High Performance CPR Acknowledgement This training package was created by Crystal Harris, Clare Collihole, Joseph Schar, and Jordan Pring. Please direct any questions to your CSO or Team Leader. Offline Reading Download as PDF Welcome Introduction Physiology of CPR High Performance CPR Positioning Rate
Metronome Depth Recoil Rotation of Compressors Minimising Interruption to Compressions Ventilation De brillation Summary References Summative Assessment Details Download PDF for of ine reading
Section 1 of 17 Welcome Welcome to the High Performance CPR E-Learning Clinical Development Package. The following package will give an introduction to HP-CPR and provide the reader a basic understanding of HP-CPR and the close relationship it has to improving survivability in our cardiac arrest (CA) patients. All references and hyperlinks will be attached if you would like to read further. Learning Objectives Introduce the theory of High Performance CPR (HP-CPR) to paramedics Review physiology of CPR Familiarise paramedics with measurable components of HP-CPR Introduce metronomes to paramedics Demonstrate an understanding of HP-CPR theory by completing a summative assessment Overview Introduction to HP-CPR Physiology of CPR A breakdown and review of the aspects of HP-CPR Including:
Position Rate Depth Recoil Rotation of compressors Minimal interruptions Metronome introduction Ventilation review Defibrillation review Successful completion of this package will require completion of the summative task with at least 80% correct answers of the multiple choice assessment. The completion of this package should take approximately 30 mins.
Section 2 of 17 Introduction Excellent quality CPR is a critical component of CA management. Improving your understanding and application of the components involved with high performance CPR will result in the improved likelihood of CA survivability. International literature from prehospital services and cardiac arrest reviews (including Australia, America, Japan, Canada) indicate the quality of EMS provided CPR is highly varied, with most services demonstrating room for improvement. The Resuscitation Academy (Seattle) have labelled HP-CPR as one of the four low hanging fruit to improve cardiac arrest survivability. It is a simple concept with low complexities. A review of current literature indicates the prognosis following an out of hospital cardiac arrest (OHCA) has not dramatically improved over the last 20 years. We are, as pre-hospital emergency clinicians, a crucial link in the chain of survival, and have a responsibility to ensure our link in this chain is as robust as possible. While the literature supports the fact that there is no magic bullet in improving CA survivability, early defibrillation and good quality CPR are, without question, essential components of surviving a cardiac arrest. [8] The steps involved to achieve high performance CPR are: Minimal breaks in compressions Full chest recoil Adequate compression depth Adequate compression rate CPR is a basic skill, but a skill that requires precise delivery. High performance CPR can significantly alter the patient s clinical course; quite literally being the difference between life and death. The concept of HP-CPR will be analysed and discussed throughout this package. Upon
completion, the paramedic will have better understanding of what HP-CPR is and why it is a critical component of paramedic practice. [1, 19]
Section 3 of 17 Physiology of CPR In order to succeed in improving survivability from CA we must first understand the physiology of CPR; in other words, we need to know what we are doing to do it better! CPR comprises of two key phases, compression and decompression. Phase 1 - Compression Phase With each chest compression the heart is squeezed between the chest wall and the patient s spine. Each effective compression causes increased pressure in the heart and aorta, resulting in a projection of blood from the heart to the brain and the rest of the body. This occurs due to the presence of one way valves within the heart and pressure differences between the thorax and the rest of the body. Research in the last decade has stimulated discussion around the mechanics of CPR manually increasing intracranial pressure (ICP); it is believed that the changes in ICP during CPR are partially due to changes in intrathoracic pressure caused during compression, and partially through the pushing of cerebrospinal fluid into the intracranial compartment. Phase 1 (compression) increases ICP; this in turn increases the resistance to cerebral perfusion. It has been postulated that this goes some way to explaining why high compression rates can lead to poor neurological outcomes. Phase 2 - Decompression Phase The phase following chest compression is the decompression phase, or the recoil phase. During recoil the removal of the hands increases the volume of the chest cavity and subsequently reduces the intrathoracic pressure. The reduction in intrathoracic pressure allows for venous return and passive refill of the heart, resulting in the next compression ejecting more blood from the heart and continuing the forward movement of blood (with the aid of valves) to vital organs. Recoil is not an
active motion and therefore it is imperative that the full recoil of the chest wall is not impeded. Recoil or return of baseline pressure also causes a subsequent decrease in ICP in the same reversed mechanism as explained in chest compression. [6] Illustrates the difference in structure of the thorax during both compression and decompression.
