Management of cardiac arrest: seven steps to survival ALAM S. KHAN,* MB, FRCP[C]
Cardiac arrest is a common medical emergency. It usually occurs suddenly and results in irreversible brain damage unless prompt, effective treatment is instituted. One plan for dealing effectively with this emergency consists of seven steps of cardiopulmonary resuscitation: (1) establishing the diagnosis and deciding whether to resuscitate; (2) administering a precordial thump, noting the time and summoning aid; (3) establishing a patent airway and performing artificial ventilation and external cardiac compression; (4) instituting general supportive measures; (5) diagnosing the cardiac arrhythmia responsible for the arrest; (6) treating the arrhythmia; and (7) managing the patient after resuscitation.
cardiaque externe: (4) mettre en oeuvre des mesures g6nerales d'appoint; (5) diagnostiquer l'arythmie responsable de l'arr.t cardiaque; (6) traiter larythmie; et (7) prendre soin du patient apres reanimation.
Coronary heart disease has an epidemic prevalence in our society, and cardiac arrest has become a common medical emergency. There are two special features of this emergency; first, cardiac arrest usually occurs suddenly and unexpectedly; and, second, resultant brain damage is invariable and irreversible unless the circulation is restored within a few minutes. Well organized, disciplined management of the patient is necessary for his or her survival. This paper discusses such an approach seven steps to survival. Because cardiac arrest usually results L'arr6t cardiaque est une urgence in early cessation of normal respiration, medicale courante. Habituellement il steps taken to manage this emergency survient soudainement et entraine des involve the maintenance of both resdommages cer6braux irreversibles piration and circulation. Cardiopulmona moms qu'un traitement rapide et efficace ne soit instaure. Une procedure ary resuscitation (CPR), therefore, is an appropriate term. There are seven permettant de faire face de fa.on steps to CPR; they are illustrated in efficace a cette urgence consiste a Fig. 1. Step 1 is to establish the diagappliquer les sept mesures de reanimation cardiopulmonaire suivantes: nosis of cardiac arrest and to decide whether the patient should be resusci(1) poser le diagnostic et decider, sil y a lieu, de reanimer; (2) administrer tated. In Step 2 a precordial thump is un coup de poing vigoureux sur l.aire given in witnessed cases, the time of precordiale, enregistrer le temps et onset of cardiac arrest is noted and faire venir de l'aide; (3) assurer des aid is summoned. Step 3 is called the ABC of CPR1 because it deals with the voies aeriennes libres et donner Ia airway, breathing and circulation; a parespiration artificielle et un massage tent airway is established, artificial ventilation is administered and external *Assistant professor, department of internal cardiac compression (ECC) is permedicine, University of Calgary; and consultant formed. These three steps can be unin cardiology, Foothills, Holy Cross and Calgary General hospitals dertaken by any trained person without Reprint requests to: Dr. A.S. Khan, Calgary equipment. Associate Clinic, 214 Sixth Ave. SW, Calgary, Further steps require the coordinated Alta. T2P ORi 162 CMA JOURNAL/JULY 23, 1977/VOL. 117
efforts of specially trained persons and the use of proper equipment. Step 4 includes general supportive measures. In step 5 the cardiac arrhythmia responsible for the arrest is diagnosed, and in step 6 it is treated. Step 7 consists of management after resuscitation. In some patients normal respiration may still be present, particularly very early after cardiac arrest, or they may take a few gasping breaths. Thus, although there is no palpable pulse, some perfusion of the tissues continues. This is true for some cases of ventricular tachycardia. For practical purposes treatment of these patients does not differ greatly from that of patients who have stopped breathing. The basic plan is meant primarily for managing cardiopulmonary arrest in patients with coronary heart disease. It can, however, be modified in cir(j. Define Problem:
Diagnosis
Salvageable Patient? © Precordial Thump Note time Call for aid
.Ji Supportive Treatment: 5 Cardiac Monitoring: ECG Diagnosis V-Line Bicarb. Blood gases Electrolytes lendotracheal intubationi l.l Definitive Treatment Ventricular Fibrillation
Ventricular Asystole
Profound Cardiovascular Collasse
Post Cardiac Resuscitation
FIG. 1-Management of cardiac arrest: seven steps of cardiopulmonary resusdtation.
