Navigating the various airway equipment available can be daunting. This article provides a brief overview of the most common pieces of airway equipment encountered in hospitals and in surgery.
The main goals of airway management include:
Securing an open airway
Ensuring ventilation of the lungs
Protecting the lungs from contamination
Airway Intervention Overview
Table of Airway Interventions
Airway interventionIs the airway protected? Airway manoeuvres No Oropharyngeal (Guedel) airway No Nasopharyngeal airway No iGel No Laryngeal mask No Proseal laryngeal mask No Endotracheal tube Yes Fibreoptic intubation Yes Cricothyroidotomy Yes
Airway Manoeuvres
Airway manoeuvres are designed to lift the tongue and pharynx soft tissues forward, opening the airway.
Head-Tilt, Chin-Lift Maneuvre
Position the patient lying down.
Open the airway using a head-tilt, chin-lift manoeuvre:
Place one hand on the patient's forehead and the other under the chin.
Tilt the forehead back and lift the chin forward to extend the neck.
Airway Management Techniques: Head-Tilt and Jaw Thrust Methods
When managing a patient's airway, a head-tilt chin-lift maneuver may be used if there is no suspicion of significant trauma involving the spine. To do this, use one hand to raise the bony part of the chin, and the other to apply gentle pressure to the forehead, shifting the head to an angle of approximately 15 degrees.
If the patient is suspected to have suffered significant trauma (with potential spinal involvement), a jaw-thrust should be used instead. In this method, use both hands to apply force behind the ramus of the mandible, displacing the lower jaw forwards and upwards.
Check out the video demonstration below to see a demonstration of these techniques.
Oropharyngeal (Guedel) airway
Key facts:
An oropharyngeal airway can help avoid obstruction of the airway caused by the tongue and soft tissues of the pharynx.
Different sizes of the airway are available for both adults and children.
Size the airway by comparing it to the patient's face: when the tip is placed at the angle of the jaw, the flange should align with the centre of the top teeth (i.e. hard airway = measure “hard to hard”).
Insert the Guedel upside down into the patient's mouth, and pass to the back of the throat before rotating 180 degrees so that it fits behind the tongue base. For children, the Guedel should be inserted the right way up (i.e. not upside down).
Issues with Guedel airways:
Guedel airways can induce a gag reflex when used on conscious or semi-conscious patients.
They can cause damage to teeth and the mucous membranes of the oral cavity.
Nasopharyngeal airway (NPA)
Key facts:
NPAs are used to bypass obstructions in the mouth, nose, nasopharynx, or base of the tongue.
Calculate the appropriate size by measuring from the patient's nose to the tragus of the ear (i.e. soft airway = measure “soft to soft”).
To insert the NPA, lubricate the tip and insert it into the correct nostril, aiming perpendicularly to the face, so that it passes along the nasal passage and down into the pharynx.
The NPA tip should sit just above the epiglottis and the flange should be at the tip of the nose.
Issues with NPAs:
NPAs should not be used in patients with suspected base of skull fractures.
They can cause trauma to the nostril.
Supraglottic airways
Overview
Key facts:
Supraglottic airways are a group of devices used to abut the larynx, above the vocal cords.
They can be used as alternatives to endotracheal airways in short or low-risk anaesthetic cases.
They may also be used in prehospital and cardiac arrest settings to achieve a more secure airway without endotracheal intubation.
If placed in cardiac arrest, simultaneous ventilation can be done without interruption of cardiac compressions.
Different types of supraglottic airways exist, with varying advantages and disadvantages.
Issues with supraglottic airways:
Supraglottic airways do not provide a definitive airway, and do not protect against aspiration.
Complications include gastric insufflation, aspiration, laryngospasm and partial airway obstruction.
Supraglottic airways should not be used if there is poor mouth opening, pharyngeal pathology or obstruction at/below the level of the larynx.
Insertionmethod:
The patient is placed supine, with the neck flexed and head extended at the atlanto-occipital joint.
The tube is inserted into the mouth and guided over the tongue until resistance is encountered.
The tube is connected to a ventilation device and airway patency confirmed with chest movement, fogging of the tube and a CO2 trace.
