Published by Hutchinson and colleagues in the New England Journal of Medicine in September 2016
Written by Dominic Allen (Medical Student), edited by Dr Lucia M Li
Introduction
After a traumatic brain injury, the brain can swell and increase the pressure inside the skull (intracranial pressure, ICP). This is referred to as intracranial hypertension. Patients with a head injury who develop intracranial hypertension are more likely to die. Because of this, intensive care units routinely monitor ICP in brain injured patients and attempt to reduce it.
One procedure used to reduce ICP is an operation called decompressive craniectomy (decompressive = reducing pressure; crani- = skull; -ectomy = removal). It involves removing a large piece of the skull and cutting into the tough membrane (dura mater) that covers the brain. This allows the swollen brain to expand and relieves the pressure inside the skull. At a later date, when the swelling has reduced, the gap in the skull is repaired (e.g. with a titanium plate). A decompressive craniectomy and the later repair are major operations, which carry their own risks. Also, brain swelling is likely to mean that the person has a very severe injury, which may lead to poor recovery regardless of treatment. So, although a decompressive craniectomy operation lowers the pressure inside the skull, its risks may outweigh its potential benefits.
This trial, the Randomised Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of Intracranial Pressure (RESCUEicp) trial, investigated the use of decompressive craniectomy as a last resort, when all other measures had failed to reduce pressure inside the skull.
Methods
This study was conducted on patients coming into hospital with a TBI and raised ICP. Certain patients were excluded, such as those under 10 years old.
Patients were given treatments to attempt to reduce their ICP in three stages. Stage 1 involved basic measures such as raising the head and giving sedatives. Stage 2 included more complex measures such as using drugs to boost blood pressure, or inserting a small tube (drain) into the skull to remove fluid.
If the ICP was still raised after this, at Stage 3 patients would be randomly selected to either receive decompressive craniectomy or be treated with barbiturates (a powerful sedative medication). This step is called randomisation and prevents biasin clinical studies. If patients treated with medications continued to have increased ICP, they could go on to have the DC operation.
The primary result measured by the study was the level of disability six months later, measured using the Extended Glasgow Outcome Scale (GOS-E), which has eight categories:
Results
A total of 398 patients took part in the trial. The surgical group had 202 patients and the barbiturate group had 196. The two groups were similar in terms of their basic characteristics (e.g. age, sex, severity of injury) and treatments they received in Stages 1 and 2 before randomisation - this is important as any differences between the groups could affect the results when they were compared.
The main result of this study is that more patients having the DC operation survived. However, many of these survivors still had a serious disability. The authors estimated that, for every 100 patients treated with surgery, there were 22 more survivors. Of these, 14 were classed as being in a vegetative state or had lower severe disability, and 8 had upper severe disability or better. The patients treated with surgery also spent less time in intensive care, but were more likely to get side-effects from their treatments e.g. infections.
Discussion
This study is the first to investigate whether a decompressive craniectomy operation results in overall benefit for head injured patients. The study also included patients from many different hospitals in the UK and around the world. It also used treatment protocols that were more close to real clinical practice than previous studies. These factors mean that the results from this study are likely to be relevant to many patients. The authors note an important limitation of their study – just over a third of patients in the barbiturate group (37%) went on to have the operation as their condition worsened, which may have affected the comparison of the two groups.
Overall, this study showed that patients who had a decompressive craniectomy were significantly more likely to survive than those managed without surgery. However, there were higher rates of vegetative state and severe disability. These results suggest that the DC operation benefits some patients more than others. Further research needs to be conducted into why this is the case, and what factors predict response to treatment after traumatic brain injury.
Written by Dominic Allen (Medical Student), edited by Dr Lucia M Li
Introduction
After a traumatic brain injury, the brain can swell and increase the pressure inside the skull (intracranial pressure, ICP). This is referred to as intracranial hypertension. Patients with a head injury who develop intracranial hypertension are more likely to die. Because of this, intensive care units routinely monitor ICP in brain injured patients and attempt to reduce it.
One procedure used to reduce ICP is an operation called decompressive craniectomy (decompressive = reducing pressure; crani- = skull; -ectomy = removal). It involves removing a large piece of the skull and cutting into the tough membrane (dura mater) that covers the brain. This allows the swollen brain to expand and relieves the pressure inside the skull. At a later date, when the swelling has reduced, the gap in the skull is repaired (e.g. with a titanium plate). A decompressive craniectomy and the later repair are major operations, which carry their own risks. Also, brain swelling is likely to mean that the person has a very severe injury, which may lead to poor recovery regardless of treatment. So, although a decompressive craniectomy operation lowers the pressure inside the skull, its risks may outweigh its potential benefits.
This trial, the Randomised Evaluation of Surgery with Craniectomy for Uncontrollable Elevation of Intracranial Pressure (RESCUEicp) trial, investigated the use of decompressive craniectomy as a last resort, when all other measures had failed to reduce pressure inside the skull.
Methods
This study was conducted on patients coming into hospital with a TBI and raised ICP. Certain patients were excluded, such as those under 10 years old.
Patients were given treatments to attempt to reduce their ICP in three stages. Stage 1 involved basic measures such as raising the head and giving sedatives. Stage 2 included more complex measures such as using drugs to boost blood pressure, or inserting a small tube (drain) into the skull to remove fluid.
If the ICP was still raised after this, at Stage 3 patients would be randomly selected to either receive decompressive craniectomy or be treated with barbiturates (a powerful sedative medication). This step is called randomisation and prevents biasin clinical studies. If patients treated with medications continued to have increased ICP, they could go on to have the DC operation.
The primary result measured by the study was the level of disability six months later, measured using the Extended Glasgow Outcome Scale (GOS-E), which has eight categories:
- Death
- Vegetative state (unable to follow commands)
- Lower severe disability (dependent on others for care)
- Upper severe disability (independent at home but not outside)
- Lower moderate disability (independent at home and outside, but with some disability)
- Upper moderate disability (independent at home and outside but with less severe disability)
- Lower good recovery (able to resume normal activities, with some problems)
- Upper good recovery (no problems)
Results
A total of 398 patients took part in the trial. The surgical group had 202 patients and the barbiturate group had 196. The two groups were similar in terms of their basic characteristics (e.g. age, sex, severity of injury) and treatments they received in Stages 1 and 2 before randomisation - this is important as any differences between the groups could affect the results when they were compared.
The main result of this study is that more patients having the DC operation survived. However, many of these survivors still had a serious disability. The authors estimated that, for every 100 patients treated with surgery, there were 22 more survivors. Of these, 14 were classed as being in a vegetative state or had lower severe disability, and 8 had upper severe disability or better. The patients treated with surgery also spent less time in intensive care, but were more likely to get side-effects from their treatments e.g. infections.
Discussion
This study is the first to investigate whether a decompressive craniectomy operation results in overall benefit for head injured patients. The study also included patients from many different hospitals in the UK and around the world. It also used treatment protocols that were more close to real clinical practice than previous studies. These factors mean that the results from this study are likely to be relevant to many patients. The authors note an important limitation of their study – just over a third of patients in the barbiturate group (37%) went on to have the operation as their condition worsened, which may have affected the comparison of the two groups.
Overall, this study showed that patients who had a decompressive craniectomy were significantly more likely to survive than those managed without surgery. However, there were higher rates of vegetative state and severe disability. These results suggest that the DC operation benefits some patients more than others. Further research needs to be conducted into why this is the case, and what factors predict response to treatment after traumatic brain injury.