cumstances such as drowning, accidental electrocution, acute pulmonary embolism, drug toxicity and cardiac trauma. Step 1. Defining the problem Diagnosing cardiac arrest
Diagnosis is simple if one looks carefully for the following signs of cardiac arrest: 1. Sudden loss of consciousness, often without warning. 2. Patient grey-white, motionless and flaccid. 3. No palpable carotid or femoral pulse. 4. Heart sounds absent. 5. Cessation of respiration if cardiac arrest is prolonged. 6. Pupils dilated within 45 to 60 seconds after heart stops. 7. Perhaps cyanosis. 8. Perhaps convulsions and twitching due to cerebral ischemia. Briefly stated, in a person who loses consciousness suddenly and in whom a carotid or femoral pulse is impalpable, CPR should be started immediately. Who should be resuscitated? 1. Unknown persons in whom a proper history is not available. 2. Persons in whom cardiac arrest has lasted for less than 10 minutes; prompt CPR may prevent irreversible damage of the brain and other vital organs. CPR should probably not be carried out in patients with known advanced terminal diseases such as cancer, and generally not in persons in whom cardiac arrest has lasted for more than 10 minutes before resuscitation is considered. Step 2.
able around the clock, should be well equipped and well organized, and must be run by trained personnel. D. Carry out immediate direct cardioversion if available. This frequently will re-establish an appropriate rhythm before step 3 becomes necessary. Step 3.
ABC of CPR1
Airway The patient's ability to breathe depends upon a patent airway. Without a patent airway, ventilation is impossible and the resulting hypoxemia may make the affected myocardium less responsive to ECC. In unconscious patients the head is usually flexed, the lower jaw drops backwards, and the tongue, which is attached to the floor of the mandible, tends to obstruct the pharynx. This has been called "swallowing of the tongue". To correct this, the following steps should be taken: Method: 1. Extend the head backwards (200 to 30.) (Fig. 3). 2. If the patient has dentures, remove them at once. 3. Apply suction to clear the air passage of vomitus and secretions.
Immediate measures
A. A precordial thump24 should be given to all patients in whom the arrest was witnessed or monitored electrocardiographically. This generates a small electrical stimulus in the heart and may terminate a cardiac arrhythmia. Method: 1. Deliver, as soon as possible, a single sharp blow over the midsternum with the fleshy portion of the fist held vertically, from about 20 to 30 cm above the chest (Fig. 2). 2. If there is no immediate response start CPR at once. B. Note the exact time of onset of cardiac arrest. C. Call for aid. Assistance can be provided by trained personnel, a fellow physician, a mobile coronary care unit5 or, in the hospital, the cardiac resuscitation team. The last two must be avail-
FIG. 2-Technique of precordial thump. Reprinted from the supplement to the Journal of the American Medical Association, Feb. 18, 1974, copyright 1974, the American Medical Association. Reprinted with permission from the American Heart Association (applies also to Figs. 3, 4 and
Breathing (ventilation) There are several ways to carry out artificial ventilation. Mouth-to-mouth resuscitation is described below because of its simplicity and efficiency, and the fact that ventilation is established immediately without any requirement for equipment. Method: 1. Extend the patient's head as far back as possible. Lift the neck towards you with one hand and gently depress the forehead with the other (Fig. 4). 2. Pinch the nostrils so as to obstruct the nasal passages. 3. Apply a clean handkerchief or gauze sponge over the mouth of the victim if available and desirable. 4. Open your mouth widely, take a deep breath, and make a tight seal around the patient's mouth with your mouth. 5. Blow into the patient's mouth. Initial ventilation should be in the form of four quick, full breaths without passive exhalation occurring. 6. Breathing should be forceful (less so for a child) and should cause the chest to rise. 7. Move your head away from the patient to let him exhale passively. 8. Repeat this cycle every 5 seconds when there is a second rescuer carrying out cardiac massage, or every 15 secconds if you are alone, so that you can carry out ECC as well. An oropharyngeal airway, endotracheal intubation, a bag-mask-valve unit and, for prolonged ventilation, a respirator may be used when available but only by experienced persons. The rescuer's expired air contains about 16% oxygen (Po2, approximately 115 mm Hg). Circulation (ECC)6 ECC results in propulsion of blood from the ventricles to the brain and other vital organs. Circulation can thus be adequately maintained until definitive treatment of cardiac arrest becomes available. It is estimated that, when properly performed, ECC can generate
5).
