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Cardiopulmonary Resuscitation (CPR) in Adults

By

Robert E. O’Connor

, MD, MPH, University of Virginia School of Medicine

Last full review/revision Dec 2019| Content last modified Dec 2019
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Topic Resources
  • Recognition of absent breathing and circulation

  • Basic life support with chest compressions and rescue breathing

  • Advanced cardiac life support (ACLS) with definitive airway and rhythm control

  • Postresuscitative care

Prompt initiation of uninterrupted chest compression and early defibrillation (when indicated) are the keys to success. Speed, efficiency, and proper application of CPR with the least possible interruptions determine successful outcome; the rare exception is profound hypothermia caused by cold water immersion, when successful resuscitation may be accomplished even after prolonged arrest (up to 60 minutes).

Overview of CPR

(See also the American Heart Association's guidelines for CPR and emergency cardiovascular care.)

Guidelines for health care professionals from the American Heart Association are followed (see figure Adult comprehensive emergency cardiac care Adult comprehensive emergency cardiac care Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ). If a person has collapsed with possible cardiac arrest, a rescuer first establishes unresponsiveness and confirms absence of breathing or the presence of only gasping respirations. Then, the rescuer calls for help. Anyone answering is directed to activate the emergency response system (or appropriate in-hospital resuscitation personnel) and, if possible, obtain a defibrillator.

If no one responds, the rescuer first activates the emergency response system and then begins basic life support by giving 30 chest compressions at a rate of 100 to 120/minute and then opening the airway (lifting the chin and tilting back the forehead) and giving 2 rescue breaths. The cycle of compressions and breaths is continued (see table CPR Techniques for Health Care Practitioners CPR Techniques for Health Care Practitioners Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ) without interruption; preferably each rescuer is relieved every 2 minutes.

When a defibrillator (manual or automated) becomes available, a person in ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) is given an unsynchronized shock (see also Defibrillation Defibrillation Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ). If the cardiac arrest is witnessed and a defibrillator is on the scene, a person in VF or VT is immediately defibrillated; early defibrillation may promptly convert VF or pulseless VT to a perfusing rhythm. It is recommended that untrained bystanders begin and maintain continuous chest compressions until skilled help arrives.

Adult comprehensive emergency cardiac care

Adult comprehensive emergency cardiac care

* If an adequate number of trained personnel are available, patient assessment, CPR, and activation of the emergency response system should occur simultaneously.

Based on the Comprehensive Emergency Cardiac Care Algorithm from the American Heart Association.

The techniques used in basic 1- and 2-rescuer CPR are listed in Table CPR Techniques for Health Care Practitioners CPR Techniques for Health Care Practitioners Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more . Mastery is best acquired by hands-on training such as that provided in the US under the auspices of the American Heart Association (1-800-AHA-USA1) or corresponding organizations in other countries.

Table
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Airway and Breathing

Mouth-to-mouth (adults, adolescents, and children) or combined mouth-to-mouth-and-nose (infants) rescue breathing or bag-valve-mask ventilation Bag-Valve-Mask Devices If no spontaneous respiration occurs after airway opening and no respiratory devices are available, rescue breathing (mouth-to-mask or mouth-to-barrier device) is started; mouth-to-mouth ventilation... read more is begun for asphyxial cardiac arrest. If available, an oropharyngeal airway may be inserted. Cricoid pressure is not recommended.

If abdominal distention develops, the airway is rechecked for patency and the amount of air delivered during rescue breathing is reduced. Nasogastric intubation to relieve gastric distention is delayed until suction equipment is available because regurgitation with aspiration of gastric contents may occur during insertion. If marked gastric distention interferes with ventilation and cannot be corrected by the above methods, patients are positioned on their side, the epigastrium is compressed, and the airway is cleared.

Circulation

Chest compression

In witnessed cardiac arrest, chest compression should be done without interruption until defibrillation is available. In an unresponsive patient whose collapse was unwitnessed, the trained rescuer should immediately begin external (closed chest) cardiac compression, followed by rescue breathing. Chest compressions must not be interrupted for >10 seconds (eg, for intubation, central IV catheter placement, or transport). A compression cycle should consist of 50% compression and 50% release; during the release phase, it is important to allow the chest to recoil fully. Rhythm interpretation and defibrillation (if appropriate) are done as soon as a defibrillator is available.

