“What happens if you stop breathing during anesthesia?”

The effect is the same as when you are not under anesthesia, i.e. your body's oxygen level goes down. The difference is that when you are under anesthesia, your body may not be able to respond to this decrease by breathing. One of the reasons for your anesthesiologist to be in the room with you during the surgery is to assess/intervene/help with situations like this.

Anesthesia providers are highly trained and skilled providers who will be present and attentive to you the entire time you are asleep. The basic elements of safe anesthesia care start with A B C. Airway, breathing and circulation. Your provider will be paying close attention continuously to these. Anesthesia care frequently suppresses breathing drive, amongst other things. It is an anticipated event in many cases and it is one that every anesthesia provider is skilled at managing. Sometimes simple positioning maneuvers or placement of an artificial airway is what is needed. Sometimes more help by using a mask with positive pressure or a breathing tube may be indicated. Whatever measures are needed, the anesthesia provide will deliver. That’s their job.

In response to your question regarding "stopping breathing" during anesthesia, physician anesthesiologists are the most highly trained experts in all types of airway management. This training includes medication-induced intentional cessation of breathing on most patients receiving general anesthesia, followed by manually-assisted or mechanically-assisted breathing using a mask or other airway device (such airway devices are normally placed into the patient's pharynx or trachea after the patient is unconscious). Some patients will receive regional-block anesthesia (such as an "epidural block"), forms of sedation, or total-intravenous anesthesia in which an airway device is not intended to be inserted. Such patients normally breathe without assistance, though they may have a small amount of supplemental oxygen supplied. In these types of anesthetics, if a situation develops in which the patient is not ventilating satisfactorily, the anesthesiologist will quickly proceed with assisted ventilation as described in the first paragraph. Such assisted breathing may be performed with a mask or other airway device.  
In summary: If you are receiving general anesthesia for a planned procedure, in most cases your breathing will be intentionally stopped and the anesthesiologist will take over control of your breathing using one of several options. If you are receiving sedation, a regional anesthetic, or total intravenous anesthesia, in which it is intended for you to breathe naturally and a situation arises in which you are not breathing satisfactorily, the anesthesiologist will take steps to assist your breathing.  

Jeffrey Anderson, MD

You will be and automatically placed on a ventilator for general anesthesia. There is no stopping breathing. Not under a general anesthesia. You are intubated. Your power to breathe is taken care of. Trouble with blood pressure changes. Heart irregular beats and such are the issues. If you are only under monitored anesthesia care meaning sedation without being intubated, then your airway and breathing must be monitored more carefully.

Thanks,

Dr. Marvin.

Typically, nothing important. Most if not all patients experience apnea (stop breathing) during an anesthetic. One of the reasons I am at the head of the bed the entire time is to monitor your breathing amongst other things. If you stop breathing, then there are a number of ways to assist you which are so routine, usually I am the only one in the operating room aware of that aspect of your experience. The surgeon, circulating nurse, and scrub tech usually have no idea, as it is such a routine issue. So, in short, don't spend 2 seconds worrying about it.

You may stop breathing by design; many general anesthetics require us to give muscle relaxants (i.e., "paralytics") that take away the ability to breath. This is why we place breathing tubes and use a ventilator.

In the event that you stop breathing during a sedation-type case, the anesthesia provider can assist you with a mask or place a breathing device. This is actually quite common and typically managed very easily.

Your anesthesia team will assist you in your breathing by masking you or inserting a device called laryngeal mask airway (LMA) or endotracheal tube (ETT). Once your spontaneous respirations resume, the devices are removed.