FIG. 3-Method of ensuring patency of airway.
FIG. 4-Technique of mouth-to-mouth ventilation.
CMA JOURNAL/JULY 23, 1977/VOL. 117 163
approximately 30 to 50%
of normal
resting cardiac output.7'8 Method: 1. Place the patient supine on a hard surface. 2. Apply the heel of one hand over the lower two thirds of the sternum, avoiding the xiphisternum and keeping the fingers free from the rib cage. Place the heel of the other hand over the first hand (Fig. 5). 3. Apply pressure vertically downwards, then relax. This process should be smooth and even, compression and relaxation being of equal magnitude. The heel of the hand should always touch the patient's chest. 4. Carry out ECC at a rate of 60 times per minute (two rescuers) or 80 times per minute (one rescuer). 5. EGG should depress the sternum 4 to 5 cm. 6. The ratio of EGG to ventilation should be 5:1 (two rescuers) or 15:2 (one rescuer). 7. Avoid complications that are due mainly to faulty technique, such as pressure on the xiphisternum (laceration of liver) or over the ribs (fracture of ribs and pneumothorax/ hemothorax).'10 8. Check the effectiveness of EGG by feeling the major arteries (carotid or femoral) and observing the pupils and the skin colour. In infants EGG can be carried out by depressing the midportion of the sternum 1 to 2 cm with two fingers of one hand. The rate of EGG should be greater for infants and small children - 80 to 100 times per minute - and so should the respiratory rate - one breath every 3 seconds. Step 4. General supportive measures 1. Keep a vein open with a 5% dextrose-in-water (D/W) solution. With a subclavian route a secure intravenous line can usually be established in these circumstances.
A AIRWAY
FIG. 5-Technique of external cardiac compression.
2. Gorrect metabolic acidosis by giving immediately sodium bicarbonate intravenously in doses of 50 mmol or one ampule. If circulation is not restored in 10 minutes, give another ampule of sodium bicarbonate. 3. Measure arterial blood gas tensions, pH and serum electrolyte concentrations. Give further bicarbonate solution only if it is indicated by these values. Excessive administration of bicarbonate solution can result in deleterious hyperosmolarity and metabolic alkalosis. 4. Administer oxygen with a bag and mask system or ventilator. This enhances arterial oxygenation in the cerebral and coronary circulation. 5. One rescuer should listen to each lung with a stethoscope to assess the efficiency of artificial ventilation. 6. Endotracheal intubation is preferable if available and carried out by a trained person. This will ensure a patent airway. Step 5. Diagnosis of arrhythmia When cardiac arrest occurs outside hospital, cardiac monitoring can be carried out with a battery-powered monitor/defibrillator. If facilities are available the rhythm can be transmitted to a central station in a hospital for interpretation and instruction regarding treatment. Gardiac monitoring will reveal the arrhythmia responsible for the cardiac arrest, which is usually ventricular fibrillation, asystole or electricalmechanical dissociation. Step 6.
