The European Resuscitation Council provides guidelines for basic and advanced life support (Figures 32.1 and 32.2).
BASIC LIFE SUPPORT
When a person is found to have collapsed, make a quick check to ensure that no live power lines are in the immediate vicin- ity. Ask them, ‘Are you all right?’, and if there is no response, call for help. Do not move the patient if neck trauma is sus- pected. Otherwise roll them on their back (on a firm surface if possible) and loosen the clothing around the throat. Assess airway, breathing and circulation (ABC).
Tilt the head and lift the chin, and sweep an index finger through the mouth to clear any obstruction (e.g. dentures).
Tight-fitting dentures need not be removed and may help to maintain the mouth sealed during assisted ventilation.
If the patient is not breathing spontaneously, start mouth- to-mouth (or, if available, mouth-to-mask) ventilation. Inflate the lungs with two expirations (over about 2 seconds each)
CARDIOPULMONARYRESUSCITATION ANDCARDIACARREST: BASIC ANDADVANCEDLIFESUPPORT 219
Table 32.1:Anti-dysrhythmic drugs: the Vaughan–Williams/Singh classification
Class Example Mode of action Comment
I Rate-dependent block of Naconductance
a Quinidine Intermediate kinetics between b and c Prolong cardiac action potential Procainamide
Disopyramide
b Lidocaine Rapid dissociation from Nachannel Useful in ventricular tachydysrhythmias Mexiletine
c Flecainide Slow dissociation from Nachannel Prolong His–Purkinje conduction: worsen
Propafenone survival in some instances
II Atenolol Beta blockers: slow pacemaker Improve survival following myocardial
depolarization infarction
III Amiodarone Prolong cardiac action potential Effective in supra-, as well as ventricular
Sotalol tachydysrhythmias. Predispose to torsades de
Dofetilide pointes (a form of ventricular tachycardia)
Ibutilide
IV Verapamil Calcium antagonists: block cardiac Used in prophylaxis of recurrent SVT. Largely Diltiazem voltage-dependent Ca2conductance superseded by adenosine for treating acute
attacks. Negatively inotropic
Table 32.2:Drugs/ions not classified primarily as anti-dysrhythmic, but used to treat important dysrhythmias
Digoxin (rapid atrial fibrillation)
Atropine (symptomatic sinus bradycardia) Adenosine (supraventricular tachycardia) Adrenaline (cardiac arrest)
Calcium chloride (ventricular tachycardia caused by hyperkalaemia)
Magnesium chloride (ventricular fibrillation)
Unresponsive?
Shout for help
Open airway
Not breathing normally?
30 chest compressions 2 rescue breaths
Check pulse
No pulse?
Precordial thump if arrest witnessed
2 breaths 30 compressions
Continue until breathing and pulse restored of emergency services arrive Figure 32.1:Adult basic life support.
and check that the chest falls between respirations. If avail- able, 100% oxygen should be used.
Check for a pulse by feeling carefully for the carotid or femoral artery before diagnosing cardiac arrest. If the arrest has been witnessed, administer a single thump to the pre- cordium. If no pulse is palpable, start cardiac compression over the middle of the lower half of the sternum at a rate of 100 per minute and an excursion of 4–5 cm. Allow two breaths per 30 chest compressions. Drugs can cause fixed dilated pupils, so do not give up on this account if drug overdose is a possibility. Hypothermia is protective of tissue function, so do not abandon your efforts too readily if the patient is severely
hypothermic (e.g. after being pulled out of a freezing lake).
Mobilize facilities for active warming.
ADVANCED LIFE SUPPORT
Basic cardiopulmonary resuscitation is continued throughout as described above, and it should not be interrupted for more than 10 seconds (except for palpation of a pulse or for administration of DC shock, when personnel apart from the operator must stand well back). ‘Advanced’ life support refers to the treatment of cardiac dysrhythmias in the setting of cardiopulmonary 220 CARDIAC DYSRHYTHMIAS
*Reversible causes
Hypoxia Tension pneumothorax
Hypovolaemia Cardiac tamponade
Hypo/hyperkalaemia/other metabolic disturbance Toxins
Hypothermia Thrombosis (coronary or pulmonary)
Unresponsive?
Open airway look for signs of life
Call resuscitation team CPR 30:2
Until defibrillator/monitor attached
Assess rhythm
Shockable (VF/pulseless VT)
Non-shockable (pulseless electrical
activity/asystole)
1 Shock 150–360 J biphasic or
360 J monophasic
Immediately resume:
CPR 30:2 for 2 min
Immediately resume:
CPR 30:2 for 2 min During CPR:
• Correct reversible causes*
• Check electrode position and contact
• Attempt /verify:
i.v. access
airway and oxygen
• Give uninterrupted
compressions when airway secure
• Give adrenaline every 3–5 mins
• Consider: amiodarone, atropine, magnesium
Figure 32.2:Adult advanced life support.
(Redrawn with permission from the European Resuscitation Council Guidelines, 2005.)
arrest. The electrocardiogram is likely to show asystole, severe bradycardia or ventricular fibrillation. Occasionally narrow complexes are present, but there is no detectable cardiac output (‘electromechanical dissociation’). The doses given below are for an average-sized adult. During the course of an arrest, other rhythm disturbances are frequently encountered (e.g. sinus bradycardia) and these are considered in the next section on other specific dysrhythmias. If intravenous access cannot be established, the administration of double doses of adrenaline (or other drugs as appropriate) via an endotracheal tube can be life-saving.
ASYSTOLE
Make sure ECG leads are attached properly and that the rhythm is not ventricular fibrillation, which is sometimes mis- taken for asystole if the fibrillation waves are of low amplitude.
If there is doubt, DC counter-shock (200J). Once the diagnosis is definite, administer adrenaline(otherwise known as epineph- rine), 1 mg intravenously, followed by atropine, 3 mg intra- venously. Further doses of adrenaline1 mg can be given every three minutes as necessary. If P-waves (or other electrical activ- ity) are present, but the intrinsic rate is slow or there is high grade heart block, consider pacing.
VENTRICULAR FIBRILLATION
The following sequence is used until a rhythm (hopefully sinus) is achieved that sustains a cardiac output. DC counter- shock (200J) is delivered as soon as a defibrillator is available and then repeated (200J, then 360J) if necessary, followed by adrenaline, 1 mg intravenously, and further defibrillation (360J) repeated as necessary. Consider varying the paddle positions and also consider amiodarone300 mg, if ventricular fibrillation persists. A further dose of 150 mg may be required in refractory cases, followed by an infusion of 1 mg/min for six hours and then 0.5 mg/min, to a maximum of 2 g.
Magnesium (8 mmol) is recommended for refractory VF if there is a suspicion of hypomagnesaemia, e.g. patients on potassium-losing diuretics. Lidocaineandprocainamide are alternatives if amiodarone is not available, but should not be given in addition to amiodarone. During prolonged resuscitation, adrenaline (1 mg i.v.) every three minutes is recommended.
ELECTROMECHANICAL DISSOCIATION
When the pulse is absent, but the ECG shows QRS complexes, this is known as electromechanical dissociation. It may be the result of severe global damage to the left ventricle, in which case the outlook is bleak. If it is caused by some potentially reversible pathology such as hypovolaemia, pneumothorax, pericardial tamponade or pulmonary embolus, volume replacement or other specific measures may be dramatically effective. If pulseless electrical activity is associated with a bradycardia, atropine, 3 mg intravenously or 6 mg via the endotracheal tube, should be given. High-dose adrenalineis no longer recommended in this situation.