Section 4 of 17 High Performance CPR Performing HP-CPR ensures that the CPR we provide is as close to the recommendations as possible, with the ultimate aim of providing the patient with the best chance of surviving their OHCA. So how do we achieve high performance CPR? HP-CPR is also described as expertly performed BLS with strict attention to: Minimally interrupted chest compressions Optimal rate of 100-120 Adequate depth of 5-6 cm in adults Allowing full recoil of chest wall (no leaning in-between compressions) Rotating compressors every 2 mins (avoiding fatigue) Controlled ventilations Use an inspiratory time of about 1 second and give enough volume to cause the chest to visibly rise. Pausing only for 2-3 seconds to ventilate during the 30:2 cycles Ventilations every 6 seconds once an advanced airway is in place (15:1 uninterrupted in adults)
Defibrillation Pre-charging of the monitor Shocking every 2 mins Minimising time off chest during defibrillation to less than 5 seconds where possible Changing of compressor during shock pause [7] The 2015 AHA Resuscitation Guidelines and the 2017 treatment recommendation summary places significant emphasis on technique of compressions, allowing for full chest recoil and having minimal interruptions. These findings along with statistics from services using HP-CPR modules were a contributing factor for the introduction of BLS accreditation at PDWs. The Heartisense device used inside SAAS mannequins provides live feedback of CPR quality by objectively measuring aspects of HP-CPR, including position, depth, rate and recoil. Common areas identified for improvement in 2017 were: Position: Positioning and posture is critical to minimising fatigue, maximising the effectiveness of compression and ensuring full recoil. Clinicians commonly fatigued faster when further away from the patient, and achieved poorer depth when using their arms and not their upper body weight to apply compression. Depth: Often, the first few compression were too shallow. Placement: Central hand placement with controlled force through both hands reduces rolling of hands and incorrect compression placement. Fatigue: Signs of fatigue were obvious, particularly in the 4th and 5th cycles, with many clinicians not achieving adequate depth, slowing their rate, and increasing their leaning on the patient. This reaffirms the need to swap compressors every 2 minutes. Objective measuring of key components of HP-CPR is an important process. Training with live feedback allows the clinician to adjust their technique to optimise CPR delivery. HP-CPR is a skill
that should be practiced often to ensure your next patient in CA receives excellent quality CPR. [19] "The most effective training is simple, realistic, scenario driven, and completely hands on. Practice like you play - Resuscitation Academy Your upcoming PDWs will have a practical focus. It is one thing to learn about the theory of HP-CPR, and another thing to enact it. Start stretching!
Section 5 of 17 Positioning Adequate positioning of the hands for CPR is of great importance. The aim of chest compression is to not only compress the heart in between the sternum and the spine, but to also increase intrathoracic pressure. The compressor must place their hand in the centre of the chest over the lower aspect of the sternum. Too low, and compression of the xiphoid process can cause trauma to other organs including liver, spleen and stomach (dependant on patient age, size and anatomy). Too high, and compression effectiveness decreases. [3, 6, 14] Hand positioning during compression.
The compressors own chest should be directly over their hands enabling them to use their upper body weight to compress the patient s chest instead of relying on just arm strength, this will aid in minimizing fatigue. Adequate positioning is also imperative in reducing the compressors risk to injury. Locking arms, good alignments and keeping the patient close to you can ensure that you are not in an awkward position and at risk of injury. [9] Shows compressors chest and shoulders in line with patient s chest. Continual reassessment of positioning should be made throughout the resuscitation. With each compression cycle, re-evaluation of position and posture should be made to maximise compression efficiency. Assessing and providing feedback on each other s position and posture is important; changing culture to allow for providing and receiving constructive, live feedback is critical in ensuring HP-CPR is being delivered at all times.