The recommended chest compression depth for adults is about 5 to 6 cm (between 2 and 2.5 in). Ideally, external cardiac compression produces a palpable pulse with each compression, although cardiac output is only 20 to 30% of normal. However, palpation of pulses during chest compression is difficult, even for experienced clinicians, and often unreliable. End-tidal carbon dioxide monitoring may provide a better estimate of cardiac output during chest compression; patients with inadequate perfusion have little venous return to the lungs and hence a low end-tidal carbon dioxide. Restoration of spontaneous breathing or eye opening indicates restoration of spontaneous circulation.

Mechanical chest compression devices are available; these devices are as effective as properly executed manual compressions and can minimize effects of performance error and fatigue. They can be helpful in some circumstances, such as during patient transport or in the cardiac catheterization laboratory.

Open-chest cardiac compression may be effective but is used only in patients with penetrating chest injuries, shortly after cardiac surgery (ie, within 48 hours), in cases of cardiac tamponade, and most especially after cardiac arrest in the operating room when the patient’s chest is already open. However, thoracotomy Thoracotomy Thoracotomy is surgical opening of the chest. It is done to evaluate and treat pulmonary problems when noninvasive procedures are nondiagnostic or unlikely to be definitive. The principal indications... read more requires training and experience and is best done only within these limited indications.

Complications of chest compression

Laceration of the liver is a rare but potentially serious (sometimes fatal) complication and is usually caused by compressing the abdomen below the sternum. Rupture of the stomach (particularly if the stomach is distended with air) is also a rare complication. Delayed rupture of the spleen is very rare. An occasional complication, however, is regurgitation followed by aspiration of gastric contents, causing life-threatening aspiration pneumonia Aspiration Pneumonitis and Pneumonia Aspiration pneumonitis and pneumonia are caused by inhaling toxic and/or irritant substances, usually gastric contents, into the lungs. Chemical pneumonitis, bacterial pneumonia, or airway obstruction... read more in resuscitated patients.

Costochondral separation and fractured ribs often cannot be avoided because it is important to compress the chest deeply enough to produce sufficient blood flow. Fractures are quite rare in children because of the flexibility of the chest wall. Bone marrow emboli to the lungs have rarely been reported after external cardiac compression, but there is no clear evidence that they contribute to mortality. Lung injury is rare, but pneumothorax Pneumothorax (Traumatic) Traumatic pneumothorax is air in the pleural space resulting from trauma and causing partial or complete lung collapse. Symptoms include chest pain from the causative injury and sometimes dyspnea... read more after a penetrating rib fracture may occur. Serious myocardial injury caused by compression is very unlikely, with the possible exception of injury to a preexisting ventricular aneurysm. Concern for these injuries should not deter the rescuer from doing CPR.

Defibrillation

Prompt direct-current cardioversion Direct-Current (DC) Cardioversion-Defibrillation The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more is more effective than antiarrhythmic drugs Drugs for Arrhythmias The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. Treatment is directed at causes. If necessary, direct antiarrhythmic therapy, including antiarrhythmic... read more ; however, the success of defibrillation is time dependent, with about a 10% decline in success after each minute of VF (or pulseless VT). Automated external defibrillators (AEDs) allow minimally trained rescuers to treat VT or VF. Their use by first responders (police and fire services) and their prominent availability in public locations has increased the likelihood of resuscitation.

Defibrillating paddles or pads are placed between the clavicle and the 2nd intercostal space along the right sternal border and over the 5th or 6th intercostal space at the apex of the heart (in the mid-axillary line). Conventional defibrillator paddles are used with conducting paste; pads have conductive gel incorporated into them. Only 1 initial countershock is now advised (the previous recommendation was 3 stacked shocks), after which chest compression is resumed. Energy level for biphasic defibrillators is between 120 and 200 joules (2 joules/kg in children) for the initial shock; monophasic defibrillators are set at 360 joules for the initial shock. Postshock rhythm is not checked until after 2 minutes of chest compression. Subsequent shocks are delivered at the same or higher energy level (maximum 360 joules in adults, or 10 joules/kg in children). Patients remaining in VF or VT receive continued chest compression and ventilation and optional drug therapy Drugs for ACLS Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more .

