Choking
CPR 30:2 with oxygen and airway adjuncts
Apply pads/monitor Attempt defibrillation
if appropriate
Assess ABCDE Recognise and treat Oxygen, monitoring,
IV access
Call resuscitation team if appropriate
Adult basic life support
Airway and ventilation
Usually in the ED, advanced airway techniques will be used from the outset. If basic techniques are used (Fig. 2.4 ):
• With the patient on his/her back, open the airway by tilting the head and lifting the chin. (Use jaw thrust instead if neck trauma suspected.)
• Remove any visible obstructions from the mouth, but leave well-fi tting dentures in place.
• Aim for each breath to last 8 1sec and make the chest rise. After each breath, maintain the head tilt/chin lift, take your mouth away from the patient’s and watch for the chest to fall as the air comes out.
1 Colquhoun MC et al . (1999). ABC of Resuscitation , 4th edition. BMJ Books, London.
Fig. 2.4 Mouth to mouth ventilation. 1
49
ADULT BASIC LIFE SUPPORT
Technique for chest compression (Fig. 2.5 )
• Place the heel of one hand over the middle of the lower half of the patient’s sternum, with the other hand on top. Extend or interlock the fi ngers of both hands and lift them to avoid applying pressure to the patient’s ribs.
• Positioned above the patient’s chest and with arms straight, press down to depress the sternum 5–6cm.
• Release all the pressure and repeat at a rate of 100–120/min.
• Compression and release phases should take the same time.
• Use a ratio of 30 chest compressions to 2 ventilations (30:2).
• Aim to change the person providing chest compressions every 2 min, but ensure that this is achieved without causing signifi cant pauses.
1 Colquhoun MC et al . (1999). ABC of Resuscitation , 4th edition. BMJ Books, London.
Fig. 2.5 Chest compressions. 1
Cardiac arrest management
Defi brillation
• Most survivors have an initial rhythm of VF/VT. The treatment for this is defi brillation. With time, the chances of successful defi brillation and survival d dramatically. Adhesive defi brillator pads have replaced manual paddles in most hospitals. Place one pad to the right of the upper sternum below the clavicle, the other in mid-axillary line level with V 6 ECG electrode position. Avoid placement over the female breast. To avoid problems with pacemakers, keep pads > 15cm away from them.
• With biphasic defi brillators, use shock energy of 150J, for (mostly older) monophasic defi brillators, select 360J energy.
• Plan for chest compressions to be as continuous as possible, with minimal delays. Having paused briefl y to assess the rhythm, recommence compressions until the defi brillator is charged. Pause briefl y to deliver a shock (removing O 2 sources and transdermal glycerol trinitrate (GTN) patches), then immediately restart CPR with 30:2 compressions:
ventilation, and continue for 2min before reassessing the rhythm or feeling for a pulse.
• In monitored patients with pulseless ventricular tachycardia/fi brillation (VT/VF) where defi brillation is not immediately available, give a single precordial thump . With a tightly clenched fi st, deliver one direct blow from a height of 820cm to the lower half of the sternum.
Airway management
Techniques for securing the airway, providing oxygenation and ventilation are covered in b Airway obstruction: basic measures, p.324. Although tracheal intubation has long been considered to be the gold standard defi nitive airway, only attempt this if suitably experienced. Laryngeal mask airway is a readily available, rapid alternative, which is easy to insert.
Whatever method is used, aim to ventilate (preferably with 100 % O 2 ) using an inspiratory time of 1sec, a volume suffi cient to produce a normal rise of the chest, at a rate of 10/min. For patients with tracheal tubes or laryngeal mask airways, ventilate without interrupting chest compressions, which should be continuous (except for defi brillation or pulse checks as appropriate).
End-tidal CO 2 monitoring is very useful to confi rm correct tracheal tube placement and indirectly measure cardiac output during CPR.
Drugs
There is little evidence that any drug improves outcome. Central venous cannulation is diffi cult, has risks and interrupts CPR. Peripheral access is easy and quick. Having given a peripheral IV drug, give a 20mL saline bolus and elevate the limb for 10–20sec. If IV access is impossible, consider intraosseous route ( b p.640). It is no longer recommended for any drugs to be given by tracheal tube. Similarly, do not attempt intracardiac injections.
