The editors and publisher would like to thank Dr. Linda Liu for contributing to this chapter in the previous edition of this work. It has served as the foundation for the current chapter.
Cardiopulmonary resuscitation (CPR) was initially defined nearly 50 years ago, as the administration of mouth-to-mouth ventilation and closed chest cardiac compressions in a pulseless patient. Since that time, significant advances in CPR and cardiovascular life support have been made. Today, the early descriptions of CPR are termed basic life support (BLS), whereas adult advanced cardiovascular life support (ACLS) and pediatric advanced cardiovascular life support (PALS) include additional invasive techniques by experienced practitioners.
Out-of-hospital resuscitation is well described, whereas in-hospital resuscitation and life support are less commonly studied. A retrospective analysis of in-hospital CPR found that between 2000 and 2009, 1 in 393 hospitalized patients received CPR, and 23% survived to discharge. Cardiac arrest in the perioperative period is unique in that it can frequently be anticipated, and health care providers and resources are immediately available.
The American Heart Association (AHA), in conjunction with the International Liaison Committee on Resuscitation (ILCOR), published updated guidelines for the administration of CPR and emergency cardiovascular care (ECC) in 2015. These guidelines, revised from the 2010 version, include added emphasis on systems of care in the prehospital, in-hospital, and postresuscitation settings, and on the continued education of CPR techniques to providers. Furthermore, instead of periodic overall updates, new evidence will now be continually evaluated and revised guidelines will be available online.
Basic Life Support
BLS includes a number of key measures, including recognition of unresponsiveness and cardiac arrest, activation of an emergency response system, early administration of CPR, and early defibrillation if indicated. In the hospital setting, a health care provider will perform the following sequence of steps, as described by the AHA algorithm: (1) ensure safety; (2) check for response; (3) activate resuscitation team; (4) simultaneously check for adequate breathing and pulse; (5) retrieve automated external defibrillator (AED) and emergency equipment; (6) begin CPR and defibrillate when defibrillator becomes available; and (7) provide two-person CPR as help arrives ( Fig. 45.1 ).
Recognition
The recognition and management of cardiac arrest in an unresponsive patient differ between laypersons and health care providers. The AHA guidelines recognize this distinction and include increased flexibility in emergency response activation either before or after breathing and pulse assessment for health care providers. The 2015 guidelines also include a larger role for dispatcher-guided CPR for laypersons in treating out-of-hospital cardiac arrest.
Health care providers should check for a pulse while simultaneously evaluating for adequate ventilation. The pulse should be assessed at either the carotid or femoral artery. The elapsed time for the pulse check should not exceed 10 seconds, in order to minimize time to start chest compressions. When monitoring respiration, occasional gasps should not be mistaken for normal breathing.
Early Cardiopulmonary Resuscitation
When initiating chest compressions, the heel of the hand is placed longitudinally on the lower half of the sternum, between the nipples. The sternum is depressed at least 5 cm (2 inches) at a rate of at least 100 compressions per minute but no faster than 120 compressions per minute. Rates more rapid than 120 compressions per minute lead to a decrease in the depth of compressions. A depth of no more than 6 cm is also recommended, as excessive compression depth has been associated with an increased rate of thoracic injury. Complete chest recoil is necessary to allow for venous return and is important for effective CPR. The pattern is 30 compressions to 2 breaths (30:2 equals 1 cycle of CPR), regardless of whether one or two rescuers are present.
Since 2010, the importance of definitive airway management has taken a secondary role to chest compressions. The old mnemonic ABCD (airway, breathing, circulation, and defibrillation) has given way to CAB (compression, airway, breathing). This is because the early initiation of high-quality chest compressions improves the likelihood of a return of spontaneous circulation (ROSC). Airway maneuvers are still attempted, but they should occur quickly, efficiently, and minimize interruptions in chest compressions. Opening the airway can be achieved by a simple head tilt–chin lift technique ( Fig. 45.2 ). A jaw thrust maneuver can be used in patients with suspected cervical spine injury. Simple airway devices, such as nasal or oral airways, can be inserted to displace the tongue from the posterior oropharynx.
Although several large out-of-hospital studies have demonstrated that chest compression-alone CPR is not inferior to traditional compression-ventilation CPR, health care providers are still expected to provide assisted ventilation. Care should be taken to avoid rapid or forceful breaths. Concern exists for reducing preload and cardiac output with excessive positive-pressure ventilation. Establishing an advanced airway during in-hospital cardiac arrest (IHCA) results in fewer interruptions to chest compressions during CPR. Complications may also occur from gastric insufflation and subsequent aspiration of gastric contents. Maximum oxygen concentration is administered in order to provide optimally saturated arterial hemoglobin concentrations. Delivered tidal volumes of approximately 400 to 600 mL are given over 1 second and should produce visible chest rise. Once an advanced airway has been established, a respiratory rate of 10 breaths/min is the goal because hyperventilation is detrimental for neurologic recovery. The decreased minute ventilation is also appropriate because cardiac output is much smaller than normal during resuscitation.
