Hypothermia arrest papers

Question 1

RCP compared to DHCA: Bosner RS, JTCS 2002 “Failure of retrograde cerebral perfusionto attenuate metabloic changes associated with hypothermic circulatory arrest” 123 (5) 943-950

Answer 1

No difference in post-arrest oxygen extraction , glucose extraction, or juglular bulb O2 between the groups.

In fact some research as actually suggested worsening outcomes with DHCA.

Overall its concluded that ACP either selective or non-selective provides the most consistent effect strategy to prevent temporary neurological dysfunction following DHCA.

Appears to be no consistent difference between the 3 proposed strategies in terms of mortality, permanent stroke, and indeed , with short periods of arrest (< 40 minutes) there is still no evidence that circulatory arrest alone without cerebral perfusion is inadequate.

Question 2

What is role for corticosteroids in DHCA

Answer 2

High dose methylprednisolone, 2 to 8 hours before CPB, reduces the cerebrovascular resistance and improves cerebral blood flow, oxygen metabolism, may serve as neuroprotective agent.

Question 3

What is Q10

Answer 3

Relationship between temperature and the cerebral metabolic rate of oxygen (CMRO) can be expressed as the temperature coefficient Q10, which reflect the rate of reduction in the metabolism for a 10 degree interval.

Question 4

What are safe periods of DHCA

Answer 4

Safe period of arrest is about 30 minutes at 15 degree
40 minutes at 10 minutes

Packing of the head in ice helps with lowering intracranial temperatres.

Question 5

What is Temporary Neurologic dysfunction

Answer 5

Varying degrees of obtundation, confusion, agitation, or transient PD

Question 6

List more about Q10

Answer 6

Q10–for every 10 degree change in temp there is a multiple by which a reaction rate will change.
If the Q10 is 3.6 that means that cerebral metabolism is decreased by a multiple of 3.6.

This is how the duration of safe hypothermia is discovered

Question 7

Deep hypothermic circulatory arrest: alternative strategies for cerebral perfusion. A review article.

E.M. Elmistekekawy, R.D. Rubens.

Answer 7

Perfusion: 2011; 26:27
DHCA-refers to the strategy of nasopharyngeal temp 20 degree to allow temporary cessation of blood flow.
This is a review from 1950 to 2010. Describes first successful DHCA series by Griepp. Debakey did first series of antegrade perfusion. Axillary cannulation by Sabik in 1990.

This is a great review paper which explains physiology and studies for all techniques.