Monitor and IV

Electrocardiographic (ECG) monitoring is established to identify the underlying cardiac rhythm. An IV line may be started; 2 lines minimize the risk of losing IV access during CPR. Large-bore peripheral lines in the antecubital veins are preferred. In adults and children, if a peripheral line cannot be established, a subclavian or internal jugular central line (see Procedure Central Venous Catheterization A number of procedures are used to gain vascular access. Most patients’ needs for IV fluid and drugs can be met with a percutaneous peripheral venous catheter. If blind percutaneous placement... read more Central Venous Catheterization ) can be placed provided it can be done without stopping chest compression (often difficult). Intraosseous and femoral lines (see Intraosseous Infusion Intraosseous Infusion A number of procedures are used to gain vascular access. Most patients’ needs for IV fluid and drugs can be met with a percutaneous peripheral venous catheter. If blind percutaneous placement... read more Intraosseous Infusion ) are the preferred alternatives, especially in children. Femoral vein catheters (see Procedure Central Venous Catheterization A number of procedures are used to gain vascular access. Most patients’ needs for IV fluid and drugs can be met with a percutaneous peripheral venous catheter. If blind percutaneous placement... read more Central Venous Catheterization ), preferably long catheters advanced centrally, are an option because CPR does not need to be stopped and they have less potential for lethal complications; however, they may have a lower rate of successful placement because no discrete femoral arterial pulsations are available to guide insertion.

The type and volume of fluids or drugs given depend on the clinical circumstances. Usually, IV 0.9% saline is given slowly (sufficient only to keep an IV line open); vigorous volume replacement (crystalloid and colloid solutions, blood) is required only when arrest results from hypovolemia (see Intravenous Fluid Resuscitation Intravenous Fluid Resuscitation Almost all circulatory shock states require large-volume IV fluid replacement, as does severe intravascular volume depletion (eg, due to diarrhea or heatstroke). Intravascular volume deficiency... read more ).

Special Circumstances

In accidental electrical shock Electrical Injuries Electrical injury is damage caused by generated electrical current passing through the body. Symptoms range from skin burns, damage to internal organs and other soft tissues to cardiac arrhythmias... read more , rescuers must be certain that the patient is no longer in contact with the electrical source to avoid shocking themselves. Use of nonmetallic grapples or rods and grounding of the rescuer allows for safe removal of the patient before starting CPR.

In drowning Drowning Drowning is respiratory impairment resulting from submersion in a liquid medium. It can be nonfatal (previously called near drowning) or fatal. Drowning results in hypoxia, which can damage... read more , rescue breathing may be started in shallow water, although chest compression is not likely to be effectively done until the patient is placed horizontally on a firm surface, such as a surfboard or float.

If cardiac arrest follows traumatic injury, airway opening maneuvers and a brief period of external ventilation after clearing the airway have the highest priority because airway obstruction is the most likely treatable cause of arrest. To minimize cervical spine injury, jaw thrust, but not head tilt and chin lift, is advised. Other survivable causes of traumatic cardiac arrest include cardiac tamponade Cardiac Tamponade Cardiac tamponade is accumulation of blood in the pericardial sac of sufficient volume and pressure to impair cardiac filling. Patients typically have hypotension, muffled heart tones, and distended... read more and tension pneumothorax Pneumothorax (Tension) Tension pneumothorax is accumulation of air in the pleural space under pressure, compressing the lungs and decreasing venous return to the heart. (See also Overview of Thoracic Trauma.) Tension... read more Pneumothorax (Tension) , for which immediate needle decompression is lifesaving. However, most patients with traumatic cardiac arrest have severe hypovolemia due to blood loss (for which chest compression may be ineffective) or nonsurvivable brain injuries.

Drugs for ACLS

Despite widespread and long-standing use, no drug or drug combination has been definitively shown to increase survival to hospital discharge in patients with cardiac arrest. Some drugs do seem to improve the likelihood of restoration of spontaneous circulation (ROSC) and thus may reasonably be given (for dosing, including pediatric, see table Drugs for Resuscitation Drugs for Resuscitation* Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ). Drug therapy for shock and cardiac arrest continues to be researched.

