Chapter 22
Emergence 101

Emergence is one of the most critical and often underestimated phases of general anesthesia. Despite occurring at the end of the case, when disaster feels averted, emergence is the perioperative phase that is most associated with anesthesia-attributable respiratory complications. It makes intuitive sense: patients are still under the influence of respiratory depressants, their CO₂ drive is blunted, and their ability to protect the airway is compromised. Add to that an airway that’s been recently instrumented, potentially swollen or reactive, and you have the perfect storm for a respiratory event.

Your mindset during emergence should prioritize safety, not speed. That may feel counterintuitive because the end of a case brings a collective exhale in the OR: surgical drapes are coming down, the team is catching up on notes, etc. But this moment demands your vigilance. If your attending isn’t immediately present, don’t hesitate to recruit a circulating nurse for assistance. They are often eager to help and are equally invested in patient safety.

Emergence ideally begins when the case is truly over, and the procedural team has turned the patient over to you. This means wounds are sealed, drapes are off, the incision is complete, and the patient is supine and fully covered. There are many false starts: sometimes the surgical team still has to mature an ostomy, perform a vaginal or rectal exam, fasten a wound vac, perform X-rays, or place casts. It’s important as a trainee to observe the flow of different types of cases before you jump the gun to emerge before it may be appropriate. Resist the urge to rush. You’ll have your entire career to become efficient. In training, your priority is safe and controlled emergence.

You can start to lighten the anesthetic cautiously toward the end of the case, but keep your eyes on the surgical field. Ideally, wait for your attending before making any major changes. Certain scenarios warrant particular caution:

Craniotomy patients with pins still in place: Never allow the patient to breathe spontaneously or cough while the head is fixed in a Mayfield head fixation device. Movement around a rigidly secured skull can cause injury.
ENT or neurosurgical cases with limited airway access: Do not begin emergence until you can physically reach and control the head and airway.
Pending frozen sections: For cases where margins were sent to pathology, confirm with the surgical team that they don’t anticipate re-opening before initiating wake-up.
Casts, wound vacs, or complex dressings: Keep the patient still and sedated until these are completed.
Prone, lithotomy, or otherwise vulnerable positioning: Avoid letting a patient wake up while in a compromised or unsafe position.
High-risk surgical fields (head, neck, vascular neurosurgery): The sympathetic surge of emergence can be dangerous. Hypertension and bucking at the end of a neck dissection, for instance, are common but preventable. Plan ahead by ensuring the patient has adequate pain control and have labetalol handy.

Emergence Pearls

Unlike induction, you don’t control emergence; the patient does. As much as we like to believe we’re in command, the reality is that emergence is shaped far more by patient physiology than by any finesse on our part. Younger patients, particularly teenagers, are at higher risk for an agitated emergence. Smokers and patients with reactive airway disease are more likely to cough and buck. Elderly patients may experience very prolonged emergence, as can patients who have had neurologic instrumentation. Patients who use psychoactive substances may exhibit severe post-extubation agitation. There’s only so much you can control, as many of these are immutable patient characteristics.

Experienced providers often share tricks to smooth emergence, such as deep extubation, cuff lidocaine, the “propofol wake-up,” and other similar maneuvers. These can reduce stimulation but cannot eliminate it; an awake patient with an endotracheal tube will inevitably cough or buck, reflecting an intact nervous system rather than poor technique. If this occurs before the surgical team is finished, the safest response is to re-sedate and regain control rather than rush extubation. A brief propofol bolus is a small price to pay for patient safety and surgical integrity. While bucking cannot be prevented entirely, it can be minimized through adequate analgesia, use of IV maintenance agents, and techniques such as filling the cuff with lidocaine to blunt airway irritation.

Most recommend beginning to allow spontaneous ventilation once the critical portions of closure are finished, and titrating opioids to maintain a respiratory rate between 8 and 12 breaths per minute. This is a reasonable window, but remember that respiratory rate alone is a blunt tool. Some patients breathing at a rate of 8 might still be in severe pain, and some patients may be tachypneic for other factors unrelated to surgical pain. Pain is subjective, and ventilation is complex. Use multiple inputs to guide your assessment.

If you find yourself dealing with a slow wake-up, don’t see it as a failure, but rather see it as a learning opportunity. Consider what you could do differently next time. There’s no such thing as a “perfect” emergence, and time is not a factor. There is only a safe emergence.

Avoid shouting at the patient in the hopes it will accelerate wakeup. Shouting does not help and may only have the result of bystanders instinctively escalating their concern. Stay calm. Keep the patient warm. Tidy up lines and monitors. Prepare for PACU. The patient will wake up when they are ready. Your job is to keep them safe until they do.

Post-extubation Airway Obstruction

You will encounter a situation where the patient demonstrates adequate extubation criteria but begins to desaturate during transport or drop off in PACU. This is a common event and results from the cessation of surgery and the stimulating effect of an endotracheal tube. Opioid respiratory depressant effects are now unchecked and may lead to hypoventilation. As you travel to PACU and hand the patient over, remember that supplemental oxygen “masks” desaturation by maintaining oxygenation in the face of rising CO₂. Don’t be lulled into a false sense of security by a 99% SpO₂. Pay attention to ensure the patient is continuously breathing:

Watch for misting on the mask
Feel breath excursion with your ungloved hand
Listen for airflow with your stethoscope over the neck
Talk to the patient
Look for paradoxical (“rocking”) chest movements, which are a pathognomonic sign for upper airway obstruction. A jaw thrust or chin lift is indicated.

The process of transport may be full of distractions, but your focus has to remain on your patient.