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TRANSPORT OF THE INJURED PATIENT: Past, present and future
Br.J. Anaesth. (1977), 49, 651
TRANSPORT OF THE INJURED PATIENT Past, present and future R. SNOOK
ROGER SNOOK, M.D., M.B., CH.B., Accident and Emergency
Department, The Royal United Hospital, Combe Park, Bath BA1 3NG.
ambulance services and medical techniques were beginning to evolve that would enable treatment to begin at an earlier stage in the care of the patient. THE PROBLEM
The movement of the injured has long been recognized as a problem. Pain inhibits movement. Movement can worsen the effects of injury, deepening shock and damaging vital structures. Vital functions may be affected by the position of the patient, but the position may have to be altered to allow treatment and movement. Treatment and movement may be influenced by distance and time, and time can influence morbidity and mortality. Ideally these problems should be identified and their effects measured. This should allow minimum standards of care to be defined, implemented, assessed and brought further up to date. Reality is often less ordered, however, and advances in ambulance design and first aid have often been made empirically and in isolation. For example, Thomas developed his famous leg splint at the time of the First World War. It was used with great effect in the latter stages of that war and again in the 1939-45 conflict. However, the adoption of the same principle in civilian practice awaited the introduction of modified splints in the 1970's (MacMahon, 1974). In considering the problems of the transport of the injured several distinct divisions may be recognized: reaching the patient; evacuating the patient to the ambulance; the ambulance journey and transfer to hospital. Reaching the patient
McKay (1969) analysed the time of survival in fatal accidents. He suggested that 43% of riders or vehicle occupants might have had a greater chance of survival if some medical treatment had been available at the scene of the accident within 10 minutes. It is important for both medical and humanitarian reasons that those caring for the injured should reach them as rapidly as is compatible with safety. To this end in the United Kingdom we have an efficient national emergency communication system
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From biblical times onwards it has been recorded that man has transported his stricken fellow being to shelter or to centres of healing. The transport was often provided by a litter which is denned in the Concise Oxford Dictionary as "a framework with couch for transporting sick and wounded . . . and carried on man's shoulders or by beasts". Later in the development of healing the litter could also be transported on a cart drawn by a horse or other animal. Such methods must have been used to move the ill and injured to the early religious centres such as those that began the long traditions of the St John organization. During times of hostility, man's inhumanity to man eventually provoked the emergence of organized compassion for the wounded soldier. The fatherfigure of this movement was M. Henri Dunant out of whose ceaseless efforts was fashioned the Red Cross. Early documents record the organization of moving hospitals following the armies and the use of horsedrawn vehicles for the collection and evacuation of the wounded. Interestingly the word "ambulance" describes either the moving hospital or the vehicle used for transporting the patient. With the passage of time the horse gave way to steam and then to the internal combustion engine and the design of ambulances evolved with this change of motive power. Pictorial evidence suggests that this change was slow and documents in the archives of the British Red Cross Society record dissatisfaction with the design of those early ambulances. In the years between the World Wars improvements in the transport of patients were largely limited by the states of development of motor engineering and medical technology. In the second half of the 20th century technical advances on both these fronts have allowed the standards of emergency patient care to advance more rapidly. Vehicles were built specifically as ambulances; in the United Kingdom local communities were obliged by Act of Parliament to organize
652
Evacuating the patient to the ambulance
Once the patient has been reached the process of history taking, examination, diagnosis and treatment can begin. An understanding of the patterns of injury and of special rescue techniques is important in this phase of patient care (Snook, 1974). In order to come to a provisional diagnosis it has been found useful to consider the mechanisms of injury and, in the case of road accidents, to recognize patterns of vehicle damage and consequent occupant injury. Except where there is a definite danger of additional injury, the patient should always be assessed before being moved. In addition, vital functions should be protected or supported. Anything from simple procedures to full cardiopulmonary resuscitation may be indicated. Special equipment may be required to release a trapped patient. In the United Kingdom this is generally the responsibility of the Fire Service and is accomplished using comprehensive sets of cutting, lifting, jacking and lighting equipment which are often carried on rescue tenders. Whenever possible the principle used is to move the structures from the patient rather than vice versa. Further down the list of priorities is the relief of pain. Preferably, this should be undertaken before moving the patient. An exception will be a patient with a spinal iniury where pain can offer a sign guarding against injudicious movement. For these patients a spinal backboard splint of the U.S.A. Farrington pattern or the U.K. Tynemouth Spinal
Splint type should be applied first and then analgesia can be given. In the phase of provisional diagnosis it is often safer and more useful if pain relief can be controlled and modified. Baskett and Withnell (1970) and Snook (1974) found that Entonox (50% nitrous oxide in oxygen) gives safe, effective and controllable analgesia in the early management of injured patients. It is now available in the majority of emergency ambulances in the United Kingdom. Pain relief may be followed by the splinting of fractures using conventional bandaging, inflatable splints or traction splints (for example, Hare and Tauranga splints) where applicable. These last two forms of splint involve some degree of reduction of the fractures so that some pain relief will be necessary before they are applied. After splinting, a blanket lift or special rescue stretcher may be required to lift the patient from the accident site onto the ambulance trolley stretcher. In difficult situations such as cave, mountain and coastal rescue special stretchers may be used. These can be adapted to the needs of the casualty and the situation, and may include sledge, wheel or sling attachments, provision for thermal insulation and even for an attendant to ride alongside the stretcher. Two of the most widely used rescue stretchers are the canvasand-bamboo "Neil-Robertson" and the tubular metal and plastic "Paraguard" stretchers. The latter has the particular virtue of folding to half-size for ease of storage. In addition to the rescue stretcher, special transport systems may be involved in bridging the gap between the accident site and the ambulance. Helicopters, hovercraft, Landrovers or lifeboats may be needed. The ambulance
It would seem that little serious attention was given to the ambulance until Bothwell (1959) described a patent ambulance. In a paper given to the Institute of Mechanical Engineers, London (1968) observed that ambulances were often designed without the least regard for the effects of illness and injury. Also in 1968 the Committee on Acute Medicine of the American Society of Anesthesiologists stated that most vehicles in use were unsatisfactory for life support. In 1967, Cullen, Douglas and Danziger reported that there was clinical evidence of an adverse response of patients to movement in an ambulance. Similar observations were made by other workers who also expressed disquiet about the "mortality of the am-
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which links the public with the emergency services by the "999" telephone call system and the various emergency services by the "flash" call system. The response to such an emergency call is to mobilize an ambulance either from a base or by sending the nearest available mobile unit. To avoid delay in reaching the patient the ambulance is identified externally by several means. Most ambulances are white and are equipped with one or more blue flashing lights and an audible warning device. Snook (1972a) found that the size of the beacon is important and that alternating horns are preferable to sirens. To reduce the time taken to reach the patient it is now technically feasible to fit the ambulance with a small device that will switch traffic lights to favour the passage of the emergency vehicle (Snook, 1972b). Such a system is of practical use and is relatively inexpensive, adding approximately 5% to the cost of the traffic light installation.