Table
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In a patient with a peripheral IV line, drug administration is followed by a fluid bolus (“wide open” IV in adults; 3 to 5 mL in young children) to flush the drug into the central circulation. In a patient without IV or intraosseous access, naloxone, atropine, and epinephrine, when indicated, may be given via the endotracheal tube at 2 to 2.5 times the IV dose. During administration of a drug via endotracheal tube, compression should be briefly stopped.

First-line drugs

The main first-line drug used in cardiac arrest is

  • Epinephrine

Epinephrine may be given 1 mg IV every 3 to 5 minutes. It has combined alpha-adrenergic and beta-adrenergic effects. The alpha-adrenergic effects may augment coronary diastolic pressure, thereby increasing subendocardial perfusion during chest compressions. Epinephrine also increases the likelihood of successful defibrillation. However, beta-adrenergic effects may be detrimental because they increase oxygen requirements (especially of the heart) and cause vasodilation. Intracardiac injection of epinephrine is not recommended because, in addition to interrupting precordial compression, pneumothorax, coronary artery laceration, and cardiac tamponade may occur.

Amiodarone 300 mg can be given once if defibrillation is unsuccessful after epinephrine, followed by 1 dose of 150 mg. It is also of potential value if VT or VF recurs after successful defibrillation; a lower dose is given over 10 minutes followed by a continuous infusion. There is no persuasive proof that it increases survival to hospital discharge.

A single dose of vasopressin 40 units, which has a duration of activity of 40 minutes, is an alternative to epinephrine (adults only). However, it is no more effective than epinephrine and is therefore no longer recommended in the American Heart Association's guidelines. However, in the unlikely case of a lack of epinephrine during CPR, vasopressin may be substituted.

Other drugs

A range of additional drugs may be useful in specific settings.

Atropine sulfate is a vagolytic drug that increases heart rate and conduction through the atrioventricular node. It is given for symptomatic bradyarrhythmias and high-degree atrioventricular nodal block. It is no longer recommended for asystole or pulseless electrical activity.

Calcium chloride is recommended for patients with hyperkalemia Hyperkalemia Hyperkalemia is a serum potassium concentration > 5.5 mEq/L (> 5.5 mmol/L), usually resulting from decreased renal potassium excretion or abnormal movement of potassium out of cells. There are... read more , hypermagnesemia Hypermagnesemia Hypermagnesemia is a serum magnesium concentration > 2.6 mg/dL (> 1.05 mmol/L). The major cause is renal failure. Symptoms include hypotension, respiratory depression, and cardiac arrest. Diagnosis... read more , hypocalcemia Hypocalcemia Hypocalcemia is a total serum calcium concentration 8.8 mg/dL ( 2.20 mmol/L) in the presence of normal plasma protein concentrations or a serum ionized calcium concentration 4.7 mg/dL ( 1.17... read more , or calcium channel blocker toxicity. In other patients, because intracellular calcium is already higher than normal, additional calcium is likely to be detrimental. Because cardiac arrest in patients on renal dialysis is often a result of or accompanied by hyperkalemia, these patients may benefit from a trial of calcium if bedside potassium determination is unavailable. Caution is necessary because calcium exacerbates digitalis toxicity and can cause cardiac arrest.

Lidocaine is not recommended for routine use during cardiac arrest. However, it may be helpful as an alternative to amiodarone for VF or VT that is unresponsive to defibrillation (in children) or after ROSC due to VF or VT (in adults).

Magnesium sulfate has not been shown to improve outcome in randomized clinical studies. However, it may be helpful in patients with torsades de pointes Long QT Syndrome and Torsades de Pointes Ventricular Tachycardia Torsades de pointes is a specific form of polymorphic ventricular tachycardia in patients with a long QT interval. It is characterized by rapid, irregular QRS complexes, which appear to be twisting... read more or known or suspected magnesium deficiency (ie, alcoholics, patients with protracted diarrhea).

Procainamide is a 2nd-line drug for treatment of refractory VF or VT. However, procainamide is not recommended for pulseless arrest in children.

