Hello. I’m Catriona Ferguson. I’m a consultant anaesthetist at the Royal National Throat, Nose and Ear Hospital, part of UCLH Foundation Trust. And I’m going to be talking about how to stabilise a patient with a compromised airway whilst waiting for expert help to arrive.
We’re going to learn about the causes of upper airway obstructions, the signs and symptoms, how to examine and investigate the patients, medical treatment, and when the patient should be intubated.
There are multiple causes of upper airway obstruction, such as inhaled foreign body, tumours, anaphylaxis, and angioedema. But they can also be caused by infection, autoimmune disease, and you occasionally see airway obstruction and the trauma patient and after neck surgery.
Signs and symptoms of airway obstruction. Dyspnoea is usually the presenting complaint. This is difficulty breathing. It’s really important if a patient tells you that they’re struggling to breathe that you take it seriously. Reassure them and tell them that you’re going to help them. You’ll often have some signs that will help you in diagnosing airway obstruction, such as tracheal tug. This is pulling down of the trachea into the chest during inspiration. You may also see recession above the clavicles or intercostal recession in really slim patients. The patient may have noisy breathing or stridor. And an important sign is difficulty swallowing, especially if the patient is completely unable to swallow or drooling. This indicates severe airway obstruction.
A more subtle sign might be voice change. This is especially difficult to diagnose when you haven’t met the patient before. All patients with airway obstruction are very distressed and often very agitated. So it’s important to remain calm and reassure the patient that you’re going to help them. I think it’s important to really emphasise about stridor. This is a harsh noise made during inspiration. It’s a very weak sign and is often over relied upon. Stridor can be absent in the most severe cases of airway obstruction. And it can also be a chronic condition and may not indicate that the patient has an acute airway problem or airway compromise. I’m now going to show a short video of a patient.
This lady has severe airway compromise from a large tumour compressing her trachea. When you listen, you can hear a soft, inspiratory noise, very mild stridor, and yet she has severe airway compromise. [VIDEO PLAYBACK] [LABOURED BREATHING] [MONITORS BEEPING]
[END PLAYBACK] All patients with severe airway obstruction should have saturation monitoring on. But it is a very late sign that patients desaturate. So normal saturation should not be reassuring about the patient’s condition. Respiratory rate is a very useful indicator. Patients increase their respiratory rate as they become more dyspnoeic. Although very rarely, when the patient’s carbon dioxide level rises, their respiratory rate may fall. Cardiovascular signs. The patient will be tachycardic and hypertensive. But again, with desaturation and hypoxia the patient may become bradycardic and hypotensive. Blood gases are a very useful indicator of how a patient is doing. In early airway obstruction, you’ll see that the oxygen saturation and PO2 is well maintained. The CO2 may be low or normal.
And in severe airway obstruction, resulting in exhaustion and imminent airway collapse, you may see the carbon dioxide rise and a fall in the PO2.
Nasal endoscopy is a useful bedside test that can be used to aid your diagnosis of the cause of airway obstruction. It can be performed with just some local anaesthetic to the nose, such as co-phenylcaine, and you can pass a normal fiberoptic scope along the floor of the nose to look at the larynx from the nasopharynx. In this patient, the patient presented with severe dyspnea and inability to swallow. On passing the nasendoscope, we could see a bright red, severely swollen epiglottis and thick secretions. And it helped us make the diagnosis of epiglottitis.
Often, it’s indicated to do X-rays or CT scans on patients with airway obstruction, but it’s vital to ensure that the patient is going to be safe whilst they are transferred and also in the X-ray department. A key factor is, can they lie flat? If a patient is unable to lie flat, they should not be taken to an X-ray department. Also, they must be escorted, have monitoring and all the equipment necessary for intubation. And it’s vital that you don’t delay treatment for investigation in these patients.
Treatment of airway obstruction. It’s vital that you reassure the patient that you’re going to help them. Let the patient sit up and give them oxygen. Adrenaline nebulizers are very useful and cause very quick benefit to most patients with airway obstruction. You put 1 mg of adrenaline in 5 mls of saline. It’s well tolerated by the patient. Very occasionally, you might use Heliox, which is a 50/50 mixture of helium and oxygen. This reduces the work of breathing and can make the patients feel better. But a key factor with this is that it is not a treatment. It’s only a holding mechanism for making the patients feel better, and other treatment must be taking place if you’re using Heliox.
Intravenous steroids are very useful. We would use dexamethasone in a dose of 0.1 mg per Kg. Antibiotics can also be useful in infective causes of airway obstruction. And you must call for help. Get a senior anaesthetist and an ENT surgeon.
Some patients with airway obstruction can benefit from continuous positive airway pressure. This can either be provided through an anaesthetic circuit or through high-flow nasal oxygen. Neck haematoma can either be post-traumatic or, more commonly, after neck surgery. We use a SHOUT airway risk tool to give an early warning of symptoms of neck haematoma in post-surgical patients, which will be discussed in another module. If a patient has neck haematoma after surgery, you should urgently inform the surgeon and the anaesthetist and consider opening the wound. Even a small haematoma can cause increased venous pressure, and this causes rapid onset of airway edoema and obstruction.
Even releasing the haematoma will not get rid of the airway edoema immediately, and the patient may still need to have that airway secured.
All patients in hospital with airway obstruction should have an airway management plan in place. It’s vital that the multidisciplinary team is involved in making this plan and that both the junior anaesthetist on site and the surgeons on site inform the consultants about the patient. It’s important when choosing an anaesthetic technique that the anaesthetist is comfortable with using the technique, and it should be a discussion between the anaesthetist and the surgeon as to which technique is chosen. I think it’s important to always consider awake intubation in the obstructed airway. You could either use a video laryngoscope or a fiberoptic. Or in some patients, the patient should go straight for front of neck access.
It’s also important that whatever technique is chosen, you have a backup plan.
Many patients with obstructed airways need a period where you wait and see if medical management is going to help them. It’s vital that we nurse these patients in a safe environment, and that will vary between different institutions. In some hospitals, it might be in a high-dependency unit or intensive care. It may be on a ward that specialises in airway problems. Or the patient may be looked after in a theatre recovery unit. The patients need to be closely observed. There needs to be an airway plan at the bedside and all the equipment that would be necessary for intubation at the bedside. There needs to be good communication and handover between teams, especially at shift change.
And a doctor should be called if there’s any deterioration. Regular medical review by senior staff is vital for safe management of these patients.
One of the most difficult decisions is when to secure the airway. Signs that a patient is in imminent danger of losing their airway– is the patient becoming exhausted? Worsening symptoms despite medical management? And especially if there’s a rise in the arterial carbon dioxide level– just remember that desaturation is a very late sign.
In conclusion, airway obstruction can be a very distressing symptom for patients and very stressful for the staff looking after the patient. It’s important that the whole multidisciplinary team comes together to help the patient and communicates well. The patient needs to be closely monitored for signs of improvement and deterioration. You need to have an airway plan and have a good backup plan and stay calm.