BRITISH JOURNAL OF ANAESTHESIA
TRANSPORT OF THE INJURED PATIENT
(1) The requirement that the vehicle shall fulfil a dual-purpose role carrying at one extreme one seriously ill patient with an attendant and at the other six to eight patients together with wheel chairs, crutches and luggage! To be able to accommodate the large group the vehicle springs have to be too hard for transporting the single sick patient. (2) Routine work forms 85% of ambulance journeys and emergency work only 15%. (3) There are economic restrictions favouring the use of a cheaper commercial van conversion rather than a purpose-built vehicle which would be more expensive. It should be noted that this saving on capital costs involves additional costs to the community from the mortality and morbidity of the ambulance journey. (Dawson (1971) estimated that an average road accident fatality cost the community approximately £16 800.) 53
(4) There are no measurable minimum standards of noise, heating, lighting and vibration in ambulances. (5) There are no ergonomic standards relating to the performance of life-support tasks within the vehicles. Collectively, these constraints have been responsible for the poor state of the development of the ambulance, which in many respects is little more than a transport van rather than a purpose-designed patient care system. None of the problems is insurmountable. It is possible to design a chassis and suspension system that gives a ride closely approaching that of a good saloon car and maintain that standard over a varying load with a variable-rate suspension system (Snook, 1972c). Similarly, it is possible to measure and design optimum environmental conditions within the vehicle to cover light, sound, heat and vibration. The ergonomic considerations for the attendant with his patient and equipment could easily be met by redesigning the interior layout of the patient compartment (N.R.D.C. Report, 1969; Smallhorn, 1970). Sadly, since the demise of the Daimler ambulance in the late 1950's (fig. 1) no British company has been able to produce commercially a purpose-built ambulance chassis. There is little doubt that this is a result of the failure of ambulance authorities to appreciate the need for such vehicles, rather than of cost or engineering problems. At least two attempts have been made recently to produce such a vehicle, taking design to the point of a pre-production prototype (fig. 2). But these appear not to have been evaluated adequately by the authorities then responsible for purchase and use of ambulances. Moreover, certain design concepts still have not been agreed. For example, a reversal of the direction of travel of the stretcher patient, so that he travelled feet first, would have many advantages. This direction would be more physiologically appropriate for changes in the speed of the vehicle, with the decelerating forces always exceeding the acceleration forces. This position would also allow the patient to be carried within the wheelbase of the vehicle, thereby reducing vibration. Ergonomically, the attendant could care for his patient more easily in the moving environment, being positioned at the head of the patient on a secure seat with forward visibility to prevent motion sickness. In European countries the situation would seem to be much the same as that in this country. It has led to research at Delft University in Holland in a different direction. Instead of designing a new vehicle,
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bulance ride" and other effects related to the transport of the patient (Mann, 1961; Glover, 1967; Gurling, 1967; Heald, 1967; Horton, 1967; Lamont, 1967; Stewart, 1967; Strange, 1967; Storrs and Taylor, 1970; Young, 1971; Snook, 1972c). In spite of these disquieting relevations there was little evidence of any serious effort to improve the situation. Snook (1972c) investigated the problems in detail and found that the interior design and layout of many emergency ambulances in current use left much to be desired. The illumination was found to be inadequate; heat loss occurred (although it could be prevented); the interior noise levels were often too high and vehicle identification and passage through traffic could be improved. Measurable differences in the vibration of the ride existed between the commercially available ambulances, a prototype purpose-built ambulance and a private car. The ride in the ambulance also affected the performance of simulated patient life-support tasks. There were measured failure rates of up to 14% for external cardiac massage and 17% for artificial ventilation. Evidence that this was an international problem came from France where Pichard (1970) described a series of 430 ambulance journeys. In 6% of these there were disturbances in the cardiovascular systems of the patients which could be related to movement. These disturbances included decreases in arterial pressure, cardiac arrhythmias and cardiac arrest. Collectively, these findings question some of the factors which have hitherto influenced ambulance design. At present the following constraints limit ambulance design:
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FIG. 2. The Dennis F.D.4 experimental pre-production prototype emergency ambulance used in the University of Bristol computer analysis trials (Snook, 1972c). The quality of the ride approached that of a good family saloon car. (Reproduced by kind permission of the Editor of Commercial Motor.)
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FIG. 1. The fleet of four Daimler Emergency Ambulances operated by the City of Bath Ambulance Service in the 1950's. (Photograph by kind permission of Mr L. Roberts.)
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FIG. 3. The floating stretcher support fitted to a conventional ambulance for patient and instrument trials. A vibration transducer attached to the "patient's legs" is coupled to a tape recorder and oscilloscope for later computer analysis of the ride characteristics. (Copyright Accident and Ambulance Research, Bath.)
