Acute management of acquired brain injury part I: an evidence-based review of non-pharmacological interventions

PRIMARY OBJECTIVE

To review the literature on non-pharmacological interventions used in acute settings to manage elevated intracranial pressure (ICP) and minimize cerebral damage in patients with acquired brain injury (ABI).

MAIN OUTCOMES

A literature search of multiple databases (CINAHL, EMBASE, MEDLINE and PSYCHINFO) and hand-searched articles covering the years 1980-2008 was performed. Peer reviewed articles were assessed for methodological quality using the PEDro scoring system for randomized controlled trials (RCTs) and the Downs and Black tool for RCTs and non-randomized trials. Levels of evidence were assigned and recommendations made.

RESULTS

Five non-invasive interventions for acute ABI management were assessed: adjusting head posture, body rotation (continuous rotational therapy and prone positioning), hyperventilation, hypothermia and hyperbaric oxygen. Two invasive interventions were also reviewed: cerebrospinal fluid (CSF) drainage and decompressive craniectomy (DC).

CONCLUSIONS

There is a paucity of information regarding non-pharmacological acute management of patients with ABI. Strong levels of evidence were found for only four of the seven interventions (decompressive craniectomy, cerebrospinal fluid drainage, hypothermia and hyperbaric oxygen) and only for specific components of their use. Further research into all interventions is warranted.

Intravascular temperature modulation as an adjunct to secondary brain injury prevention in a patient with an epidural hematoma

Epidural hematomas (EDHs) account for 10% of fatal injuries in patients with head trauma. Up to 35% of patients suffering EDHs develop secondary brain injury within days after the initial trauma. Secondary brain injury can profoundly affect a patient's subsequent neurologic recovery and functional status. This case study presents a patient who developed an EDH following severe head trauma with signs and symptoms of secondary brain injury; intravascular temperature modulation was used to treat the secondary injury for a prolonged period of 13 days. The patient showed a complete neurologic recovery with return to work 6 months after her injury.

Cooling strategies for patients with severe cerebral insult in ICU (Part 2)

Critically ill patients who have sustained a severe cerebral insult will be actively cooled should they develop an elevated body core temperature. Patients who require therapeutic hypothermia for neuroprotection may require the same cooling strategies. A literature review suggested limited evidence to support cooling strategies currently used within one intensive care unit. An experimental approach was used to examine the effects of paracetamol and four external cooling strategies on patients with severe cerebral insult It is suggested that paracetamol is effective in reducing body core temperature and that fans may not. However, data obtained from the study of the four external cooling strategies were inconclusive.

A review of cooling patients with severe cerebral insult in ICU (Part 1)

A review of the literature was undertaken to determine the existence of any evidence to support cooling strategies used in the ICU. The focus of the review was to examine previous findings on the specific problems of cooling patients with severe cerebral insult. Cooling methods that use external physical cooling strategies as well as the effects of antipyretics and vasoactive drugs were examined. Overall, it would appear that conclusions for practice remain unclear. The findings led to the implementation of a pilot study, the findings of which will be discussed in Part 2.

Hypothermia as an adjunctive treatment for severe bacterial meningitis

Brain injury due to bacterial meningitis results in a high mortality rate and significant neurologic sequelae in survivors. The objective of this study was to determine if the application of moderate hypothermia shortly after the administration of antibiotics would attenuate the inflammatory response and increase in intracranial pressure that occurs in meningitis. For this study we used a rabbit model of severe Group B streptococcal meningitis. The first component of this study evaluated the effects of hypothermia on blood-brain barrier function and markers of inflammation in meningitic animals. The second part of the study evaluated the effects of hypothermia on intracranial pressure, cerebral perfusion pressure and brain edema. This study demonstrates that the use of hypothermia preserves CSF/serum glucose ratio, decreases CSF protein and nitric oxide and attenuates myeloperoxidase activity in brain tissue. In the second part of this study we show a decrease in intracranial pressure, an improvement in cerebral perfusion pressure and a decrease in cerebral edema in hypothermic meningitic animals. We conclude that in the treatment of severe bacterial meningitis, the application of moderate hypothermia initiated shortly after antibiotic therapy improves short-term physiologic measures associated with brain injury.

Head injury: complications and management

Considerable effort and substantial funding has gone towards the development of a neuroprotective agent that could be given after brain trauma to reduce mortality and improve functional recovery. There have been many failed or inconclusive studies to date. In Europe two promising studies have been stopped or shelved (Lubeluzole, Janssen-Cilag and BAYx3702, Bayer) and the future of pharmacological neuroprotection after traumatic brain injury is in doubt. Clinicians managing patients with a head injury are therefore left with the detection and prevention of secondary insults to the brain, including the management of medical complications of brain injury, and non-pharmaceutical interventions that might beneficially modify the brain's response to trauma. Of the potential interventions, moderate hypothermia is the most promising.