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EMERGENCY
CASE WITH A COMPLICATED AIRWAY
The complicated airway means obstruction: either existing already
in the awake patient or waiting to happen as soon as consciousness
is lost.
Causes of obstruction include:
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Vomit |
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Oedema |
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Blood |
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Abscess
or tissue infection |
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Slough |
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Pus |
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Abnormal
anatomy |
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Debris |
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Foreign
body |
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Tumour |
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Tissue
damage. |
The
obstruction might be at the mouth, inside the mouth, in or
around the neck. With a foreign body, there may be obstruction
further down in the airway, in the trachea. It may be related
to the proposed surgery or be unrelated in origin and an unwelcome
surprise.
There are so many different causes and scenarios relating to a blocked airway
that detailed management protocols are impossible to give. If you are presented with
a complicated airway, remember that the patient was breathing when he
came to you, otherwise he would have died somewhere on the way. Good management
depends on:
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Preserving
the airway for as long as possible |
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Increasing
the oxygen reserve in the lungs |
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Inducing
anaesthesia |
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Securing
the airway, under controlled conditions, by passing a
tracheal tube. |
Principles
for induction of anaesthesia in obstructed airway
| 1 |
Assess
the need to hurry. Have a diagnosis and a plan before
starting. If possible, have a more experienced anaesthetist
in the operating room or nearby. |
| 2 |
Gather
everything you might need for a difficult airway. Some
or all of the following may be useful:
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Intubating
bougies |
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Laryngoscope:
two, if possible, with different blades |
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Stylets |
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Different
sizes of endotracheal tubes: put a lubricated stylet
in the
smallest tube |
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Laryngeal
mask airway |
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Different
size oropharyngeal and nasopharyngeal airways |
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Different
shaped masks |
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Emergency
laryngotomy puncture set. |
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| 3 |
Use
a little head-up tilt of the table, which usually assists
the airway. A child can sit on the table or even on your
knee for the induction and then be laid horizontally when
asleep. |
| 4 |
Have
the sucker switched on with a Yankauer fitted and soft
catheters ready. |
| 5 |
Assess
the regurgitation risk, especially if the patient has
also swallowed a lot of blood. Assign a person to give
cricoid pressure. |
| 6 |
Use
the pulse oximeter. |
| 7 |
Have
a drip running, with intravenous induction drugs ready
drawn up. |
| 8 |
Be
well protected: patients with airway trauma may cough
blood at you.
Gloves are essential; a mask and glasses will prevent blood getting in your eyes
or mouth. |
| 9 |
Do
not examine any wound or lift any dressing around the
airway until everything is in place: this action may
cause the patient to cough and the airway may be lost
or haemorrhage may start. |
| 10 |
Try
to fit a mask to the airway and give oxygen. Observe
the pulse oximeter and the movement of the bag or bellows.
This will tell you the effectiveness of pre-oxygenation
and how easy inhalation induction will be. |
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Induce
anaesthesia. Never give any intravenous anaesthetic drug,
especially
suxamethonium, unless you are sure that you can ventilate by mask and that endotracheal
intubation will be possible or an LMA can be passed. |
Giving an intravenous drug will cause loss of the airway and
stop the breathing. Can you handle that? If not, do not give
an intravenous drug.
With facial trauma, the destruction of bone and tissue makes
holding the mask and pre-oxygenation more difficult, but intubation
after suctioning may be easier. In extreme cases of neck trauma
(such as assault by knife), the trachea can be intubated through
the neck wound.
The classical method is to use inhalation anaesthesia with
halothane when faced with a potentially obstructed airway.
In practice, this is not always successful: induction takes
a long time if ventilation is poor or obstructed. Struggling
or coughing may make things worse, increase bleeding and result
in total airway obstruction. You may start with one method
and find yourself forced to use another or a combined intravenous
plus inhalation technique.
Always have an alternative plan, which takes into account the
patient’s condition, your own skills and the resources
available. Be flexible, be prepared for your plan to go wrong
and do not get fixed on one choice of anaesthesia.
Postoperative airway management is likely to be more complicated
than the preoperative status because of:
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Tissue
swelling |
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Residual
narcosis |
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Postoperative
(“reactive”) haemorrhage |
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Haematoma
formation. |
Therefore, before doing anything to the airway, check what airway management
facilities will be available postoperatively. Avoid managing a patient
with a persistent obstructed airway in a district hospital operating room,
with nowhere except an ordinary ward to send him or her postoperatively.
You may choose to refer such a patient to the central hospital with an
intensive care unit and avoid any procedures on the airway.
Alternatively, you could intubate at your hospital and travel with the patient to
the referral centre.
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