NREMT Essay: 2010 AHA Guidelines
National Registry of EMT's Implementation of
2010 AHA Guidelines for CPR and Emergency Cardiovascular Care
In consideration for implementation of the recently released 2010 American Heart Association Guidelines for CPR and Emergency Cardiovascular Care, the NREMT has completed a review of the available published documents to date. The NREMT Standards & Examination Committee has discussed the impact of the recommended changes to our national EMS certification materials. We recognize the projected implementation plans, instructor updates, and anticipated publication of all related AHA educational support materials. Consequently, the NREMT will be implementing all associated recommendations of the AHA Guidelines 2010 for CPR and Emergency Cardiovascular Care as of November 1, 2011 (Paramedic only) and January 1, 2012 (all other levels).
The NREMT will continue to require that all candidates for national EMS certification by the NREMT possess a current and valid CPR credential equivalent to the AHA's CPR for Healthcare Provider. Therefore, the remainder of this discussion will highlight our understanding of the more significant changes contained in the 2010 American Heart Association Guidelines for CPR and Emergency Cardiovascular Care.
Basic Life Support
Perhaps the most significant changes from previous AHA recommendations have occurred in Basic Life Support. Immediate recognition of cardiac arrest is the first link in the "Chain of Survival." However, the A-B-C (Airway, Breathing, Chest compressions) sequence for CPR has been changed to reflect a C-A-B (Chest compressions, Airway, Breathing) sequence in all patients except newly born infants. EMS professionals should not confuse this new sequence for CPR with the age-old A-B-C (Airway, Breathing, Circulation) order for patient assessment. The C-A-B sequence mnemonic for CPR is to reinforce the need to begin chest compressions as quickly as possible in any patient who has suffered sudden cardiac arrest. AHA Guidelines 2010 recommend that each cycle of CPR begins with chest compressions and not ventilations. Healthcare providers should be able to immediately assess an unresponsive patient and quickly determine sudden cardiac arrest based on the following findings:
- Patient responsiveness
- Absence of breathing or abnormal breathing, i.e., gasping or agonal respirations
- Pulse check for no more than 10 seconds
If the patient is unresponsive, apneic or breathing with agonal respirations and no pulse is definitely palpated within 10 seconds, CPR should commence immediately (beginning with chest compressions) and the AED should be used as soon as it is available. It should also be noted that "Look, listen and feel for breathing" is no longer recommended for assessment of the airway or breathing in the unresponsive patient. It is also appropriate for the rescuer to adjust the order of interventions based upon the most likely cause of arrest. For example, if an asphyxial cause of cardiac arrest such as drowning is suspected, the rescuer should begin chest compressions with rescue breathing for 5 cycles (2 minutes) before requesting additional assistance. If the rescuer witnesses the sudden collapse of a patient in cardiac arrest, additional assistance should be requested, CPR initiated and the AED used when it becomes available. It is also recommended that Healthcare Providers practice resuscitation scenarios in teams similar to the crew configurations in which they work.
The second link in the "Chain of Survival" consists of early CPR with an emphasis on chest compressions. AHA Guidelines 2010 reinforces the need to deliver high-quality CPR to patients. Compressions should be performed at a rate of at least 100/minute and a depth of at least 2" in an adult patient. While the recommended compression rate does not change for infants and children, the recommended compression depth should be 1/3 the anterior-posterior diameter of the chest, or approximately 2" in children and 1.5" in infants. The chest should completely recoil after each compression and interruptions should be minimized throughout. Compressors should be rotated every 2 minutes during resuscitation. A 30:2 compression-to-ventilation ratio is recommended in adults, children and infants excluding newly born infants. When 2 Healthcare Providers are present, they should perform CPR at a 15:2 ratio in children and infants.
Ventilations should be delivered over 1 second and be sufficient to cause visible chest rise in all patients. After an advanced airway is placed, ventilations should be delivered at a rate of 1 breath every 6-8 seconds (8-10 ventilations/minute) asynchronously with chest compressions. Excessive ventilations must be avoided and have been shown to adversely affect the quality of CPR. The use of cricoid pressure during ventilations is no longer recommended.