Early Defibrillation
A defibrillator is attached to the patient as soon as possible. Proper electrode pad placement on the chest wall is to the right of the upper sternal border below the clavicle and to the left of the nipple with the center in the midaxillary line ( Fig. 45.3 ). Most electrode pads now come with diagrams showing their correct positioning. Alternative locations include anterior-posterior, anterior–left infrascapular, and anterior–right infrascapular. Right anterior axillary to left anterior axillary is not recommended.
The amount of energy (joules [J]) delivered is dependent on the type of defibrillator used. Two major defibrillator types (monophasic and biphasic) are available. Monophasic waveform defibrillators deliver a unidirectional energy charge, whereas biphasic waveform defibrillators deliver an in-series bidirectional energy charge. Based on evidence from implantable defibrillators, bidirectional energy delivery is probably more successful in terminating ventricular tachycardia (VT) and ventricular fibrillation (VF). In addition, biphasic waveform shocks require less energy than traditional monophasic waveform shocks (120 to 200 J vs. 360 J, respectively) and may therefore cause less myocardial damage.
The time until defibrillation is critical to survival, especially because the most frequent initial cardiac rhythm in adult patients is VT/VF. Defibrillation should occur as soon as possible when recognizing a VT/VF arrest. CPR should be initiated while emergency equipment is being retrieved. In one study of IHCAs, 30% of patients received delayed defibrillation. Patients receiving delayed defibrillation have slower rates of ROSC and survival to hospital discharge. Furthermore, each additional minute of delay was associated with worse outcomes. Chest compressions should be resumed immediately following defibrillation.
Ancillary Devices and Alternative Techniques
The 2015 AHA guidelines reviewed the evidence for ancillary devices used during CPR and found insufficient support to recommend any of the following: impedance threshold device, active compression-decompression CPR with impedance threshold device, mechanical piston device for chest compressions, and load distributing band devices.
There was also insufficient evidence to recommend the routine use of extracorporeal CPR (venoarterial extracorporeal membrane oxygenation [ECMO]) for patients in cardiac arrest. However, there may be some benefit in carefully selected patients who suffer from witnessed in-hospital arrest secondary to reversible causes.
Adult Advanced Cardiac Life Support
Adult ACLS includes several interventions besides BLS in order to manage cardiac arrest. These interventions can include airway manipulation, medication administration, arrhythmia management, and transition to postresuscitation care. However, the key element of ACLS remains high-quality CPR, which includes correctly performed chest compressions, minimal compression interruption, and early cardiac defibrillation. The additional components of ACLS and specific arrhythmia management will be discussed later. As there were no updates to the bradycardia and tachycardia algorithms from 2010, they will not be reviewed in detail. Figs. 45.4 and 45.5 summarize the management of the patient with bradycardia or tachycardia with a pulse. All algorithms are readily available online.
Monitoring Cardiopulmonary Resuscitation
A number of physiologic variables can be used to monitor CPR. Continuous monitoring of end-tidal carbon dioxide (P etco 2 ) with waveform capnography can be beneficial during resuscitation. In addition to confirmation of advanced airway placement, P etco 2 can guide the rescuers in adequacy of chest compressions. Alternative physiologic measures during CPR include arterial relaxation diastolic pressure, arterial pressure monitoring, and central venous oxygen saturation. Specific target values during resuscitation are still being evaluated. Furthermore, a prolonged reduction in P etco 2 should not be used in isolation for prognostication, and it should certainly not be used in patients without an endotracheal tube. Bedside cardiac ultrasound can also be considered when managing cardiac arrest, but its use is not routinely recommended. If it is utilized, an experienced sonographer should perform the ultrasound and interruptions in chest compressions should be minimized.
Airway Management
The 2015 AHA guidelines, consistent with the ILCOR review, recommend either a bag-mask or advanced airway device (endotracheal tube or supraglottic airway) for providing oxygenation and ventilation during CPR. The choice of technique depends on the skill of the provider. Because chest compressions are often not performed during endotracheal intubation, the rescuer should compare the need for compressions against the need for definitive airway management Chest compressions are not interrupted for longer than 10 seconds during airway management and are resumed immediately following endotracheal intubation. If the intubation attempt is unsuccessful, placement of a laryngeal mask airway can be considered (also see Chapter 16 ). Insertion of an advanced airway can be deferred until after the patient fails to respond to several cycles of CPR and defibrillation. However, the clinical course of the arrest should be considered. For example, a patient with severe pulmonary edema may benefit from endotracheal intubation sooner rather than later. There are no formal recommendations for the timing of advanced airway placement.
Continuous waveform capnography is recommended as the measurement of choice for the assessment of advanced airway placement. Clinical evaluation should also occur, which includes auscultation of bilateral breath sounds and visualization of bilateral chest rise. If capnography is not available, alternative methods include esophageal detector device, nonwaveform capnogram, and ultrasound. Once the endotracheal tube is confirmed to be in the trachea, it is secured in place. One breath is delivered every 6 seconds (10 breaths/min) without synchronization with compressions.
