Welcome to ICU: Airway Management

Starting in intensive care can feel overwhelming, especially when it comes to managing airways. This guide will walk you through the basics in simple terms, so you feel more confident when you encounter these situations.

Why Do We Intubate Patients in ICU?

In the ICU, we intubate patients (put a breathing tube into their windpipe) for several key reasons:

Protecting the airway – When patients are unconscious or have a reduced level of consciousness (typically a Glasgow Coma Scale of 8 or less), they cannot protect their own airway from saliva or stomach contents.

Supporting breathing – When patients cannot breathe adequately on their own due to respiratory failure, we need to help them with mechanical ventilation.

Managing shock – Patients in severe shock may need intubation to reduce the work of breathing and allow the body to focus on recovering.

Preventing deterioration – Sometimes we intubate before things get worse, such as when someone has severe facial burns or swelling that might block their airway.

Other common reasons include persistent or recurrent low oxygen levels despite supplemental oxygen, upper airway obstruction with pooling secretions, recurrent seizures that cannot be controlled, and recent aspiration of stomach contents.

Understanding the Endotracheal Tube (ET Tube)

The ET tube is a flexible plastic tube that sits in the trachea. Here’s what you need to know:

Size – Adult tubes are typically 7.0-8.0 mm for women and 8.0-9.0 mm for men. The number refers to the internal diameter in millimetres. 

The cuff – There’s a balloon (cuff) near the end of the tube that we inflate once it’s in position. This creates a seal to prevent leakage and protects against aspiration of stomach contents. The cuff pressure should be monitored and kept between 20-30 cmH₂O – too low and there’s a risk of aspiration, too high and there’s a risk of tracheal damage.

Depth – We typically place the tube so that 21-23 cm is at the teeth for men and 19-21 cm for women. Always check the chest X-ray afterward to confirm correct position. The tip of the tube should sit in the mid-trachea, approximately 2-4 cm above the carina (the point where the trachea divides into the two main bronchi).

Components – The tube has a 15 mm connector at the top that attaches to the ventilator circuit or bag-valve-mask. There’s also a pilot balloon that shows whether the cuff is inflated – if this is deflated or damaged, the cuff won’t seal properly.

Preparing for Intubation: Your Role as a Foundation Doctor

Whilst you won’t be performing intubations as a foundation doctor, you play a crucial role in preparation and assistance. Being well-prepared can make the difference between a smooth procedure and a complicated one.

Equipment checklist:

– Laryngoscope (check the light works – have both direct and video laryngoscope available)

– Range of ET tube sizes (typically 7.0, 7.5, 8.0, 8.5 mm)

– 10 ml syringe for cuff inflation

– Bougie or stylet

– Working suction (test it before you start)

– Bag-valve-mask with oxygen supply

– Capnography device

– Tape or tube holder to secure the tube

– Backup airway equipment (supraglottic airway device like an i-gel or LMA)

– Monitoring equipment (pulse oximeter, blood pressure, ECG)

Medications ready:

– Induction agents (e.g. etomidate, thiopentone, ketamine or propofol)

– Muscle relaxants (e.g. rocuronium, atracurium or suxamethonium)

– Vasopressors (ephedrine, phenylephrine or metaraminol) drawn up and ready

– Emergency drugs nearby (adrenaline, atropine)

Patient positioning:

– Head of bed elevated to 20-30 degrees if possible (improves preoxygenation)

– Patient’s head in “sniffing the morning air” position – neck slightly flexed, head extended

– Remove pillows if they’re obstructing positioning

– Ensure adequate access to the patient’s head

Rapid Sequence Intubation (RSI)

RSI is the standard technique for emergency intubation in ICU. The goal is to get the tube in quickly and safely whilst minimising the risk of aspiration (stomach contents going into the lungs).

The basic steps are:

1. Preparation – Check equipment, ensure suction is working, have backup plans ready.

2. Preoxygenation – Give 100% oxygen for 3-5 minutes to build up oxygen reserves. This can be done with a non-rebreather mask, bag-valve-mask, non-invasive ventilation, or high-flow nasal oxygen. The goal is to “fill the tank” with oxygen so the patient can tolerate the period of apnoea (not breathing) during intubation.