Definitive treatment
Ventricular fibrillation In this situation the ventricular myocardium twitches in an uncoordinated manner, resulting in complete absence of cardiac output. Prompt, complete depolarization of all the cardiac muscles abolishes the chaotic, purposeless and ineffective electrical activity and allows one of the heart pacemakers, usually the sinoatrial node, to resume its pacemaker function and the heart to function in a coordinated and effective manner. Method: 1. Defibrillate the heart immediately with a direct-current shock of 400 W es. Maximum energy should always be used in patients weighing more than 50 kg. 2. Repeat in 10 seconds if the first attempt was ineffective. 3. Gontinue GPR in the periods between the defibrillation attempts and intracardiac injections of drugs. 4. If the fibrillation is of low amplitude and unresponsive to cardioversion,
164 GMA JOURNAL/JULY 23, 1977/VOL. 117
inject adrenalin, S to 10 mL of a 1:10 000 solution, into the heart. This may result in coarse fibrillation and thus permit successful cardioversion. The injection may be repeated every 3 to 5 minutes during cardiac arrest. To ensure that the injection is made within the heart cavity, withdraw blood into the syringe. 5. Defibrillate again. 6. Inject lidocaine (Xylocaine), 100 mg intravenously, and start an infusion of 4 mg/mm. 7. Administer sodium bicarbonate if indicated. 8. Defibrillate again. 9. Evaluate serum electrolytes and blood gases; search for and treat the basic cause of the arrest. Asystole With asystole the ventricles are essentially motionless, with no electrical or mechanical activity, and therefore there is no cardiac output. Method: 1. Inject adrenalin, S to 10 mL of a 1:10 000 solution, into the heart. 2. Administer sodium bicarbonate if indicated. 3. Give calcium chloride, 10 mL, intravenously or into the heart. Repeat every 3 to 5 minutes up to three times if indicated. 4. Install a transvenous or transthoracic pacemaker. 5. Evaluate serum electrolytes and blood gases; search for and treat the basic cause of the arrest. 6. When there is profound sinus bradycardia or bradycardia with atrioventricular block, give 0.5 to 1 mg of atropine sulfate intravenously. If there is no response, start an intravenous drip of isoproterenol, 1 to 2 mg in 500 mL of 5% D/W. Electrical-mechanical dissociation In electrical-mechanical dissociation effective cardiac output is lost despite a recordable cardiac rhythm. The diagnosis is established by the absence of a palpable carotid or femoral pulse or a readable systemic blood pressure with a cardiac rhythm demonstrated on the electrocardiographic monitor. Treatment should be similar to that of cardiogenic shock. Sometimes after defibrillation sinus rhythm is restored but mechanical recovery may take some time. In this situation EGG should be continued. Step 7. Management after resuscitation 1. Record vital signs - blood pressure, respiratory rate and temperature.
2. Record a 12-lead electrocardiogram; determine the cardiac rhythm and look for evidence of myocardial ischemia or infarction. Institute continuous electrocardiographic monitoring. 3. Make chest radiographs to assess (a) complications of the cardiac arrest or resuscitation measures, including aspiration pneumonia and hemopericardium, and (b) change in cardiac status, from heart size and pulmonary vasculature, particularly for evidence of left ventricular failure. 4. Examine the blood for hemoglobin concentration, leukocyte count, electrolyte concentrations, arterial blood gas tensions and pH. 5. Record intake and output of fluids to assess renal function. 6. Insert an endotracheal tube and use artificial ventilation if indicated. 7. Insert a nasogastric tube if there is gastric dilatation. 8. Evaluate the neurologic status. 9. Monitor left ventricular function by a Swan-Ganz catheter if indicated. 10. Develop a working diagnosis. When to stop CPR 1. If spontaneous electrical and mechanical activity of the heart does not occur after adequate CPR for 45 minutes. 2. When the pupils are persistently fixed and dilated but not because of drugs or hypothermia. 3. When blood has stagnated in the retinal vessels. 4. When there is persistent electrical-mechanical dissociation. I acknowledge with appreciation the useful suggestions from my colleagues. References 1. Standards for cardiopulmonary resuscitation (GPR) and emergency cardiac care (EGG). JAMA 227 (suppl): 833, 1974 2. HARWOOD-NASH DCF: Thumping of the precordium in ventricular fibrillation. S Air Med 1 36: 280, 1962
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GG: Closed-chest cardiac massage. JAMA 173: 1064, 1960 7. DEL GuaRcso LRM, COOMARA5WAMY RP, STATE D: Cardiac output and other hemodynamic variables during external cardiac massage in man. N Engi I Med 269: 1398, 1963
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4. PENNINOTON JE, TAYLOR J, LOWN B: Chest thump for reverting ventricular tachycardia.