Algorithms
Pulseless Arrest
Cardiac dysrhythmias that produce pulseless cardiac arrest are (1) VF, (2) VT, (3) pulseless electrical activity (PEA), and (4) asystole ( Fig. 45.6 ). During pulseless cardiac arrest, the primary goals are to provide effective chest compressions and early defibrillation if the rhythm is VF or VT. Drug administration is of secondary importance because the efficacy of pharmacologic interventions has been difficult to measure or prove. After initiating CPR and defibrillation, rescuers can then establish intravenous access, obtain a more definitive airway, and consider drug therapy, all while providing continued chest compressions and ventilation.
Ventricular Fibrillation/Ventricular Tachycardia
If the cardiac arrest is witnessed, the health care provider immediately places the defibrillator pads on the patient’s chest, determines the rhythm, and delivers a shock if VF or VT is present (see Fig. 45.6 ). CPR is resumed immediately after delivery of the shock and continued for five cycles or about 2 minutes, followed by reevaluation of the cardiac rhythm. If the patient remains in VF/VT, the defibrillator is charged to the appropriate energy level while CPR is still being performed, as determined by the manufacturer’s instructions. A biphasic defibrillator is preferred over monophasic, and a single shock is preferred over sequential (also called stacked ) shocks.
If VF or VT persists after one to two sets of CPR-defibrillation cycles, a vasopressor is given ( Table 45.1 ). Epinephrine, 1 mg intravenously (IV), may be administered every 3 to 5 minutes. Drug administration is timed to minimize interruptions in chest compressions. If the patient remains in VT/VF, amiodarone, an antiarrhythmic, can improve the likelihood of restoring and maintaining ROSC. The role of antiarrhythmics in improving survival following VF/VT arrest is not clear. A currently ongoing trial, ROC-ALPS seeks to provide information regarding the use of lidocaine, amiodarone, and placebo in managing arrhythmia during cardiac arrest. Magnesium sulfate can be considered if torsades de pointes is suspected.
| Drug Name | Dose | Indication |
|---|---|---|
| Adenosine | 6 mg IV/IO May repeat 12 mg IV/IO (cut dose in half if using central line) | For stable narrow QRS tachycardia or monomorphic VT (contraindicated with preexcitation syndrome) |
| Amiodarone | 300 mg IV/IO May repeat 150 mg IV/IO 150 mg IV/IO over a 10-min period Maintenance infusion of 1 mg/min for 6 h, then 0.5 mg/min Maximum total dose of 2.2 g/24 h | For pulseless VT/VF For stable VT or uncertain wide QRS tachycardia and narrow QRS tachycardias |
| Atropine a | 0.5 mg IV/IO May repeat to total dose of 3 mg | For bradycardia |
| Diltiazem | 15 to 20 mg (0.25 mg/kg) IV/IO over a 2-min period May repeat in 15 min at 20-25 mg/kg (0.35 mg/kg) Maintenance infusion of 5-15 mg/h, titrate to heart rate | For stable narrow QRS tachycardia (contraindicated with preexcitation syndrome) |
| Dopamine | 2 to 10μg/kg/min by infusion | For bradycardia instead of a pacer, while awaiting a pacer, or if a pacer is ineffective or not tolerated |
| Epinephrine a | 1 mg IV/IO Repeat every 3 to 5 min 2 to 10μg/min by infusion | For pulseless cardiac arrest For bradycardia instead of a pacer, while awaiting a pacer, or if a pacer is ineffective or not tolerated |
| Esmolol | 0.5 mg/kg IV/IO load, followed by an infusion at 0.05 mg/kg/min May repeat the 0.5-mg/kg bolus and increase the infusion to 0.1 mg/kg/min Maximum infusion of 0.3 mg/kg/min | For stable narrow QRS tachycardias (contraindicated with preexcitation syndrome) |
| Lidocaine a | 1 to 1.5 mg/kg IV/IO May repeat 0.5 mg to 0.75 mg/kg Maximum total of three doses or 3 mg/kg | For pulseless VT/VF when amiodarone is NOT available |
| Magnesium | 1 to 2 g IV/IO | For torsades de pointes |
| Metoprolol | 5 mg IV/IO May repeat every 5 min Maximum total dose of 15 mg | For stable narrow QRS tachycardias (contraindicated with preexcitation syndrome) |
| Procainamide | 20 to 50 mg/min IV/IO (max 17 mg/kg) until arrhythmia suppressed Maintenance infusion of 1 to 4 mg/min | For stable wide QRS tachycardia |
| Sotalol | 100 mg (1.5 mg/kg) IV/IO over 5 min | For stable wide QRS tachycardia |
| Verapamil | 2.5 to 5 mg IV/IO over a 2-min period May repeat 5 to 10 mg over a 15- to 30-min period Maximum total dose of 20 mg | For stable narrow QRS tachycardia (contraindicated with preexcitation syndrome) |
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