Therapeutic Hypothermia
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OVERVIEW
- the currently preferred term for therapeutic hypothermia is targeted temperature management (TTM)
- induced hypothermia successfully used in cardiac surgery -> protects against global cerebral ischaemia (deep hypothermic arrest)
- described since the 1950s in various clinical settings it has remained an unproven therapy
- recently there have been animal and human studies demonstrating benefit (improved survival and neurological outcome) in cardiac arrest victims.
CLINICAL USES
Cardiac Arrest
Traumatic Brain Injury
Lack of Effect of Induction of Hypothermia after Acute Brain Injury (NEJM, 2001)
- MRCT, US, 9 centers
- n = 392
-> improves ICP but no reduction in mortality
-> patients older than 45 do worse with induced hypothermia
-> if they arrive hypothermic -> do not warm to 37 C (poorer outcome)
-> if you have a low temperature on arrival you have a more significant TBI
HYPHIT Study
- hypothermia in paediatric TBI (Canadian)
- MCRCT
-> lack benefit
Systematic Review (2007)
- 12 trials
- n = 1100
- overall benefit if cooled to 32-34 C in severe TBI
- need to cool for > 48 hrs (5-7 days: length of maximal elevated ICP and oedema)
- get cool within 4-8 hrs
- fever in TBI is bad
AREAS UNDER INVESTIGATION
- stroke patients
- perinatal asphyxia
- nyocardial ischemia
PRACTICAL ISSUES
- difficulty achieving hypothermia rapidly
- shivering + relaxants -> delay neurological assessment and mask seizures
- hypothermia can cause diuresis -> electrolyte disorders
- arrhythmia risk
- infection risk
- bleeding risk
- immunosuppression
References and Links
LITFL
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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