ULTIMATE COMPUTING - Quantum Consciousness Studies

Anesthesia: Another Side of Consciousness 149
Figure 7.1: Levels of anesthetic depth from different systems displayed on a
common axis. Guedel’s (1937) stages and planes serve as a standard. EEG
levels (Courtin, Bickford and Faulconer, 1950), jaw and forearm relaxation (Galla,
Rocco and Vandam, 1958), Woodbridge’s (1957) classification of nothria, and
stage one for ether (Artusio, 1955) are also represented. With permission from
Grantham and Hameroff (1985).
In Guedel’s stage one (Figure 7.1), the patient progresses from alertness and
sensibility to pain to total amnesia, analgesia, and sedation. Breathing is slow and
regular, with use of both diaphragmatic and rib muscles; the eyelid reflex
(twitching of the eyelids in response to gentle brushing) is intact. Stage two has
been variously termed the stage of delirium, excitement, unconsciousness, or the
“dream state.” The patient may pass through this stage sedately or may manifest
wild, uninhibited activity. Breathing is irregular and unpredictable, pupils of the
eye may be dilated, ocular muscles are active, and eyelid reflex active. In this
stage the patient is at risk for unwanted reflex activity such as vomiting, spasm of
the airways and cardiac dysrhythmias. The stage two excitement phase caused by
anesthetics is somewhat puzzling. Early explanations described inhibition of
neocortical “inhibitory” brain circuits, leading to unchecked primitive activity.
However, anesthetic effects on single neurons may also show an excitatory phase,
thus anesthetic induced “excitation” may be a molecular level effect at low
concentrations. Guedel’s stage three has four different “planes” of progressively
deeper anesthesia during which surgery may be performed. Muscle relaxation is
slight in plane one, but progresses to complete abdominal muscle relaxation in
planes three and four. Breathing is very irregular and periodic in plane one, as in
normal sleep. With plane two, a pause develops between inhalation and
exhalation, and inhalation becomes shorter relative to exhalation. Paralysis of rib
muscles begins in plane three, and diaphragmatic breathing is prominent. In plane
four, paradoxical movement of the rib cage occurs with inhalation, breathing is
irregular, and if anesthetic depth is not lightened breathing will stop altogether.
Eye muscles are active initially in plane one, however the eyes become immobile
when plane two is reached. The eyelid reflex disappears in plane three. The pupils