S3C18 - Cerebral resuscitation and therapeutic hypothermia

Question 1

Irreversible brain injury occurs after __ hours of complete lack of blood flow:

Answer 1

2h

-however 5min of transient ischemia sets off a cascade of events that lead to irreversible brain damage once reperfusion occurs = reperfusion disease/postresusciation syndrome

Question 2

Postresuscitation syndrome

Answer 2

• after cardiac arrest and ROSC there remains a period of no cerebral blood flow - some regions may take hours or days to regain flow
• due to disruption in cerebral autoregulation
• ischemia causes disruption of BBB which leads to mitochondrial dysfxn, the number of mitochondrial that are affected in a neuron determines whether it lives or dies
• free radicals released from other organs worsen PS

Question 3

Postresuscitation syndrome: diagnosis

Answer 3

• failure to withdraw from noxious stimulus 72h after resuscitation is currently the most specific and sensitive clinical evaluation for irreversible brain damage after cardiac arrest
• can also measure serum and CSF enolase, S-100B, creatine phosphokinase BB
• CT usually normal 24h later, start to see changes d2-6
• somatosensory evoked potentialson day 3 ROSC are suggestive of poor outcomes in those who remain comatose

Question 4

Postresuscitation syndrome: treatment

Answer 4

-priorities: circulation, ventilation, oxygenation to prevent further secondary brain damage
-prevent rapid rewarming and fever
-ICED therapy: induced cooling to eliminate deficits
-Map >80
-contraindications: trauma, sepsis, dementia
bleeding, brain mets
-start

Question 5

Therapeutic hypothermia evidence

Answer 5

• 2 studies in 2002 showed improved mortality and neurological outcome in VF/VT arrests, and subsequent studies showed benefit for more broad range of cardiac arrest
• 2013 study showed that cooling did not need to be so aggressive, target of 36C had similar improved outcomes (TTM trial)
• UTD: target 32-36C
• if mild then target 36C, if sever neuro deficits then 32C