Intra-arrest Care

How to optimise CPR

No benefit to CPR > 60mm depth. However, although pauses are associated with worse outcomes it might not be that it’s because it increases likelihood of terminating CPR.

ETCO2 is increasingly important and improvements in ETCO2 have been seen with increasing depth of CPR but not rate.

Best option:

  • Rate 100-120
  • Depth 5-6 cm
  • Minimise interruptions
  • Use physiologically directed CPR (ETCO2 or blood pressure?) where possible

Peri-shock pause: an independent predictor of survival from out-of-hospital shockable cardiac arrest

Association Between Chest Compression Interruptions and Clinical Outcomes of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest

Mechanical chest compression for out of hospital cardiac arrest: Systematic review and meta-analysis


Drugs During CPR


  • Evidence based on animal experiments
  • Beta affects are detrimental
  • Reduces cerebral microcirculation!
  • Associated with improved short term but worsened long term outcomes

Outcome when adrenaline (epinephrine) was actually given vs. not given – post hoc analysis of a randomized clinical trial

A randomised placebo controlled trial of adrenaline in cardiac arrest—The PACA trial

Vasopressin no better than adrenaline

Amiodarone improved ROSC but no survival benefit

However, OOHCA is different to IHCA and Greek trial suggested favourable neurological outcome with adren/vaso/steroids

Vasopressin, Steroids, and Epinephrine and Neurologically Favorable Survival After In-Hospital Cardiac Arrest

Bad quality CPR won’t be saved by drugs

No benefit from high-dose (i.e. > 1mg) adrenaline


Cerebral Oximetry during and after CA

Cerebral oximeters use a variety of different arrangements of lights and detectors and assume a fixed ratio of arterial and venous blood, normally 25-30:70-75. Balance O2 delivery and uptake in real time. Normal range 60-75% and used more extensively in neurosurgical and cardiothoracic surgical settings.

Trends are probably more useful than individual values; however, really high initial values might be worth pursuing longer? Data limited. There is evidence that people with higher cerebral oxygenation values do better but overlap is significant between group and lacks specificity.

Increase in cerebral oxygenation during advanced life support in out-of-hospital patients is associated with return of spontaneous circulation

Cerebral oximetry and return of spontaneous circulation after cardiac arrest: A systematic review and meta-analysis

Cerebral Oximetry as a Real‐Time Monitoring Tool to Assess Quality of In‐Hospital Cardiopulmonary Resuscitation and Post Cardiac Arrest Care


Identifying the cause of CA during CPR

Most CA are due to cardiac causes and account for 20-30% of all deaths. Most of this is IHD.


Hypoxia should be treated empirically. Hypovolaemia may be more difficult to diagnose if concealed, e.g. AAA, GI, spleen. Otherwise, follow the guidelines and get what you can from the history +/- ancillary tests such as echo.

The spectrum of epidemiology underlying sudden cardiac death