Anesthesia (Monitored Anesthesia Care, MAC)
What is Monitored Anesthesia Care?
Monitored Anesthesia Care (MAC) is a type of anesthesia that is administered for minor procedures. It is sometimes called “twilight anesthesia” or “conscious sedation.” Patients technically remain awake during the procedure, but are very relaxed. The level of sedation varies depending on what is being done surgically or medically. Some patients are just a bit groggy, others go to sleep and later have no memory of the procedure. A combination of medications are used so patients, in addition to being sleepy, they do not feel pain.
Some examples of when MAC is used include having wisdom teeth removed in a dentist’s office or carpal tunnel surgery in a surgical center. It is often used for certain diagnostic procedures such as colonoscopies or endoscopies where some discomfort is associated with the procedure if done without any anesthesia, but not enough discomfort so that general anesthesia is required. MAC allows the patient to essentially sleep through the procedure and wake up immediately when it is over. The medications wear off quickly and the patient goes home the same day.
Patient care and safety
The anesthesia provider will review the patient’s medical history and any previous experiences with any and all types of anesthesia. It is important for the provider to be aware of all medications the patient is taking whether over-the-counter or prescription. Even herbs and other dietary supplements need to be reported to the anesthesia provider.
The provider needs to be aware of all allergies and whether or not the patient smokes or drinks alcohol. Only after obtaining all relevant information can the provider make an individual choice as to which medications are appropriate for each individual patient.
There are very few side effects to this type of anesthesia and patients generally, do not spend a night in the hospital. They have the procedure and anesthesia done in a surgery center where they return home at the end of the day.
Delivering the anesthesia
The anesthesia medications are given by intravenous injection. This provides sedation but not to the level of general anesthesia. Some patients experience a light sleep and are unaware of what is happening. Even these patients can be awakened if the procedure requires it. Other patients can respond to questions and instructions, but are too groggy to be totally aware of what is happening.
MAC is usually accompanied by a local anesthetic that is injected into the tissue at the surgical site. An anesthesia provider will be with the patient throughout the entire surgical or diagnostic procedure. The provider monitors the patient’s vital signs, including oxygenation of the blood, blood pressure and respiration. The amount of the anesthesia can be adjusted depending on the patient’s consciousness level and needs of the doctor or surgeon who is performing the procedure.
It is possible, but not common, that the level of anesthesia may need to progress to general anesthesia. Since the provider is with the patient continuously, the level of anesthesia can be easily adjusted if the circumstances require. Emergency paraphernalia is always available as a precautionary measure.
After the procedure
Patients initially feel somewhat groggy and possibly confused as the anesthesia begins to wear off. It wears off quickly and the patients recover as quickly. Patients may feel as if they slept through the entire procedure and have no memory of it. Side effects are minimal, but having a slight headache or experiencing some nausea are not unusual reactions.
Since patients are given sedation, they are advised to have someone drive them home and not to operate heavy machinery for at least 24 hours or sign any legal documents. Having someone stay with them for 24 hours is also advised.