In Reply:--We find it difficult to accept Larson's contention that he and his patients have a common understanding as to the meaning of these terms when, as evidenced by this correspondence, even we who are educated in the field cannot agree. Our experience is quite the opposite of his. We commonly receive patients who, based on hearsay, insist on one anesthetic or another with little concept of what they are talking about. They may grasp, for example, the term "general anesthetic" as to a life raft in the storm of their fears. In the ensuing discussion, it may become clear that the real issue is that the patient does not want to be aware during the surgery. Careful and empathetic explanation that this can be achieved without "general anesthesia" is not always successful in prying loose that grip. This is just one of many examples we could offer as to how these terms frustrate communication.
As to the definition of "general anesthesia," we do not agree that it is simply a drug-induced loss of consciousness where there is no awareness of pain and the patient does not move during cardiopulmonary bypass. Several percent of patients receiving "general anesthesia" may have awareness and recall of the intraoperative events--a figure not much different than that for patients undergoing rhinoplasty under "local anesthesia with sedation". [1]The latter, incidentally, are often adamant about not wanting a "general anesthetic," as if the avoidance of this term makes the procedure less intimidating.
We agree that nociception under inhalational anesthesia is not pain per se. This is why we introduced the issue speaking of "nociceptive afferent stimuli." "Pain is when it hurts" is the traditionally accepted definition. However, with recent advances regarding nociceptive hyperexcitability ("windup") perhaps we need to be more inclusive. The patient's consciousness may not remember the pain, but the nervous system does and is changed because of it. The patient also may not remember the surgery, but no one would suggest it was not performed.
Regarding the term "conscious sedation," we maintain our position that its self-contradiction makes it ridiculous. Does it refer to the sedated patient who speaks to you or only to the patient who remembers having spoken to you? Does it refer to the patient who is barely arousable or only to the patient who is spontaneously conversing. It would be more meaningful if we spoke of "sedation" to a described level. To this end, a universally accepted sedation scale would be useful.
It appears that Larson has confused our dissatisfaction with the terminology for a commentary on how to conduct an anesthetic. We agree that of often it is desirable to add an inhalational agent to an epidural anesthetic or to administer a sedative-amnestic agent and an opioid analgesic before performing a regional anesthetic. However, what is an "ordinary anesthetic?" Are not most anesthetics "combined" in one fashion or another? Where we differ is that we would not tell patients they are to have "an epidural anesthetic and a general anesthetic." We would rather tell them they are to receive a general anesthetic but that, beforehand, we will be inserting an epidural catheter to help block any pain both during and after the operation. Or we might tell them they are to receive an epidural anesthetic but also other drugs so that they will sleep during the operation. It may be subtle, and it may be clumsy, but there is a difference.
In having raised the issue, we did not mean to suggest that we also had the solution to these problems of terminology. To the contrary, we are frustrated by them. It is our hope that useful suggestions will arise as a result of these communications.
Bruce Ben-David, M.D., Hilton Levin, M.B.B.Ch., Eric Solomon, M.B.Ch.B., Department of Anesthesiology, Herzlia-Haifa Medical Center, 15 Horev Street, Haifa, Israel.
(Accepted for publication May 27, 1995.)