Temperature and Traumatic Brain Injury
OVERVIEW
- induced hypothermia has been used for years to reduced cerebral metabolic rate.
- manipulation of temperature has been shown to effect certain types of brain injury (therapeutic hypothermia in out-of-hospital cardiac arrest).
- the data in traumatic brain injury differs.
DEFINTIONS
- normothermia: T 36-38 C
- hypothermia: T < 36 C – hyperthermia: T > 38 C
- therapeutic hypothermia: T 32-33 C (usually for 48 hours post injury)
THERAPEUTIC HYPOTHERMIA
NEJM, 2001
- MRCT
- normothermia vs moderate hypothermia (T33 C for 48 hours)
- improved ICP but no reduction in mortality
- patients > 45 years do worse with induced hypothermia
- if a patient arrives hypothermic -> do not warm to 37 (poorer outcome)
- if a patient arrives hypothermic -> they will have a significantly worse TBI
- increased risk of ventilatory acquired pneumonia
BTF Guidelines
- moderate quality trials
- cooling to 32-33 C
- no reduction in mortality
- patients treated with hypothermia were more likely to have favourable neurological outcomes (Glasgow Outcome Score of 4 or 5)
- need to cool for 48 hours
FEVER
- aggressive avoidance of fever early in TBI beneficial (lowers ICP)
- aim for normothermia (?what is normothermia)
- ?how long is it beneficial to control fever
AN APPROACH
First 48 hours
- if cold on arrival, don’t actively warm
- if normothermic, maintain
- if hyperthermic, treat cause and cool to normothermia
- don’t use therapeutic hypothermia
After 48 hours
- cool if having trouble controlling ICP (after having attempted other treatments and informing neurosurgeons)
- otherwise allow to be febrile
References and Links
- Brain Trauma Foundation Guidelines – Guidelines for the Management of Severe TBI
- CCC – Traumatic brain injury: Overview
- Clifton GL, Miller ER, Choi SC, Levin HS, McCauley S, Smith KR Jr, Muizelaar JP, Wagner FC Jr, Marion DW, Luerssen TG, Chesnut RM, Schwartz M. Lack of effect of induction of hypothermia after acute brain injury. N Engl J Med. 2001 Feb 22;344(8):556-63. PubMed PMID: 11207351. [Free Fulltext]
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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