N Engi I Med 283: 1192, 1970 5. PANTRIDGE JF, GEDDES JS: A mobile intensivecare unit in the management of myocardial infarction. Lancet 2: 271, 1967
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Comparative hemodynamics during open vs. closed cardiac resuscitation. JAMA 193: 93, 1965 9. FLETCHER GF: Hazardous complications of closed chest massage. Am Heart 1 77: 431, 1969 10. MORGAN R, GRACE WJ: Laceration of the liver from closed chest cardiac massage. N Engi I Med 265: 82, 1961
CMA JOURNAL/JULY 23, 1977/VOL. 117
165
Cardiac arrest is a common medical emergency. It usually occurs suddenly and results in irreversible brain damage unless prompt, effective treatment is instituted. One plan for dealing effectively with this emergency consists of seven steps of cardiopulmonary resuscitation: (1) establishing the diagnosis and deciding whether to resuscitate; (2) administering a precordial thump, noting the time and summoning aid; (3) establishing a patent airway and performing artificial ventilation and external cardiac compression; (4) instituting general supportive measures; (5) diagnosing the cardiac arrhythmia responsible for the arrest; (6) treating the arrhythmia; and (7) managing the patient after resuscitation.
cardiaque externe: (4) mettre en oeuvre des mesures g6nerales d'appoint; (5) diagnostiquer l'arythmie responsable de l'arr.t cardiaque; (6) traiter larythmie; et (7) prendre soin du patient apres reanimation.
Coronary heart disease has an epidemic prevalence in our society, and cardiac arrest has become a common medical emergency. There are two special features of this emergency; first, cardiac arrest usually occurs suddenly and unexpectedly; and, second, resultant brain damage is invariable and irreversible unless the circulation is restored within a few minutes. Well organized, disciplined management of the patient is necessary for his or her survival. This paper discusses such an approach seven steps to survival. Because cardiac arrest usually results L'arr6t cardiaque est une urgence in early cessation of normal respiration, medicale courante. Habituellement il steps taken to manage this emergency survient soudainement et entraine des involve the maintenance of both resdommages cer6braux irreversibles piration and circulation. Cardiopulmona moms qu'un traitement rapide et efficace ne soit instaure. Une procedure ary resuscitation (CPR), therefore, is an appropriate term. There are seven permettant de faire face de fa.on steps to CPR; they are illustrated in efficace a cette urgence consiste a Fig. 1. Step 1 is to establish the diagappliquer les sept mesures de reanimation cardiopulmonaire suivantes: nosis of cardiac arrest and to decide whether the patient should be resusci(1) poser le diagnostic et decider, sil y a lieu, de reanimer; (2) administrer tated. In Step 2 a precordial thump is un coup de poing vigoureux sur l.aire given in witnessed cases, the time of precordiale, enregistrer le temps et onset of cardiac arrest is noted and faire venir de l'aide; (3) assurer des aid is summoned. Step 3 is called the ABC of CPR1 because it deals with the voies aeriennes libres et donner Ia airway, breathing and circulation; a parespiration artificielle et un massage tent airway is established, artificial ventilation is administered and external *Assistant professor, department of internal cardiac compression (ECC) is permedicine, University of Calgary; and consultant formed. These three steps can be unin cardiology, Foothills, Holy Cross and Calgary General hospitals dertaken by any trained person without Reprint requests to: Dr. A.S. Khan, Calgary equipment. Associate Clinic, 214 Sixth Ave. SW, Calgary, Further steps require the coordinated Alta. T2P ORi 162 CMA JOURNAL/JULY 23, 1977/VOL. 117
efforts of specially trained persons and the use of proper equipment. Step 4 includes general supportive measures. In step 5 the cardiac arrhythmia responsible for the arrest is diagnosed, and in step 6 it is treated. Step 7 consists of management after resuscitation. In some patients normal respiration may still be present, particularly very early after cardiac arrest, or they may take a few gasping breaths. Thus, although there is no palpable pulse, some perfusion of the tissues continues. This is true for some cases of ventricular tachycardia. For practical purposes treatment of these patients does not differ greatly from that of patients who have stopped breathing. The basic plan is meant primarily for managing cardiopulmonary arrest in patients with coronary heart disease. It can, however, be modified in cir(j. Define Problem:
Diagnosis
Salvageable Patient? © Precordial Thump Note time Call for aid
.Ji Supportive Treatment: 5 Cardiac Monitoring: ECG Diagnosis V-Line Bicarb. Blood gases Electrolytes lendotracheal intubationi l.l Definitive Treatment Ventricular Fibrillation
Ventricular Asystole
Profound Cardiovascular Collasse
Post Cardiac Resuscitation
FIG. 1-Management of cardiac arrest: seven steps of cardiopulmonary resusdtation.