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are about 36 in the country at the moment, based largely in rural areas. The hospital flying squads are necessarily based in urban areas; there are about 10 around the country. There can be little doubt that a higher standard of patient care must improve morbidity and mortality. As a start every ambulanceman should be trained in the use of, and equipped with, a laryngoscope so that he can see what he is doing with a sucker. This one improvement would do much to improve both patient care and the motivation of ambulance crews. Similarly, every ambulance should carry infusion apparatus and fluids for a doctor or advanced ambulanceman to use in an emergency. The necessary training in hospitals of the ambulance staff and the medical personnel could be easily provided in conjunction with anaesthetic and accident and emergency departments. In many cases self-instruction methods can be used (Baskett et al., 1976). Transfer from ambulance to hospital
Little need be said about this phase except to draw attention to one of the few papers discussing the movement of critically ill patients within hospitals (Waddell, 1975). He described renewed bleeding from a fractured pelvis, cardiac arrhythmias and other cardiovascular effects of movement. There were also difficulties in continuing treatment during movement and a plea was made for a greater awareness of the hazards of moving the critically ill. The movement of individual patients on stretchers is another area for improvement. A universal stretcher top compatible with ambulance, accident area and operating theatre equipment would save much patient disturbance but would have to include such considerations as resistance to glass fragments, radiotranslucency and electrical conductivity for the discharge of static, defibrillation and diathermy charges. The concept of a universal interchangeable trolley could include the universal top. There are further problems with the universal trolley in the conflicting requirements of the ambulance and hospital services. The ambulance trolley needs to be low, compact and light to allow it to be lifted and accommodated in a limited space; the hospital need is for strength, a standard work height and the ability to accept attachments such as large Entonox and oxygen cylinders, dripstands, cotsides, arm boards, etc. A universal trolley top system, can however, be made to fit the various needs for the several stages of patient care and is exemplified by the West German Automobile Club (A.D.A.C.) system with com-
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they have concentrated on the stretcher inside the ambulance. A separate suspension system has been devised to carry the stretcher and isolate it from the floor of the ambulance. This device was known as the "Vleugelbrancard" or "Floating Stretcher Support" (fig. 3). Two pre-production prototypes were made by 1969 and by 1973 the units were in commercial production. The first unit in this country was lent to the City of Bath Ambulance Service for a patientsubjective assessment trial and computer analysis of the characteristics of the ride. The results (Snook and Pacifico, 1976) showed a statistically significant improvement in the ride as assessed by the subjects. The computer analysis demonstrated that the vibration to which the patient is exposed could be reduced by up to two-thirds. Such a solution to ambulance transport is admittedly a design compromise. An ambulance which could give the same reduction in vibration would have advantages over stretcher isolation. Estimates suggest that the two systems cost similar amounts, but the stretcher suspension system is commercially available whereas a purpose-built ambulance has yet to be designed. Is there another answer ? If patients were resuscitated, stabilized and relieved of pain before the journey this might partly obviate the need for a specialized vehicle. Clinical research into methods of pre-hospital emergency patient care (Snook, 1972c, 1974) showed that morbidity and mortality can be reduced and that this can also be "cost effective". Methods have been developed to investigate the effects of ambulance transport in critically ill patients (Waddell, Scott et al., 1975; Waddell, Stuart et al., 1975). There were measurable changes in the arterial pressure and arterial carbon dioxide tension during and immediately after movement of patients by ambulance. It was noted that "resuscitation before transfer, continuing medical care during the journey and hence a slower, smoother journey seemed to be important factors in the management of these patients". There are several ways of providing such "immediate care". The advanced training of ambulance men in cardiopulmonary care (comparable to but not the same as the American Paramedic and Emergency Medical Technician schemes (Stewart, 1977)) is one. Others include the provision of care by general practitioners organized in specially equipped groups (Easton, 1970) and hospital-based flying squads (Snook, 1972d). The general practitioner schemes are voluntary and supported by public donations: there
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TRANSPORT OF THE INJURED PATIENT patability between helicopters, ambulances and the receiving emergency units.
CONCLUSION
Perhaps, in the past, we have been too ready to leave the transport of the injured (and ill) to the ambulanceman without supporting him with the necessary research, training and equipment to enable him to offer the highest standards of patient care. This state should not be allowed to continue and yet the Department of Health and Social Security (1976) and the Royal College of Physicians (Joint Working Party, 1975) have recently published diametrically opposing views on the subject. The Department has decided to limit advanced training for ambulancemen whilst the College supports the concept in the field of coronary care! What of the future? Research is continuing at various centres investigating human response to vibration and the patient response to the ambulance ride. Existing ambulance design is being improved, ambulanceman training programmes advance and the medical rescue or immediate care schemes expand. The results are being evaluated clinically and statistically. The specialities of anaesthesia and accident and emergency medicine can and should continue developments in this field. Both are involved in intensive care both as an actual hospital area and as a concept of continuing patient care. Regrettably, this area of patient care is starved of funds, hence die rate of progress is not that which is technically feasible. Nevertheless, substantial progress has been made in the last decade. REFERENCES
Adams Cowley, R. (1973). An economical and proved helicopter programme for transporting the emergency critically ill and injured patients in Maryland. J. Trauma, 13, 1029. Baskett, P. J. F., Lawler, P. G. P., Hudson, R. B. S., Makepiece, A. W., and Cooper, C. (1976). Resuscitation teaching room in a district general hospital: concept and practice. Br. Med. J., 1, 568. Withnell, A. (1970). Use of Entonox in the ambulance. Br. Med.J., 2, 41.
