Trauma Procedures
Contents:
Surgical Airway : Cricothyroidotomy
The essential indication for a surgical airway is the need
for an airway.
However, the usual first preference is for orotrachael
intubation. (Nasotrachael intubation is slower and should be attempted only
if the patient is haemodynamically stable and can be hand ventilated for
long enough to obtain optimum pre-oxygenation). The hard collar may be temporarily
removed if the neck is protected by in-line immobilisation. A Surgical Airway
should be performed if orotrachael intubation is unsuccessful.
Situations in which a Surgical Airway should be considered
as the primary method include Major Maxillo-Facialary Injury (eg compound
mandibular fractures, Le Forte III Midface Fracture), Oral Burns, Fractured
Larynx.
The simplest technique is needle cricothyroidotomy. This
involves placing a 12 Gauge Cannula into the trachea via the cricothyroid
membrane. This will allow adequate ventilation for up to 45 minutes, hypercapnea
being the main limiting factor. This may buy enough time to obtain expert
airway assistance and attend to other emergency procedures. (NB This is
the prefered technique for children under the age of 12.)
Formal Crycothyroidotomy is the classic surgical airway.
It is safer and quicker then attempting Formal Tracheostomy in the Emergency
Room. The patients cervical spine is immobilised in the neutral position.
A Right Handed Surgeon stands on the patient's right. The area is preped
and draped. Local anaesthetic with adrenaline is used only in the conscious
patient who has a patent airway. In an asphyxiated / dying patient there
is insufficient time.
The thyroid cartilage is stabilised with the left hand
as the right hand makes the incision. The first incision is 3cm long transverse
incision through the skin overlying the crycothyroid membrane (closer to
the crycoid cartilage then then the thyroid cartilage). The second pass
of the scalpel is again transverse, through the crycothyroid membrane into
the airway. With the scalpel blade protruding into the airway, it is rotated
90 degrees so that it is now longitudinal, holding the two edges of the
incised membrane apart.
The left hand now releases the thyroid cartilage and picks
up an artery forcep. The artery forcep is placed into the airway, through
the exposed gap, and opened so as to take over from the scalpel as the means
of holding the incised edges apart. The scalpel can now be removed and placed
in the sharps tray. The right hand then picks up the endotracheal tube or
tracheostomy tube and inserts it into the airway, directed towards the chest.
The best size ET tube for an adult cricothyroidotomy is a size 6.0.
After confirming adequate position, the tube should be
secured and suctioned. A definitive airway will be required as soon as the
patient is stable, fully assessed and appropriate interventions have been
performed.
Fortunately, with skilled airway doctors in most trauma
centres, surgical airways are rarely required.
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