Cardiac Arrest: TTM (2013) (Target Temperature Management 33°C vs. 36°C after Out-of Hospital Cardiac Arrest)

Question 1

TTM Clinical Q

Answer 1

For patients with out-of-hospital cardiac arrest, does hypothermia to a goal of 33°C reduce all-cause mortality when compared to a goal of 36°C?

Question 2

TTM Bottom Line

Answer 2

In patients with out-of-hospital cardiac arrest, targeted temperature management to a goal of 33°C was not associated with reduction in all-cause mortality or improvement in neurologic outcomes when compared a goal of 36°C.

Question 3

TTM Primary Outcome

Answer 3

All-cause mortality by the end of the trial

Question 4

cold temps increase rates of what 4 things

Answer 4

decreased cardiac output, infection, electrolyte abnormalities, and need for sedation

Question 5

TTM inclusion criteria

Answer 5

• ≥18 years in age
• Out-of-hospital arrest of presumed cardiac origin with subsequent persistent ROSC (>20 minutes without chest compressions)
• Unconsciousness, defined by GCS <8 at after attaining sustained ROSC

Question 6

TTM Critcisms

Answer 6

• Population less selective than in prior trials as both those with shockable and non-shockable rhythms were included
• Unable to detect whether improvements in the standard of care in critical care medicine have reduced the ability to detect a small benefit from the target temperature
• The treatment teams were not blinded
• Participants with prolonged ROSC are unlikely to regain neurological function and may have introduced bias
• Initiation of cooling at an earlier point (e.g during the arrest itself) may have improved outcomes
• The investigators did not use newer measurement scales to assess neurological recovery
• Unclear if higher rate of bystander CPR may have improved outcomes
• Unclear use of midazolam and propofol, both of which are thought to be neuroprotective agents
• Unclear if the investigators had a prescreening protocol