Phenytoin may rarely be used to treat VF or VT, but only when VF or VT is due to digitalis toxicity and is refractory to other drugs. A dose of 50 to 100 mg/minute every 5 minutes is given until rhythm improves or the total dose reaches 20 mg/kg.

Sodium bicarbonate is no longer recommended unless cardiac arrest is caused by hyperkalemia, hypermagnesemia, or tricyclic antidepressant overdose with complex ventricular arrhythmias. In children, sodium bicarbonate may be considered when cardiac arrest is prolonged (> 10 minutes); it is given only if there is good ventilation. When sodium bicarbonate is used, arterial pH should be monitored before infusion and after each 50-mEq dose (1 to 2 mEq/kg in children).

Dysrhythmia Treatment

VF or pulseless VT is treated with one direct-current shock, preferably with biphasic waveform, as soon as possible after those rhythms are identified. Despite some laboratory evidence to the contrary, it is not recommended to delay defibrillation to administer a period of chest compressions. Chest compression should be interrupted as little as possible and for no more than 10 seconds at a time for defibrillation. Recommended energy levels for defibrillation vary: 120 to 200 joules for biphasic waveform and 360 joules for monophasic. If this treatment is unsuccessful, epinephrine 1 mg IV is administered and repeated every 3 to 5 minutes. Defibrillation at the same energy level or higher is attempted 1 minute after each drug administration. If VF persists, amiodarone 300 mg IV is given. Then, if VF/VT recurs, 150 mg is given followed by infusion of 1 mg/minute for 6 hours, then 0.5 mg/minute. Current versions of AEDs provide a pediatric cable that effectively reduces the energy delivered to children. (For pediatric energy levels, see Defibrillation Defibrillation Despite the use of CPR, mortality rates for out-of-hospital cardiac arrest are about 90% for infants and children. Mortality rates for in-hospital cardiac arrest for infants and children are... read more ; for drug doses, see table Drugs for Resuscitation Drugs for Resuscitation* Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more .)

Asystole can be mimicked by a loose or disconnected monitor lead; thus, monitor connections should be checked and the rhythm viewed in an alternative lead. If asystole is confirmed, the patient is given epinephrine 1 mg IV repeated every 3 to 5 minutes. Defibrillation of apparent asystole (because it “might be fine VF”) is discouraged because electrical shocks injure the nonperfused heart.

Pulseless electrical activity is circulatory collapse that occurs despite satisfactory electrical complexes on the ECG. Patients with pulseless electrical activity receive 500- to 1000-mL (20 mL/kg for children) infusion of 0.9% saline. Epinephrine may be given in amounts of 0.5 to 1.0 mg IV repeated every 3 to 5 minutes. Cardiac tamponade can cause pulseless electrical activity, but this disorder usually occurs in patients after thoracotomy and in patients with known pericardial effusion or major chest trauma. In such settings, immediate pericardiocentesis or thoracotomy is done (see figure Pericardiocentesis Treatment Pericarditis is inflammation of the pericardium, often with fluid accumulation. Pericarditis may be caused by many disorders (eg, infection, myocardial infarction, trauma, tumors, metabolic... read more Treatment ). Tamponade is rarely an occult cause of cardiac arrest but, if suspected, can be confirmed by ultrasonography or, if ultrasonography is unavailable, pericardiocentesis.

Termination of Resuscitation

CPR should be continued until the cardiopulmonary system is stabilized, the patient is pronounced dead, or a lone rescuer is physically unable to continue. If cardiac arrest is thought to be due to hypothermia, CPR should be continued until the body is rewarmed to 34° C.

The decision to terminate resuscitation is a clinical one, and clinicians take into account duration of arrest, age of the patient, and prognosis of underlying medical conditions. The decision is typically made when spontaneous circulation has not been established after CPR and ACLS measures have been done. In intubated patients, an end-tidal carbon dioxide (ETCO2) level of < 10 mm Hg is a poor prognostic sign.

