Author: Gavin Lloyd / Editor: Gavin Lloyd / Codes: C3AP6 / Published: 11/03/2011 / Review Date: 11/03/2014
This session involves:
- Clinically identifying patients with airway compromise
- Responding to these with simple airway manoeuvres
- Selecting and introducing airway adjuncts appropriately
- Recognising the need for ventilation and delivering this effectively
Look at Fig 1, a sagittal view of the adult airway from the mouth and nasal cavities to the trachea. Partial or complete obstruction can occur at any point. Any patient with a lowered conscious level is vulnerable to airway obstruction, purely through relaxation of smooth muscle occlusion of the nasopharynx by the soft palate, the oropharynx by the tongue and the laryngopharynx by the epiglottis.
Resistance to airflow may otherwise arise as a consequence of numerous insults listed in the table, the most common of which are highlighted in italics.
Fig 1: Pharyngeal airway
|In the lumen||In the wall||From outside the airway|
||Penetrating neck injury|
|Secretions||Trauma to larynx (blunt and penetrating)||Tumour|
|Blood||Tumour||Oesophageal foreign body|
Table: Causes of airway obstruction (apart from smooth muscle relaxation)
Identification of Patients with Airway Difficulty or Predicted Airway Difficulty
Conscious patients with airway compromise typically sit upright intuitively. Look for the swollen tongue in angioedema cases, inflammation and sooty sputum following thermal injury, neck haematoma following blunt or penetrating injury, an associated rash in anaphylaxis and the increased work of breathing seen in severe asthma. Listen for stridor or wheeze. Gently feel for unstable facial fractures and the crepitus and surgical emphysema of laryngeal injury.
In unconscious patients, look for abnormal chest and abdominal wall movement, suggesting airway obstruction and the lack of fogging of the oxygen mask. Listen for the snoring noise of partial airway obstruction.
Fig 2: Lack of fogging of the oxygen face mask during normal inspiration
Fig 3: Fogging of the oxygen face mask due to normal expiration
Unconscious patients are vulnerable to aspiration from:
Use gentle suction under direct vision to remove these with a wide bore rigid sucker.
When faced with an actively vomiting or regurgitating patient, or where there is a significant amount of blood in the airway, turn the patient on their side and tip the trolley head down.
Turning the patient is not an option where cervical spine injury is suspected, unless you can maintain the head and neck in-line with the torso.
Taking the sucker off the end of the suction tube may help clear thick undigested food, otherwise the sucker becomes blocked.
Turning the unconscious patient on their side and tipping the trolley head down may be the best way of avoiding aspiration.
The chin-lift manoeuvre
Unconscious patients lying supine on a trolley are vulnerable to airway obstruction.
Their oral axis (OA), pharyngeal axis (PA) and laryngeal axis (LA) are malaligned (Fig 4).
Placement of a pillow or folded blanket beneath their head, together with a chin-lift manoeuvre should improve the alignment of the axes, i.e. open up the angle depicted in blue, between the OA and LA.
Fig 4: Malalignment of the oral, pharyngeal and laryngeal axes in a patient in the supine position, and altered alignment of the axes following placement of a pillow or folded blanket beneath the head, and following a chin-lift manoeuvre
The pillow effectively flexes the neck in relation to the torso; the chin-lift manoeuvre extends the head in relation to the neck. The so called sniffing position is achieved.
Beware application of a chin-lift manoeuvre without raising the occiput. This may lead to hyperextension of the neck, further compromising the airway.
Gentle movement is advised in patients with fixed neck deformities.
You can achieve the sniffing position in most patients with a pillow and chin-lift.
The chin-lift manoeuvre obese patients
In obese patients, especially those with short necks, the pillow may compromise the airway further by causing flexion of the head in relation to the neck (Fig 5). As a result, their chin is brought into closer proximity to their chest. This will also make subsequent intubation more difficult, if this is planned.
The solution is to place a pillow under the patients shoulders and a number of pillows under their head to elevate the chin above the chest (Fig 6).
Fig 5: Neutral position and malalignment of the axes in an obese patient
Fig 6: Sniffing position, improved alignment of the axes in an obese patient
The jaw thrust
The jaw thrust (Fig 7) effectively lifts the mandible forwards, lifting the tongue off the posterior pharynx at the same time.
The key is to hook the left little finger underneath the angle of the jaw. Use the ring and middle fingers to secure further grip under the mandible and the index finger and thumb to help secure a tight seal between mask and face. Holding this position may become tiring. The same result (forward displacement of the tongue) may be achieved by the use of the oropharyngeal airway.
Fig 7: The jaw thrust
The chin-lift is suitable for those patients who, with an open airway, are breathing adequately. A high flow oxygen mask can be applied.
A jaw thrust is more suitable for patients who require bag-mask ventilation, since it is difficult to apply a mask and a chin-lift simultaneously.
Since movement of the head and neck is contraindicated in the context of suspected significant cervical spine injury, use a jaw thrust, not the chin-lift manoeuvre (or indeed a pillow).
In trauma patients, apply the jaw thrust not the chin-lift manoeuvre.
The oropharyngeal and nasopharyngeal airways are designed to address airway obstruction. They also free the airway practitioner, as, in most patients, the oropharyngeal airway (in particular) produces the same result as a jaw thrust. In such circumstances oxygen can be applied via an oxygen mask.
