European Resuscitation Council Guidelines for Resuscitation 2010 ...
European Resuscitation Council Guidelines for Resuscitation 2010 ...
European Resuscitation Council Guidelines for Resuscitation 2010 ...
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1318 C.D. Deakin et al. / <strong>Resuscitation</strong> 81 (<strong>2010</strong>) 1305–1352<br />
The tubes are sized in millimetres according to their internal<br />
diameter, and the length increases with diameter. The traditional<br />
methods of sizing a nasopharyngeal airway (measurement against<br />
the patient’s little finger or anterior nares) do not correlate with the<br />
airway anatomy and are unreliable. 326 Sizes of 6–7 mm are suitable<br />
<strong>for</strong> adults. Insertion can cause damage to the mucosal lining of the<br />
nasal airway, resulting in bleeding in up to 30% of cases. 327 If the<br />
tube is too long it may stimulate the laryngeal or glossopharyngeal<br />
reflexes to produce laryngospasm or vomiting.<br />
Oxygen<br />
During CPR, give oxygen whenever it is available. There are no<br />
data to indicate the optimal arterial blood oxygen saturation (SaO 2 )<br />
during CPR. There are animal data 328 and some observational clinical<br />
data indicating an association between high SaO 2 after ROSC and<br />
worse outcome. 329 A standard oxygen mask will deliver up to 50%<br />
oxygen concentration, providing the flow of oxygen is high enough.<br />
A mask with a reservoir bag (non-rebreathing mask), can deliver<br />
an inspired oxygen concentration of 85% at flows of 10–15 l min −1 .<br />
Initially, give the highest possible oxygen concentration. As soon<br />
as the arterial blood oxygen saturation can be measured reliably,<br />
by pulse oximeter (SpO 2 ) or arterial blood gas analysis, titrate the<br />
inspired oxygen concentration to achieve an arterial blood oxygen<br />
saturation in the range of 94–98%.<br />
Suction<br />
Use a wide-bore rigid sucker (Yankauer) to remove liquid (blood,<br />
saliva and gastric contents) from the upper airway. Use the sucker<br />
cautiously if the patient has an intact gag reflex; pharyngeal stimulation<br />
can provoke vomiting.<br />
Ventilation<br />
Provide artificial ventilation as soon as possible <strong>for</strong> any patient in<br />
whom spontaneous ventilation is inadequate or absent. Expired air<br />
ventilation (rescue breathing) is effective, but the rescuer’s expired<br />
oxygen concentration is only 16–17%, so it must be replaced as soon<br />
as possible by ventilation with oxygen-enriched air. The pocket<br />
resuscitation mask is used widely. It is similar to an anaesthetic<br />
facemask, and enables mouth-to-mask ventilation. It has a unidirectional<br />
valve, which directs the patient’s expired air away from<br />
the rescuer. The mask is transparent so that vomit or blood from the<br />
patient can be seen. Some masks have a connector <strong>for</strong> the addition<br />
of oxygen. When using masks without a connector, supplemental<br />
oxygen can be given by placing the tubing underneath one side and<br />
ensuring an adequate seal. Use a two-hand technique to maximise<br />
the seal with the patient’s face (Fig. 4.6).<br />
High airway pressures can be generated if the tidal volume or<br />
inspiratory flow is excessive, predisposing to gastric inflation and<br />
subsequent risk of regurgitation and pulmonary aspiration. The<br />
possibility of gastric inflation is increased by:<br />
• malalignment of the head and neck, and an obstructed airway;<br />
• an incompetent oesophageal sphincter (present in all patients<br />
with cardiac arrest);<br />
• a high airway inflation pressure.<br />
Conversely, if inspiratory flow is too low, inspiratory time will<br />
be prolonged and the time available to give chest compressions<br />
is reduced. Deliver each breath over approximately 1 s and transfer<br />
a volume that corresponds to normal chest movement; this<br />
represents a compromise between giving an adequate volume,<br />
minimising the risk of gastric inflation, and allowing adequate time<br />
<strong>for</strong> chest compressions. During CPR with an unprotected airway,<br />
Fig. 4.6. Mouth-to-mask ventilation.<br />
give two ventilations after each sequence of 30 chest compressions.<br />
Self-inflating bag<br />
The self-inflating bag can be connected to a facemask, tracheal<br />
tube or supraglottic airway device (SAD). Without supplemental<br />
oxygen, the self-inflating bag ventilates the patient’s lungs with<br />
ambient air (21% oxygen). The delivered oxygen concentration can<br />
be increased to about 85% by using a reservoir system and attaching<br />
oxygen at a flow 10 l min −1 .<br />
Although the bag-mask device enables ventilation with high<br />
concentrations of oxygen, its use by a single person requires considerable<br />
skill. When used with a face mask, it is often difficult to<br />
achieve a gas-tight seal between the mask and the patient’s face,<br />
and to maintain a patent airway with one hand while squeezing<br />
the bag with the other. 330 Any significant leak will cause hypoventilation<br />
and, if the airway is not patent, gas may be <strong>for</strong>ced into<br />
the stomach. 331,332 This will reduce ventilation further and greatly<br />
increase the risk of regurgitation and aspiration. 333 Cricoid pressure<br />
can reduce this risk 334,335 but requires the presence of a trained<br />
assistant. Poorly applied cricoid pressure may make it more difficult<br />
to ventilate the patient’s lungs. 334,336–339<br />
The two-person technique <strong>for</strong> bag-mask ventilation is preferable<br />
(Fig. 4.7). One person holds the facemask in place using a jaw<br />
thrust with both hands, and an assistant squeezes the bag. In this<br />
way, a better seal can be achieved and the patient’s lungs can be<br />
ventilated more effectively and safely.<br />
Once a tracheal tube or a supraglottic airway device has been<br />
inserted, ventilate the lungs at a rate of 10 breaths min −1 and continue<br />
chest compressions without pausing during ventilations. The<br />
laryngeal seal achieved with a supraglottic airway device is unlikely<br />
to be good enough to prevent at least some gas leaking when inspiration<br />
coincides with chest compressions. Moderate gas leakage is<br />
acceptable, particularly as most of this gas will pass up through the<br />
patient’s mouth. If excessive gas leakage results in inadequate ventilation<br />
of the patient’s lungs, chest compressions will have to be