05 Nov High Performance Cardio Pulmonary Resuscitation (CPR)
By Keith Kirkpatrick – Chief, Kawartha Lakes Paramedic Services
The national average of surviving an out of hospital sudden cardiac arrest in adults is about five per cent. Of the approximately 40,000 people who die in Canada per year as a result of sudden cardiac arrest, most are over the age of 35 and most could have been saved.
Since the 1960s, a great deal of time, thought and research by agencies such as the American Heart Association (AHA) has focused on the goal of improving out of hospital cardiac arrest survival rates.
I first learned CPR in 1978 when I was a life guard at a community pool. At that time, we were told the importance of CPR and that it was the Holy Grail for resuscitation. When I first became an ambulance attendant in 1981, I quickly realized that CPR was not really very effective. In fact, during my early years in the paramedic profession, I only remember two saves. Both were witnessed by us, the ambulance crew, and we were within 10 minutes of a hospital and advanced life support (including defibrillation).
When I became an Advanced Care Paramedic in 1989, I thought that my access to a defibrillator, IV skills and numerous medications, would mean that I would be able to resuscitate all of my patients. However, unless we witnessed the arrest or there was intervention by a citizen or other first responder, patients did not survive.
Flash forward to today. Now, we truly understand that resuscitation success depends on community response: it is now common to encounter citizens who have been trained in CPR; we have public access defibrillation and First Responders with defibrillators (fire, police) in addition to well-educated and well-equipped paramedics.
Today, I am the Chief of Kawartha Lakes Paramedic Service and, from my past role as a practicing paramedic and my work with the Heart and Stroke Foundation, I have bought into the American Heart Association approach to the emergency chain of survival – early access (911), early CPR, early defibrillation and early advanced life support care. As a result, our service has invested in:
- Community CPR campaigns for citizens,
- Automatic External Defibrillation (AED), Public Access Defibrillation (PAD) programs – targeted all city owned spaces, schools and community buildings and events,
- Fire / Police (City and OPP) AED response,
- 60% of our full time paramedics are ACP level (94% of Return of Spontaneous Circulation for cardiac arrests in 2017 had ACP as the transport caregiver),
- CPR compression device on all paramedic vehicles.
Here’s our community statistics for Return of Spontaneous Circulation (ROSC) for adult cardiac arrests and arrival at hospital with a good pulse and Blood Pressure:
- 2015 – 22% ROSC
- 2016 – 18% ROSC
- 2017 – 21% ROSC
- 2018 (Jan 1 – Sept 30) – 23% ROSC
Unfortunately, I do not have access to statistics related to patients whom are discharged home due to privacy concerns, but if you think of community response, ROSC should be considered a benchmark of system delivery.
Kawartha Lakes is a rural municipality with 75,000 people living in a community spread over 3,000km. The largest communities are Lindsay, Fenelon Falls and Bobcaygeon. Approximate 66 per cent of our 22,000 calls are done in these three communities and, theoretically, that is where 66 per cent of our cardiac arrests occur.
Another important point is that every one of our ROSC adult patients in 2017 had early intervention by citizens or was a witnessed cardiac arrest by a first responder. Now that I’m done bragging about our municipalities response, here are the hallmarks to success:
- High performance CPR is compressions (100-120 per minute), depth of compression (1/3 to 1/2 the chest diameter of a patient), decompression (recoil) and minimize compression interruptions (Chest compression fraction should be greater than 80 per cent),
- Citizen education for adult CPR should focus on hands only or compression only CPR with AED and PAD understanding (the rational is for the ease of learning the required skills and being able to perform them safely with confidence),
- Police and Fire response should focus on effective professional level CPR / AED with minimal compression interruptions,
- Paramedics should focus on continued CPR (emphasis on compressions), advanced life support interventions with early attachment of the mechanical compression device and rapid transport to hospital.
Way back in 1978, we lacked the understanding that we now have about compressions performed during CPR. Compressions are truly the building block to everything else we do to try and resuscitate an adult patient who is in sudden cardiac arrest. When you compress the chest, it is not just the heart you are compressing but the entire chest. The downward movement of the compression is squeezing the heart and the large blood vessels (aorta) to create forward momentum, or in other words, a systolic blood pressure. The systolic blood pressure is what provides perfusion (oxygenated blood) of the vital organs (especially the brain).
Just as important as the downward compression is the recoil, or decompression, that must occur during the relaxation or upward movement after a good CPR compression. This is important because it allows for blood to move back into the chest (large blood vessels and heart) during the diastole (lower or second number of a blood pressure reading). The diastole phase is important because this is the time that the heart is perfused via the coronary arteries. Ensuring oxygen of the heart muscle itself will help with increasing Adenosine Triphosphate (ATP) which is the energy required for muscles (including the heart) to work.
Something else to consider is that if you don’t have a good relaxation (diastole) phase during compressions, it will create pressure on the right side of the heart and decrease filling time of the heart. This will ultimately decrease cardiac output. Further to this, is that the backup of blood will engorge the venous system and cause increasing inter-cranial pressure which will impair brain perfusion. Brain perfusion is one of the core goals of CPR as brain death will occur within four to six minutes after cardiac arrest if CPR and resuscitation interventions do notoccur. After 10 minutes, it is unlikely that a successful resuscitation will occur.
In summary, as we begin Resuscitation Month (month of November), we are reminded that out of hospital cardiac arrest resuscitation success is built upon the foundation of effective CPR compressions followed by early defibrillation, early advanced life support, rapid transportation and effective hospital capabilities in the emergency department and beyond (i.e. ICU, STEMI Lab, cardiac rehabilitation etc.). With the support of our community partners, these elements are put into action by our dedicated and skilled paramedics each and every shift with the end goal of saving lives. For a small rural municipality, we have made excellent strides in out of hospital cardiac arrest survivability but, without the building block of CPR compressions, it all falls apart. The citizen element of early access (911) and early CPR cannot be overlooked or forgotten as the most important part of managing sudden cardiac arrest.