Cardiac Arrest: HACA (2002) ( Hypothermia to Improve the Neurologic Outcome After Cardiac Arrest)

Question 1

HACA Clinical Q

Answer 1

In patients with cardiac arrest due to VF or pulseless VT, does mild hypothermia improve neurologic outcomes compared with standard care normothermia?

Question 2

HACA Bottom Line

Answer 2

Among patients with return of spontaneous circulation after cardiac arrest due to VF or pulseless VT, mild therapeutic hypothermia (32-34° C) improved neurologic outcomes and reduced mortality at six months.

Question 3

HACA Primary outcome

Answer 3

favorable neurologic outcome at 6 months

Question 4

HACA NNT for mortality

Answer 4

7

Question 5

HACA NNT for improved neuro outcome

Answer 5

6

Question 6

HACA Inclusion criteria

Answer 6

• Age 18-75 years
• Return of spontaneous circulation(ROSC)after witnessed cardiac arrest, VF or pulseless VT, or presumed cardiac origin of the arrest
• Estimated interval of 5-15 mins from collapse to first attempt at resuscitation by emergency medical personnel
• Estimated Interval of ≤60 mins from collapse to ROSC

Question 7

HACA criticisms

Answer 7

• Physicians could not be blinded to treatment assignments
• Only 8% of all patients assessed for eligibility were included in the trial, restricting study population to group of patients with high risk of brain damage. Further studies warranted to determine whether findings extend to patients at lower risk for brain damage and to those with cardiac arrest due to causes other than VF.
• No report of brainstem reflexes before randomization so unclear if groups were balanced in regards to coma severity
• Small trial