Mikkel Torp Steinberg has analyzed the rhythms of several thousand patients with cardiac arrest in order to find a better method of cardiopulmonary resuscitation.


  1. Almost all shockable rhythms early in the CPR cycle stay shockable after a period of chest compressions.
  2. Defibrillation should not be delivered in the compression phase of mechanical chest compressions.

  3. Active decompression to above the normal chest level increases cardiac output and blood flow to the brain during cardiac arrest.


Thesis: The impact of chest compressions on defibrillation success during out-of-hospital cardiac arrest and haemodynamics in an experimental animal model
Candidate: Mikkel Torp Steinberg
Time: December 20, 2018 at 13:15
Place: Oslo University Hospital, Ullevål, Building 36: Auditorium
Link to university website


(1) ECG analysis one minute post-shock compare very well to ECG analyses two minutes later, right before the next possible shock in patients with out-of-hospital cardiac arrest. Pauses from chest compressions during ECG analysis immediately prior to a potential shock may reduce the likelihood of return of spontaneous circulation and survival. Thus, using analyses from earlier in the CPR cycle could possibly be a method to avoid this problem. However, a few patients with shockable rhythms one minute post-shock have returned to spontaneous circulation before the next possible shock and could potentially be shocked back to cardiac arrest.

The study includes 3409 analysable shocks from 1657 patients with cardiac arrest included in the large, multinational CIRC study. More than 99 % of those with a shockable rhythm immediately prior to next possible shock also had a shockable rhythm two minutes earlier. Three of the 13 patients without a shockable rhythm had returned to spontaneous circulation.

(2) When a shock is delivered during the compression phase of a mechanical chest compression cycle, the outcome is worse than when pausing from compressions during shocks. Automatic, mechanical compressions make it possible to avoid short breaks before shock is given, but previous results from the CIRC study have indicated that it could be harmful to continue with compressions during shocks. However, Steinberg’s results show that this is only true when shocks are given during the compression phase, and not during decompression or between compressions.

(3) In a randomized controlled trial on pigs with cardiac arrest, active mechanical decompression to two centimeters above anatomical chest levels during CPR, increased cardiac output, carotid artery blood flow and blood flow to the brain compared to regular mechanical chest compressions. However, several of the 19 pigs included were injured by the active decompression method.


(1) Steinberg, M. T., Olsen, J. A., Brunborg, C., Persse, D., Sterz, F., Lozano Jr, M., Brouwer, M. A., Westfall, M., Souders, C. M., van Grunsven, P. M., Travis, D. T., Lerner, E. B., & Wik, L., (2015). Minimizing pre-shock chest compression pauses in a cardiopulmonary resuscitation cycle by performing an earlier rhythm analysisResuscitation87, 33-37.

(2) Steinberg, M. T., Olsen, J. A., Brunborg, C., Persse, D., Sterz, F., Lozano Jr, M., Westfall, M., Travis, D. T., Lerner, E. B. & Wik, L. (2016). Defibrillation success during different phases of the mechanical chest compression cycleResuscitation103, 99-105.

(3) Steinberg, M. T., Olsen, J. A., Eriksen, M., Neset, A., Norseng, P. A., Kramer-Johansen, J., Hardig, B. M., & Wik, L. (2018). Haemodynamic outcomes during piston-based mechanical CPR with or without active decompression in a porcine model of cardiac arrestScandinavian journal of trauma, resuscitation and emergency medicine26(1), 31.

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