cumstances such as drowning, accidental electrocution, acute pulmonary embolism, drug toxicity and cardiac trauma. Step 1. Defining the problem Diagnosing cardiac arrest
Diagnosis is simple if one looks carefully for the following signs of cardiac arrest: 1. Sudden loss of consciousness, often without warning. 2. Patient grey-white, motionless and flaccid. 3. No palpable carotid or femoral pulse. 4. Heart sounds absent. 5. Cessation of respiration if cardiac arrest is prolonged. 6. Pupils dilated within 45 to 60 seconds after heart stops. 7. Perhaps cyanosis. 8. Perhaps convulsions and twitching due to cerebral ischemia. Briefly stated, in a person who loses consciousness suddenly and in whom a carotid or femoral pulse is impalpable, CPR should be started immediately. Who should be resuscitated? 1. Unknown persons in whom a proper history is not available. 2. Persons in whom cardiac arrest has lasted for less than 10 minutes; prompt CPR may prevent irreversible damage of the brain and other vital organs. CPR should probably not be carried out in patients with known advanced terminal diseases such as cancer, and generally not in persons in whom cardiac arrest has lasted for more than 10 minutes before resuscitation is considered. Step 2.
able around the clock, should be well equipped and well organized, and must be run by trained personnel. D. Carry out immediate direct cardioversion if available. This frequently will re-establish an appropriate rhythm before step 3 becomes necessary. Step 3.
ABC of CPR1
Airway The patient's ability to breathe depends upon a patent airway. Without a patent airway, ventilation is impossible and the resulting hypoxemia may make the affected myocardium less responsive to ECC. In unconscious patients the head is usually flexed, the lower jaw drops backwards, and the tongue, which is attached to the floor of the mandible, tends to obstruct the pharynx. This has been called "swallowing of the tongue". To correct this, the following steps should be taken: Method: 1. Extend the head backwards (200 to 30.) (Fig. 3). 2. If the patient has dentures, remove them at once. 3. Apply suction to clear the air passage of vomitus and secretions.
Immediate measures
A. A precordial thump24 should be given to all patients in whom the arrest was witnessed or monitored electrocardiographically. This generates a small electrical stimulus in the heart and may terminate a cardiac arrhythmia. Method: 1. Deliver, as soon as possible, a single sharp blow over the midsternum with the fleshy portion of the fist held vertically, from about 20 to 30 cm above the chest (Fig. 2). 2. If there is no immediate response start CPR at once. B. Note the exact time of onset of cardiac arrest. C. Call for aid. Assistance can be provided by trained personnel, a fellow physician, a mobile coronary care unit5 or, in the hospital, the cardiac resuscitation team. The last two must be avail-
FIG. 2-Technique of precordial thump. Reprinted from the supplement to the Journal of the American Medical Association, Feb. 18, 1974, copyright 1974, the American Medical Association. Reprinted with permission from the American Heart Association (applies also to Figs. 3, 4 and
Breathing (ventilation) There are several ways to carry out artificial ventilation. Mouth-to-mouth resuscitation is described below because of its simplicity and efficiency, and the fact that ventilation is established immediately without any requirement for equipment. Method: 1. Extend the patient's head as far back as possible. Lift the neck towards you with one hand and gently depress the forehead with the other (Fig. 4). 2. Pinch the nostrils so as to obstruct the nasal passages. 3. Apply a clean handkerchief or gauze sponge over the mouth of the victim if available and desirable. 4. Open your mouth widely, take a deep breath, and make a tight seal around the patient's mouth with your mouth. 5. Blow into the patient's mouth. Initial ventilation should be in the form of four quick, full breaths without passive exhalation occurring. 6. Breathing should be forceful (less so for a child) and should cause the chest to rise. 7. Move your head away from the patient to let him exhale passively. 8. Repeat this cycle every 5 seconds when there is a second rescuer carrying out cardiac massage, or every 15 secconds if you are alone, so that you can carry out ECC as well. An oropharyngeal airway, endotracheal intubation, a bag-mask-valve unit and, for prolonged ventilation, a respirator may be used when available but only by experienced persons. The rescuer's expired air contains about 16% oxygen (Po2, approximately 115 mm Hg). Circulation (ECC)6 ECC results in propulsion of blood from the ventricles to the brain and other vital organs. Circulation can thus be adequately maintained until definitive treatment of cardiac arrest becomes available. It is estimated that, when properly performed, ECC can generate
5).