Rapid defibrillation, the third link in the "Chain of Survival," should be implemented with minimal interruption of compressions. If the arrest was witnessed and the AED is immediately available, the rescuers should begin chest compressions and use the AED as soon as possible. If the arrest was unwitnessed, rescuers may initiate CPR while preparing to check the rhythm with the AED. It is appropriate to consider 1½-3 minutes of CPR before attempting defibrillation in this instance. Rescuers should follow all manufacturer's recommended directions for shock administration. Optimal energy levels and waveform characteristics have not been determined. Chest compressions must resume immediately following delivery of each shock. AED electrode pad placement in any of the following 4 positions is reasonable:
- Anterior-left infrascapular
- Anterior-right infrascapular
If the patient has an implanted defibrillator or pacemaker, it may be reasonable to avoid placing the electrode pads directly over the implanted device. Positioning the pads at least 8 cm (3") away from the device appears to prevent damage. However, defibrillation should not be delayed because of alternate pad placement.
When using the AED in infants and children, an initial dose of 2-4 Joules/kg may be considered. Subsequent shocks should be at least 4 Joules/kg and higher energy levels may be considered not to exceed 10 Joules/kg. For children 1-8 years of age, use of a pediatric dose-attenuator system is recommended. If unavailable, a standard AED should be used. For infants under 1 year of age, the use of a manual defibrillator is preferred. If unavailable, the use of a pediatric dose-attenuator system is recommended. If neither manual defibrillator nor attenuated AED are available, the rescuer should use a standard AED.
When managing patients with acute coronary syndrome, administration of supplemental oxygen is not needed if there is no evidence of respiratory distress and the oxyhemoglobin saturation is at least 94%. If the patient is dyspneic, hypoxemic or has obvious signs of heart failure, oxygen administration should be titrated to maintain an oxyhemoglobin saturation of at least 94%.
The management of suspected stroke patients should focus on rapid recognition of symptoms and appropriate treatment and delivery of the patient to an appropriately prepared facility capable of providing proper stroke management within 3 hours of the onset of symptoms. Out-of-hospital care providers should provide specific interventions when the patient's oxyhemoglobin saturation is less than 94%, the patient's systolic BP is less than 90 mmHg or if the patient is hypoglycemic as confirmed by glucometer measurement.
Neonatal resuscitation should be managed in A-B-C fashion as the primary cause of arrest in the newly born is asphyxial. Suctioning immediately after birth, including suctioning with a bulb syringe, should be reserved for babies who have an obvious obstruction to spontaneous breathing or require positive pressure ventilation. Non-vigorous babies with meconium-stained amniotic fluid should receive endotracheal suctioning as soon as possible. For babies born at term, it is best to begin resuscitation with room air rather than 100% oxygen. Resuscitation with oxygen should be monitored by pulse oximetry since hyperoxia can be toxic to the newborn, especially in pre-term babies. After providing positive pressure ventilation or supplemental oxygen administration, the out-of-hospital care provider should evaluate the heart rate, respiratory rate and oxyhemoglobin saturation by pulse oximeter. When delivering full-term and pre-term infants who do not require resuscitation, the out-of-hospital care provider should delay clamping of the umbilical cord for at least 1 minute.
If CPR is required in the neonate, a 3:1 compression-to-ventilation ratio is recommended. However, if the cause of arrest is known to be of a cardiac-related cause, a higher ratio (15:2 compression-to-ventilation ratio with 2 rescuers) should be considered. Once spontaneous circulation has been restored, oxygen administration should be titrated to maintain an oxyhemoglobin saturation of at least 94% but less than 100%. Therapeutic hypothermia may be beneficial and should also be considered after resuscitation from cardiac arrest. However, if the heart rate remains undetectable after 10 minutes of resuscitation, it is appropriate to consider termination of resuscitation efforts.
Finally, AHA Guidelines 2010 suggests that termination of BLS resuscitation may be considered if:
- The arrest was not witnessed by the EMS provider.
- Spontaneous circulation did not return after 3 complete rounds of CPR and AED analyses.
- No shocks from the AED were administered.
Advanced Life Support
The fourth link in the "Chain of Survival" is effective advanced life support. Compared to the BLS content, there are substantially less changes for ALS care identified in AHA Guidelines 2010. The advanced life support provider must understand that a solid BLS foundation of resuscitation increases the likelihood of ROSC with ALS interventions. To date, no definitive clinical evidence has been found to show that early intubation or drug therapy improves neurologically intact survival from sudden cardiac arrest to hospital discharge. Vascular access, drug delivery and placement of an advanced airway should not cause significant interruptions in chest compressions or delay the delivery of shocks. ALS capabilities must be integrated appropriately within a system of post-cardiac arrest care in order to positively affect survival and neurologic outcomes.
