Clinical Corners in Sleep Medicine

The development of central sleep apnea with an oral appliance

Alon Y. Avidan *

University of Michigan Hospital System, 8D-8702 University Hospital, Box 0117, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0117, USA

Received 2 June 2004; received in revised form 1 June 2005; accepted 1 June 2005

A 32-year-old gentleman presented to the sleep disorders

center complaining of apneic spells during sleep, which

were witnessed by his bed partner, and of snoring and

daytime sleepiness. His body mass index (BMI) was

34 kg/m2, his neck circumference was 18 in. and his

oropahryngeal examination revealed a Mallampati classifi-

cation of III.

The results of the baseline sleep study are illustrated in

Table 1, column A. His respiratory disturbance index (RDI)

was 12.6 with a minimum oxygen saturation of 89%. He was

subsequently referred for a CPAP titration, and a pressure of

7 cm was recommended. The patient attempted to use CPAP

for three months, but he is a frequent traveler and felt that the

CPAP machine was too cumbersome to travel with.

He was subsequently evaluated in a multidisciplinary

alternative to CPAP clinic where he was seen by a sleep

specialist, a dentist, a maxillofacial surgeon and an

otorhynolaryngologist. The decision, based on the

1389-9457/$ - see front matter q 2006 Published by Elsevier B.V.

doi:10.1016/j.sleep.2005.06.013

* Corresponding author. Tel.: C1 734 615 3136; fax: C1 736 647 9064.

patient’s preference and consultations with the subspe-

cialists, was to try an oral appliance. He was prescribed

Dental Sleep Relief Appliance (DeSRAw). A diagram of

DeSRA is provided in Fig. 1 courtesy of David Heeke,

DDS. After using the appliance for 7 weeks he returned

for a follow-up visit and reported that the appliance had

helped his snoring, according to his bed partner, but that

he had not noted significant improvement in his

sleepiness. The results of a follow-up sleep study while

using the DeSRAw appliance after 2 months of therapy is

indicated in column B. Snoring was eliminated but the

patient had a higher RDI in comparison to his original

study, and frequent central apneas were now recorded

while the patient used the oral appliance.

Discussion question:

What could explain the central sleep apnea noted in the

follow-up sleep, and what should be the response to this

finding?

Sleep Medicine 7 (2006) 187–188

www.elsevier.com/locate/sleep

Table 1

Sleep study insults

Study A Study B

Recording time (min) 480.5 415.6

Sleep time (min) 421 323.6

Sleep time in the supine position 259 300

Number of apneic episodes 88 146

Obstructive apneas 9 2

Mixed apneas 1 1

Central apneas 3 96

Wake apneasa 17 7

Hypopneas 58 40

Number of apneic episodes/hour 12.6 27

Number of apneic episodes/hour 8.8 29.7

NREM

Number of apneic episodes/hour 24.0 10.3

REM

Minimum % oxygen 89 89

Baseline % oxygen 97 96

Snoring Moderate and frequent Rare

a Apneas during short periods of sleep obtained within epochs scored as

wakefulness.

Fig. 1. Dental Sleep Relief Appliance (DeSRAw) courtesy of David Heeke,

DDS. The DeSRA, which is made of a soft elastometric material, works by

repositioning the jaw in an anterior position and allowing the airway to

remain clear.

A.Y. Avidan / Sleep Medicine 7 (2006) 187–188188