January 02, 2011

Anesthesia Sleep is Actually a Coma and Implications for Snoring Evaluations

On December 30, 2010, the New England Journal of Medicine published a paper titled "General anesthesia, sleep, and coma". The article goes on to describe normal sleep as well as sleep induced by anesthesia at time of surgery. What researchers have found is that anesthesia-induced sleep actually is more like a deeply unconscious coma patient than someone sleeping.

This actually makes sense to me... When a person sleeps, they can be aroused if noxious stimuli is introduced causing the person to wake up... and most likely yell at the person trying to wake them up. However, in a coma patient, the person does not "wake" up no matter what is being done to them.

During surgery, the last thing you want is for the person to wake up. As such, a coma-state would be preferred rather than a true sleep state.

This finding does have implications for snoring research as there have been several papers (see references below) in the recent past that proposed the use of anesthesia in order to pinpoint where a person's snore is coming from.

Why would this exam be helpful at all? Because one could perform a variety of endoscopic evaluations while a patient is sleeping (or rather coma) to find the culprit tissue vibration causing the snore. Is it the soft palate or nose or tongue or voicebox or a combination of factors? Such an exam is not possible if the person is "sleeping" as they would just wake up.


Without knowing where the snoring is coming from, treatment is at best a good guess.

This sleep research does potentially cause one to pause and wonder whether an exam of snoring during anesthesia is an accurate portrayal of snoring during sleep.

After all... a coma is not the same as regular sleep. It does follow that potentially, snoring during a coma is not the same as that found in regular sleep which would invalidate any exam findings regarding snoring localization.

In fact... I wouldn't be surprised if snoring sources found during anesthesia-induced coma is more severe (and potentially different) than that found during regular sleep and may needlessly lead the surgeon to pursue more aggressive snoring surgery than truly required.

Clearly, more research is needed. Indeed, in one paper published back in 1998, snoring was produced during anesthesia in 45.3% of non-snorers and could not even be produced in 18.1% of snorers!!!


References:
General anesthesia, sleep, and coma. N Engl J Med. 2010 Dec 30;363(27):2638-50. Press Release

Validity of sleep nasendoscopy in the investigation of sleep related breathing disorders. Laryngoscope. 2005 Mar;115(3):538-40.

Acoustic parameters of snoring sound to compare natural snores with snores during 'steady-state' propofol sedation. Clin Otolaryngol. 2006 Aug;31(4):341-2; author reply 342.

Propofol-induced sleep: polysomnographic evaluation of patients with obstructive sleep apnea and controls. Otolaryngol Head Neck Surg. 2010 Feb;142(2):218-24.

The value of sedation nasendoscopy: a comparison between snoring and non-snoring patients. Clin Otolaryngol Allied Sci. 1998 Feb;23(1):74-6.


Fauquier blog
Fauquier ENT

Dr. Christopher Chang is a private practice otolaryngology, head & neck surgeon specializing in the treatment of problems related to the ear, nose, and throat. Located in Warrenton, VA about 45 minutes west of Washington DC, he also provides inhalant allergy testing/treatment, hearing tests, and dispenses hearing aids.

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