Postresuscitative Care

Restoration of spontaneous circulation (ROSC) is only an intermediate goal in resuscitation. The ultimate goal is survival to hospital discharge with good neurologic function, which is achieved by only a minority of patients with ROSC. To maximize the likelihood of a good outcome, clinicians must provide good supportive care (eg, manage blood pressure, temperature, and cardiac rhythm) and treat underlying conditions, particularly acute coronary syndromes Overview of Acute Coronary Syndromes (ACS) Acute coronary syndromes result from acute obstruction of a coronary artery. Consequences depend on degree and location of obstruction and range from unstable angina to non–ST-segment elevation... read more .

Postresuscitation laboratory studies include arterial blood gases (ABG), complete blood count (CBC), and blood chemistries, including electrolytes, glucose, BUN (blood urea nitrogen), creatinine, and cardiac markers. (Creatine kinase is usually elevated because of skeletal muscle damage caused by CPR; troponins, which are unlikely to be affected by CPR or defibrillation, are preferred.) Arterial PaO2 should be kept near normal values (80 to 100 mm Hg). Hematocrit should be maintained at 30% (if cardiac etiology is suspected), and glucose at 140 to 180 mg/dL (7.7 to 9.9 mmol/L); electrolytes, especially potassium, should be within the normal range.

Coronary angiography

When indicated, coronary angiography should be done emergently (rather than later during the hospital course) so that if percutaneous coronary intervention (PCI) is needed, it is done as soon as possible. The decision to do cardiac catheterization Cardiac Catheterization Cardiac catheterization is the passage of a catheter through peripheral arteries or veins into cardiac chambers, the pulmonary artery, and coronary arteries and veins. Cardiac catheterization... read more Cardiac Catheterization after resuscitation from cardiac arrest should be individualized based on the electrocardiogram (ECG), the interventional cardiologist's clinical impression, and the patient's prognosis. However, guidelines suggest doing emergency angiography for adult patients in whom a cardiac cause is suspected and who have

  • ST-segment elevation (STEMI), or new left bundle branch block (LBBB) on the ECG

Some researchers advocate liberal use of cardiac catheterization after ROSC, doing the procedure on most patients unless the etiology is clearly unlikely to be cardiac (eg, drowning) or there are contraindications (eg, intracranial bleeding).

Neurologic support

Only about 10% of all cardiac arrest survivors have good central nervous system function (cerebral performance category [CPC] score] 1 or 2—see table Cerebral Performance Category Scale Cerebral Performance Category Scale (Adult)* Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ) at hospital discharge. A CPC score of 1 is indicative of good cerebral performance (patient is conscious, alert, able to work but may have mild neurologic or psychologic deficit). A CPC score of 2 is indicative of moderate cerebral performance ( patient is conscious, able to do activities of daily living (ADLs) and work in a simple environment. Hypoxic brain injury is a result of ischemic damage and cerebral edema (see pathophysiology of cardiac arrest Pathophysiology Cardiac arrest is the cessation of cardiac mechanical activity resulting in the absence of circulating blood flow. Cardiac arrest stops blood from flowing to vital organs, depriving them of... read more ). Both damage and recovery may evolve over 48 to 72 hours after resuscitation.

Table
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Maintenance of oxygenation and cerebral perfusion pressure (avoiding hypotension) may reduce cerebral complications. Both hypoglycemia and hyperglycemia may damage the post-ischemic brain and should be treated.

In adults, targeted temperature management (maintaining body temperature of 32 to 36° C) is recommended for patients who remain unresponsive after spontaneous circulation has returned (1 Postresuscitative care references Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more , 2 Postresuscitative care references Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ). Cooling is begun as soon as spontaneous circulation has returned. Techniques to induce and maintain hypothermia can be either external or invasive. External cooling methods are easy to apply and range from the use of external ice packs to several commercially available external cooling devices that circulate high volumes of chilled water over the skin. For internal cooling, chilled IV fluids (4° C) can be rapidly infused to lower body temperature, but this method may be problematic in patients who cannot tolerate much additional fluid volume. Also available are external heat-exchange devices that circulate chilled saline to an indwelling IV heat-exchange catheter using a closed-loop design in which chilled saline circulates through the catheter and back to the device, rather than into the patient. Another invasive method for cooling uses an extracorporeal device that circulates and cools blood externally then returns it to the central circulation. Regardless of the method chosen, the goal is to cool the patient rapidly and to maintain the core temperature between 32° C and 36° C. Currently, there is no evidence that any specific temperature within this range is superior, but it is imperative to avoid hyperthermia.

