Airway Management

Airway management is an important skill in Emergency Medicine, Critical care (including Intensive care and High Dependency (HDU)) as well as in anaesthetics.

Without a sufficient airway, a patient will suffer permanent brain damage with 3-4 minutes.

Basic Airway Manoeuvres 

Head Tilt – tilt the patient’s head backwards, by pushing down the forehead – pushing it down into the head.

Chin Lift – usually used in conjunction with head tilt. Place your fingers under the chin and pull upwards. When used in combination with head tilt, this helps open up the airway. Try to avoid digging you fingers into the soft tissues underneath the chin. Do not attempt a head tilt / chin lift if there is any suspicion of c-spine injury in the history. 

Jaw Thrust – a little more uncomfortable for the patient than the head tilt / chin lift combination – but often your patient may only be semi conscious. Standing at the head of the bed, place your fingers at the angle of the mandible, and pull the mandible anteriorly. It requires quite a bit of force. This forcibly opens up the airway and life the tongue away from the back of the mouth. Usually more effective than a head tilt and chin lift at keeping the airway open. Holding a jaw thrust for any length of time is difficult!

Airway Assessment

1. Open the patient’s mouth, do head tilt and chin lift (or jaw thrust – whichever is appropriate) and check for any obstructions. If you can see any obvious foreign body or other obstruction you can remove it manually with
   your finger – but beware of the patient biting (particularly in seizure). Do NOT do a blind finger sweep.
2. If there appears to be fluid or secretion in the mouth, use suction to remove them. Get a suction tube (Yankaeur Sucker), tell the patient what you are going to do, and that it might be unpleasant. Put the plastic nozzle part on the end of the tube. You can squeeze the tube (put a kink in it and squeeze it) to control the flow of air. Try to be gentle!

   

3. Re-assess the airway after each manoeuvre or adjunct. Look and feel for breathing in the same way as you would do in BLS. Can you hear breathing? Can you see breathing? If the patient is still not breathing, attempt at jaw thrust. 
   1. If the patient has no monitoring, you should also be feeling for a carotid pulse at the same time – but note that the BLS guidelines have no requirement for feeling a pulse – if you are in any doubt about cardiac output – START CPR!

Upper Airway Adjuncts

e.g. The patient is still having trouble breathing. They may be gasping, but they are still conscious and attempting to take their own breaths

1. Try using a non re-breathing mask. Connect it to 15L O2
2. Remember you may still need to open the airway by performing a head tilt / chin lift or a jaw thrust – don’t forget to keep doing this if the patient keeps moving!
3. If the tongue keeps getting in the way, or they keep biting their mouth closed,then you should use a Guedel airway (aka oropharyngeal tube) – this is a short plastic tube that sits in the mouth and prevents the tongue from falling backwards and obstructing the airway. Once inserted, don’t forget to put the re-breathing mask over the mouth.
4. Inserting the Guedel tube – choose the correct size. To do this, measure it up against the patient’s cheek – a correctly sized tube should reach from the corner of the mouth to the angle of the mandible. Once you are happy you have the right size, put it in upside down (with it curling up to roof of mouth) then once you are past the back of the tongue rotate it through 180′, so that it curves downwards.
   1. In children, the Guedel should not be inserted ‘upside down’, due to risk of damage to the palate. You should insert it the right way up to avoid rotation. You may need to use a tongue depressor to help with this.
   2. Guedel airways are dangerous  in conscious patients. They initiate the gag reflex which can cause vomiting and aspiration. They are particularly dangerous in the intoxicated patient with variable conscious level (and often a stomach full of alcohol!)
5. An alternative is the nasopharyngeal airway – this is a little rubber tube that you pass into the nostril. Before you insert it, have a good look around the nostril – is there trauma? Is one occluded? Are there big blisters/sores, scars, polyps? Obviously use common sense and go for a nostril that looks normal – don’t insert it if it looks like there is trauma. Normally the right nostril is slightly bigger than the left due to the natural shape of the septum.
   1. Put KY jelly on it! KY jelly is water soluble, and thus absorbed by the body when it has done its job of lubricating. Insert it slowly and carefully. Inserting it too aggressively can shear the mucous membrane, and this may cause a lot of bleeding. Rotate it gently as you pass the tube.
   2. There may be a safety pin on the end – this is just to prevent the tube being snorted up the nostril by mistake.
   3. DO NOT USE when there is head trauma – if there is a fractured base of skull there is a risk of up pushing it all the way into the brain.

Face Mask / Bag and Mask

1. Remember to attach it to oxygen at the wall and turn it on to 15L/min. Then, standing at the head of the bed, seal the mask around the mouth with both hands, and give breaths by sequeezing the bag.
2. It is possible to operate the bag and mask with one person, but it is probably better to have two – you need one person to make sure the mask is making a good seal, and another person to squeeze the bag. The person who is holding on the mask should also do the head tilt & chin lift / jaw thrust as necessary; lift the patient’s jaw up and into the mask – don’t push the mask down onto the patient’s face!
3. Be careful when you squeeze the bag – if you squeeze too hard you’ll end up forcing air into the stomach. Also, bear in mind the ‘bag’ is usually around 2L in size, and a normal tidal volume is around 500mls. A small gentle squeeze of the bag will usually deliver enough oxygen.

