Re: Some people having surgery 'feel' the operation.

Steve, what a great question!

There are indeed three things that the surgeon expects the anesthesiologist to accomplish during surgery on a patient, as you mentioned: no pain, no consciousness, and no movement. This is generally accomplished with the use of two types of drugs. The first one (which can actually be a mixture, called a cocktail, of various chemicals all having somewhat the same attributes but each compound much less toxic at the lower doses that can be given when they are all mixed together) will take care of the first two items on the list, you loose consciousness and should feel no pain. These first two effects can be aided by the pre-operative administration of one of many potential tranquilizers that further reduces pain perception and makes the patient less concerned about everything that is about to happen to him. The second compound is a paralyzing agent that stops all skeletal muscle contraction and, in those surgical cases where paralysis is indicated as a necessary component, is administered only on the operating table. Paralysis is induced as an endotrachial tube is simultaneously passed into the trachea to keep the individual alive for the obvious reason that since the diaphragm is skeletal muscle, the anesthesiologist must breath for the patient when the paralyzing agent is administered.

This answers one of your speculations about getting physiological clues that the patient is in pain. The paralyzed diaphragm means that no change in respiration rate will ever be seen. There could be some changes in cardiovascular function but this might not be interpreted as an indication of pain but a spinal reflexive response to the surgical procedure. In some surgical cases the anesthesiologist will also administer an amnestic (compound causing amnesia or memory loss) agent so that even if the patient can’t have very high doses of anesthetic (because of preexisting organ failure conditions like liver, or heart, or kidney damage) then the patient won’t remember anything that happened during the procedure after waking up.

Of course no doctor wants the patient to be in pain but it is a reality that sometimes a mistake in the dosing of a patient, or an unusually fast metabolic processing or clearance of a particular anesthetic agent by a particular patient allows for some pain perception at the conscious level. If I were on the operating table I would sure rather have the anesthesiologist err on the side of an underdoseing rather than an overdosing.

There are a number of good books on anesthesiology and I have one that is like the Bible of anesthesiology by Vincent J. Collins called "Principles of Anesthesiology". I have the second edition published by Lea & Febiger from 1976. I am sure you can find a more up-to-date edition in your library if you want to know more about the subject. Lea & Febiger is no longer in business but has been taken over by Saunders, I think.

Within the next decade there will probably be developed the means to monitor the level of anesthesia (consciousness) accurately throughout surgery. That will be nice when it comes.

Happy reading!

Dr. Swanson