Numerous pharmacologic treatments, including free radical scavengers, antioxidants, glutamate inhibitors, and calcium channel blockers, are of theoretic benefit; many have been successful in animal models, but none have proved effective in human trials.

Blood pressure support

Current recommendations are to maintain a mean arterial pressure (MAP) of > 80 mm Hg in older adults or > 60 mm Hg in younger and previously healthy patients. In patients known to be hypertensive, a reasonable target is systolic blood pressure (BP) 30 mm Hg below prearrest level. MAP is best measured with an intra-arterial catheter. Use of a flow-directed pulmonary artery catheter for hemodynamic monitoring has been largely discarded.

BP support includes

  • IV 0.9% saline

  • Sometimes inotropic or vasopressor drugs

  • Rarely intra-aortic balloon counterpulsation

Patients with low MAP and low central venous pressure should have IV fluid challenge with 0.9% saline infused in 250-mL increments.

Although use of inotropic and vasopressor drugs has not proved to enhance long-term survival, older adults with moderately low MAP (70 to 80 mm Hg) and normal or high central venous pressure may receive an infusion of an inotrope (eg, dobutamine started at 2 to 5 mcg/kg/minute). Amrinone or milrinone are alternatives that are rarely used (see table Drugs for Resuscitation Drugs for Resuscitation* Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ).

If this therapy is ineffective, the inotrope and vasoconstrictor dopamine may be considered. Alternatives are epinephrine and the peripheral vasoconstrictors norepinephrine and phenylephrine (see table Drugs for Resuscitation Drugs for Resuscitation* Cardiopulmonary resuscitation (CPR) is an organized, sequential response to cardiac arrest, including Recognition of absent breathing and circulation Basic life support with chest compressions... read more ). However, vasoactive drugs should be used at the minimal dose necessary to achieve low-normal MAP because they may increase vascular resistance and decrease organ perfusion, especially in the mesenteric bed. They also increase the workload of the heart at a time when its capability is decreased because of postresuscitation myocardial dysfunction.

If MAP remains < 70 mm Hg in patients who may have sustained a myocardial infarction (MI), intra-aortic balloon counterpulsation should be considered. Patients with normal MAP and high central venous pressure may improve with either inotropic therapy or afterload reduction with nitroprusside or nitroglycerin.

Intra-aortic balloon counterpulsation can assist low-output circulatory states due to left ventricular pump failure that is refractory to drugs. A balloon catheter is introduced via the femoral artery, percutaneously or by arteriotomy, retrograde into the thoracic aorta just distal to the left subclavian artery. The balloon inflates during each diastole, augmenting coronary artery perfusion, and deflates during systole, decreasing afterload. Its primary value is as a temporizing measure when the cause of shock is potentially correctable by surgery or percutaneous intervention (eg, acute MI with major coronary obstruction, acute mitral insufficiency, ventricular septal defect).

Dysrhythmia treatment

Postresuscitation rapid supraventricular tachycardias occur frequently because of high levels of beta-adrenergic catecholamines (both endogenous and exogenous) during cardiac arrest and resuscitation. These rhythms should be treated if extreme, prolonged, or associated with hypotension or signs of coronary ischemia. An esmolol IV infusion is given, beginning at 50 mcg/kg/min.

Patients who had arrest caused by VF or VT not associated with acute MI are candidates for an implantable cardioverter-defibrillator (ICD). Current ICDs are implanted similarly to pacemakers and have intracardiac leads and sometimes subcutaneous electrodes. They can sense arrhythmias and deliver either cardioversion or cardiac pacing as indicated.

Postresuscitative care references

More Information

  • American Heart Association's guidelines for CPR and emergency cardiovascular care

Drugs Mentioned In This Article

Drug Name Select Trade
No US brand name
LEVOPHED
NITROPRESS
NITRO-DUR
ADRENALIN
VASOSTRICT
CORDARONE
XYLOCAINE
DILANTIN
ADENOCARD
ATROPEN
EVZIO
BREVIBLOC
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