THE UNIFIED AIRWAY A CPMC Regional CME Event

- An Integrated Approach

Saturday October 1, 2011

SLEEP APNEA: THE SILENT AIRWAY CONTRIBUTOR

Brandon Lu, M.D., M.S.

San Francisco Critical Care Medical Group

OBSTRUCTIVE SLEEP APNEA

• Repetitive upper airway closure during sleep resulting in repeated reversible blood oxygen desaturation and fragmented sleep1,2

• Severity measured by Apnea-Hypopnea Index (AHI):– Apnea: ≥ 90% decrease in airflow from baseline,

for ≥ 10 sec– Hypopnea: ≥ 30% decrease in airflow from

baseline, for ≥ 10 sec; accompanied by ≥ 4% desaturation from baseline1. Young et al., Am J Respir Crit Care Med 2002;165

2. Hiestand et al., Chest 2006;1303. Iber et al., The AASM Manual for the Scoring of Sleep and Associated Events. 2007.

OSA: 2-MIN EPOCH OF SLEEP STUDY

OSA: SCOPE OF THE PROBLEM

• Estimated prevalence:

• Up to 90% of people with OSA are undiagnosed5

AHI > 5 AHI > 15Men Women Men Women

Wisconsin1 24 9 9 4Pennsylvania2,4

17 - 7 2

SHHS3 46 18

1.Young et al., N Engl J Med 1993;328 2.Bixler et al., Am J Respir Crit Care Med 2001;163 3.Nieto et al., JAMA 2000;283 4. Bixler et al., Am J Respir Crit Care Med 198;1575. Young et al., Sleep 1997;20

OSA: ASSOCIATED MORBIDITIES

• Cardiovascular disease• Hypertension, CAD, CHF, arrhythmias, stroke

• Metabolic syndrome, diabetes• Daytime sleepiness, e.g. motor vehicle

accidents• Dementia• Mood disorder• Mortality

SLEEP APNEA AND INTERMITTENT HYPOXEMIA

OSA AND THE SYMPATHETIC SYSTEM

Somers et al., J Clin Invest 1995;96

OSA: SYMPTOMS AND ASSOCIATED FINDINGS

• Obese• Loud snoring• Witnessed apneas• Daytime sleepiness• Unrefreshing sleep• Males• Hypertension• DM• Memory and learning

impairments

• Hypothyroidism• Acromegaly• Nasal obstruction• Craniofacial

abnormalities (i.e., Down’s syndrome, Pierre-Robin syndrome)

PHYSICAL EXAMINATION

• Neck size greater than 17.5 inches (men)

• BMI greater than 30• Pharynx - Thick side

walls• Uvula - Long • Soft palate - Low• Tonsils - Large • Nasal Obstruction• Retrognathia

Mallampati classification

EPWORTH SLEEPINESS SCALE

• How likely are you to fall asleep in the following situations, in contrast to feeling just tired?

• 0 = would never doze• 1 = slight chance of dozing• 2 = moderate chance of dozing• 3 = high chance of dozing

• >10 indicates daytime sleepiness

SITUATION CHANCE OF DOZINGSitting and Reading

____Watching TV

____Sitting inactive in a public place (e.g. in a

theater or a meeting) ____

As a passenger in a car without a break for an hour ____

Lying down in the afternoon when circumstances permit ____

Sitting and talking with someone ____

Sitting quietly after lunch without alcohol ____

In a car, while stopped for a few minutes in traffic ____

Johns, Sleep 1994

WHEN TO REFER FOR SLEEP STUDY

• Loud snoring, witnessed apneas, etc.• Daytime sleepiness• Physical exam, including obesity• Comorbidities (cardiovascular,

metabolic, etc)

WHAT TO DO BEFORE SLEEP STUDY

• Treat nasal obstruction/congestion• Startling Resistor: upstream obstruction

leads to suction force downstream

• Oral breathing vs. nasal breathing• Oral breathing results in increased upper

airway resistance (12.4 vs. 5.2 cmH2O∙L-1∙s-1) and collapse during sleep

Smith et al., J Appl Physiol. 1988 Meurice et al., Am J Respir Crit Care Med. 1996Fitzpatrick et al., Eur Respir J. 2003.