Both are in general tolerated only in unconscious patients. Unless you anticipate an improvement in conscious level in the short term, consider the need for intubation.
Toleration of an oropharyngeal airway is one of the best indicators of an unprotected airway.
The correct size oropharyngeal airway should reach from the patients incisors, to the angle of the jaw (Figs 8 and 9).
Fig 8: The oropharyngeal airway should reach from the patients incisors to the angle of the jaw
Fig 9: The flanged front end of the oropharyngeal airway should sit just in front of the teeth
- Insert curved side uppermost, twisting it through 180 once inserted halfway
- The flanged front end should sit just in front of the teeth
- Confirm an improvement in ventilation has been achieved
Note: An oropharyngeal airway may precipitate vomiting or rarely, laryngospasm. In both situations, remove it promptly.
The key advantage over the oropharyngeal airway is the ability of the nasopharyngeal airway to relieve airway obstruction in those patients whose mouths are difficult to open, typically patients undergoing a seizure. Unless it is too long, it is unlikely to stimulate the oropharynx and is better tolerated in lighter patients.
The disadvantage of a nasopharyngeal airway is occasional nasal haemorrhage as a complication,rarely profuse.
Check the oropharynx post-insertion for blood. Avoid using it in patients with obvious, significant mid-face injury.
Use the nasopharyngeal airway in patients with airway compromise whose mouths are difficult to open.
The internal diameter is stamped on the side of the tube.
A 6mm size for women and 7mm for men is recommended.
- Lubricate the tube with gel and insert into the right nostril aiming gently towards the occiput, curved side down, with a little twisting motion if necessary
- Change to a smaller airway if there is firm resistance
- Check for bleeding in the oropharynx
- Check for improvement in airway patency
Fig 10: Nasopharyngeal airways
Having secured a patent airway, ask yourself whether the patient needs:
- Assisted ventilation
- An oxygen mask
You can subjectively gauge the adequacy of the patients spontaneous ventilation by the depth and rate of chest wall movement.
If in doubt check the pCO2 by arterial blood gas analysis.
If ventilation is required you will need:
- The correct size facemask, which is one that fits snugly from the bridge of the nose to just above the chin (Fig 11)
- A self-inflating bag (Fig 12)
Fig 11: Facemask fitting snugly from the bridge of the nose to just above the chin
Fig 12: Self-inflating bag
Check the airway does not need suctioning first, then:
- Apply the mask firmly to the patients face using the index finger and thumb in a capital C shape (Fig 13)
- Hook the little finger under the angle of the mandible and grip more mandible with the ring and middle fingers
- Raise the spread fingers to effect the jaw thrust
- Squeeze the bag firmly with the right hand, release, pause and repeat at a rate of 10 breaths per minute (Fig 14)
Fig 13: Single operator hand position
Fig 14: Single operator hand position
Single operator bag-mask ventilation is not an easy skill. Practice on a manikin (most emergency departments will have one).
Adequate ventilation can be confirmed by looking for chest wall rise and fall, and improvement in oxygen saturation. More resistance in the bag then you might anticipate suggests a problem.
Recognise your limitations as a single-handed airway practitioner. If you sense a problem ask someone to squeeze the bag as per your instructions, whilst you attempt to provide better airway patency and mask seal using your right hand opposite your left (Fig 15).
Fig 15: Two person bag-mask ventilation
The table gives examples where it may be difficult to secure an adequate seal or difficulty in ventilating, because of high airway pressures. Solutions are offered.
|Poor mask seal||Solution||Difficult ventilation||Solution|
|Blood and vomit creating a slippery surface||Clear the airway with suction; use a towel to dry the patients face||History of snoring||Attention to correct head/neck positioning +/-adjuncts +/- two-person technique|
|Edentulous patient||Replace the dentures or pack the cheeks with gauze if dentures missing||Abdominal distension including obesity, third trimester and ascites||Consider elevating the head end in non-traumatic patients|
|Unstable facial fractures||
||Stiff or immobilised neck||No options available. Do not force elderly patients necks|
|Beard||Apply gel to improve the seal||COPD/asthma||Aggressive medical therapy|
|Facial asymmetry||Use a two-person technique||Big tongue||Consider oropharyngeal airway|
Table: Markers for difficult bag-mask ventilation
Difficulty in ventilation
Rarely you may find that ventilation is still difficult, in which case:
- Call for senior help, if you havent already
- Check you have achieved optimum patient positioning
- Try two nasopharyngeal airways and an oropharyngeal airway
- If there is still no improvement, try a laryngeal mask airway
- If there is still no improvement allow some head and neck repositioning in trauma patients, since lack of airway patency overrides cervical spine considerations
- The sniffing position can be achieved in most patients with a pillow and chin-lift
- Turning the unconscious patient on their side and tipping the trolley head down may be the best way of avoiding aspiration
- In trauma patients, apply the jaw-thrust not the chin-lift manoeuvre
- Toleration of an oropharyngeal airway is one of the best indicators of an unprotected airway
- Use the nasopharyngeal airway in patients with airway compromise whose mouths are difficult to open
- Single operator bag-mask ventilation is not an easy skill. Practice on a manikin