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Alternative transport systems Road vehicles are used for the majority of emergency journeys in this country, but situations arise where alternative methods are needed, at least for part of the journey. Lifeboat and inshore rescue boats, together with the rescue helicopters of the armed services, provide much of the coastal transport. Fixed-wing aircraft are most usually used for the planned transfers of patients over long distances or difficult terrain. Hovercraft have not yet been used to any extent. The helicopter has particular advantages for evacuating patients from coasts and the sea and is also of use where road transport is impractible because of floods, heavy snow and earthquakes. The use of helicopters in evacuating front-line casualties in the Korean and Vietnam wars (Neel, 1968; White, 1971) received considerable attention. Whilst the results were impressive, much of the success must be in part related to the continuous occurrence and the limited distribution of the casualties. Efforts to translate the lessons of war into benefits for peacetime civilian communities have been made in several countries. In Maryland in the United States the centralization of the emergency services together with the distances involved in travel from the rural communities led to the development of a helicopter evacuation service (Adams Cowley, 1973). To make the maximum use of the helicopters and to minimize costs other public services are also provided, with the understanding that rescue takes precedence. There was a measurable reduction in mortality as the service expanded and Adams Cowley stated that "for every 30 min that elapses between the accident and the time the patient gets definitive care, the mortality can be expected to increase threefold". In West Germany the A.D.A.C. initiated an integrated service using helicopters and conventional ambulances. They claim a saving of 700 lives in a 4-year period involving the treatment of 7500 casualties (Burghart, 1974). In Toulouse in France the S.A.M.U. Flying Medical Unit uses helicopters to evacuate casualties from the accident site. It involves the integration of the gendarmes in traffic control to allow landing on the highway adjacent to the crash (Lareng, 1973). The necessary equipment for aeromedical transport is described by Moylan and Pruitz (1973) of the United States Army Institute of Surgical Research.
Wider accounts of the medical and physiological constraints of air transport are given by Snook (1974) and Oxer (1975). In the United Kingdom the use of helicopters in civilian patient care is limited by four factors: the sparse distribution of helicopter bases, the wide scatter of accidents, the system of charging for individual flights and the delays in administrative sanction of individual journeys. These last two help perpetuate the low rate of use, whether by accident or design!
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Neel, S. (1968). Army aeromedical evacuation procedures in Vietnam. Implications for rural America. J.A.M.A., 204, 309. Oxer, H. F. (1975). Aeromedical evacuation of the seriously ill. Br. Med. J., 3, 692. Pichard, E. (1970). The effect of acceleration and vibration on sick persons during transport. Rev. Corps Same, 11, 611. Smallhorn, A. (1970). Emergency care vehicles. Br. Hosp. J. Soc. Serv. Rev., 80, 1638. Snook, R. (1972a). The use of flashing beacons. Fire Protection Rev., 5, 214. (1972b). Automatic traffic light control. Fire, 65, 3. (1972c). Medical aspects of ambulance design. Br. Med. J., 3, 574. (1972d). Accident flying squad. Br. Med.J., 3, 569. (1974). Medical Aids at Accidents. London: Update Publications. Pacifico, R. (1976). Ambulance ride: fixed or floating stretcher. Br. Med. J., 2, 405. Med.J., 3,678. Stewart, A. B. (1967). Mortality of the ambulance ride. Horton, J. (1967). Mortality of the ambulance ride. Br. Br. Med. J., 3, 797. Med. J., 3, 678. Stewart, R. D. (1977). The training of paramedical perJoint Working Party (1975). J. R. Coll. Physicians Lond., sonnel. Br. J. Anaesth., 49, 659. 10,5. Storrs, C. N., and Taylor, M. R. H. (1970). Transport of Lamont, D. (1967). Accident services. Br. Med.J., 2, 374. sick newborn babies. Br. Med. J., 3, 328. Lareng, L. (1973). Flying medical unit. Anesth. Analg. Strange, F. G. St C. (1967). Mortality of the ambulance ride. Br. Med.J., 3, 560. (.Paris), 30, 3. London, P. S. (1968). Design for ambulances. Proc. Inst. Waddell, G. (1975). Movement of critically ill patients within hospital. Br. Med. J., 2, 417. Mech. Eng., 182, 188. Scott, P. D. R., Lees, N. W., and Ledingham, I. McA. McKay, G. M. (1969). Some features of traffic accidents. (1975). Effects of ambulance transport on critically ill Br. Med. J., 4, 799. patients. Br. Med. J., 1, 386. MacMahon, A. G. (1974). Pre-hospital management of the Stuart, B., Tehrani, M. A., McGarrity, G., Reyes, A., fractured femur using the Tauranga-Thomas splint. Smith, H. C , Ledingham, I. McA., Green, H. L., and 5. Afr. Med.J., 48, 835. Weller, C. (1975). Intra-arterial monitoring of critically Mann, T. P. (1961). Temperatures in ambulances. Lancet ill patients in ambulances. Br. Med. J., 4, 206. 1, 1257. White, M. S. (1971). Results of early aeromedical evacuaMoylan, J. A., and Pruitz, B. A. (1973). Aeromedical transtion of Vietnam casualties. Aerosp. Med., 42, 780. portation. J.A.M.A., 224, 1271. Young, A. E. (1971). Transporting patients with chest National Research Development Corporation (1969). The injuries. Br. Med. J., 4, 364. Ogle report on emergency ambulances. Bothwell, P. (1959). Design of ambulances. Med. Officer, 101, 159. Burghart, H. (1974). The use of helicopters as mobile intensive units in disaster control and rescue service in the Federal Republic. Resuscitation, 3, 143. Cullen, C. H., Douglas, W. K., and Danziger, A. M. (1967). Mortality of the ambulance ride. Br. Med. J., 3, 438. Dawson, R. F. F. (1971). Cost of road accidents in Great Britain. Transport and Road Research Laboratory Report 396. Department of Health and Social Security (1976). Health Note 76/204. Easton, K. C. (1970). The general practitioner and the rescue services. Community Health {Bristol), 2, 81. Glover, J. R. (1967). Mortality of the ambulance ride. Br. Med. J., 3, 678. Gurling, K. J. (1967). Mortality of the ambulance ride. Br. Med. J., 3, 797. Heald, C. B. (1967). Mortality of the ambulance ride. Br.
