Part 7: Adult Advanced Cardiovascular Life Support

Key Links: 2010 CPR Guidelines Part 7, 2010 CPR Guidelines Part 8, 2015 CPR Guidelines Part 5, 2015 CPR Guidelines Part 7, 2017 Adult BLS Update, 2018 ACLS Update, 2019 ACLS Update

Introduction

Basic life support (BLS), advanced cardiovascular life support (ACLS), and post–cardiac arrest care are labels of convenience that each describe a set of skills and knowledge that are applied sequentially during the treatment of patients who have a cardiac arrest.

Oxygen Administration During CPR

Because blood flow is typically the major limiting factor to oxygen delivery during CPR, it is theoretically important to maximize the oxygen content of arterial blood by maximizing inspired oxygen concentration.

When supplementary oxygen is available, it may be reasonable to use the maximal feasible inspired oxygen concentration during CPR.

Passive Oxygen Delivery During CPR

Some EMS systems have studied the use of passive oxygen flow during chest compressions without positive pressure ventilation, an option known as passive oxygen administration. Evidence regarding this approach includes the passive oxygen flow as part of a bundle of care including opening the airway and emphasis on high-quality, minimally-interrupted chest compressions and a program of continuous quality improvement.

We do not recommend the routine use of passive ventilation techniques during conventional CPR for adults. However, in EMS systems that use bundles of care involving continuous chest compressions, the use of passive ventilation techniques may be considered as part of that bundle.

These updated recommendations do not preclude the 2015 recommendation that a reasonable alternative for EMS systems that have adopted bundles of care is the initial use of minimally interrupted chest compressions (ie, delayed ventilation) for witnessed shockable OHCA.

Airway and Ventilation

Overview of Airway Management and Ventilation

The purpose of ventilation during CPR is to maintain adequate oxygenation and sufficient elimination of carbon dioxide.

Research has not identified the optimal tidal volume, respiratory rate, and inspired oxygen concentration required during resuscitation from cardiac arrest.

Both ventilation and chest compressions are thought to be important for victims of prolonged ventricular fibrillation (VF) cardiac arrest and for all victims with other presenting rhythms.

During cardiac arrest with CPR, normal ventilation-perfusion relationships can be maintained with a minute ventilation that is much lower than normal because CPR produces systemic and pulmonary blood flow that is substantially lower than normal (≈ 25% to 33% of normal).

During CPR with an advanced airway in place, a lower rate of rescue breathing reduces risk of hyperventilation.

Advanced airway placement in cardiac arrest should not delay initial CPR and defibrillation for VF cardiac arrest.

Bag-Mask Ventilation

All healthcare providers should be familiar with the use of the bag-mask device.

Bag-mask ventilation is a challenging skill that requires practice for continuing competency.

Bag-mask ventilation is an acceptable method of providing ventilation and oxygenation during CPR

Bag- mask ventilation is most effective when performed by 2 trained and experienced providers.

Bag-mask ventilation is particularly helpful when placement of an advanced airway is delayed or unsuccessful.

Use an adult (1 to 2 L) bag and deliver approximately 600 mL of tidal volume sufficient to produce chest rise over 1 second.

Be sure to open the airway adequately with a head tilt–chin lift, lifting the jaw against the mask and holding the mask against the face, creating a tight seal.

During CPR give 2 breaths (each 1 second) during a brief (about 3 to 4 seconds) pause after every 30 chest compressions.

It is reasonable that before placement of an advanced airway (supraglottic airway or tracheal tube), EMS providers perform CPR with cycles of 30 compressions and 2 breaths.

It may be reasonable for EMS providers to use a rate of 10 breaths per minute (1 breath every 6 seconds) to provide asynchronous ventilation during continuous chest compressions before placement of an advanced airway.

These updated recommendations do not preclude the 2015 recommendation that a reasonable alternative for EMS systems that have adopted bundles of care is the initial use of minimally interrupted chest compressions (ie, delayed ventilation) for witnessed shockable OHCA.

Bag-mask ventilation can produce gastric inflation with complications, including regurgitation, aspiration, and pneumonia. Gastric inflation can elevate the diaphragm, restrict lung movement, and decrease respiratory system compliance.

There is inadequate evidence of a difference in survival or favorable neurologic outcome with the use of bag-mask ventilation compared with endotracheal intubation or other advanced airway devices. See, also, Advanced Airways, below.

Either bag-mask ventilation or an advanced airway strategy may be considered during CPR in adult cardiac arrest in any setting.

Airway Adjuncts

Cricoid Pressure

The routine use of cricoid pressure in cardiac arrest is not recommended.

If cricoid pressure is used in special circumstances during cardiac arrest, the pressure should be adjusted, relaxed, or released if it impedes ventilation or advanced airway placement.

Oropharyngeal and Nasopharyngeal Airways

To facilitate delivery of ventilation with a bag-mask device, oropharyngeal airways can be used in unconscious (unresponsive) patients with no cough or gag reflex and should be inserted only by persons trained in their use.