The fi rst drug used in cardiac arrest (after oxygen) is adrenaline. In the case of VF/VT, administer adrenaline after three shocks, whereas in asystole/PEA, give it as soon as possible (see b Adult life support algorithm, p.52).
51
CARDIAC ARREST MANAGEMENT
Non-shockable rhythms: PEA and asystole
Pulseless electrical activity ( PEA ) is the clinical situation of cardiac arrest with an ECG trace compatible with cardiac output. PEA may be caused by:
• Failure of the normal cardiac pumping mechanism (eg massive MI, drugs such as B -blockers, Ca 2 + antagonists or electrolyte disturbance, eg hypokalaemia, hyperkalaemia).
• Obstruction to cardiac fi lling or output (eg tension pneumothorax, pericardial tamponade, myocardial rupture, pulmonary embolism (PE), prosthetic heart valve occlusion, and hypovolaemia).
Prompt and appropriate correction of these can result in survival. Remember potentially reversible causes as the 4H’s and 4T’s (see Table 2.1 ).
Asystole is the absence of cardiac (particularly ventricular) electrical activity.
If unsure if the rhythm is asystole or fi ne VF, continue chest compressions and ventilation in an attempt to increase the amplitude and frequency of VF, and make it more susceptible to defi brillation.
Length of resuscitation
The duration of the resuscitation attempt depends upon the nature of the event, the time since the onset, and the estimated prospects for a successful outcome. In general, continue resuscitation while VF/pulseless VT persists, always provided that it was initially appropriate to commence resuscitation. If VF persists despite repeated defi brillation, try changing pad position or defi brillator.
Asystole unresponsive to treatment and arrests which last > 1hr are rarely associated with survival. However, exceptions occur — particularly in younger patients, hypothermia, near drowning, and drug overdose.
Mechanical CPR
There are several devices available that can provide mechanical CPR.
These include the ‘AutoPulse’ circumferential load-distributing band chest compression device (comprising a pneumatically actuated constricting band and backboard) and the ‘LUCAS’ gas-driven sternal compression device (with accompanying suction cup to provide active decompression). Widespread use of these devices may develop if early encouraging results are confi rmed by larger studies. Mechanical CPR is potentially very useful in situations where the resuscitation attempt is prolonged (eg cardiac arrest associated with hypothermia, poisoning or following fi brinolytic treatment for PE), ensuring consistent CPR over a long period of time and freeing up an additional member of the team.
Table 2.1
4H’s 4T’s
Hypoxia Tension pneumothorax
Hypovolaemia Tamponade (cardiac)
Hyper/hypokalaemia/metabolic disorders
Toxic substances (eg overdose)
Hypothermia Thromboembolic/mechanical obstruction
Advanced life support algorithm 1
1 Resuscitation Council (UK) guidelines , 2010 ( www.resus.org.uk ).
Fig. 2.6
CPR 30:2 Attach defibrillator/monitor
Minimise interruptions
Shockable (VF/Pulseless VT)
1 Shock
During CPR
•Ensure high-quality CPR: rate, depth, recoil
•Plan actions before interrupting CPR
•Give oxygen
•Consider advanced airway and capnography
•Continuous chest compressions when advanced airway in place
•Vascular access (intravenous, intraosseous)
•Give adrenaline every 3–5 min
•Correct reversible causes
Reversible causes
•Hypoxia
•Hypovolaemia
•Hypo-/hyperkalaemia/metabolic
•Hypothermia
•Thrombosis - coronary or pulmonary
•Tamponade - cardiac
•Toxins
•Tension pneumothorax
Non-Shockable (PEA/Asystole) Call resuscitation team Unresponsive?
Not breathing or only occasional gasps
Return of spontaneous
circulation
Immediately resume CPR for 2 min Minimise interruptions
Immediately resume CPR for 2 min Minimise interruptions Immediate post cardiac
arrest treatment
•Use ABCDE approach
•Controlled oxygenation and ventilation
•12-lead ECG
•Treat precipitating cause
•Temperature control/
therapeutic hypothermia Assess rhythm
53
NOTES ON USING THE ADVANCED LIFE SUPPORT ALGORITHM