TRANSPORT OF THE INJURED PATIENT Past, present and future R. SNOOK
ROGER SNOOK, M.D., M.B., CH.B., Accident and Emergency
Department, The Royal United Hospital, Combe Park, Bath BA1 3NG.
ambulance services and medical techniques were beginning to evolve that would enable treatment to begin at an earlier stage in the care of the patient. THE PROBLEM
The movement of the injured has long been recognized as a problem. Pain inhibits movement. Movement can worsen the effects of injury, deepening shock and damaging vital structures. Vital functions may be affected by the position of the patient, but the position may have to be altered to allow treatment and movement. Treatment and movement may be influenced by distance and time, and time can influence morbidity and mortality. Ideally these problems should be identified and their effects measured. This should allow minimum standards of care to be defined, implemented, assessed and brought further up to date. Reality is often less ordered, however, and advances in ambulance design and first aid have often been made empirically and in isolation. For example, Thomas developed his famous leg splint at the time of the First World War. It was used with great effect in the latter stages of that war and again in the 1939-45 conflict. However, the adoption of the same principle in civilian practice awaited the introduction of modified splints in the 1970's (MacMahon, 1974). In considering the problems of the transport of the injured several distinct divisions may be recognized: reaching the patient; evacuating the patient to the ambulance; the ambulance journey and transfer to hospital. Reaching the patient
McKay (1969) analysed the time of survival in fatal accidents. He suggested that 43% of riders or vehicle occupants might have had a greater chance of survival if some medical treatment had been available at the scene of the accident within 10 minutes. It is important for both medical and humanitarian reasons that those caring for the injured should reach them as rapidly as is compatible with safety. To this end in the United Kingdom we have an efficient national emergency communication system
Downloaded from http://bja.oxfordjournals.org/ by guest on March 22, 2016
From biblical times onwards it has been recorded that man has transported his stricken fellow being to shelter or to centres of healing. The transport was often provided by a litter which is denned in the Concise Oxford Dictionary as "a framework with couch for transporting sick and wounded . . . and carried on man's shoulders or by beasts". Later in the development of healing the litter could also be transported on a cart drawn by a horse or other animal. Such methods must have been used to move the ill and injured to the early religious centres such as those that began the long traditions of the St John organization. During times of hostility, man's inhumanity to man eventually provoked the emergence of organized compassion for the wounded soldier. The fatherfigure of this movement was M. Henri Dunant out of whose ceaseless efforts was fashioned the Red Cross. Early documents record the organization of moving hospitals following the armies and the use of horsedrawn vehicles for the collection and evacuation of the wounded. Interestingly the word "ambulance" describes either the moving hospital or the vehicle used for transporting the patient. With the passage of time the horse gave way to steam and then to the internal combustion engine and the design of ambulances evolved with this change of motive power. Pictorial evidence suggests that this change was slow and documents in the archives of the British Red Cross Society record dissatisfaction with the design of those early ambulances. In the years between the World Wars improvements in the transport of patients were largely limited by the states of development of motor engineering and medical technology. In the second half of the 20th century technical advances on both these fronts have allowed the standards of emergency patient care to advance more rapidly. Vehicles were built specifically as ambulances; in the United Kingdom local communities were obliged by Act of Parliament to organize
652
Evacuating the patient to the ambulance
Once the patient has been reached the process of history taking, examination, diagnosis and treatment can begin. An understanding of the patterns of injury and of special rescue techniques is important in this phase of patient care (Snook, 1974). In order to come to a provisional diagnosis it has been found useful to consider the mechanisms of injury and, in the case of road accidents, to recognize patterns of vehicle damage and consequent occupant injury. Except where there is a definite danger of additional injury, the patient should always be assessed before being moved. In addition, vital functions should be protected or supported. Anything from simple procedures to full cardiopulmonary resuscitation may be indicated. Special equipment may be required to release a trapped patient. In the United Kingdom this is generally the responsibility of the Fire Service and is accomplished using comprehensive sets of cutting, lifting, jacking and lighting equipment which are often carried on rescue tenders. Whenever possible the principle used is to move the structures from the patient rather than vice versa. Further down the list of priorities is the relief of pain. Preferably, this should be undertaken before moving the patient. An exception will be a patient with a spinal iniury where pain can offer a sign guarding against injudicious movement. For these patients a spinal backboard splint of the U.S.A. Farrington pattern or the U.K. Tynemouth Spinal
Splint type should be applied first and then analgesia can be given. In the phase of provisional diagnosis it is often safer and more useful if pain relief can be controlled and modified. Baskett and Withnell (1970) and Snook (1974) found that Entonox (50% nitrous oxide in oxygen) gives safe, effective and controllable analgesia in the early management of injured patients. It is now available in the majority of emergency ambulances in the United Kingdom. Pain relief may be followed by the splinting of fractures using conventional bandaging, inflatable splints or traction splints (for example, Hare and Tauranga splints) where applicable. These last two forms of splint involve some degree of reduction of the fractures so that some pain relief will be necessary before they are applied. After splinting, a blanket lift or special rescue stretcher may be required to lift the patient from the accident site onto the ambulance trolley stretcher. In difficult situations such as cave, mountain and coastal rescue special stretchers may be used. These can be adapted to the needs of the casualty and the situation, and may include sledge, wheel or sling attachments, provision for thermal insulation and even for an attendant to ride alongside the stretcher. Two of the most widely used rescue stretchers are the canvasand-bamboo "Neil-Robertson" and the tubular metal and plastic "Paraguard" stretchers. The latter has the particular virtue of folding to half-size for ease of storage. In addition to the rescue stretcher, special transport systems may be involved in bridging the gap between the accident site and the ambulance. Helicopters, hovercraft, Landrovers or lifeboats may be needed. The ambulance
It would seem that little serious attention was given to the ambulance until Bothwell (1959) described a patent ambulance. In a paper given to the Institute of Mechanical Engineers, London (1968) observed that ambulances were often designed without the least regard for the effects of illness and injury. Also in 1968 the Committee on Acute Medicine of the American Society of Anesthesiologists stated that most vehicles in use were unsatisfactory for life support. In 1967, Cullen, Douglas and Danziger reported that there was clinical evidence of an adverse response of patients to movement in an ambulance. Similar observations were made by other workers who also expressed disquiet about the "mortality of the am-
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which links the public with the emergency services by the "999" telephone call system and the various emergency services by the "flash" call system. The response to such an emergency call is to mobilize an ambulance either from a base or by sending the nearest available mobile unit. To avoid delay in reaching the patient the ambulance is identified externally by several means. Most ambulances are white and are equipped with one or more blue flashing lights and an audible warning device. Snook (1972a) found that the size of the beacon is important and that alternating horns are preferable to sirens. To reduce the time taken to reach the patient it is now technically feasible to fit the ambulance with a small device that will switch traffic lights to favour the passage of the emergency vehicle (Snook, 1972b). Such a system is of practical use and is relatively inexpensive, adding approximately 5% to the cost of the traffic light installation.