To facilitate delivery of ventilation with a bag-mask device, the nasopharyngeal airway can be used in patients with an obstructed airway. However, in the presence of known or suspected basal skull fracture or severe coagulopathy, an oral airway is preferred.

Advanced Airways

It is important that all healthcare providers be trained in delivering effective oxygenation and ventilation with a bag and mask. Because there are times when ventilation with a bag-mask device is inadequate, ideally ACLS providers also should be trained and experienced in insertion of an advanced airway.

Either bag-mask ventilation or an advanced airway strategy may be considered during CPR for adult cardiac arrest in any setting.

Providers must be aware of the risks and benefits of insertion of an advanced airway during a resuscitation attempt. The provider should weigh the need for minimally interrupted compressions against the need for insertion of an endotracheal tube or supraglottic airway,

Although insertion of an endotracheal tube can be accomplished during ongoing chest compressions, intubation can frequently result in undesirable interruption of compressions. As a result, providers must weigh the potential benefit of advanced airway insertion against the potential risk of interruption in chest comressions, as well as the potential risk if misplacement of the advanced airway.

If bag-mask ventilation is judged to be adequate and advanced airway placement will interrupt chest compressions, providers may consider deferring insertion of the airway until the patient fails to respond to initial CPR and defibrillation attempts or demonstrates ROSC.

Effective use of an advanced airway requires maintenance of knowledge and skills through frequent practice.

Providers should have a second (backup) strategy for airway management and ventilation in readiness if unable to establish the first-choice airway adjunct. Bag-mask ventilation may serve as such a backup strategy.

Once an advanced airway is inserted, immediately perform a thorough assessment to ensure that the airway is properly positioned. This assessment should not interrupt chest compressions (see Clinical Assessment of Tracheal Tube Placement, below).

Advanced Airway Choice

Either bag-mask ventilation or an advanced airway strategy may be considered during CPR in adult cardiac arrest in any setting.

Bag-mask ventilation requires skill and proficiency. The choice of bag-mask device versus advanced airway insertion, then, is determined by the skill and experience of the provider as well as the needs of the patient (See (Figure 1)).

If an advanced airway is used, the supraglottic airway can be used for adults with out of hospital cardiac arrest in settings with low tracheal intubation success rate or minimal training opportunities for endotracheal tube placement.

If an advanced airway is used, either the supraglottic airway or endotracheal tube can be used for adults with out-of-hospital cardiac arrest in settings with high tracheal intubation success rates or optimal training opportunities for endotracheal tube placement.

If an advanced airway is used in the in-hospital setting by expert providers trained in theseprocedures, either the supraglottic airway or endotracheal tube can be used.

Recommendations for advanced airway placement presume that the provider has the initial training and skills as well as the ongoing experience to insert the airway and verify proper position with minimal interruption in chest compressions.

Frequent experience or frequent retraining is recommended for providers who perform endotracheal intubation.

Emergency Medical Services systems that perform prehospital intubation should provide a program of ongoing quality improvement to minimize complications and to track overall supraglottic airway and endotracheal tube placement success rates.

Figure 1: Schematic representation of ACLS recommendations for use of advanced airways during CPR.

Clinical Assessment of Tracheal Tube Placement

For a patient with perfusing rhythm who requires intubation, pulse oximetry and electrocardiographic (ECG) status should be monitored continuously during airway placement. Intubation attempts should be interrupted to provide oxygenation and ventilation as needed.

Attempts at endotracheal intubation during CPR have been associated with unrecognized tube misplacement or displacement as well as prolonged interruptions in chest compression.

Clinical assessment to confirm endotracheal intubation consists of visualizing chest expansion bilaterally and listening over the epigastrum (breath sounds should not be heard) and the lung fields bilaterally (breath sounds should be equal and adequate). A devices should also be used to confirm correct placement of the tube in the trachea.

Continuous waveform capnography is recommended in addition to clinical assessment as the most reliable method of confirming and monitoring correct placement of an endotracheal tube.

If continuous waveform capnometry is not available, a nonwaveform carbon dioxide (CO2) detector, esophageal detector device, or ultrasound used by an experienced operator is a reasonable alternative.

False-negative readings (ie, failure to detect CO₂ despite tube placement in the trachea) may be present during cardiac arrest for several reasons.

• most common reason: blood flow and delivery of CO₂ to the lungs is low. In this case, focus is necessary to improve the quality of CPR (ensuring that compressions are of appropriate rate and depth, allowing complete chest recoil after each compression, minimizing interruptions in chest compressions, and voiding excessive ventilation)
• false negative results also reported with pulmonary embolus, because pulmonary blood fow and delivery of CO₂ to the lungs are reduced.

A colorimetric CO₂ detection device may display a constant color rather than a breath-to-breath color change if the detector is contaminated with gastric contents.

If CO₂ is not detected after endotracheal intubation and the clinical exam suggests that the tube is in place, a second method is needed to confirm tube placement, such as direct visualization or the use of an esophageal detector device.