TYPES OF SLEEP STUDY

• Diagnostic study• Split night study• CPAP titration study• Home study

WHEN TO REFER TO A SLEEP PHYSICIAN

• No guideline• Troubleshoot

- Mask, pressure, alternate therapeutic options• Follow-up

- Medicare guideline requires documentation within 90 days of CPAP initiation:

• Face-to-face evaluation documenting benefit• Objective evidence of adherence reviewed by

treating physician (>4 hr use on 70% of nights)• Critical mass

POSITIVE AIRWAY PRESSURE

Types of Home Nocturnal Positive Airway Pressure Devices Type of Device Pressure Delivery Indication Mechanism Continuous Pressure Unchanged through

the night OSA Prevents upper airway

obstruction Bilevel Pressure Separate inspiratory

and expiratory pressure

1) OSA 2) Ventilatory Failure

In OSA may increase patient comfort and compliance

Auto Pressure Delivered pressure changes breath to breath

1) Estimating CPAP requirements in OSA 2) Improving OSA patient comfort and compliance

Measurement of changes in flow are compensated for by increased pressure delivered on a breath to breath basis

COMFORT FEATURES OF CPAP: C-FLEX / EPR

• PEF sensing allows a reduction in flow during exhalation

• Comfort mode• Not for ventilation, only for

maintenance of a patent upper airway

I E I E I

10

5

0

Pressure

SURGICAL OPTIONS FOR OSA

Uvulopalatopharyngoplasty (UPPP)

Shortens uvula, trims soft palate, and sutures back the anterior and posterior pharyngeal pillars; tonsillectomy is performed if indicated.

Genioglossus advancement

Enlarges the hypopharyngeal space by pulling forward the tongue base at the geniotubercle through a mandibular osteotomy Won et al., Proc Am Thorac Soc. 2008

SURGICAL OPTIONS FOR OSA

Maxillomandibular advancement osteotomy

Advances the maxilla and mandible to enlarge the retrolingual and retropalatal spaces

Adenotonsillectomy

First-line therapy for obstructive sleep apnea in children; both adenoid and tonsillar tissue are removed, and the lateral pharyngeal walls are sutured to prevent collapse Won et al., Proc Am Thorac Soc. 2008

PALATAL IMPLANTS

http://www.snoring911.com/treatments.php

SURGICAL OPTIONS FOR OSA

• Tracheostomy: effective; last resort• MMA: severe OSA who can’t use CPAP and OA not an

option• UPPP: does not reliably normalize AHI in mod/sev OSA; try

CPAP or OA first• Multi-level or stepwise surgery: acceptable in patients

with narrowing of multiple sites in the upper airway• LAUP: not routinely recommended (standard)• RFA: can be considered in mild/mod OSA who can’t use

CPAP or OA• Palatal implants: may be effective in mild OSA who can’t

use CPAP or OAPractice Parameters for the Surgical Modifications of the Upper Airway for Obstructive Sleep Apnea in Adults. AASM 2010

ORAL APPLIANCES

“Oral appliances are indicated for use in patients with mild to moderate OSA who prefer them to CPAP therapy, or who do not respond to, are not appropriate candidates for, or who fail treatment attempts with CPAP…Follow-up polysomnography or an attended cardiorespiratory (Type 3) sleep study is needed to verify efficacy…” AASM, SLEEP, 2006.

OSA AND COUGH

• 108 consecutive referrals for suspected OSA: 33% of OSA pts reported chronic cough (>2 mos.) - predominantly females (61% vs. 17%), more nocturnal heartburn (28% vs. 5%) and rhinitis (44% vs. 14%) compared to those without SDB.

• 75 chronic cough pts without pulmonary pathology; 35/38 (92%) who underwent sleep study had OSA; 93% given CPAP and had improvement in cough

Chan et al., Eur Respir J. 2010Sundar et al., Cough 2010

OSA AND GERD

•  1116 patients with PSG-diagnosed OSA and 1999 participants in a general health survey:- Weekly nocturnal reflux symptoms present in 10.2%

OSA pts vs. 5.5% general population (p<0.001) and 13.9% severe versus 5.1% mild OSA

- Frequent nocturnal reflux symptoms were associated with severity of OSA (OR 3.0, severe versus mild OSA, P<0.001) after correcting for multiple factors

• Nocturnal reflux associated with transient lower esophageal sphincter relaxation (TLESR) but not by negative intra-esophageal pressure during OSA

Shepherd et al., J Sleep Res 2011Kuribiyashi et al., Neurogastroenterol Motil 2010

OSA AND GERD

• Patient with OSA and GER showed decreased 24-hr acid contact time after treatment with CPAP

Tawk et al., Chest 2006