Why is the patient moving despite being under general anesthesia?
TL;DR:
- Patient movement under anesthesia is not due to the patient waking up.
- If feasible, please alert me before deeply stimulating the patient (e.g. extractions, injections).
- Using local anesthetic on patients under general anesthesia is always welcome and helps quite a bit.
- My deep apologies for any and all patient movements.
Longer version:
To my esteemed dental colleagues:
At times during cases in which we collaborate, the patient moves despite being under general anesthesia. I understand this can cause concern. Please allow me to share some information regarding why this occurs and ways we can collaborate to provide optimal care for our patients.
1. Patients move when under general anesthesia because the depth of anesthesia at that moment is insufficient for the degree of stimulation that occurred. This means that anytime you anticipate stimulating the patient more severely (e.g. extractions, injections, etc.), it would be helpful if you alert me at least a minute or two ahead of time so that I can deepen the anesthesia before the greater stimulation occurs.
2. One question that naturally arises is why we do not simply provide a greater depth of anesthesia during the entire procedure so that #1 above is never a concern. That is an option, but it comes with many, many drawbacks, including:
A. Greater risk of side effects (especially post-procedure nausea, respiratory depression, involuntary shivering, etc.),
B. Slower emergence from anesthesia afterwards and a longer duration of time between the end of the dental procedure and when the patient can safely depart from the clinic, and
C. A higher likelihood that the parents will later call with concerns about their child not yet returning “back to normal” due to a longer duration of post-procedure somnolence.
3. When concerns are expressed about the patient moving, typically the reason for concern is the assumption that the patient may be waking up, is experiencing the discomfort of the procedure, and may complain afterwards of such. Please rest assured that the patient is not waking up. Even though the depth of anesthesia at that moment was apparently insufficient for the stimulation occurring at the time, the depth of anesthesia is still far greater than the minimum threshold necessary to keep the patient asleep (and without any ability to recall what was occurring). An approximate analogy would be how someone asleep at home might move at times in response to sound and yet have no recall of the incident afterwards. In short, the patient moving does not indicate that he/she is waking up.
4. Having said the above, I certainly apologize for any and all patient movements under anesthesia. It is definitely not my desire that the patient move, especially when those movements interfere with the feasibility of the dental procedure. The only reason the patient ever moves is because of my choosing to error on the side of less rather than more as well as the high degree of variability that exists among patients in terms of how much anesthesia is just enough to prevent all movements.
5. For any procedures in which you would normally inject local anesthetic for an awake patient, it would be helpful if you did so as well for patients under anesthesia. I understand this may be a surprising request since it may seem unnecessary to provide local (or regional) anesthesia when the patient is asleep. However, injecting local anesthesia helps to substantially decrease the degree of stimulation received by the patient’s body (just like when the patient is awake) and hence allows for less patient movements, a more shallow depth of anesthesia, and less side effects afterwards. Dental procedures are just as stimulating to patients under anesthesia as to those who are awake; the only difference is that the patient under anesthesia does not remember the experience. The patient’s body experiences the stimulation all the same though.
Thank you for your time and for the privilege of working with you and participating in the care of our patients. Please feel free to let me know if you have any questions.
Amos Yang, MD 