Section 6 of 17 Rate The likelihood of ROSC increases significantly with higher mean chest compression rate to a point. In a hospital study 75% of patients achieved ROSC with 90 or more chest compressions/minute compared to only 42% with 72 or fewer chest compressions/minute. Compression rate efficiency decreases at rates above 120 compressions/min. [19] ANZCOR recommends compressions should be delivered at a rate for all ages of between 100 and 120 per minute. Each compression should be of equal duration to ensure good flow and rhythm. Compression rates of less than 100 and greater than 140 have been associated with lower rates of survival. Compression rates above the recommended rate of 120 have been shown to reduce heart fill time and volume and therefore reducing the amount of circulated blood. Audio visual tools such as metronomes are recommended for monitoring and measuring rates. [9, 12, 14]
Section 7 of 17 Metronome The use of metronomes is associated with a greater ability to remain at an optimal rate of compression. This was proven in a study of 155 medical personnel. The study compared compression rates both when using a metronome and without. Results showed that when a metronome was utilised, compressions were conducted at the optimal rate more often, with accuracy of rate jumping from 50% to 72%. Most clinicians in this study who were not in the desired range, were found to be compressing too quickly. [3] Metronomes provide auditory feedback for compression performance. The auditory tone of the metronome relays a precise indication of recommended compression rate which allows the clinician to rectify a rate error immediately. Most new ECG monitors/defibrillators have built in metronomes, such is the perceived benefit of these devices. SAAS is currently in the process of considering external, portable metronomes for each defibrillator to be used in cardiac arrests. Metronomes will be used in your upcoming training.
Section 8 of 17 Depth A paper published in 2014 - Optimal Chest Compression Depth During Out Of Hospital Cardiac Arrest Resuscitation of Adults, demonstrated the probability of survival directly correlated to chest compression depth. Data showed that survival of patients peaked at a depth of 45.6 mm with the highest survival rates between 40.3mm and 55.3mm. Linking depth of compression data and rate of compressions it was also found that in cases where the rate of compression was higher than the recommended 120 compressions per minute, the depth of compression was adversely affected in 53%. [13] Illustrating the correlation and peak between depth of compression and rate of survival. Depth of compression is recommended at 40mm in most infants and 40-50mm in most children. Adolescents should be regarded as adults in terms of depth, with a depth of 50-60 mm, but not exceeding 60 mm.
ANZCOR reiterate this and recommend depth of compression at 40mm in infants, 40-50mm in children and 50-60mm in adults. 1/3 the antero-posterior (AP) diameter of the chest can be a useful guide in compressing paediatric chests. [3]
Section 9 of 17 Recoil Recoil of the chest during CPR is the return of the chest wall to normal anatomy and height. Full recoil cannot be reached if there remains a pressure on the chest during the decompression phase. To achieve full recoil, the sternum must return to normal height briefly after each compression. One way to obtain full recoil is on an upward stroke of a compression ensure your hands are removed slightly but not completely from the chest wall. Avoid leaning on the chest by setting up with a good posture prior to starting CPR. [9] If decompression is incomplete, the next compression is not as effective due to inadequate blood volume return in the heart and lungs. Inadequate decompression (recoil) compromises both coronary artery and cerebral blood flow. Even limited periods of incomplete decompression can have a lingering effect on coronary and cerebral perfusion pressures, which may remain low even after this deficiency in CPR has been corrected.
