TTM @ #EuAsia19

Optimal depth, timing and duration based on recent clinical trials (K Sunde)

Cardiac arrest is a complex disease

  • several different causes (many untreatable, irreversible, extreme challenging)
  • large heterogeneity
  • challenges the system due to the limited/crucial time-intervals (hypoxia/extreme ischemia)
  • large differences in quality of care within and inbetween systems (both during ALS and in post resuscitation care)
  • very high mortality

Depth and Timing

ILCOR Statement 2003 –

Unconscious adult patients with spontaneous circulation after out-of hospital cardiac arrest should be cooled to 32-34°C for 12-24 hrs when the initial rhythm was VF.

For any other rhythm, or cardiac arrest inhospital, such cooling may also be beneficial.

Outcome, timing and adverse events in therapeutic hypothermia after out-of-hospital cardiac arrest.

  • timing, speed and duration of hypothermia had no impact on outcome!

Confounding aspects regarding early/fast cooling

  • the lack of protection against a drop in core temperature is due to a larger and deeper brain injury! (link)
  • If you are really “dead” you are colder and it is very easy to cool you fast! (link)

Intra-Arrest Transnasal Evaporative Cooling: A Randomized, Prehospital, Multicenter Study (PRINCE: Pre-ROSC IntraNasal Cooling Effectiveness) link

Duration of TTM

Targeted Temperature Management for 48 vs 24 Hours and Neurologic Outcome After Out-of-Hospital Cardiac Arrest

Prolonged targeted temperature management in patients suffering from out-of-hospital cardiac arrest

Conclusion

  • Cardiac arrest is complex, with large heterogeneity and very high mortality
  • Large differences in quality of care within and inbetween systems
  • Concerning pathophysiology and TTM: depth, speed and duration impacts on the reperfusion injury/brain injury
  • We are concluding based on pragmatic trials not optimizing the intervention tested or considering the ongoing pathophysiology!
  • Outcome assessment: cognitive function/QoL years after the arrest!

Haemodynamic Management During Targeted Temperature Management (Huang CH)

Multiple reasons for haemodynamic instability post-cardiac arrest

Haemodynamic Response Correlated to Outcome – Reversible myocardial dysfunction in survivors of out-of-hospital cardiac arrest.

Cardiovascular Response & Haemodynamic Changes In Hypothermia Treatment

  • Changes in CV β-adrenoceptor (reduced response)
  • Bradycardia
  • Increase in stroke volume
  • Reduced intravascular volume during hypothermia is by 10– 35%

Lower heart rate is associated with good one-year outcome in postresuscitation patients (link)

Survivors Have Higher Mean Arterial Pressure (link)

Lowest value of DAP over the first 6 h after ICU admission for predicting unfavourable neurological outcome at 3 months (link)

Postresuscitation hemodynamics during therapeutic hypothermia after out-of-hospital cardiac arrest with ventricular fibrillation: A retrospective study

Taiwanese Protocol