Martin Smith

Bio

Martin Smith is a consultant in Neurocritical Care at the National Hospital for Neurology and Neurosurgery, University College London Hospitals and Honorary Professor at University College London. He has a clinical and research interest in monitoring and managing the acutely injured brain. Martin is Neuroscience Section Editor of Intensive Care Medicine and a Senior Editor of Anesthesia and Analgesia. He is Past President of the Society for Neuroscience in Anesthesiology and Critical Care.


Neurocritical care and traumatic brain injury

Individualised physiological optimisation improves outcomes after TBI, but blind adherence to generic targets does not.
The management of severe traumatic brain injury (TBI) has undergone extensive revision following evidence that longstanding and established practices are not as efficacious or innocuous as previously believed. Very few specific interventions have been shown to improve outcome in large randomized controlled trials and, with the possible exception of avoidance of hypotension and hypoxaemia, most are based on observational studies or analysis of physiology and pathophysiology. Further, the substantial temporal and regional pathophysiological heterogeneity after TBI means that some interventions may be ineffective, unnecessary or even harmful in certain patients at certain times. Improved understanding of pathophysiology and advances in neuromonitoring and imaging techniques have led to the introduction of more effective and individualised treatment strategies that have translated into improved outcomes for patients. In particular, the sole goal of identifying and treating intracranial hypertension has been superseded by a focus on the prevention of secondary brain insults using a systematic, stepwise approach to maintenance of adequate cerebral perfusion and oxygenation. As well as being used to guide treatment interventions, multimodal neuromonitoring also gives clinicians confidence to withhold potentially dangerous therapy in those with no evidence of brain ischemia/hypoxia or metabolic disturbance. The days of blind adherence to generic physiological targets in the management of severe TBI have been replaced by an individualised approach to optimisation of physiology which has translated into improved outcomes for patients.

Controversies in Brain Death

There is a need for international consensus in the determination of brain death to address the challenges and controversies that continue to surround it.

Almost fifty years since the concept of brain death was first introduced, some individuals and whole nations still struggle with its concept and justification. Many controversies continue to surround brain death, although there is broad consensus that human death is ultimately death of the brain. This crucially involves the irreversible loss of the capacity for consciousness combined with the irreversible loss of the capacity to breathe since, taken together, these elements represent the most basic manner in which a human being can interact with their environment.

Confusingly brain death is defined in two different ways based on ‘whole’ brain and ‘brainstem’ formulations, although the clinical determination of both is identical. It is not widely appreciated that death is a process, and this leads to misunderstanding by both the public and professionals; reports of brain dead patients ‘being kept alive’ on a ventilator are familiar. Pragmatically, once a threshold of irreversibility in the dying process has been reached, and brain death is such a point, it is not necessary to wait for the death of the whole organism for the inevitable consequence of its biological death to be certain.

The majority of countries specify that a clinical diagnosis of brain death is sufficient for the determination of death in adults, but there are major international differences in the criteria for the determination of brain death. There is unanimity that confirmation of absent brainstem reflexes is fundamental, but wide variations in requirements for the apnoea test. The diagnosis of brain death is robust when established diagnostic criteria are strictly applied but, somewhat worryingly, deviation from jurisdiction-specific diagnostic guidance is relatively common.

This lecture will discuss the history and development of the concepts and diagnosis of brain death internationally, examine current challenges and controversies, and make the case for an international consensus.


Almost fifty years since the concept of brain death was first introduced, some individuals and whole nations still struggle with its concept and justification. Many controversies continue to surround brain death, although there is broad consensus that human death is ultimately death of the brain. This crucially involves the irreversible loss of the capacity for consciousness combined with the irreversible loss of the capacity to breathe since, taken together, these elements represent the most basic manner in which a human being can interact with their environment.

Confusingly brain death is defined in two different ways based on ‘whole’ brain and ‘brainstem’ formulations, although the clinical determination of both is identical. It is not widely appreciated that death is a process, and this leads to misunderstanding by both the public and professionals; reports of brain dead patients ‘being kept alive’ on a ventilator are familiar. Pragmatically, once a threshold of irreversibility in the dying process has been reached, and brain death is such a point, it is not necessary to wait for the death of the whole organism for the inevitable consequence of its biological death to be certain.

The majority of countries specify that a clinical diagnosis of brain death is sufficient for the determination of death in adults, but there are major international differences in the criteria for the determination of brain death. There is unanimity that confirmation of absent brainstem reflexes is fundamental, but wide variations in requirements for the apnoea test. The diagnosis of brain death is robust when established diagnostic criteria are strictly applied but, somewhat worryingly, deviation from jurisdiction-specific diagnostic guidance is relatively common.

This lecture will discuss the history and development of the concepts and diagnosis of brain death internationally, examine current challenges and controversies, and make the case for an international consensus.



© 2017 SMACC

Website by Off the Page eMarketing

Log in with your credentials

Forgot your details?