FIG. 3-Method of ensuring patency of airway.
FIG. 4-Technique of mouth-to-mouth ventilation.
CMA JOURNAL/JULY 23, 1977/VOL. 117 163
approximately 30 to 50%
of normal
resting cardiac output.7'8 Method: 1. Place the patient supine on a hard surface. 2. Apply the heel of one hand over the lower two thirds of the sternum, avoiding the xiphisternum and keeping the fingers free from the rib cage. Place the heel of the other hand over the first hand (Fig. 5). 3. Apply pressure vertically downwards, then relax. This process should be smooth and even, compression and relaxation being of equal magnitude. The heel of the hand should always touch the patient's chest. 4. Carry out ECC at a rate of 60 times per minute (two rescuers) or 80 times per minute (one rescuer). 5. EGG should depress the sternum 4 to 5 cm. 6. The ratio of EGG to ventilation should be 5:1 (two rescuers) or 15:2 (one rescuer). 7. Avoid complications that are due mainly to faulty technique, such as pressure on the xiphisternum (laceration of liver) or over the ribs (fracture of ribs and pneumothorax/ hemothorax).'10 8. Check the effectiveness of EGG by feeling the major arteries (carotid or femoral) and observing the pupils and the skin colour. In infants EGG can be carried out by depressing the midportion of the sternum 1 to 2 cm with two fingers of one hand. The rate of EGG should be greater for infants and small children - 80 to 100 times per minute - and so should the respiratory rate - one breath every 3 seconds. Step 4. General supportive measures 1. Keep a vein open with a 5% dextrose-in-water (D/W) solution. With a subclavian route a secure intravenous line can usually be established in these circumstances.
A AIRWAY
FIG. 5-Technique of external cardiac compression.
2. Gorrect metabolic acidosis by giving immediately sodium bicarbonate intravenously in doses of 50 mmol or one ampule. If circulation is not restored in 10 minutes, give another ampule of sodium bicarbonate. 3. Measure arterial blood gas tensions, pH and serum electrolyte concentrations. Give further bicarbonate solution only if it is indicated by these values. Excessive administration of bicarbonate solution can result in deleterious hyperosmolarity and metabolic alkalosis. 4. Administer oxygen with a bag and mask system or ventilator. This enhances arterial oxygenation in the cerebral and coronary circulation. 5. One rescuer should listen to each lung with a stethoscope to assess the efficiency of artificial ventilation. 6. Endotracheal intubation is preferable if available and carried out by a trained person. This will ensure a patent airway. Step 5. Diagnosis of arrhythmia When cardiac arrest occurs outside hospital, cardiac monitoring can be carried out with a battery-powered monitor/defibrillator. If facilities are available the rhythm can be transmitted to a central station in a hospital for interpretation and instruction regarding treatment. Gardiac monitoring will reveal the arrhythmia responsible for the cardiac arrest, which is usually ventricular fibrillation, asystole or electricalmechanical dissociation. Step 6.