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(1) The requirement that the vehicle shall fulfil a dual-purpose role carrying at one extreme one seriously ill patient with an attendant and at the other six to eight patients together with wheel chairs, crutches and luggage! To be able to accommodate the large group the vehicle springs have to be too hard for transporting the single sick patient. (2) Routine work forms 85% of ambulance journeys and emergency work only 15%. (3) There are economic restrictions favouring the use of a cheaper commercial van conversion rather than a purpose-built vehicle which would be more expensive. It should be noted that this saving on capital costs involves additional costs to the community from the mortality and morbidity of the ambulance journey. (Dawson (1971) estimated that an average road accident fatality cost the community approximately £16 800.) 53
(4) There are no measurable minimum standards of noise, heating, lighting and vibration in ambulances. (5) There are no ergonomic standards relating to the performance of life-support tasks within the vehicles. Collectively, these constraints have been responsible for the poor state of the development of the ambulance, which in many respects is little more than a transport van rather than a purpose-designed patient care system. None of the problems is insurmountable. It is possible to design a chassis and suspension system that gives a ride closely approaching that of a good saloon car and maintain that standard over a varying load with a variable-rate suspension system (Snook, 1972c). Similarly, it is possible to measure and design optimum environmental conditions within the vehicle to cover light, sound, heat and vibration. The ergonomic considerations for the attendant with his patient and equipment could easily be met by redesigning the interior layout of the patient compartment (N.R.D.C. Report, 1969; Smallhorn, 1970). Sadly, since the demise of the Daimler ambulance in the late 1950's (fig. 1) no British company has been able to produce commercially a purpose-built ambulance chassis. There is little doubt that this is a result of the failure of ambulance authorities to appreciate the need for such vehicles, rather than of cost or engineering problems. At least two attempts have been made recently to produce such a vehicle, taking design to the point of a pre-production prototype (fig. 2). But these appear not to have been evaluated adequately by the authorities then responsible for purchase and use of ambulances. Moreover, certain design concepts still have not been agreed. For example, a reversal of the direction of travel of the stretcher patient, so that he travelled feet first, would have many advantages. This direction would be more physiologically appropriate for changes in the speed of the vehicle, with the decelerating forces always exceeding the acceleration forces. This position would also allow the patient to be carried within the wheelbase of the vehicle, thereby reducing vibration. Ergonomically, the attendant could care for his patient more easily in the moving environment, being positioned at the head of the patient on a secure seat with forward visibility to prevent motion sickness. In European countries the situation would seem to be much the same as that in this country. It has led to research at Delft University in Holland in a different direction. Instead of designing a new vehicle,
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bulance ride" and other effects related to the transport of the patient (Mann, 1961; Glover, 1967; Gurling, 1967; Heald, 1967; Horton, 1967; Lamont, 1967; Stewart, 1967; Strange, 1967; Storrs and Taylor, 1970; Young, 1971; Snook, 1972c). In spite of these disquieting relevations there was little evidence of any serious effort to improve the situation. Snook (1972c) investigated the problems in detail and found that the interior design and layout of many emergency ambulances in current use left much to be desired. The illumination was found to be inadequate; heat loss occurred (although it could be prevented); the interior noise levels were often too high and vehicle identification and passage through traffic could be improved. Measurable differences in the vibration of the ride existed between the commercially available ambulances, a prototype purpose-built ambulance and a private car. The ride in the ambulance also affected the performance of simulated patient life-support tasks. There were measured failure rates of up to 14% for external cardiac massage and 17% for artificial ventilation. Evidence that this was an international problem came from France where Pichard (1970) described a series of 430 ambulance journeys. In 6% of these there were disturbances in the cardiovascular systems of the patients which could be related to movement. These disturbances included decreases in arterial pressure, cardiac arrhythmias and cardiac arrest. Collectively, these findings question some of the factors which have hitherto influenced ambulance design. At present the following constraints limit ambulance design:
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FIG. 2. The Dennis F.D.4 experimental pre-production prototype emergency ambulance used in the University of Bristol computer analysis trials (Snook, 1972c). The quality of the ride approached that of a good family saloon car. (Reproduced by kind permission of the Editor of Commercial Motor.)
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FIG. 1. The fleet of four Daimler Emergency Ambulances operated by the City of Bath Ambulance Service in the 1950's. (Photograph by kind permission of Mr L. Roberts.)
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FIG. 3. The floating stretcher support fitted to a conventional ambulance for patient and instrument trials. A vibration transducer attached to the "patient's legs" is coupled to a tape recorder and oscilloscope for later computer analysis of the ride characteristics. (Copyright Accident and Ambulance Research, Bath.)
