Extubation can refer to removal of either an endotracheal tube (ETT) or a supraglottic airway such as a Laryngeal Mask Airway (LMA). While extubation is often performed awake it can also be done deep, with the still anesthetized. Deep extubation has advantages and is less stressful for the patient. However deep extubation must be done carefully to avoid potential complications.
Advantages of Deep Extubation
There are many reasons to consider deep extubation of your patient. Extubation of the awake patient is often accompanied by coughing and bucking. Increased blood pressure and pulse rate can trigger cardiopulmonary stress and increased intracranial pressure. Bronchospasm can occur from airway stimulation. Coughing increases the risk of oropharyngeal bleeding after head and neck surgery. Bucking strains fresh hernia or abdominal incisions. Vomiting and aspiration from gagging on the tube are possible. Deep extubation minimizes those risks.
COVID-19 brings yet another more current reason to consider deep extubation. Coughing spreads aerosols, which can potentially spread the SARS-CoV-2 virus. Since it’s possible for even a COVID-19 negative test to be a false negative depending on when it was administered, minimizing aerosols can be extremely important for staff safety.
Disadvantages of Deep Extubation
Mis-timing deep extubation during stage 2 of emergence can lead to laryngospasm and potential loss of the airway. Extubation when the patient still lacks full protective airway reflexes can also lead to aspiration. Safe deep extubation requires planning and preparation.
Plan For The End At The Beginning
While we spend a great deal of thought on induction and intubation, it’s unfortunately easy to approach extubation much more cavalierly. You must always prepare for problems in case your patient fails extubation. This is especially true if you are considering deep extubation.
Who Should Not Be Extubated Deep?
Deep extubation, when the patient still lacks full protective airway reflexes, is a calculated risk. Any patient at high risk for airway obstruction, vomiting, or aspiration should NOT be extubated deep. Do NOT perform deep extubation on patients with:
- full stomachs
- gastrointestinal ileus or diabetic gastroparesis
- upper or lower GI obstruction
- known history of difficult intubation or difficult ventilation
- obvious signs of potential airway difficulty such as super morbid obesity or airway trauma
- airway edema from trauma or administration of large volumes of IV fluids or colloids
- fixed instrumentation impeding reintubation, such as halo traction or a jaw that is wired shut.
The Difficult Airway Society (Figure 16) and the American Society of Anesthesiologists’s Task Force on Management of the Difficult Airway have published clinical practice guidelines for managing the difficult airway, including an extubation algorithm. For further discussion of management of the difficult airway, and complications that can arise in airway management see:
10 Rules for Approaching Difficult Intubations: Always prepare for Failure
Boredom Interrupted: 10 Causes of Airway Complications and How to Avoid Them
Does This Patient Meet Extubation Criteria?
To even consider deep extubation, your patient should meet awake extubation criteria except, of course, for obeying commands and having intact airway reflexes. Routine extubation criteria include:
- inspiratory capacity of at least 15 ml/kg;
- no hypoxia, hypercarbia, or major acid/base imbalance;
- no cardiopulmonary instability;
- intact muscle power;
- absence of retraction during spontaneous respiration;
- absence of a distended stomach.
In other words, you want your patient to be stable, able to breathe without help, at minimal risk of vomiting and aspirating, and able to protect the airway. There are rare instances when extubation without meeting these criteria may be appropriate. However a patient who fails to meet all criteria should be extubated awake. An example of a case requiring a decision of whether to extubate or not extubate can be found here:
To Extubate or Not to Extubate: That Is the Question
Technique Of Deep Extubation
Approach deep extubation with careful attention to detail. These are the steps that I follow. Deep extubation is most easily performed if the patient has been given inhalational anesthesia since the gas will allow them to breath spontaneously while still blunting their cough reflex against the endotracheal tube.
Reverse Any Muscle Relaxation
Ensure that any muscle relaxant is effectively reversed. Deep extubation prevents you from assessing head lift and other tests of strength. Therefore, when performing deep extubation you must rely on train of four and sustained tetanus, recognizing that those measures can sometimes be misleading. Typical neuromuscular monitoring is crude. A patient can still have up to 65-75% motor blockade with an intact train of four, and up to 50% with sustained tetanus. Time your reversal to give it optimal time to work. Neostigmine, for example, needs 7-8 minutes for peak action.
