RESOURCE CENTER

General Anesthesia Is a Reversible Coma,Not a Deep Sleep

Debbie C. Sandlin-Leming, RN, CPAN

EVERY DAY, approximately 60,000 patients

undergo general anesthesia in the United States.1

Results of a three-year study published in Decem-ber 2010 in The New England Journal of Medicine

indicate that general anesthesia is not a deep sleep

as long believed, but is instead a drug-induced re-

versible coma that includes specific behavioral

and physiological traits including unconscious-

ness, amnesia, analgesia, and akinesia.1 Modern

general anesthesia began at Massachusetts General

Hospital approximately 160 years ago and, fittingly,this study was also conducted there.2 In the study,

the investigators demonstrate that the electro-

encephalogram (EEG) of a coma patient closely

resembles the high-amplitude, low-frequency ac-

tivity seen in a general anesthesia patient, and

that general anesthesia patients exhibit symptoms

of functional brainstem death.1

Origins of General Anesthesia

Chloroform, the first known drug to induce sleep,

was used by James Young Simpson in 1831 in En-

gland.2 As chloroform became recognized asa sleep agent, it was successfully given to Queen

Victoria during the birth of Prince Leopold in

1853.2 Chloroform unfortunately led to many

deaths and was not a good anesthetic drug.

In 1846, Dr. William T. G. Morton, a Boston dentist,

demonstrated the use of ether as a general anes-

Debbie C. Sandlin-Leming, RN, CPAN, is the Manager of

Outpatient Surgical Services, Southern Hills Medical Center,

Nashville, TN.

Address correspondence to Debbie C. Sandlin-Leming, Peri-

Anesthesia Services, Southern Hills Medical Center, 391 Wal-

lace Road, Nashville, TN, 37211; e-mail address: debbie

.sandlin@hcahealthcare.com.

� 2011 by American Society of PeriAnesthesia Nurses

1089-9472/$36.00

doi:10.1016/j.jopan.2011.01.005

122 Jou

thetic agent during surgery to remove a jaw tumor

at Massachusetts General Hospital.2 Although at

the time, ether was hailed as the ‘‘greatest giftever made to suffering humanity,’’2 it had many

side effects including severe postoperative nausea

and vomiting. Over the years, general anesthesia

has been refined with newer agents, resulting in

fewer adverse side effects.

Pertinent Definitions

Coma is defined as a state of prolonged uncon-

sciousness, usually caused by trauma, stroke, brain

tumor, or drug and/or alcohol intoxication. The

patient in a coma presents with closed eyes, unre-

sponsive pupils, irregular breathing, and lack of

response to pain, except for reflex movements.3

General anesthesia is defined as a treatment that

renders a patient unconscious for surgical proce-

dures and prevents the brain from responding

to the pain of the procedure.4 Additional traits of

general anesthesia include amnesia, analgesia,

and akinesia.1,4

Study Physicians

One member of the research team for this project

was Dr. Nicholas D. Schiff of Weill Cornell Medical

College in New York, an expert in coma recovery,

and Director of the Laboratory of Cognitive Neuro-

modulation. He conducts research examining neu-

rophysiological mechanisms of arousal and the

pathophysiology of impaired consciousness.5

Dr. Emery N. Brown, a professor of Anesthesia

at Harvard Medical School, Director of the Neuro-

science Statistics Research Laboratory of the

Department of Anesthesia and Critical Care at

Massachusetts General Hospital and Professor of

Computational Neuroscience at Massachusetts

rnal of PeriAnesthesia Nursing, Vol 26, No 2 (April), 2011: pp 122-123

RESOURCE CENTER 123

Institute of Technology, was another member of the

research team.6

The third member of the research team was

Dr. Ralph Lydic, Professor of Anesthesiology, Pro-fessor of Physiology, and Associate Chair of Anes-

thesia Research at the University of Michigan,

who specializes in sleep.7

Implications for the Future

According to Dr. Brown, better understanding of

general anesthesia as a comalike state could some-

day help patients who are in a more permanent

vegetative state as they emerge back to conscious-

ness, similar to the process of a patient waking up

from general anesthesia.8 Dr. Brown also says that

the knowledge of the workings of anesthesia mayhelp by showing the similarity of brain shutdowns

on EEGs in coma and in general anesthesia.

In conclusion, a better understanding of sleep and

coma may lead to new approaches to general anes-

thesia based on new ways to alter consciousness,

provide analgesia, induce amnesia, provide muscle

relaxation, and reverse coma.1

References

1. Brown E, Lydic R, Schiff N. General anesthesia, sleep and

coma. N Engl J Med. 2010;363:2638-2950.

2. James S, ABC News. Anesthesia induces coma, not sleep.

December 30, 2010. Available at: http://www.abcnews.go

.com/print?id512503522. Accessed January 3, 2011.

3. MayoClinic.com, Mayo Clinic Staff. Coma. Available at:

http://www.mayoclinic.com/health/coma/DS00724/METHOD5print. Accessed January 3, 2011.

4. General anesthesia. Available at: http://www.bing.com/

health/article/mayo-127115/General-anesthesia?q=general+

anesthesia. Accessed January 3, 2011.

5. Weill Cornell Physicians Home Page. Nicholas D. Schiff,

MD. Neurology. Available at: http://www.weillcornell.org/

ndschiff. Accessed January 6, 2011.

6. Faculty Profile. Emery N. Brown, MD, PhD. Available

at: http://sleep.med.harvard.edu/people/faculty/150/Emery+

N+Brown+MD+PhD. Accessed January 6, 2011.

7. Neuroscience Graduate Program, University of

Michigan. Ralph Lydic, PhD. Available at: http://www

.umich.edu/�neurosci/faculty/rlydic.htm. Accessed January 6,

2011.

8. Harmon K. The body under general anesthesia tracks

closer to coma than sleep. Available at: http://www.scientific

american.com/article.cfm?id5general-anesthesia-coma&print5true. Accessed January 3, 2011.