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are about 36 in the country at the moment, based largely in rural areas. The hospital flying squads are necessarily based in urban areas; there are about 10 around the country. There can be little doubt that a higher standard of patient care must improve morbidity and mortality. As a start every ambulanceman should be trained in the use of, and equipped with, a laryngoscope so that he can see what he is doing with a sucker. This one improvement would do much to improve both patient care and the motivation of ambulance crews. Similarly, every ambulance should carry infusion apparatus and fluids for a doctor or advanced ambulanceman to use in an emergency. The necessary training in hospitals of the ambulance staff and the medical personnel could be easily provided in conjunction with anaesthetic and accident and emergency departments. In many cases self-instruction methods can be used (Baskett et al., 1976). Transfer from ambulance to hospital
Little need be said about this phase except to draw attention to one of the few papers discussing the movement of critically ill patients within hospitals (Waddell, 1975). He described renewed bleeding from a fractured pelvis, cardiac arrhythmias and other cardiovascular effects of movement. There were also difficulties in continuing treatment during movement and a plea was made for a greater awareness of the hazards of moving the critically ill. The movement of individual patients on stretchers is another area for improvement. A universal stretcher top compatible with ambulance, accident area and operating theatre equipment would save much patient disturbance but would have to include such considerations as resistance to glass fragments, radiotranslucency and electrical conductivity for the discharge of static, defibrillation and diathermy charges. The concept of a universal interchangeable trolley could include the universal top. There are further problems with the universal trolley in the conflicting requirements of the ambulance and hospital services. The ambulance trolley needs to be low, compact and light to allow it to be lifted and accommodated in a limited space; the hospital need is for strength, a standard work height and the ability to accept attachments such as large Entonox and oxygen cylinders, dripstands, cotsides, arm boards, etc. A universal trolley top system, can however, be made to fit the various needs for the several stages of patient care and is exemplified by the West German Automobile Club (A.D.A.C.) system with com-
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they have concentrated on the stretcher inside the ambulance. A separate suspension system has been devised to carry the stretcher and isolate it from the floor of the ambulance. This device was known as the "Vleugelbrancard" or "Floating Stretcher Support" (fig. 3). Two pre-production prototypes were made by 1969 and by 1973 the units were in commercial production. The first unit in this country was lent to the City of Bath Ambulance Service for a patientsubjective assessment trial and computer analysis of the characteristics of the ride. The results (Snook and Pacifico, 1976) showed a statistically significant improvement in the ride as assessed by the subjects. The computer analysis demonstrated that the vibration to which the patient is exposed could be reduced by up to two-thirds. Such a solution to ambulance transport is admittedly a design compromise. An ambulance which could give the same reduction in vibration would have advantages over stretcher isolation. Estimates suggest that the two systems cost similar amounts, but the stretcher suspension system is commercially available whereas a purpose-built ambulance has yet to be designed. Is there another answer ? If patients were resuscitated, stabilized and relieved of pain before the journey this might partly obviate the need for a specialized vehicle. Clinical research into methods of pre-hospital emergency patient care (Snook, 1972c, 1974) showed that morbidity and mortality can be reduced and that this can also be "cost effective". Methods have been developed to investigate the effects of ambulance transport in critically ill patients (Waddell, Scott et al., 1975; Waddell, Stuart et al., 1975). There were measurable changes in the arterial pressure and arterial carbon dioxide tension during and immediately after movement of patients by ambulance. It was noted that "resuscitation before transfer, continuing medical care during the journey and hence a slower, smoother journey seemed to be important factors in the management of these patients". There are several ways of providing such "immediate care". The advanced training of ambulance men in cardiopulmonary care (comparable to but not the same as the American Paramedic and Emergency Medical Technician schemes (Stewart, 1977)) is one. Others include the provision of care by general practitioners organized in specially equipped groups (Easton, 1970) and hospital-based flying squads (Snook, 1972d). The general practitioner schemes are voluntary and supported by public donations: there
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TRANSPORT OF THE INJURED PATIENT patability between helicopters, ambulances and the receiving emergency units.
CONCLUSION
Perhaps, in the past, we have been too ready to leave the transport of the injured (and ill) to the ambulanceman without supporting him with the necessary research, training and equipment to enable him to offer the highest standards of patient care. This state should not be allowed to continue and yet the Department of Health and Social Security (1976) and the Royal College of Physicians (Joint Working Party, 1975) have recently published diametrically opposing views on the subject. The Department has decided to limit advanced training for ambulancemen whilst the College supports the concept in the field of coronary care! What of the future? Research is continuing at various centres investigating human response to vibration and the patient response to the ambulance ride. Existing ambulance design is being improved, ambulanceman training programmes advance and the medical rescue or immediate care schemes expand. The results are being evaluated clinically and statistically. The specialities of anaesthesia and accident and emergency medicine can and should continue developments in this field. Both are involved in intensive care both as an actual hospital area and as a concept of continuing patient care. Regrettably, this area of patient care is starved of funds, hence die rate of progress is not that which is technically feasible. Nevertheless, substantial progress has been made in the last decade. REFERENCES
Adams Cowley, R. (1973). An economical and proved helicopter programme for transporting the emergency critically ill and injured patients in Maryland. J. Trauma, 13, 1029. Baskett, P. J. F., Lawler, P. G. P., Hudson, R. B. S., Makepiece, A. W., and Cooper, C. (1976). Resuscitation teaching room in a district general hospital: concept and practice. Br. Med. J., 1, 568. Withnell, A. (1970). Use of Entonox in the ambulance. Br. Med.J., 2, 41.