[19]
Section 10 of 17 Rotation of Compressors Compressor fatigue can impact all aspects of CPR including positioning, rate, depth and recoil. Timely rotation of compressors is vital in ensuring all aspects of CPR are effective and the patient receives high quality compressions at all times. ANZCOR explain that often, compression quality can decrease within the first minute of the first cycle, yet it can take 5 minutes for the compressor to report feeling fatigued. ANZCOR suggest a rotation of compressors every two minutes to minimise the effects of fatigue. Any signs of fatigue during compressions need to be addressed immediately; ideally, by selfidentification, but also by other clinicians participating in the resuscitation. Fatigue can also be recognised by a corresponding decline in waveform amplitude on the capnogram. Colleagues should address suboptimal compressing by coaching as soon as possible. If after coaching the compressor is still unable to perform adequate CPR then it is reasonable to swap out a compressor mid-cycle. Fatigue is a real issue that affects us all; we must always put the patient s best interest before egos. The development of fatigue does not give any indication of effort or competency either. Resuscitations are a team based performance; no individual should be made to feel targeted and no individual should be scrutinised for acknowledging they require assistance from their team. [9, 14]
Section 11 of 17 Minimising Interruption to Compressions In understanding the physiology of CPR, it seems obvious that minimising the time that compressions are interrupted is beneficial for the patient. Compression interruptions are sometimes not obvious; not compressing while charging, changing compressors mid cycle, rhythm checks, poor positioning, poor coordination of shock cycles, and miscommunication with compressor changes all contribute to unnecessary pauses in compressions. [17] Any pause in compressions reduces coronary and cerebral perfusion pressures. Research has found that once compressions have stopped it can take up to a minute of high quality compressions to regain adequate perfusion pressures. This means that for every pause it can take half of the subsequent shock cycle to return to optimal perfusion pressures. [9]
illustration of the drop in perfusion associated with a pause in compression Some pauses in compressions are at present, unavoidable; rhythm checks, defibrillation, and ventilations (prior to insertion of an advanced airway). During these unavoidable pauses, it is recommended that, where possible, compressions stop for no more than 3-5 seconds. The aim is not to eradicate pauses but to reduce the need and time of unnecessary pauses. Effective use of waveform capnography to indicate increased cardiac output suggestive of ROSC can virtually eliminate the need to pause for pulse checks. Scene preparation, leadership and communication are variables that can have a significant impact on minimising interruption to compressions. Ensuring early 360 access to the patient can have a big impact in allowing clinicians to operate effectively. Counting compressions out loud for the last 5 to ensure the ventilator is ready, pre charging the monitor and rapidly returning to compressions post rhythm check or defibrillation, are examples of how we can effectively work as a team to ensure we bring hands off time to an absolute minimum. [9]
Section 12 of 17 Ventilation Current ANZCOR Guidelines align with SAAS teaching for ventilation in a standard cardiac arrest: Commence 30 chest compressions followed by 2 ventilations, and continue with a ratio of 30:2. For children, after initial 2 ventilations, continue with 15 chest compressions followed by 2 ventilations (a ratio of 15:2). After an advanced airway (supraglottic airway/tracheal tube) is placed during CPR, it is reasonable to ventilate the lungs at a rate of 6 to 10 ventilations per minute without pausing during chest compressions to deliver ventilations Hyperventilation is associated with increased intrathoracic pressure and decreased coronary and cerebral perfusion. Positive pressure ventilations (PPV) increase intrathoracic pressure reducing venous return to the heart, and right ventricular preload. A reduction of venous drainage from the head increases ICP, leads to an increased resistance to forward blood flow and a subsequent reduction of oxygenated blood supply to the brain. One study on animals demonstrated excessive ventilations were associated with a significant decrease in cerebral and myocardial perfusion pressures and markedly increased morbidity. [20] ARC guidelines state ventilation volume should not exceed any more than visible chest rise and fall. The Resuscitation Academy suggests that during practice using the 3 finger squeeze technique is an