3. Induction – A sedative drug (usually etomidate or ketamine) is given. These drugs make the patient unconscious.

4. Paralysis – A muscle relaxant is given immediately after (usually rocuronium or suxamethonium). This relaxes all the muscles, including those of the airway, making it easier to see the vocal cords and pass the tube.

5. Intubation – There is a 30-60 second period given for the drugs to work, then the tube is inserted. The person intubating will use a laryngoscope to visualise the vocal cords and pass the tube between them.

6. Confirmation – The tube position is checked to ensure it is in the trachea as opposed to the oesophagus. This is done using capnography (carbon dioxide detection) and chest auscultation. Capnography is the gold standard – you should see a waveform showing CO₂ with each breath.

Key medications:

– Etomidate – Causes less drop in blood pressure in comparison to other induction agents, making it preferred in haemodynamically unstable patients.

– Ketamine – Also relatively safe for blood pressure compared to other induction agents. It’s particularly good for patients with asthma or bronchospasm as it causes bronchodilation.

– Propofol – Causes more cardiovascular depression, so generally avoided in unstable patients, but may be used in those with normal blood pressure.

– Rocuronium – Muscle relaxant that works in 60 seconds. Can be reversed with sugammadex if needed.

– Suxamethonium – Faster muscle relaxant (works in 30-45 seconds) but generally has more side effects. Contraindicated in certain conditions like hyperkalaemia, burns more than 24 hours old, and neuromuscular disorders.

What Can Go Wrong?

Intubation in ICU is much riskier than in the operating theatre because the patients are already very unwell. Studies show that complications occur in about 40-45% of ICU intubations.

The most common problems are:

Cardiovascular instability – Blood pressure can drop. This happens because the sedation drugs lower blood pressure, and the patient may already be intravascularly deplete.

Severe hypoxaemia – Oxygen levels drop below 80%. This is why preoxygenation is so important.

Cardiac arrest – The most serious complication, usually due to severe hypoxaemia or cardiovascular collapse. 

Failed first attempt – About 20-30% of intubations require more than one attempt. Each additional attempt increases the risk of complications. This is why limiting attempts and having a clear backup plan is so important.

Aspiration – Stomach contents entering the lungs. This is why we use RSI and why patients should be kept nil by mouth when intubation is anticipated.

Oesophageal intubation – The tube going into the oesophagus instead of the trachea. This is why confirmation with capnography is essential – you won’t see CO₂ if the tube is in the oesophagus.

The Difficult Airway

Sometimes intubation is predicted to be difficult based on the patient’s anatomy. Warning signs include:

– Limited mouth opening (less than 3 cm or 2 finger breadths)

– Large tongue

– Short neck or obesity

– Previous difficult intubation

– Facial trauma or swelling

– Reduced neck mobility

– Prominent upper teeth

– Small jaw (micrognathia)

– Beard (can make mask ventilation difficult)

If a difficult airway is anticipated, the team should:

– Get senior help early – don’t wait until there’s a problem

– Ensure two experienced clinicians are present

– Ensure everyone present is aware of the plan if intubation fails

Video Laryngoscopy

Video laryngoscopy uses a camera to give you a better view of the vocal cords on a screen. Studies show it increases first-attempt success rates and reduces complications compared to traditional direct laryngoscopy. Many ICUs now recommend using video laryngoscopy for all intubations when available.

Advantages:

– Better view of the vocal cords, especially in patients with difficult anatomy

– Allows others in the room to see what the intubator sees, which is useful for teaching

– May reduce the need for neck extension

– Associated with higher first-pass success rates

Disadvantages:

– Requires different technique – the screen view can be different from what you’d see with direct laryngoscopy

– Can be more difficult to pass the tube even when you can see the cords well

– Equipment can fog up or become soiled with secretions

Confirming Tube Placement

This is absolutely critical. Never assume the tube is in the right place.

