Discovery Health: Anesthesia (Reporting) Nightmares
Posted by Clark Venable on 3/1/2005
I watched 'Anesthesia Nightmares' on the Discovery Health channel last night (listing). As an anesthesiologist, the awareness and recall of surgery are of grave concern to me, so I tuned in for what I hoped would be an informative, informed, hour of Discovery Health television. What I saw amounted to fearmongering.
Let me state at the outset that I do not doubt the ordeals described by the victims interviewed in the show. Awareness and recall under anesthesia happen. How often they happen has recently been answered by an article titled The incidence of awareness during anesthesia: a multicenter United States study. The study was funded by the company that makes depth of anesthesia monitors (Aspect), but I can't find fault with their data:
Before I point out some of the specific information I disagree with, let me make a few general points.
I. Not every occurrence of awareness is the kind of 'anesthesia nightmare' described in the show. This should have been pointed out during the report. From the article referenced above:
Summary of Awareness Descriptions (n = 25)
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II. We know the risk of awareness is higher in certain kinds of operations (trauma resuscitations, open heart surgery, and emergency cesarean sections are three that come to mind) and in certain kinds of patients (patient with significant coexisting medical conditions such as heart disease or renal failure). In those cases there is a trade-off between depth of anesthesia and patient well-being. There can also be awareness during an unanticipated difficult airway (the first dose of injected anesthetic begins to wear off before the inhaled anesthetic is started.
III. We sometimes are asked to do anesthetics which would not be our first choice. Certain orthopedic spine procedures require special monitoring which is in turn affected by anesthetic levels. We have to modify our preferred anesthetic to take into account this new requirement--and the risk of awareness is higher if we can't use inhaled agents, for example.
Let me now give some quotes from the show that I think are misleading and explain why I think so:
Narrator: "The gas was not working, but like all surgical patients, Joe had also been given a paralytic drug"
This is false. Most surgical patients do not receive a paralytic drug. Intra-abdominal, intrathoracic, intracranial cases do because the surgery could not be done without them, but that's not a majority of cases. We try to avoid giving paralytics unless they're clearly indicated.
Dr. Frank Sweeny: "There are a variety of theories about what anesthesia is, but really I can summarize it in three words: We Don't Know"
This is simply a poor choice of words on Dr. Sweeny's part or Discovery Health taking it his quote out of context. Although it is true we do not precisely understand the mechanisms of some anesthetics, we do know a great deal about how these drugs work as evidenced by the safe and uneventful conduct of the vast majority of anesthetics given each day.
Narrator: "Anesthesiologists have to find a delicate balance between three types of drugs: paralytics to prevent movement, analgesics to dull pain, and narcotics to induce unconsciousness"
Well, not quite. Anesthesiologist seek a balance between drugs that cause unconsciousness, amnesia, anxiolysis, attenuation of the stress response, and muscle relaxation (for a history, see this article). Narcotics are used to block pain and therefore attenuate the stress response (but so do drugs like beta blockers). Narcotics do not induce unconsciousness (very well). We use inhaled anesthetics (such successors to ether) and intravenous anesthetics (such as successors to sodium pentothal) for that. It is this line that makes me think that the creators of this show did not allow an anesthesiologist to screen the final product for accuracy.
Narrator: "What no one in the operating room realized is that the canisters of anesthetic gas were empty"
This can happen, but if the pre-anesthetic checklist is used properly, it won't. Checking anesthetic levels is on the checklist. In addition, one of our inhaled anesthetics (Desflurane) has a vaporizer with a built-in alarm for when the anesthetic level gets low that can then be refilled without having to turn the vaporizer off (thus eliminating the risk of forgetting to turn the vaporizer back on).
Narrator: "A muscle relaxant is used to keep the body still during surgery"
A muscle relaxant is used to relax (paralyze) the muscles. We keep the patient still by making sure they are sufficiently anesthetized. Reflexly giving more paralytic if a patient moves is the wrong response. First insure lack of awareness, lack of pain, adequate anesthetic levels, then consider re-dosing the muscle relaxant.
Narrator: "Studies have shown that mistakes happen in 3% of all operations."
That may be true, but it's far too vague to have any bearing here. Mistakes by whom? Of what magnitude? Did harm actually come to the patient?
Finally the show introduces the brain monitor called Bis (for Bispectral Index), and the person introducing it is a Dr. Don Mathews. What the series does not indicate is that Dr. Mathews is on the speakers buereau for Aspect medical, maker of the Bis monitor. Dr. Mathews narrates a case where the patient actually requires less anesthesia than he thought--and that's exactly my experience with the Bis monitor. After using it for several years, I have never deepened someone's anesthetic because of what the monitor showed, only lightened it. The Bis monitor, and others like it, is being studies intensely in the literature, but I don't think there's a consensus yet. Bis measures level of hypnosis. Not depth of anesthesia. Using Bis makes no difference in the incidence of painful awareness.
It's late and I want to get this posted, but reserve the right to add a Part II should the urge arise.
For more information, see the JCAHO Sentinel Event Alert on "Preventing, and managing the impact of, anesthesia awareness" published in October 2004.
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