effective way to achieve adequate ventilation volume. Lower tidal volumes during resuscitation do not appear to significantly affect the arterial partial pressure of oxygen (PaO2). Excessive ventilation volumes however, have proven negative effects of reducing cardiac output and increasing the risk of gastric insufflation. [3, 6, 18] It is widely stated throughout the literature that hyperventilation causes a decrease in cerebral perfusion; HP-CPR principles state we must aim for ventilating at a rate of 6 to 10 per minute. We must also ensure that compression breaks are not unnecessarily prolonged for ventilations, this can be achieved by administering quick ventilations (1 second/ ventilation). Shortening ventilation time also decreases mean intrathoracic pressures, allowing for greater blood flow. [6] In adults, evidence suggests that in the very first period following a cardiac arrest (apart from a hypoxic arrest secondary to a respiratory or obstructive cause) passive ventilation (gas exchange through the mechanics of chest compression) is acceptable while commencement of CPR is undertaken and an airway is secured. It is during this phase that we place greater emphasis on the value of compressions over ventilations. It would be reasonable to expect a rhythm check, defibrillation and 2 minute cycle all commence while an i-gel is inserted. The i-gel has a recorded average of 11 seconds to insert and a 90% first time insertion success. Because of the quick and easy nature of the i-gel, and the fact that it can be inserted while compressions continue, it is reasonable to insert this adjunct in CA in the first instance. This ensures all ventilations are performed through an advanced airway (reducing the risk of gastric insufflation), and once secured, can reduce the cognitive load of the clinician ventilating. A reasonably reliable reflection of capnography can also be gained with a properly functioning i-gel in situ. Remember, in paediatrics, it is still advisable to ventilate ASAP due to the likelihood of hypoxia being a reversible cause. [16] After insertion of an advanced airway, such as the i-gel, compression and ventilation ratios can now be conducted at 15:1 with asynchronous ventilations in adults. For paediatrics, it is recommended that because of the increased focus of correcting hypoxia and lack of data examining asynchronous ventilations through a supra-glottic airway (SGA) device, compression/ventilation ratios should remain at 15:2 (with a pause for ventilations). The intubated paediatric however, can be ventilated while compressions continue. [9, 16, 21] In terms of High Performance CPR, effective ventilations are described as: Controlled ventilation
Use an inspiratory time of about 1 second and give enough volume to cause the chest to visibly rise Pausing of compressions for only 2-3 seconds Asynchronous ventilations about every 6 seconds post advanced airway insertion (except in paediatrics) ETCO2 detectors applied as soon as possible [7]
Section 13 of 17 Defibrillation Early defibrillation is still our chief priority in any shockable CA. How does defibrillation fit in the HP-CPR model? Most of these concepts have already been adopted in SAAS practice: Have the defibrillator charged and ready to shock/disarm every 2 minutes While charging, maintain compressions until the point that the defibrillator is charged The peri shock pause (when we confirm shockable/non-shockable rhythm) is to be kept to less than 5 seconds where possible. Interchange of compressors at the completion of every shock cycle [9, 7]
Section 14 of 17 Summary HP-CPR is the application of high quality CPR, with special care taken to ensure skills are performed in a standardised manner in accordance with current best practice: Hand positioning on the second half of the sternum Compression depth of 40mm in infants, 40-50mm in children and 50-60mm in adults Ensuring chest recoil Compressions performed at a rate of 100-120 with the use of a metronome where achievable set at a rate of 110 A compression to ventilation ration of 30:2 prior to an advanced airway insertion and 15:1 (uninterrupted compressions) after insertion in adults; ensuring patients are not hyperventilated Use an inspiratory time of about 1 second and give enough volume to cause the chest to visibly rise Continued compressions while charging 2 minutely defibrillations with pre-charging at 1.45mins Rotation of compressors at the end of every shock cycle to minimize fatigue As an ambulance service, we should be industry leaders in the quality of CPR we deliver our patients. HP-CPR is the new way of thinking about CPR, going back to basics and focussing on
delivering excellent quality basic life support (BLS) with elements of advanced life support (ALS) introduced where required. Be prepared for lots of practical sessions in your upcoming conference!
Section 15 of 17 References References.pdf 114.8 KB
Section 16 of 17 Summative Assessment Details Successful completion of the online package will require at least 80% correct responses to the 11 MCQs. You are allowed three attempts for the quiz. Please speak to your team leader if you have used up all three attempts. Once you have passed the quiz, you can obtain your certificate of completion by returning to your portal. Go to quiz
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