Based on science
LUCAS compressions are based on the international guidelines for CPR; the optimal frequency and depth, an equal compression and decompression time, a full recoil of the chest between each compression with a minimum interruptions.
On this page you will get an overview of the hemodynamic efficacy. Click on the submenus on the left menu bar to learn more about LUCAS clinical efficacy and safety.
Square shaped duty cycle for higher efficacy
The picture below shows the pressure curves created by manual CPR on a real patient and its decrease in quality over time, as well as the pressure curves of LUCAS in the same patient, which creates a more consistent pressure. The square shaped pressure curve reflects the LUCAS duty cycle.
The LUCAS duty cycle allows for time to push blood to the brain (compression) and then time to refill and perfuse the heart (decompression back to zero). This perfect cycle has shown to increase the flow to vital organs.
Courtesy Prof. H Bonnemeier, Kiel, Germany
More flow to the brain
Both human (measured by Doppler and cerebral oximetry) and animal studies have shown increase in blood flow to the brain with LUCAS compared to manual CPR.
In two of the studies the brain flow increased by 60% with LUCAS, from ~40% of the normal flow with manual CPR to reach ~65% of normal flow with LUCAS compressions. When the brain flow reaches over 50% of the normal flow it could result in return of consciousness during CPR, which has been reported during LUCAS CPR.
Human measurements of cerebral oxymetry by Wagner et al ICU Director 2013 (4);1: 22-32.
Human doppler data on intracerebral artery flow by Carmona et al 2011; 82S1: 30, AP090.
Animal data on cortical cerebral flow by Rubertsson et al, Resuscitation 65 (2005): 357-363.
More flow to the heart
A coronary perfusion pressure above 15 mmHg has been shown as the threshold of survival. Every interruption in compressions leads to a drastic fall in coronary artery pressure which takes time to rebuild.
Human data has shown normal coronary artery flow (TIMI III) and/or good coronary perfusion pressures with LUCAS during prolonged resuscitation events*.
Several animal studies on LUCAS have shown significantly increased or normalized coronary perfusion pressures and/or coronary artery flow with LUCAS compared to manual CPR**.
*Examples of human data :Wagner et al. Circulation. 2010;122:A91, and Larsen et al. Resuscitation 81 (2010) 493–497
**Examples of animal data: Wagner et al. BMC Cardiovascular Disorders 2011, 11:73): Liao et al. BMC Cardiovascular Disorders 2010;10:53: Steen et al. Resuscitation. 2002; 55: 289-299.
ETCO2 is commonly used as an indicator of circulation and tissue oxygenation during cardiopulmonary resuscitation. LUCAS has shown to significantly increase ETCO2 levels compared to manual CPR in a controlled pre-hospital study.
Axelsson et al, Resuscitation. 2009; 80(10): 1099-103.
Less detrimental interruptions
Both real clinical use* and manikin studies** have shown that LUCAS can be applied quickly and increase flow time compared to manual CPR during the resuscitation event.
In a pre-hospital real use study** the hands-on ratio with manual CPR was on average 78% with manual CPR and 91% with LUCAS - as measured over the entire resuscitation episodes of approx. 33-40 minutes. The hands-on time of manual CPR decreased from 81% on the scene to 73% during transport, whereas LUCAS stayed at the same high hands-on ratio (90-92%) both on scene and during transport.
*Examples on human study: Maule Y, Urgence Pratique. 2011;106:47-48.
** Examples on manikin studies: Munch et al Intenziv und Notfallsmedizin 2010; 4: 295, Wyss et al, Cardiovascular Medicine 2010; 13(3): 92-96.
***Pre-hospital study on LUCAS 1(V1): Olasveengen et al Resuscitation. 2008; 76(2): 185-90
Defibrillation during LUCAS compressions
There is scientific evidence that defibrillation during compressions can improve the outcome of cardiac arrest treatment but for safety reasons defibrillation during manual CPR is not recommended. However, with LUCAS it is possible to defibrillate during ongoing compressions. LUCAS allows for application of the defibrillation electrodes outside the suction cup. Defibrillation during ongoing LUCAS CPR has been used routinely in clinical settings since the launch in 2003.
An experimental study has concluded that defibrillation can be delivered during ongoing LUCAS compressions without compromising efficacy, thus obviating the need for potentially detrimental compression pauses.*
* Walcott et al, Circulation. 2007; 116: II 386 Abstract 1811