Given the simplicity of the esophageal detector device, it can be used as the initial method for confirming correct tube placement in addition to clinical assessment in the victim of cardiac arrest when waveform capnography is not available.

The esophageal detector device may yield misleading results in patients with morbid obesity, late pregnancy or status asthmaticus, or when there are copious endotracheal secretions, because the trachea tends to collapse in the presence of these conditions (leading to the incorrect conclusion that the tube is not in the trachea).

Postintubation Airway Management and Ventilation

Automatic Transport Ventilators

Manually triggered, oxygen-powered, flow limited resuscitators may be considered for the management of patients who do not have an advanced airway in place and for whom a mask is being used for ventilation during CPR.

During prolonged resuscitative efforts the use of an automatic transport ventilator (pneumatically powered and time- or pressure- cycled) may provide ventilation and oxygenation similar to that possible with the use of a manual resuscitation bag, while allowing the EMS team to perform other tasks.

Rescuers should avoid using the automatic mode of the oxygen-powered, flow-limited resuscitator during CPR because it may generate high positive end-expiratory pressure (PEEP) that may impede venous return during [and between] chest compressions and compromise forward blood flow.

Suction Devices

Both portable and installed suction devices should be available for resuscitation emergencies.

Portable units should provide adequate vacuum and flow for pharyngeal suction.

The suction device should be fitted with large- bore, nonkinking suction tubing and semirigid pharyngeal tips.

Several sterile suction catheters of various sizes should be available for suctioning the lumen of the advanced airway, along with a nonbreakable collection bottle and sterile water for cleaning tubes and catheters.

The installed suction unit should be powerful enough to provide an airflow of >40 L/min at the end of the delivery tube and a vacuum of >300 mm Hg when the tube is clamped.

The amount of suction should be adjustable for use in children and intubated patients.

Overview of the Management of Cardiac Arrest

The management of adult cardiac arrest is depicted in the Adult Cardiac Arrest Algorithm (see Figure 2) and the Adult Cardiac Arrest Circular Algorithm (see Figure 3) as a series of actions that will be performed in sequence by the single rescuer until the arrival of additional rescuers. Once two or more rescuers are present, many of the actions can be performed simultaneously.

Figure 2: Adult Cardiac Arrest Algorithm

Figure 3: ACLS Cardiac Arrest Circular Algorithm

The proper sequence of resuscitation actions are determined by the arrest rhythm. The four arrest rhythms are:

• ventricular fibrillation (VF): disorganized electrical activity with no organized contraction of the ventricle
• pulseless ventricular tachycardia (pVT): organized electrical activity of the myocardium that does not allow sufficient time for ventricular filling and does not generate significant forward flow of blood or a pulse
• pulseless electrical activity (PEA): this term encompasses a heterogeneous group of organized electric rhythms that occur at rates that should produce pulses, but do not. The reason can be that the rhythm is not associated with ventricular contraction, or the ventricular contraction is too weak to generate a palpable pulse, or there are other circumstances such as massive hemorrhage that compromise circulation even with a normally beating heart.
• asystole (or brady-asystole or ventricular asystole): absence of detectable ventricular electric activity (or where ventricular beats are very few and far between) with or without atrial electric activity

Because successful high-quality CPR forms the basis for treatment of cardiac arrest with any presenting rhythm, interventions during resuscitation are organized around two-minute periods of uninterrupted CPR. If VF/pVT is present, rhythm checks and shock delivery occur between these 2-minute periods of CPR, with attempts made to minimize interruptions in chest compressions.

Rhythm checks should be brief, and if an organized rhythm is observed, a pulse check should be performed. If there is any doubt about the presence of a pulse, chest compressions should resume immediately.

Once cardiac arrest is identified, CPR begins and rescuers attach a monitor/defibrillator to determine the arrest rhythm. The treatment will then follow either the “Ventricular Fibrillation (VF)/Pulseless Ventricular Tacyhycardia (pVT)” left branch of the algorithm or the “Asystole/Pulseless Electrical Activity (PEA)” right branch of the algorithm .

• VF/pVT: emphasis is on delivering high-quality CPR and shocks. IV epinephrine and an antiarrhythmic are given for shock-refractory VF/pVT
• Asystole/PEA: emphasis is on delivering high-quality CPR and administration of epinephrine

Note that patients who present with VF/pVT may become asystolic or develop PEA, requiring a change in treatment that is depicted in the Asystole/PEA branch of the algorithm. Patients who present with Asystole/PEA may develop ventricular fibrillation during the course of the resuscitation, requiring a change in treatment to that depicted in the VF/pVT branch of the algorithm .

The Adult Cardiac Arrest Circular Algorithm depicts the same actions shown in the Adult Cardiac Arrest Algorithm in a slightly different way. The circle of actions applies to the care of patients with both VF/pVT and Asystole/PEA arrest rhythms.

In all ACLS algorithms, drug doses and specific details about skills are provided in boxes located to the right side of the algorithms.