful IV and endotracheal intubation was 14 minutes (P = .07). Fourteen patients (14.7%) were admitted to the operating room or intensive care unit. Only three of the study group (3.2%) survived. [Aprahamian C, Darin JC, Thompson BM, Mateer JR, Tucker JF: Traumatic cardiac arrest: Scope of paramedic services. Ann Emerg Med June 1985;I4:583-586.]

INTRODUCTION Paramedic intervention in the trauma patient remains controversial. Gervin and Fischer 1 report increased mortality in paramedic-treated penetrating cardiac injuries. Smith and colleagues z express concern that prolonged times in attempting to gain intravenous (IV) access are deleterious. Lewiss is doubtful that paramedic services will be beneficial in urban environments when the transport time to the nearest hospital is five to 15 minutes. Blaisdell 4 supports paramedic use of endotracheal intubation for airway management, but decries the lack of available data for continued use of IV access. The purpose of our study was to investigate 1) the level of prehospital advanced life support (ALS) services provided to the injured trauma patients in an urban emergency medical services (EMS) system (eg, endotracheal intubation, IV access, volume infusion, nasogastric intubation, pericardiocentesis, needle thoracostomy); 2) procedure success rate under field conditions; 3) how the use of the procedure affected time spent at the scene; and 4) how hospital selection may affect transport times.

Charles Aprahamian, MD, FACS Joseph C Darin, MD, FACS Bruce M Thompson, MD James R Mateer, MD John F Tucker, MD Milwaukee, Wisconsin From the Section of Trauma and Emergency Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin. Received for publication October 18, 1984. Accepted for publication February 12, 1985. Presented at the Scientific Assembly of the American College of Emergency Physicians in Dallas, Texas, October 1984. This research was supported in part by the American Trauma Society. Address for reprints: Charles Aprahamian, MD, Section of Trauma and Emergency Medicine, 8700 West Wisconsin Avenue, Milwaukee, Wisconsin 53226.

METHODS Milwaukee paramedics complete a 1,000-hour curriculum, of which 13 weeks are didactic and based at the medical center and nine weeks are supervised field experience. At the completion of their training the students must pass a state licensure examination to be able to administer drugs, initiate IV fluids, provide endotracheal intubation, and perform thoracentesis, pericardiocentesis, and cardiac defibrillation. These services are provided under voice control from a single station staffed by advanced cardiac life support (ACLS)- and advanced trauma life support (ATLS)-trained senior residents and staff physicians. Competence of the individual paramedic is monitored through run-report examinations and mandatory monthly morbidity and 14:6 June 1985

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m o r t a l i t y conferences; the c o m p e tence of the entire system is monitored through tracer conditions. The Milwaukee system services an area of 145.6 square miles with a population of 821,000. There are 18 hospitals, with Milwaukee Regional Traum a C e n t e r being the o n l y t r a u m a center. Our EMS system is tiered, and the paramedics respond only to calls in which ALS activities are anticipated. This allows the skill load to be shared by a limited n u m b e r of paramedics, and it p r o m o t e s greater skill retention. 5 On receipt of a call, the dispatcher notes the time and initiates a tiered r e s p o n s e t h a t i n c l u d e s an EMTm a n n e d fire e n g i n e as a first res p o n d e r , an E M T - m a n n e d r e s c u e squad, and a paramedic unit. The time the call is received, arrival of fire department personnel to the scene, time leaving the scene, and arrival at the hospital are recorded. The dispatch time covers the time of receipt of the call to arrival of fire department personnel. Scene time is time actually spent at the scene. Transport time extends from time of scene departure to arrival at the hospital. Paramedic data relative to type of equipment and ALS skills utilized, physical findings, and other social and medical information are recorded and entered subsequently into a computer. The paramedic records from January 1, 1981, to December 31, 1982, were reviewed to identify those trauma patients w h o were in cardiac arrest when first seen by the paramedics. Data such as age, sex, mechanism of injury, various response times, vital signs, ECG rhythm, ALS procedures used, hospital destination, and emerg e n c y d e p a r t m e n t (ED) d i s p o s i t i o n were reviewed and analyzed to determine the procedure success rate, its impact on response times, and hospital selection.

