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 .