ReviewThe role of evidence based medicine in neurotrauma
Introduction
It is over 20 years since the introduction of evidence based medicine when it was announced that a new paradigm was emerging. This paradigm shift de-emphasised intuition and unsystematic clinical experience when considering clinical decision making and stressed the importance of examining evidence from clinical research [1]. The levels of evidence were stratified according to strength and a pyramid constructed with the meta-analysis of randomised controlled trials placed at the apex and seen to provide the highest level of evidence. Clinical judgement and background information such as pathophysiology were relegated to the base of the pyramid and were deemed to provide the lowest level of evidence (Fig. 1).
For many years a well designed randomised controlled trial published in a reputable medical journal was seen to be the only way to advance clinical practice and there can be no doubt that within the field of neurosurgery there are notable examples. These include the International Subarachnoid Aneurysm Trial (ISAT) investigating the role of coiling versus clipping of intracranial aneurysms [2], the Clifton studies investigating the role of hypothermia in traumatic brain injury (TBI) [3], [4] and the Medical Research Council Corticosteroid Randomization After Significant Head injury (MRC CRASH) study that investigated the role of steroids in the field of TBI [5]. It is however becoming increasingly apparent that there may be some limitations when attempting to apply this approach across all aspects of clinical practice, not least in the context of neurotrauma where surgery is often performed as a life saving intervention [6], [7]. In addition, it is increasingly recognised that considerable clinical experience is required not only to critically evaluate the quality of the evidence but also to assess the validity of the conclusions that are often presented by the investigators. Indeed it has been suggested that even the most rigorous trials have methodological flaws such that the conclusions of many studies are either exaggerated or indeed incorrect [8]. Given these limitations the time may have come for another paradigm shift that re-emphasises the importance of a clear understanding of pathophysiology and acknowledges the role of clinical experience such that the evidence can be critically evaluated in its appropriate context.
A contemporary example of this issue is seen when considering the role of decompressive craniectomy in the management of neurotrauma [9]. There is currently a great deal of evidence available regarding clinical efficacy of the procedure however considerable expertise is required in order interpret this evidence and the impact that it should have on clinical practice.
The aim of this narrative review is to highlight the importance of so called “background information” when considering the surgical management of severe TBI and this includes the underlying pathophysiology of the condition and the contemporary medical management. Thereafter the evidence currently available for clinical efficacy will be critically evaluated.
Section snippets
Pathophysiology
There are two important concepts that require consideration when managing patients with severe TBI. The first is the neuroexcitatory cascade and the second is the Monro–Kellie doctrine.
Decompressive craniectomy
By temporarily removing a large section of the calvarium, decompressive craniectomy challenges the Monro–Kellie doctrine by expanding the “rigid box” and providing extra space into which the injured brain can expand. The aims of the procedure are to reduce ICP and prevent death due to brainstem compression following tonsillar herniation, to reduce secondary brain injury due to impaired cerebral perfusion, and to improve clinical outcome.
Currently there would appear to be sufficient evidence
Reducing mortality
In the context of trauma numerous non-randomised cohort studies have demonstrated that surgical decompression can control intractable intracranial hypertension in situations where the patient is thought unlikely to survive without surgical intervention [6], [7], [32], [33], [34]. Likewise in the context of ischaemic stroke where the use of ICP monitoring is less widespread, decompressive surgery has been shown to be beneficial in the setting of deteriorating consciousness levels and pupillary
Decompressive craniectomy: Critical examination of the evidence
There is little doubt that these were well organised, multicentre studies based on genuine clinical equipoise and they do provide the only level one evidence for clinical efficacy of decompressive craniectomy in the adult population.
The hypothesis of the DECRA study was that early decompressive surgery would lower the ICP, improve cerebral perfusion and thereby prevent secondary brain injury. This hypothesis was based on the clear association between raised ICP and poor outcome following TBI
Conclusions
There can be little doubt that an evidence based approach in medicine provides valuable information on which to base clinical practice, however it is becoming increasingly apparent that there are limitations when attempting to apply this approach across certain aspects of surgery, not least in the context of a lifesaving intervention. It is also apparent that some of the conclusions presented do not always hold up to closer scrutiny.
In the context of decompressive craniectomy for severe TBI
Conflicts of Interest/Disclosures
The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.
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A multi-agent system to support evidence based medicine and clinical decision making via data sharing and data privacy
2016, Decision Support SystemsCitation Excerpt :Evidence based medicine (EBM) is becoming common in today's healthcare delivery. Almost all branches of medicine practice EBM [38,41] and many examples can be found in the medical literature – rhinoplasty [33], facial plastic surgery [35], hand and upper extremity surgery [9], and neurotrauma [23]. EBM requires an integrated system where the clinician can gain access to not only the best practices and evidence in assessing the benefits and risks of a treatment, but also the patient information that might be scattered across the healthcare organization.
Decompressive Craniectomy for Severe Traumatic Brain Injury: A Systematic Review
2016, World NeurosurgeryCitation Excerpt :The first major RCT, DECRA (Decompressive Craniectomy Trial),7 showed that the use of early bifrontal DC in patients with diffuse injury, when compared with standard nonsurgical care, effectively decreased mean ICP, although it did not significantly improve outcome at 6 months.7 The limitations of DECRA and controversy over its findings have been extensively discussed, and the lack of generalizability of the findings of DECRA to typical patients of severe TBI highlights an ongoing need for quality evidence to support the use of surgical decompression in this population.4,8-10 The RescueICP (Randomized Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of Intracranial Pressure) trial randomized 400 patients to DC after failing maximum medical therapy.11
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