RESULTS During the 24 months of the study, the Milwaukee EMS system handled 103,873 EMS calls. O n l y 16,558 of t h e s e calls r e p r e s e n t e d p a r a m e d i c runs. T h e paramedics treated 3,675 trauma cases. Ninety-five of the trauma cases (2.6%) were pulseless nonbreathers when they first were seen by the paramedics. For the purposes of our study, 100% intubation and IV access were considered the standard. 96/584

TABLE 1. Demographics No. Patients

Etiology

Average Age (range)

Sex (M/F)

Blunt Penetrating Other trauma

32 43 20

35 (5-77) 29 (14-66) 23 ( .2O). Sixty-two patients had both IV access and ET t u b e s p l a c e d (Table 4). T h e s c e n e t i m e for t h e s e p a t i e n t s averaged 22 m i n u t e s . O n l y six patients did not have IV access or ET tubes placed; the average scene time for these patients was 14 minutes. In evaluating these data for differences in 14:6 June 1985

rimes between groups, no significant overall effect based on success or lack of success in starting IV or ET tubes was observed using one-way analysis of variance (F = 1.261, P > .10). O r t h o g o n a l tests using the t-ratio and contrasting the unsuccessful IV a n d ET c a t e g o r y a g a i n s t t h e o t h e r three categories yielded only marginal significance (P = .07). This lack of statistical significance was due in part to the small n u m b e r of subjects (n = 6) in the "Neither" category. Only 33 patients had volume infusions recorded. Patients suffering b l u n t a n d p e n e t r a t i n g t r a u m a s had v o l u m e s r a n g i n g f r o m 200 to 3,000 mL; patients in the "other" t r a u m a group had volumes of 30 to 100 mL. The average volume infusion for the 33 p a t i e n t s w i t h t h i s i n f o r m a t i o n available was 860 mL. Three of the patients were declared dead at the scene following paramedic intervention; the bodies were transported to the morgue by private conveyance (Table 5). Seven patients were considered dead after paramedic intervention, but they were transported by n o n p a r a m e d i c a m b u l a n c e s to prearAnnals of Emergency Medicine

r a n g e d h o s p i t a l s to be p r o n o u n c e d dead. E i g h t e e n p a t i e n t s were transported to the closest hospital by paramedics. Fifteen of these had "other" trauma as the cause of arrest. T h e r e m a i n i n g 67 p a t i e n t s w e r e transported by paramedic vans to the t r a u m a center, w h e r e 12 were pronounced dead w i t h o u t additional physician intervention. The remaining 55 had their prehospital ALS activities continued; six s u b s e q u e n t l y died in the operating room. Five patients were a d m i t t e d to t h e ICU, w h e r e t h r e e died. The remaining two patients were two of the patients in VF w h o survived. DISCUSSION Our s t u d y group was restricted to patients who were clinically dead. Criteria for initiating CPR 6 have been developed. Patients failing to m e e t the accepted criteria are declared dead at the scene and are taken to the morgue or are transported to strategically located hospitals to be declared dead. All our patients had t r a u m a scores less than 1 from perhaps less than one m i n u t e to as m a n y as six m i n u t e s . The initial ECG identified 44 patients with treatable electrical dysrhythmias. In addition, there were 51 patients w h o were asystolic. T h r e e patients with asysto]ic rhythm were admitted alive, and they subsequently died. In n o n t r a u m a t i c cardiac arrest pres e n t i n g as a s y s t o l e , we h a v e previously noted an 8.4% incidence of VF masquerading as asystole. 7 Hypotensive patients often cannot generate a sufficient pulse or blood pressure to be auscultated or a pulse p r e s s u r e to be palpated. We believe that perceived traumatic cardiac arrest with EMD on ECG represents severe h y p o v o l e m i a w i t h no pulses rather than cardiac arrest. Bec a u s e t h e m a j o r i t y of p r e h o s p i t a l e m e r g e n c y care is provided by basic e m e r g e n c y m e d i c a l t e c h n i c i a n s who do n o t h a v e E C G m o n i t o r i n g capability, the incidence of t r a u m a patients who are believed dead but m a y have potentially solvable problems will remain unknown. There m a y be those who would argue that the 20 cases of "other" traum a seen in our series should not be included in our review. We agree that the cardiac arrest state found in blunt and p e n e t r a t i n g i n j u r i e s is p r o b a b l y h y p o v o l e m i c in origin, or at least is 585/97