Get Patient Breathing Spontaneously
Having your patient breathing spontaneously is a safety precaution. It allows you to gauge that he/she has adequate respiratory rate and tidal volume. Any tachypnea more than 25 breaths per minute at this point can alert you to the need for more opiate pain relief. Spontaneous respiration lets you titrate any opiates slowly to effect, avoiding apnea.
Have Airway Equipment Ready
Always have the equipment needed toreintubate at the bedside whenever you extubate. Be prepared to immediately ventilate your patient if they should become apneic or go into laryngospasm. Have an assistant available to help. Remember that reintubation in an emergent situation is often more difficult than the initial intubation.
Suction the Airway
Secretions are the enemy. Any secretions falling on the vocal cords after extubation can trigger laryngospasm. Secretions sucked into the trachea can cause aspiration. Suction the oropharynx well. If the patient reacts to suctioning they are not deep enough for deep extubation.
Consider Placing An Oral Airway
Having an oral airway in place before extubation is a nice precaution. For awake extubation it prevents the patient from biting the ETT. Inserting an oral airway after extubation can be more difficult if your patient clenches their jaw shut. If the patient resists placing an oral airway they are not deep enough for deep extubation.
Provide 100% Preoxygenation
Return to 100% FiO2 early enough during surgical closure so that the patient is fully preoxygenated for extubation. If there is apnea or laryngospasm, this pre-oxygenation will help protect your patient from hypoxia while you are treating.
Ensure Patient Is Deep (Not In Stage 2)
It’s the goal of every anesthesia provider to have their patient awake, stable, comfortable, and headed to recovery within minutes of the end of surgery. To this end we slowly decrease the depth of anesthesia during closure so that when that last stitch goes in our patient ready to extubate. A planned deep extubation does not preclude that, but it does mean you have to ensure your patient is deep, and not in stage 2, when you actually pull the ETT or LMA out.
Before deep extubation, check for signs of stage 2 such as dysconjugate gaze or irregular breathing. If the patient appears deep, then test reactive airway reflexes. Suction the airway, as already suggested. Deflate and reinflate the ETT cuff, or gently jostle the tube. Failure to react means the patient is deep enough to extubate.
If the patient holds his breath, or even more obviously coughs, then the patient is too light. At this point you must decide either to continue with deep extubation, or proceed to awake extubation. If you still want deep extubation, then increase the gas concentration for a minute or two to quickly and briefly deepen anesthesia. Some providers give a small dose of IV lidocaine or propofol. The goal is to blunt reactive airway reflexes — not stop breathing or significantly delay wake up. Check reflexes again before extubating.
Perform The Deep Extubation
Pull out the tube. After extubation your room crew may assume the risk is over and immediately try to disconnect monitors and move your patient to the gurney. Stop them! Any extubation is one of the most dangerous times during your anesthetic.
Immediately after extubation, replace your ventilation mask and verify that your patient is breathing with an open airway. Make sure the pulse oximeter is still on. It’s common for the patient to hold their breath for a few seconds after pulling out the tube. Keep the airway open with a jaw thrust. If no breathing in 30 seconds or so gently assist breathing.
When breathing begins make sure it’s adequate. Up until moments ago your patient’s airway was stented open by either an ETT or LMA. The patient may still need some pressure support until oropharyngeal muscle tone returns and the patient wakens. Continue to support the chin until the patient can keep their airway open on their own.
When possible, raise the back of the bed to optimize ventilation and improve respiratory mechanics.
What If Laryngospasm Occurs?
Once the laryngospasm reflex is triggered in a semi-conscious patient, it often persists for a dangerously long time because the part of the brain that would normally turn it off is “asleep”. Getting the patient out of stage II will break the spasm. This can be done either by deepening the anesthetic (with gas or IV agents) or allowing the patient to awaken to the point where the reflex stops itself. However, hypoxia can develop quickly. If the spasm isn’t broken, this hypoxia can lead to cardiac arrest. Waiting out the spasm usually isn’t an option. Call for help immediately and don’t hesitate to administer a small dose of propofol or muscle relaxant if it persists for longer than a few breaths. For a longer discussion of laryngopsasm see:
Laryngospasm is a Life-Threatening Emergency
Whether you extubate deep or awake, always optimize your patient for the extubation. Hemodynamics should be stable; preoxygenate well; suction the airway clear of secretions; and make sure muscle relaxation is reversed. always be prepared for a failed extubation.