Continuous quantitative waveform capnography is recommended for intubated patients. It serves as the most reliable method of confirming and monitoring correct placement of an endotracheal tube. EMS providers should observe a persistent capnographic waveform with ventilation that reflects the amount of end-tidal CO2 in exhaled gases (PETCO2). This waveform is so specific and sensitive to CO2 levels that it also serves as a physiologic monitor of the effectiveness of chest compressions, ventilations and the return of spontaneous circulation.
In monitored patients, the time from VF to shock delivery should be under 3 minutes. While the defibrillator is being prepared, CPR should be performed. A brief period of chest compressions can deliver oxygen and energy to the heart, increasing the likelihood that a shock will terminate VF and cause a return of spontaneous circulation. After 1 shock is delivered, CPR should begin immediately, starting with chest compressions. Single shocks followed by immediate CPR are recommended instead of stacked shocks. If the initial biphasic shock is unsuccessful in terminating VF, subsequent energy levels should be at least equivalent and higher energy levels may be considered if available. When performing synchronized cardioversion to treat atrial fibrillation, the initial biphasic energy dose should be 120-200 Joules or equivalent monophasic shock (200 Joules). When treating atrial flutter or other supraventricular rhythms, synchronized cardioversion should begin with an initial biphasic or monophasic energy dose of 50-100 Joules, and subsequent shocks should be increased in a stepwise fashion. When attempting to cardiovert stable monomorphic ventricular tachycardia, the recommended initial biphasic or monophasic energy dose recommended is 100 Joules, and it may be reasonable to increase subsequent shocks in a stepwise fashion.
A precordial thump may be considered for patients with witnessed, monitored, unstable ventricular tachycardia (including pulseless ventricular tachycardia) if a defibrillator is not immediately ready for use as long as it does not delay CPR and delivery of a shock.
The following medication recommendations should also be noted:
- Atropine is not recommended for management of pulseless electrical activity and asystole.
- Adenosine is recommended for the initial diagnosis and treatment of stable, undifferentiated, regular, monomorphic, wide complex tachycardia. However, it should not be used for the treatment of irregular wide complex tachycardias.
- Morphine should be administered with caution to patients who have unstable angina and non-STEMI. It is indicated for the management of chest discomfort in the setting of STEMI that is unresponsive to administration of nitrates.
- Atropine is recommended for the management of acute symptomatic bradycardia that persists despite adequate airway and breathing. If atropine is ineffective, an intravenous infusion of beta-adrenergic agonists with rate-accelerating effects (dopamine, epinephrine) or transcutaneous pacing can be effective.
- 5. Calcium administration is not recommended in the management of pediatric cardiac arrest unless there is documented hypocalcemia, calcium channel blocker overdose, hypermagnesemia or hyperkalemia.
Integrated post-cardiac arrest care has been added as the fifth link in the "Chain of Survival." After spontaneous circulation is restored following cardiac arrest, the arterial oxyhemoglobin saturation should be monitored. Oxygen administration should be titrated to maintain and arterial oxyhemoglobin saturation of at least 94% but less than 100%. In order to avoid hyperoxia, the provider should adjust the FiO2 to the lowest concentration necessary to achieve an SpO2 of at least 94% but less than 100% saturation. Providers should also implement appropriate procedures for tissue and organ donation that support both the family members' and patient's desires.
When managing patients with acute AMI and acute coronary syndromes, the treatments should be aimed at preserving left ventricular function, preventing heart failure and limiting other related complications. It is recommended that a STEMI system of care be implemented that includes 12-lead ECG transmission or interpretation by EMS providers who provide advance notification to the receiving facility in order to reduce the time to reperfusion and triage the patient appropriately.
Finally, AHA Guidelines 2010 suggests that termination of ALS resuscitation may be considered if:
1. The arrest was not witnessed by anyone.
2. No bystander CPR was provided.
3. Spontaneous circulation did not return after complete ALS care in the field.
4. No shocks were administered.
For a complete review of 2010 AHA Guidelines for CPR and ECC from which the above is based, the reader is encouraged to visit www.heart.org/cpr and download the November 2, 2010 edition of Circulation.