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c o m p o u n d e d by t h e h y p o v o l e m i c state, and that the cardiac arrests associated w i t h h a n g i n g , d r o w n i n g , or electrocution are more hypoxic or are similar to arrests associated with cardiac disease. Because our objective was to determine the procedure success rate, we included the cases. T h e average s c e n e t i m e for the "other" trauma group was 30 minutes, compared to 18 and 21 m i n u t e s for the blunt and penetrating injuries groups (Table 3). This increase may represent the added time to treat the cardiac arrests w i t h drugs; the s h o r t e r t i m e with b l u n t trauma reflected the concem of an early transport to the hospital following assessment and stabilization. In our system the fire departm e n t does not allow paramedics to enter an actual or suspected homicide scene u n t i l the area has been secured by the police. This in part may exp l a i n the 2 1 - m i n u t e scene t i m e for penetrating injuries. The overall average scene time for the patients was 22 m i n u t e s . Sixtytwo patients (65%) had both IV access and ET intubation; the scene time for these patients was 22 minutes. Only six patients (6.3%} did not get IV or ET tubes, and their scene time was 14 m i n u t e s (Table 4). When IV access or endotracheal intubation, but not both, was successful, the s c e n e t i m e remained the same. This suggests that patients with unsuccessful i n t u b a t i o n and IV access are transported earlier. We do not offer the times as ideal, but we report them as representative of the time for getting to the patient, assessment, extrication from vehicles or buildings, administration of basic and

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advanced life support measures, and preparation for leaving the scene. S m i t h and colleagues a were concemed that if the time to initiate an IV equals or exceeds the transportation time the volumes infused will be i n a d e q u a t e to replace the p o t e n t i a l blood loss during the IV start-up time. Our study does not provide the necessary time or v o l u m e data to answer their question. Nevertheless, we have altered our protocol to require that a pressure i n f u s i o n device be applied, and we have since used volume infusions of 1,000 to 3,000 mL on a regular basis for the trauma patient. Eight paramedic u n i t s service the EMS system; they transported 85 patients in our study group. Eighteen of these patients (21%) were taken to the closest hospital because 15 were from the "other" t r a u m a group, and were believed to be suffering cardiac arrest because of a cardiorespiratory problem. The r e m a i n i n g sixty-seven patients (79%) were taken to the trauma center. Transport times for the 55 patients who had prehospital ALS continued in the ED averaged 10 m i n u t e s (range, 3 to 20 minutes). The transport time for the six patients who were operated on was l l m i n u t e s (range, 8 to 14 m i n u t e s ) . For the five p a t i e n t s taken to the intensive care unit, the t r a n s p o r t t i m e averaged 13 m i n u t e s (range, 5 to 20 minutes). Fourteen of the 95 clinically dead patients were admitted either to the operating room or the intensive care unit. One could view this as a prehospital successfui resuscitation rate of 14.7%. Three of these 95 patients left the hospital, a save rate of 3.2%.

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CONCLUSION Paramedics can be trained to provide IV access and ET i n t u b a t i o n in critically injured patients under difficult circumstances. In clinically dead trauma patients, IV access and ET intubation can be achieved in 74% and 85%, respectively. The average scene time in patients with successful IV/ ET is 22 minutes; for those with unsuccessful IV/ET, the time is 14 miw utes.

REFERENCES 1. Gervin AS, Fischer RP: The importance of prompt transport in salvage of patients with penetrating heart wounds, j Trauma 1982;22:443-448. 2. Bodai BI, Smith JP, Frey CF: Prehospital stabilization of critically injured trauma patients: A failed concept. Presentation at the 43rd Annual Meeting of the American Association for the Surgery of Trauma, September 1983. 3. Border JR, Lewis FR, Aprahamian C, et ah Panel: Prehospital trauma care - - stabilize or scoop and run. J Trauma 1983;23: 708-711. 4. Blaisdell FW: Trauma: Myths and magic. The Tenth Annual William T Fitts Lectureship in Trauma, 44th Annual Meeting of the American Association for the Surgery of Trauma, September 1984. 5. McManus WE Darin JC: Can the welltrained EMT-paramedic maintain skills and knowledge? JACEP 1976;5:984-986. 6. Standards for cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECC). JAMA 1974;227(suppl):833-868. 7. T h o m p s o n BM, Brooks RC, Pionkowski RS, et ah Immediate countershock treatment of asystole. Ann Emerg Med 1984;13:827-829.

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