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Airway management and ventilation
Airway management and ventilation
Patients requiring resuscitation often have anobstructed airway, usually secondary to loss of
consciousness, but occasionally it may be the primarycause of cardiorespiratory arrest .
Obstruction of the airway may be partial or complete.It may occur at any level, from the nose
and mouth down to the trachea .
Oxigen Mask
Recognition of airway obstruction
The ‘look, listen and feel’ approach is a simple,systematic method of detecting airway obstruction.
• Look for chest and abdominal movements.• Listen and feel for airflow at the mouth and nose.Once any degree of of obstruction is recognised ,
aply first basic air management : head tilt and chin lift , an alternative is jaw trust .
Oropharyngeal airways
An estimate of the size requiredis obtained by selecting an airway with a length
corresponding to the vertical distance between the patient’s incisors and the angle of the jaw .
If the glossopharyngeal and laryngeal reflexesare present, vomiting or laryngospasm may be
caused by inserting an oropharyngeal airway; thus,insertion should be attempted only in comatose
patients.
Nasopharyngeal airways
In patients who are notdeeply unconscious, a nasopharyngeal airway istolerated better than an oropharyngeal airway.
Sizes of 6—7mm are suitable foradults. Insertion can cause damage to the mucosal
lining of the nasal airway, with bleeding in up to30% of cases .
Oxygen
Give oxygen whenever it is available. A standard oxygen mask will deliver up to 50% oxygen
concentration, providing the flow of oxygenis high enough.
A mask with a reservoir bag (nonrebreathingmask), can deliver an inspired oxygen
concentration of 85% at flows of 10—15 l min
Suction
Use a wide-bore rigid sucker (Yankauer) to removeliquid (blood, saliva and gastric contents) from
the upper airway.The sucker can provoke vomiting.
The pocket resuscitation mask
It is similar to an anaesthetic facemask, and enables mouth-to-mask ventilation.
It has a unidirectional valve, which directs thepatient’s expired air away from the rescuer .
Use a two-hand technique to maximise the seal with the patient’s face .
Give two ventilations after each sequence of30 chest compressions.
Self-inflating bag
Without supplemental oxygen, the self-inflating bag ventilatesthe patient’s lungs with ambient air (21% oxygen).This can be increased to about 45% by attachingoxygen directly to the bag. If a reservoir systemis attached and the oxygen flow is increased to
approximately 10 l min, an inspired oxygen concentrationof approximately 85% can be achieved. Try to achieve a
good seal between the mask and the patient’sface, and to maintain a patent airway with one hand
while squeezing the bag with the other hand .
Laryngeal mask airway (LMA)
It is a wide-bore tube with an elliptical inflated cuff designed to seal around the laryngeal opening . Ventilation using the LMA is more efficient and
easier than with a bag-mask. Disadvantages of the LMA are the increased risk of aspiration and inability to
provide adequate ventilation in patients with low lung and/or chestwall compliance , in comparision with
endotracheal intubation .
I-Gel
The Combitube
It is a double-lumen tube introducedblindly over the tongue, and provides a
route for ventilation whether the tube has passedinto the oesophagus or the trachea .
Tracheal intubation
Tracheal intubation is the optimal method of providingand maintaining a clear and secure airway . The
advantage is :maintenance of a patent airway, which is protected from aspiration
of gastric contents or blood from the oropharynx;ability to provide an adequate tidal volume reliablyeven when chest compressions are uninterrupted;the potential to free the rescuer’s hands for othertasks; the ability to suction airway secretions; and
the provision of a route for giving drugs.
Tracheal intubation
No intubation attempt should take longer than 30 s; if intubation
has not been achieved after this time, recommencebag-mask ventilation. After intubation, tube placementmust be confirmed and the tube secured adequately .
Unrecognised oesophageal intubation is the mostserious complication . Primary assessment
includes observation of chest expansion bilaterally,auscultation over the lung fields bilaterally in the axillae
(breath sounds should be equal and adequate) and over the epigastrium (breath sounds should not be heard) , and
secondary use an exhaled carbon-dioxide detection device .
Tracheal intubation
Cricoid pressureDuring bag-mask ventilation and attempted intubation,cricoid pressure applied by a trained assistant should
prevent passive regurgitation of gastric contents and the consequent risk of pulmonary aspiration.
Securing the tracheal tubeAccidental dislodgement of a tracheal tube can occur at any
time, but may be more likely during resuscitation and during transport. Use either conventional tapes or ties, or
purpose-made tracheal tube holders.
Cricothyroidotomy
Occasionally, it will be impossible to ventilate anapnoeic patient with a bag-mask, or to pass a tracheal
tube or alternative airway device (patients with extensive facial trauma or laryngeal obstruction due to oedema or foreign
material).Needle cricothyroidotomy is a much more temporary procedure
providingonly short-term oxygenation. Surgical cricothyroidotomy provides
a definitive airway that can be used to ventilate thepatient’s lungs until semi-elective intubation or tracheostomy
is performed .
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