Trauma overview

The trauma system—background

In most developed countries, there have been significant reductions in mortality and morbidity from injury as a result of a systematic approach to trauma care. The majority of these reductions have resulted from prevention strategies, including seatbelt legislation, drink-driving legislation, improved road engineering, motorcycle and bicycle helmet use and road safety and workplace injury awareness campaigns. Changes in both trauma system configuration and individual patient management have brought about improvements in the survival rate of those who are seriously injured, although the impact has not been as great as that of injury prevention.

Civilian interest in injury morbidity and mortality was initially most evident in the United States because of the high incidence of urban violence and road trauma and owing to lessons learnt from the wars of the 20th century. Research into systems of trauma care began with epidemiological work by Trunkey and others in examining trauma deaths. These researchers developed the concept of a trimodal distribution of trauma deaths. Trunkey proposed that about 50% of deaths occurred within the first hour as a result of major blood vessel disruption or massive brain and/or spinal cord injury. This could be improved only by prevention strategies. A second more important group (from the therapy perspective) accounted for about 30% of deaths and included patients with major truncal injury causing respiratory and circulatory compromise. The remaining 20% of patients were said to die much later from acute respiratory distress syndrome (ARDS), multiple organ failure (MOF), sepsis and diffuse brain injury. Trunkey initially identified the second group as most likely to benefit from improvements in trauma system organization, and it is a tribute to the effectiveness of such schemes that the number of patients dying from avoidable factors within the first few hours of injury has generally declined. Such improvements in trauma system provision have resulted in a redistribution of the three groups proposed by Trunkey, and it is now generally accepted that far fewer than 30% are included in the second group. Furthermore, with improved initial management, complications such as MOF and ARDS have decreased to such an extent that, in mature trauma systems, even the third peak is now minimal, with the vast majority of deaths occurring from major head injury and massive organ disruption in the first 1 to 2 hours.

Trauma care systems have been developed to ensure a multidisciplinary approach and a continuum of care from the roadside or scene of injury through hospital care to rehabilitation. Identifying weakness in such a system is always difficult because of the delay between cause and effect. Suboptimal management does not usually lead to immediate death: for example, a period of hypoxia may result in organ failure many hours later. Another difficulty is the relatively low incidence of death. Although this is of course to be welcomed, it does make statistical analysis more difficult when the ‘adverse event’ occurs uncommonly. Careful audit of the entire trauma process and accurate measurement of ‘input’ (i.e. injury severity) and ‘output’ (i.e. death or quality of survival) is essential if the process of trauma care is to be further improved.

The trauma system—pre-hospital

Whereas the initial work on trauma system development focused on the need for centres of expertise and trauma management, it is now accepted that the pre-hospital phase is of critical importance. The linchpin of a mature trauma system is a highly skilled and resourced pre-hospital service following the key principle of: the right patient to the right level of care in the shortest time . Timely access to the care of an effective pre-hospital service followed by the triage of the injured patient to the closest most appropriate facility are essential. Specifically, high-risk patients should be taken to a hospital capable of managing critically ill trauma patients. A diagrammatic representation of one integrated trauma system, at its inception in 1999, is provided in Fig. 3.1.1 , as it remains relevant today.

Criteria for identifying those patients who may require resuscitation at a tertiary level trauma centre or ‘major trauma service (MTS)’ will depend on resources. In the most developed trauma systems, ‘mechanism of injury’ criteria are usually included in the pre-hospital triage tool. This ensures high sensitivity of the tool but leads to considerable overtriage. In less resourced settings, it may be appropriate to identify high-risk patients on the basis of abnormal vital signs and obvious major injury. The elements of a trauma system’s triage tool may include most or all of the predictors of life-threatening injury listed in Table 3.1.1 .

The appropriate application of pre-hospital triage guidelines relies on adequate resourcing. In regions with developed trauma systems, pre-hospital staff are expected to provide a range of advanced life support interventions including patient intubation and chest decompression, thereby ensuring that further organ injury is limited during the pre-hospital phase. The pre-hospital care providers armed with these skills may be doctors (as in some European countries, for example) or highly trained paramedics (as in the United States, Australia and the United Kingdom).

The trauma system—intra-hospital