Laryngeal Mask Airway

1. Laryngeal mask airway (LMA) – these are sometimes used as an alternative to intubation in a non-critical care setting – e.g. in theatre in patients that are expected to be straight forward. They are also used in emergency settings to maintain an airway – often if a more definitive airway could to be obtained (e.g. in failed intubation). An LMA does NOT provide a ‘definitive’ airway – it doesn’t protect the patient from aspiration. The mask is placed over the entrance to the trachea, thus alleviating any problems higher up the airway. You then ventilate the patient using a bag and 15/L O2 (or ventilator).
2. The mask slides down through the mouth, along the hard palate, with the mask deflated. The amount of air in the mask is partly personal preference – some doctors advocate for a completely empty mask, but most prefer a small amount of air – this can prevent the tip of themas from folding back on itself when placing the LMA. Slide the LMA in with the mask facing the posterior pharyngeal wall – no need to do it upside down (like with a Guedel airway). Don’t forget to use lube – although in reality, the region is often lubricated enough by natural means. Once you’re happy it’s in place, inflate the cuff with air using the valve. Only use about 20ml. Then check it’s working by filling with air and watching the chest rise. You should also listen over the lungs for air flow, and over the epigastrium to check no air is going into the stomach.
   1. How and where to hold the LMA as you push it in is also a matter of personal preference.
   2. The depth of insertion varies from patient to patient. Don’t force it in against resistance.
   3. Often when the mask is re-inflated, this helps it to sit back in place. As it inflates, the LMA will often rise up a couple of centimetres out of the mouth.
   4. Some newer brands of LMA are made of a more rigid gel material which does not require re-inflation or deflation.
3. They are not frequently used in emergency medicine because they do not produce a perfect seal around the airway, thus there is still a risk of aspiration. They are preferred in anaesthetics because in elective surgery, the patients are fasted, thus less risk of aspiration, and there is less trauma to the airway than an ET tube. They are also easier to insert.
4. LMAs come in different sizes. The sizing in not related to the sizing of endotracheal tubes. Sizes are 1-5 – 1 for babies, 3-4 for standard sizes adults.

Endotracheal Intubation – A “definitive” airway

Endotracheal intubation – is THE definitive management in a patient with severe breathing difficulties. However, the patient needs to be unconscious to tolerate the tube. This often means the patient has to be sedated before they are intubated . In general, any patient with a GCS <8 is at risk of losing their airway and should be considered for intubation.

• Ensure the patient has received adequate ventilation before attempting the procedure – this is sometimes called pre-oxygenation.  This usually means the patient has been adequately ventilated with a bag & mask for several minutes. .
• Check that the equipment is in date
• Check that the balloon is inflated properly – sometimes this has perished
• Get the right size – this is roughly size 7-8 for men and size 6-7 for women. If you are unsure, then size 8 is a good all round fit.
• Collect the rest of your equipment; syringe (for air), KY jelly, stethoscope, McGill forceps, introducer, laryngoscope.
• Note that the laryngoscope is a left-handed tool – you hold this with your left hand and the slide the tube in with your right.
• Get the laryngoscope – and slide it slowly and gently into the mouth. You should stand behind the patient’s head. You want to get the largnscope in as far as the epiglottic vallecula. This is the region just behind the tongue, but just in front of the epiglottis. Once you are happy the laryngoscope is here, lift up and lever the tongue out of the way – do NOT use the teeth as a pivot – you will break them. You have to lift and push the laryngoscope away from you, which can be quite heavy and difficult. At the same time, bend down and look, you need to be looking for the vocal cords. You may need to press on the patient’s forehead at this stage to keep the head still.
• Seeing the vocal cords – once you can see these, slide the tube in. Put lube on beforehand if you think this is necessary. You should watch as the tube goes into the larynx. Push it a reasonable way in – there is a rough guide on the side of the tube to tell you where to stop
• If you go too far you will end up in the right main bronchus. Only the right lung will inflate, and eventually the left lung may collapse.
• Fill up the balloon – one you are happy you are in, fill up the balloon with no more than 10ml of air – as soon as you see the front of the trachea move on the surface of the neck, then stop. Usually you should put about 5ml in.
• Check you are in – get a colleague to do the bag on the end of the tube – this should be filling up the lungs. Whilst they are doing this, you should listen on the lungs (approx 3 places on each) to check they are filling with air, and also listen of the epigastrium to check that this is not filling with air.
• Finishing off – you might want to stick a Guedel tube in the mouth to stop them biting down on your nice endotracheal tube. Also you need to tie the tube in place – to do this use a slipknot around the tube itself, then tie the two ends around the patient’s neck.

Ventilation vs oxygenation

Invasive and non-invasive ventilation

CPAP – Continuous Positive Airway Pressure

• Moving the dynamic closure point of the airway further distally, in a similar way to pursed lip breathing, thus recruiting more airways, and allowing for a greater gaseous exchange, and thus increasing the PaO2.
• It can also literally force alveoli to have a larger surface area (stretch the alveoli) which can be useful in conditions where there is fluid in the alveoli, as the fluid becomes spread more thinly, and thus better gaseous exchange can occur across it
• The pressure at which air is delivered is determined on an individual basis. The pressure is measured in cm H2O. A typical value is 4-16cm H2O.

BIPAP – Bi-level Positive Airway Pressure

BiPAP – Bi-level positive airways pressure is similar to CPAP. The equipment used is often the same, however, the ventilator used in this instance is able to detect inspiration, and adjusts to give a higher pressure during inspiration. Thus, two pressure levels are provided – one on inspiration, and one on expiration. The pressure on inspiration (IPAP) is much greater than the pressure on expiration (EPAP). The IPAP will always be higher than the EPAP!

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• BLS – Basic Life Support
• Inserting a Chest Drain
• Lumbar Puncture (LP)
• Suturing