Science and Technology of Head Up CPR Keith Lurie MD Professor of Emergency Medicine and Internal Medicine University of Minnesota Minneapolis, Minnesota USA April 4, 2018
Minneapolis, Minnesota 2
Disclosures Dr. Lurie is co-inventor of the impedance threshold device (ITD)(ResQPOD), active compression decompression (ACD) CPR (ResQPump), and HeadUpCPR devices Dr. Lurie is a professor at the U of MN, a practicing cardiac electrophysiologist in St. Cloud MN, a medical researcher at Hennepin County Medical Center, and a consultant for ZOLL and Minnesota Resuscitation Solutions Contact info: keithlurie@icloud.com
Reference The Physiology of Cardiopulmonary Resuscitation Anesthesia and Analgesia 2016.122:767-783 Lurie K, Nemergut E, Yannopoulos D, and Sweeney M
Cardiac Arrest Today 1 MILLION OHCAs annually in Europe and U.S. <10% Overall Survive Neurologically intact
2018: Survival with Good Brain Function
What does progress look like?
>30% Survival with Good Brain Function
Inspiration
Index Case 1987 Saved by a Household Plunger San Francisco General Hospital CPR: The P Stands for Plumber s Helper. Lurie et al - JAMA 1990
Opening Doors New Approach to CPR New Approach to Brain Injury New Approach to Hypotension
Active Compression Decompression (ACD) CPR Metronome Force Gauge Suction Cup Handle Only CPR device approved to lift with 10kg of force
Randomized Clinical Trial (Paris, France) Survival After Cardiac Arrest 40% 35% 30% STD (n = 377) ACD (n = 373) 25% 20% 15% 10% 5% 0% ROSC 1 Hr ICU Admit 24 Hr Hosp Disch * 1 Yr * *Statistically significant Plaisance P et al. A comparison of standard CPR and ACD resuscitation for out-of-hospital cardiac arrest. N Engl J Med. 1999;341:569-75.
A Discovery
Founding Concept & Design CONCEPT and DESIGN: Each time the chest wall recoils following a compression, the impedance threshold device (ITD) transiently blocks air/oxygen from entering the lungs, creating a small vacuum in the chest, resulting in enhanced venous blood flow back to the heart
ResQTrial: 2 CPR Methods Standard CPR (S- CPR) ACD-CPR + ITD (ACD+ITD) versus
Compression Phase Standard CPR (S-CPR) vs. ACD+ITD S- CPR Chest Compressions Increase in intrathoracic pressure Cause forward blood flow ACD+ITD Force respiratory gases from lungs Minimal expiratory resistance from ResQPOD
Decompression Phase S-CPR vs. ACD+ITD S- CPR Passive Recoil Airway (Intrathoracic) Pressure Ventilation Minimal change in intrathoracic pressure Small circulation Chest Compressions ACD+ITD Active Recoil Passive Chest Wall Recoil intrathoracic pressure Preload increased cardiac output ICP lowered cerebral perfusion Active Chest Wall Recoil
Blood Flow (ml/min/gm) Blood Flow to Heart and Brain Porcine V-Fib Model 1.0 normal 0.8 0.6 S-CPR S-CPR + ITD ACD-CPR ACD-CPR + ITD 0.4 normal 0.2 Left Ventricle Brain ACD+ITD work synergistically to achieve desired effect Lurie et al. Circulation 1995;91:1629-32 (ACD +/- ITD) and Lurie et al. J Cardio Electrophysiology 1997;8(5):584-600
Mechanism of Benefit ACD+ITD lowers ICP faster and for a longer duration during CPR Metzger et al. Critical Care Medicine, 2012
Survival to Hospital Discharge with Favorable Neurologic Outcome ResQTrial Primary Endpoint 10 9 8 7 6 Survival to hospital discharge with good brain function after cardiac arrest of primary cardiac etiology S-CPR ResQCPR 6,0 9,0 5 4 3 2 1 0 n=813 n=842 Cardiac Etiologies *49% improvement P = 0.019 OR 1.58 CI (1.07, 2.36) Aufderheide et al. Lancet, 2011
One Year Survival S-CPR ResQCPR p-value Relative Increase Cardiac etiology (n=1655) All patients (n=2470) 6.0% (48/794) 9.0% (74/822) 0.03 49% 5.8% (68/1171) 7.8% (96/1233) 0.062 34% 1-Year survival substantially higher with ACD+ITD CPR
Saving the Heart AND Brain Real Life After ROSC
93 What Position is best? Head Down Head Up Flat
What is the optimal head/heart position? A B C
Head Up vs Head Flat CPR Inherent limitation Chest compressions increase arterial and venous pressures simultaneously, delivering a bidirectional high pressure compression wave to the brain with every compression.