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Alternative transport systems Road vehicles are used for the majority of emergency journeys in this country, but situations arise where alternative methods are needed, at least for part of the journey. Lifeboat and inshore rescue boats, together with the rescue helicopters of the armed services, provide much of the coastal transport. Fixed-wing aircraft are most usually used for the planned transfers of patients over long distances or difficult terrain. Hovercraft have not yet been used to any extent. The helicopter has particular advantages for evacuating patients from coasts and the sea and is also of use where road transport is impractible because of floods, heavy snow and earthquakes. The use of helicopters in evacuating front-line casualties in the Korean and Vietnam wars (Neel, 1968; White, 1971) received considerable attention. Whilst the results were impressive, much of the success must be in part related to the continuous occurrence and the limited distribution of the casualties. Efforts to translate the lessons of war into benefits for peacetime civilian communities have been made in several countries. In Maryland in the United States the centralization of the emergency services together with the distances involved in travel from the rural communities led to the development of a helicopter evacuation service (Adams Cowley, 1973). To make the maximum use of the helicopters and to minimize costs other public services are also provided, with the understanding that rescue takes precedence. There was a measurable reduction in mortality as the service expanded and Adams Cowley stated that "for every 30 min that elapses between the accident and the time the patient gets definitive care, the mortality can be expected to increase threefold". In West Germany the A.D.A.C. initiated an integrated service using helicopters and conventional ambulances. They claim a saving of 700 lives in a 4-year period involving the treatment of 7500 casualties (Burghart, 1974). In Toulouse in France the S.A.M.U. Flying Medical Unit uses helicopters to evacuate casualties from the accident site. It involves the integration of the gendarmes in traffic control to allow landing on the highway adjacent to the crash (Lareng, 1973). The necessary equipment for aeromedical transport is described by Moylan and Pruitz (1973) of the United States Army Institute of Surgical Research.
Wider accounts of the medical and physiological constraints of air transport are given by Snook (1974) and Oxer (1975). In the United Kingdom the use of helicopters in civilian patient care is limited by four factors: the sparse distribution of helicopter bases, the wide scatter of accidents, the system of charging for individual flights and the delays in administrative sanction of individual journeys. These last two help perpetuate the low rate of use, whether by accident or design!
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Neel, S. (1968). Army aeromedical evacuation procedures in Vietnam. Implications for rural America. J.A.M.A., 204, 309. Oxer, H. F. (1975). Aeromedical evacuation of the seriously ill. Br. Med. J., 3, 692. Pichard, E. (1970). The effect of acceleration and vibration on sick persons during transport. Rev. Corps Same, 11, 611. Smallhorn, A. (1970). Emergency care vehicles. Br. Hosp. J. Soc. Serv. Rev., 80, 1638. Snook, R. (1972a). The use of flashing beacons. Fire Protection Rev., 5, 214. (1972b). Automatic traffic light control. Fire, 65, 3. (1972c). Medical aspects of ambulance design. Br. Med. J., 3, 574. (1972d). Accident flying squad. Br. Med.J., 3, 569. (1974). Medical Aids at Accidents. London: Update Publications. Pacifico, R. (1976). Ambulance ride: fixed or floating stretcher. Br. Med. J., 2, 405. Med.J., 3,678. Stewart, A. B. (1967). Mortality of the ambulance ride. Horton, J. (1967). Mortality of the ambulance ride. Br. Br. Med. J., 3, 797. Med. J., 3, 678. Stewart, R. D. (1977). The training of paramedical perJoint Working Party (1975). J. R. Coll. Physicians Lond., sonnel. Br. J. Anaesth., 49, 659. 10,5. Storrs, C. N., and Taylor, M. R. H. (1970). Transport of Lamont, D. (1967). Accident services. Br. Med.J., 2, 374. sick newborn babies. Br. Med. J., 3, 328. Lareng, L. (1973). Flying medical unit. Anesth. Analg. Strange, F. G. St C. (1967). Mortality of the ambulance ride. Br. Med.J., 3, 560. (.Paris), 30, 3. London, P. S. (1968). Design for ambulances. Proc. Inst. Waddell, G. (1975). Movement of critically ill patients within hospital. Br. Med. J., 2, 417. Mech. Eng., 182, 188. Scott, P. D. R., Lees, N. W., and Ledingham, I. McA. McKay, G. M. (1969). Some features of traffic accidents. (1975). Effects of ambulance transport on critically ill Br. Med. J., 4, 799. patients. Br. Med. J., 1, 386. MacMahon, A. G. (1974). Pre-hospital management of the Stuart, B., Tehrani, M. A., McGarrity, G., Reyes, A., fractured femur using the Tauranga-Thomas splint. Smith, H. C , Ledingham, I. McA., Green, H. L., and 5. Afr. Med.J., 48, 835. Weller, C. (1975). Intra-arterial monitoring of critically Mann, T. P. (1961). Temperatures in ambulances. Lancet ill patients in ambulances. Br. Med. J., 4, 206. 1, 1257. White, M. S. (1971). Results of early aeromedical evacuaMoylan, J. A., and Pruitz, B. A. (1973). Aeromedical transtion of Vietnam casualties. Aerosp. Med., 42, 780. portation. J.A.M.A., 224, 1271. Young, A. E. (1971). Transporting patients with chest National Research Development Corporation (1969). The injuries. Br. Med. J., 4, 364. Ogle report on emergency ambulances. Bothwell, P. (1959). Design of ambulances. Med. Officer, 101, 159. Burghart, H. (1974). The use of helicopters as mobile intensive units in disaster control and rescue service in the Federal Republic. Resuscitation, 3, 143. Cullen, C. H., Douglas, W. K., and Danziger, A. M. (1967). Mortality of the ambulance ride. Br. Med. J., 3, 438. Dawson, R. F. F. (1971). Cost of road accidents in Great Britain. Transport and Road Research Laboratory Report 396. Department of Health and Social Security (1976). Health Note 76/204. Easton, K. C. (1970). The general practitioner and the rescue services. Community Health {Bristol), 2, 81. Glover, J. R. (1967). Mortality of the ambulance ride. Br. Med. J., 3, 678. Gurling, K. J. (1967). Mortality of the ambulance ride. Br. Med. J., 3, 797. Heald, C. B. (1967). Mortality of the ambulance ride. Br.