Definitive treatment
Ventricular fibrillation In this situation the ventricular myocardium twitches in an uncoordinated manner, resulting in complete absence of cardiac output. Prompt, complete depolarization of all the cardiac muscles abolishes the chaotic, purposeless and ineffective electrical activity and allows one of the heart pacemakers, usually the sinoatrial node, to resume its pacemaker function and the heart to function in a coordinated and effective manner. Method: 1. Defibrillate the heart immediately with a direct-current shock of 400 W es. Maximum energy should always be used in patients weighing more than 50 kg. 2. Repeat in 10 seconds if the first attempt was ineffective. 3. Gontinue GPR in the periods between the defibrillation attempts and intracardiac injections of drugs. 4. If the fibrillation is of low amplitude and unresponsive to cardioversion,
164 GMA JOURNAL/JULY 23, 1977/VOL. 117
inject adrenalin, S to 10 mL of a 1:10 000 solution, into the heart. This may result in coarse fibrillation and thus permit successful cardioversion. The injection may be repeated every 3 to 5 minutes during cardiac arrest. To ensure that the injection is made within the heart cavity, withdraw blood into the syringe. 5. Defibrillate again. 6. Inject lidocaine (Xylocaine), 100 mg intravenously, and start an infusion of 4 mg/mm. 7. Administer sodium bicarbonate if indicated. 8. Defibrillate again. 9. Evaluate serum electrolytes and blood gases; search for and treat the basic cause of the arrest. Asystole With asystole the ventricles are essentially motionless, with no electrical or mechanical activity, and therefore there is no cardiac output. Method: 1. Inject adrenalin, S to 10 mL of a 1:10 000 solution, into the heart. 2. Administer sodium bicarbonate if indicated. 3. Give calcium chloride, 10 mL, intravenously or into the heart. Repeat every 3 to 5 minutes up to three times if indicated. 4. Install a transvenous or transthoracic pacemaker. 5. Evaluate serum electrolytes and blood gases; search for and treat the basic cause of the arrest. 6. When there is profound sinus bradycardia or bradycardia with atrioventricular block, give 0.5 to 1 mg of atropine sulfate intravenously. If there is no response, start an intravenous drip of isoproterenol, 1 to 2 mg in 500 mL of 5% D/W. Electrical-mechanical dissociation In electrical-mechanical dissociation effective cardiac output is lost despite a recordable cardiac rhythm. The diagnosis is established by the absence of a palpable carotid or femoral pulse or a readable systemic blood pressure with a cardiac rhythm demonstrated on the electrocardiographic monitor. Treatment should be similar to that of cardiogenic shock. Sometimes after defibrillation sinus rhythm is restored but mechanical recovery may take some time. In this situation EGG should be continued. Step 7. Management after resuscitation 1. Record vital signs - blood pressure, respiratory rate and temperature.
2. Record a 12-lead electrocardiogram; determine the cardiac rhythm and look for evidence of myocardial ischemia or infarction. Institute continuous electrocardiographic monitoring. 3. Make chest radiographs to assess (a) complications of the cardiac arrest or resuscitation measures, including aspiration pneumonia and hemopericardium, and (b) change in cardiac status, from heart size and pulmonary vasculature, particularly for evidence of left ventricular failure. 4. Examine the blood for hemoglobin concentration, leukocyte count, electrolyte concentrations, arterial blood gas tensions and pH. 5. Record intake and output of fluids to assess renal function. 6. Insert an endotracheal tube and use artificial ventilation if indicated. 7. Insert a nasogastric tube if there is gastric dilatation. 8. Evaluate the neurologic status. 9. Monitor left ventricular function by a Swan-Ganz catheter if indicated. 10. Develop a working diagnosis. When to stop CPR 1. If spontaneous electrical and mechanical activity of the heart does not occur after adequate CPR for 45 minutes. 2. When the pupils are persistently fixed and dilated but not because of drugs or hypothermia. 3. When blood has stagnated in the retinal vessels. 4. When there is persistent electrical-mechanical dissociation. I acknowledge with appreciation the useful suggestions from my colleagues. References 1. Standards for cardiopulmonary resuscitation (GPR) and emergency cardiac care (EGG). JAMA 227 (suppl): 833, 1974 2. HARWOOD-NASH DCF: Thumping of the precordium in ventricular fibrillation. S Air Med 1 36: 280, 1962
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GG: Closed-chest cardiac massage. JAMA 173: 1064, 1960 7. DEL GuaRcso LRM, COOMARA5WAMY RP, STATE D: Cardiac output and other hemodynamic variables during external cardiac massage in man. N Engi I Med 269: 1398, 1963
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4. PENNINOTON JE, TAYLOR J, LOWN B: Chest thump for reverting ventricular tachycardia.
N Engi I Med 283: 1192, 1970 5. PANTRIDGE JF, GEDDES JS: A mobile intensivecare unit in the management of myocardial infarction. Lancet 2: 271, 1967
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Comparative hemodynamics during open vs. closed cardiac resuscitation. JAMA 193: 93, 1965 9. FLETCHER GF: Hazardous complications of closed chest massage. Am Heart 1 77: 431, 1969 10. MORGAN R, GRACE WJ: Laceration of the liver from closed chest cardiac massage. N Engi I Med 265: 82, 1961
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