If there is no CO2 trace present, the airway is not patent and must be removed or adjusted.
Laryngeal mask airway (LMA)
Key facts:
A laryngeal mask airway (LMA) is a reusable supraglottic device.
It consists of a silicone rubber tube ending with an elliptical, spoon-shaped mask designed to fit over the larynx.
The inflatable mask rim forms a low-pressure seal over the laryngeal inlet.
Reinforced laryngeal masks are also available to prevent kinking.
Proseal is a type of LMA that has an additional inflatable segment that provides a greater seal within the larynx and a gastric port for drainage of gastric secretions.
Self-inflating bag-valve resuscitator
Key facts:
A self-inflating bag-valve resuscitator is also known by other names like ambu bag, bag valve mask (BVM), self-inflating bag and manual resuscitator.
A BVM is usually used to provide ventilation and oxygenation before the placement of a definitive airway.
The device is composed of a face mask connected to a flexible air chamber by a shutter valve. The tubing connects the BVM to a flowmeter or oxygen cylinder.
When the face mask is placed securely on the patient's face to form a seal, air entrainment is reduced and high levels of oxygen can be delivered. With the help of a reservoir bag, an FiO2 of 100% can be achieved.
Patients can breathe spontaneously through the system or they can be ventilated by squeezing the bag, given that a firm seal is formed between the patient's face and the mask.
Typically, one person performs the airway opening manoeuvres and keeps the mask on the patient's face with a secure seal, while the other person squeezes the bag. It is possible for one person to do both if trained.
The shutter valve and bag can also be connected to airway devices such as an LMA, iGel or ETT.
Suction
Key facts:
In emergencies, airways may become full of secretions, saliva, stomach contents, blood, and other debris. Suction can be used to clear the airway and improve visibility during laryngoscopy.
Suction devices should be available in all hospital beds and portable ones for patient transfers.
Yankaur suction is a firm plastic tube with a large opening, used to clear the oropharynx.
Suction catheters are flexible tubes that can be inserted into an ETT or tracheostomy tube to remove secretions from the airway.
Laryngoscopes
Key facts:
Laryngoscopy is a process used to visualize the larynx, either directly or indirectly. It is often used to pass an endotracheal tube through the vocal cords to gain a protected airway.
Laryngoscopes are used to help with endotracheal intubation as part of an anesthetic induction. They should only be handled by trained clinicians.
Macintosh laryngoscopes come in a handle with attachable blades of various sizes, each with their own light for viewing the vocal cords. Before use, be sure to check the connection and light.
The laryngoscope is held in the left hand and the blade is inserted along the right side of the tongue and placed in the groove between the tongue and epiglottis. Soft tissues should be lifted in the direction of the handle to reveal the vocal cords.
A video laryngoscope has a built-in camera and laryngoscope blade which allows the larynx and vocal cords to be viewed onscreen. It is not as useful in patients with blood or secretions in the airway due to the camera being obstructed.
Issues with supraglottic airways:
There is a significant risk of damaging teeth and oropharyngeal tissues.
Endotracheal tubes
Key facts:
Endotracheal tubes (ETT) come in various lengths and diameters. Generally, the rule of thumb is 7.
Endotracheal Tubes
Endotracheal tubes (ETT) are placed in the trachea to provide an airway during general anaesthesia and mechanical ventilation. They come in different diameters and lengths to accommodate different patients. Generally, the diameter of an ETT is 8.0-8.5mm for adult males and 7.0-7.5mm for adult females.
One end of the tube has a universal plastic connector and the distal end is shaped to ensure ventilation of both right and left bronchi. It also has a small hole (known as Murphy's eye) which can be used for ventilation should the end of the tube become obstructed. Centimetre markings indicate the depth to which the tube has been inserted - usually 20-24cm at the level of the teeth.
An inflatable cuff seals the trachea to protect against airway contamination and gas leaks. The cuff and pilot balloon should be tested before the tube is used. Variations of endotracheal tubes are available, including tubes with additional suction ports, reinforced tubes with metal rings to reduce kinking, and nasal endotracheal tubes for intubation of the trachea through the nose.