Capnography – The gold standard. You should see a square waveform showing CO₂ with each breath. If there’s no CO₂ trace, the tube is not in the trachea (unless the patient is in cardiac arrest).

Auscultation – Listen over both lungs (in the axillae) and over the stomach. You should hear equal breath sounds in both lungs and no sounds over the stomach. However, this alone is not reliable.

Chest X-ray – can be done after intubation to confirm the tube position and check for complications like pneumothorax. The tip should be 2-4 cm above the carina.

Misting – Condensation in the tube with each breath suggests it’s in the airway, but this is not reliable.

Chest rise – you should be able to see visibly rise with each ventilated breath

Direct visualisation – Seeing the tube pass through the vocal cords is reassuring but doesn’t guarantee it hasn’t moved (or that you were in the trachea!).

Tracheostomy

A tracheostomy is a surgical opening in the front of the neck that goes directly into the trachea. We consider this when patients need prolonged ventilation (typically more than 10-15 days).

Benefits of tracheostomy:

– More comfortable for the patient

– Requires less sedation, allowing patients to be more awake and interactive

– Easier to wean from the ventilator

– Easier to clear secretions

– Allows the patient to eat (with appropriate precautions)

– Potentially allows speech with a speaking valve

– Lower airway resistance compared to an ET tube

– Reduced risk of laryngeal injury from prolonged intubation

– Easier nursing care and patient mobility

Timing: There’s no perfect answer, but most ICUs consider tracheostomy after 10-14 days of intubation if the patient is likely to need ongoing ventilatory support. The decision is individualised based on the patient’s condition, trajectory of improvement, and likelihood of successful weaning.

Types:

– Percutaneous – Done at the bedside using a needle and dilators. This is the most common technique in ICU. It’s quicker and doesn’t require transfer to theatre, but requires appropriate anatomy and expertise.

– Surgical – Done in theatre by surgeons, preferred if there are anatomical concerns (short neck, obesity, abnormal anatomy, previous neck surgery or radiotherapy). Also preferred in emergency situations or if percutaneous technique has failed.

Complications of tracheostomy:

Early complications (within 7 days) include bleeding, tube displacement or obstruction, pneumothorax, subcutaneous emphysema (air under the skin), and infection.

Late complications (after 7 days) include tracheal stenosis (narrowing of the trachea), granulation tissue formation and tracheo-oesophageal fistula (abnormal connection between trachea and oesophagus).

Your role with tracheostomy patients:

– Understand the type of tube in place (cuffed vs uncuffed, fenestrated vs non-fenestrated)

– Know how to suction the tracheostomy

– Recognise signs of tube displacement or obstruction

– Understand when to call for senior help

– Know where emergency equipment is kept (spare tracheostomy tubes, tracheal dilators) ventilated. Consider sedation holds and spontaneous breathing trials when appropriate.

Recognising the Deteriorating Patient

As a foundation doctor, you need to recognise when a patient might need intubation and escalate early:

Airway concerns:

– Stridor or noisy breathing

– Inability to speak in full sentences

– Drooling or inability to swallow secretions

– Facial or neck swelling

– Burns to face or airway

Breathing concerns:

– Tachypnoea or bradypnea 

– Reduced oxygen saturations despite high-flow oxygen

– Exhaustion or reduced respiratory effort

– Use of accessory muscles

– Paradoxical breathing

Circulation concerns:

– Hypotension

– Tachycardia or bradycardia

– Signs of shock (cold peripheries, prolonged capillary refill, reduced urine output)

Disability concerns:

– Glasgow Coma Scale ≤8

– Inability to protect airway (absent gag reflex)

– Agitation or confusion in hypoxic patient

– Seizures

Remember

Airway management in ICU is a team effort. You’re not expected to manage airways alone as a foundation doctor. Your role is to recognise when intubation is needed, prepare properly, assist senior colleagues, and know when to call for help.

The most important thing is patient safety – if you’re unsure, ask. Every experienced intensivist has been where you are now!

Written by Dr Parsa Nazari FY2, and reviewed by Dr Wasim Silmi CT1 Anaesthetics