Head Up vs Head Flat CPR Inherent limitation Chest compressions increase arterial and venous pressures simultaneously, delivering a bidirectional high pressure compression wave to the brain with every compression.
What is the optimal head position during CPR? Hypothesis: Since chest compressions increase ICP, elevation of the head with circulatory enhancement technologies (e.g. ITD and/or ACD) to generate good flows will: 1. Increase brain blood flow 2. Reduce the concussion with each compression 3. Lower ICP 4. Improve neurological outcomes
Change of Position: Head Down Supine 0 CPR 30 Head down CPR Ao ICP CerPP Debaty et al, Resuscitation, 2014 Change of position (CPR + ITD: rate 100/min)
Change of Position: Head Up Supine 0 CPR 30 Head up CPR Ao ICP CerPP Debaty et al, Resuscitation, 2014 Change of position (CPR + ITD: rate 100/min)
Limitations of Flat CPR Venous blood backs up in the brain thereby raising ICP Potential for a brain concussion with every compression Blood flow through the lungs is reduced due to pulmonary congestions (think of lungs as a wet boggy sponge) These limitations are overcome with Head Up CPR
Whole Body Head-Up Tilt: Effect of Angle on Mean Aortic and Intracranial Pressure during CPR+ITD ICP decreases proportionally to head elevation during CPR+ITD 32 Debaty et al. Resuscitation, 2015
Pressure (mmhg) Head-Up CPR: Is the ITD Needed? 40 30 CPP *, ** * CerPP *, ** * 0 CPR + ITD 30 CPR + ITD 30 CPR Only 20 10 0 0 +30 +30 0 +30 +30 CPR angle ( ) The ITD is needed to optimize Head up CPR Debaty et al, Resuscitation, 2014
Brain Blood Flow Depends on Head Position Brain blood flow is highest with head elevation
Concussion with Every Compression 3 5
Evolution of Head Up CPR A B Unique Benefits of D C D Lower ICP Lower RA pressure Higher CerPP Higher CorPP Preserves central blood volume Lower PVR?
A Simple Change in Position ACD+ITD and Conventional CPR VS 30 o Untreated VF 8 minutes Conventional CPR flat - 2 minutes Randomize between CPR flat vs head and shoulders up for 20 minutes
Coronary perfusion pressure mmhg Coronary Perfusion Pressures after 8 min of VF 30 o Head and Thorax Elevation vs Flat 80 70 60 50 40 ACD+ITD Head Up (n=8) 30 20 ACD+ITD Flat (n= 8) 10 S-CPR Head Up (n=6) 0 Ryu et al Resuscitation 2016. 8 min VF Pre-VF 0 5 10 15 20 Time (Minutes) S-CPR Flat (n=6)
mmhg Cerebral Perfusion Pressures / Blood Flow 70 60 50 40 30 20 10 ACD+ITD Head Up (n=8) ACD+ITD Flat (n=8) S-CPR Head Up (n=6) S-CPR Flat (n=6) 0-10 Pre-VF 0 5 10 15 20 Time (Minutes) S-CPR is what most patients receive today! Ryu et al.. Resuscitation 2016 3 9
Brain Blood Flow after 5 and 15 of CPR (% of baseline blood flow with beating heart) SUP = supine or flat HUP = Head up * P<0.01 Blood flow to the brain is doubled with HeadUP CPR vs flat after 15 min of CPR Moore et al, Resuscitation, in press 2017