"It's something I can say with confidence, even one case of this is too many," he said.
Apfelbaum explained that in certain patients, easing back on anesthesia for brief periods during surgery to minimize the medication's depressive impacts on essential body functions is necessary to keep the patient alive. For example this can occur "in open heart surgery or a major trauma procedure or during a Caesarean, where the life of the patient or the fetus was endangered and the margin between life and death is extraordinarily slim."
In those patients, said to be at higher risk for surgical awareness, moments of cognition and comprehension may be more common. But that's somewhat different than the completely unintended intraoperative awareness cases described at Pomerado, he said.
The issue is complicated further, Apfelbaum emphasized, because every patient is different. The patient's age, level of disease and brain activity, type of anesthetic drug used, patients' medication history, prior alcohol consumption or other drugs regularly used, general sensitivity, and body mass index can all play a role in determining how much anesthesia is necessary to do the job. And how much might not be quite enough.
Determining it for each patient might be described as anesthesiologist's art as well as a science.
Apfelbaum told me that anesthesiology researchers are trying to get a better handle on when certain surgical patients are at greater risk of waking and being aware of what's happening. But unfortunately, there is no way to detect the degree of a patient's consciousness during surgery. At least not yet.