Simon Bowler Director Medicine

Mater Adult Hospital

Mater Private Hospital

Queensland Sleep

Sleep apnea: the essentials

Sleep Apnea Most OSA is straightforward

Most does not need specialist attention

Areas of uncertainty

CPAP vs no CPAP therapy in borderline cases

Disconnect between symptoms and measurements

More complex forms (eg central)

Commercial drivers need specialist review

Who should have a sleep study?

How do you assess severity of OSA?

Who needs CPAP – who doesn’t?

What is the risk of untreated OSA?

What to do if patient doesn’t tolerate CPAP?

Can changing posture cure sleep apnea

Does weight loss fix sleep apnea

Sleep apnea, driving and the law?

Wisconsin Sleep Cohort

Study

NEJM 1996;328:1230

How common is sleep apnoea? 30-60 yr old public servants

602 polysomnograms

AHI>15 (ie sig. OSAS) in

• 17% male heavy snorers 7.5% all males

• 7% female heavy snorers 2% of all females..

Scenario Peter aged 48

Bulldozer driver coal fields

Well. BMI 35

Hypertension on Coversyl

Snores - some apneas

No daytime somnolence ESS 6

No MV accidents

5

Nasal obstruction:

Alcohol / sedatives

reduce muscle tone

& reduce compensatory

increases in dilator activity

Supine sleep

Genetics: eg receding jaw

resp response

Increased sub mucosal tissue:

Obesity (NB neck circumference),

Acromegaly

Tonsillar enlargement

Reduced sleep time..

Etiological /exacerbating factors Male gender

Post menopausal status:

Which snorers should have a

sleep study?

No daytime somnolence ESS ≤ 10 ESS>10

No study Study

Normotensive Hypertensive

No observed apneas Observed apneas

Neck circum < 40cm Neck circum ≥ 40cm

No cardiovascular pathology Cardiovascular pathology

No high risk occupation High risk occupation

Lancet 1981;317:862

Pete’s PSG

9

Peter’s

PSG

10

5.7% time SaO2<90%..

Tot RDI 32.5/h

Non supine 24.7/h Supine 52.9 /h RDI

354 min Tot sleep

90% Sleep effic. 30.8/hr Arousal index

Assessing sleep apnea severity Respiratory Disturbance Index events/hr

normal mild moderate severe

RDI ≤5 5-19 20-35 >35

Plus modifying factors

Extent/duration hypoxic episodes

Duration apnoeas / hypopnea

Fragmentation of sleep - loss of cycling

11

Pete’s RDI 32.5

Treatment based on AHI

1. General meas: Wt reduction 2. attention to nasal patency 3.± avoid supine

sleep

AHI

0 10 15 20 30

Mild Moderate Severe

(If sleepy++; marked supine or REM effects or hypoxia) ….

(If less sleepy; intolerant CPAP)

MAS

CPAP

± MAS

± CPAP

Pete’s RDI

Scenario

Pete: “I’m feeling fine - no way

I’m wearing a Darth Vader mask

to bed”

Wife Susan says: “You’ll have a

heart attack and die if you don’t -

or end up paraplegic in a car

accident”

13

The consequences of OSA Susan: from the web:

NIH: “When your sleep is interrupted throughout the

night, you can be drowsy during the day. People with

sleep apnea are at higher risk for car crashes, work-

related accidents and other medical problems. If you

have it, it is important to get treatment.”

ASA: “..increased chance of heart attack or stroke

..x4 as likely to have a motor vehicle accident

14

CARDIOVASCULAR

DISEASE

15

Sleep apnea and CV disease

16

Metabolic syndrome

Sleep apnea Cardiovascular

events

?

17 Marin Lancet 2005; 365: 1046

Fatal events

Months

Non Fatal events

Months

OSA CPAP and

CV outcomes

Outcomes: MI / CVA vs normals

Marin Lancet 2005; 365: 1046

Caveats

•not a randomised study

• differences between CPAP / no CPAP groups not excluded

• no account of subsequent Rx or compliance

18

• Severe untreated OSA had x3 the chance of a heart attack or

stroke compared with normal or treated severe OSA

Meta analysis of CPAP and Syst BP

Fava C Chest 2013 Online 10.1378/chest.13-1414

CPAP produces small but

significant drop in BP

Consequences of OSA

20

Insulin resistance

Sympathetic dysfunction

T2 Diabetes

Lipid metabolism

Inflammation

Oxidative stress

Endothelial dysfunction

Coagulation abnormalities

Metabolic dysregulation

Dysrhythmias

Hundreds of episodes a

night of semi asphyxiation,

hypoxia, sympathetic

overdrive, recurrent arousal

and fragmented sleep

experienced over years can

be very bad for some / most

but perhaps not all patients

Sleep and driving

21

CPAP and driving skills: reaction time

22 Mazza ERJ 2006 28: 1020

OSA pre

CPAP

OSA post

CPAP

NL x 2

CPAP + number of

MVA’s

23 George Thorax 2001;56:508

n= 210

age 52± 11y

BMI 35±10

RDI 54±29

OSA No OSA

For Pete ?

24

• An asymptomatic patient

• What to do

• Will CPAP make him feel better?

Treatment based on AHI

1. General meas: Wt reduction 2. attention to nasal patency 3.± avoid supine

sleep

AHI

0 10 15 20 30

Mild Moderate Severe

(If sleepy++; marked supine or REM effects or hypoxia) ….

(If less sleepy; intolerant CPAP)

MAS

CPAP

± MAS

± CPAP

Pete’s RDI

CPAP will in disease modeling:

Increase the probability of survival by 25%.

Decrease the relative risk of having a cardiovascular event

by 46%

Decrease the relative risk of having a stroke by 49%

Decrease the relative risk of having an RTA by 31%.

Increase the probability of event-free survival by 92%.

for a cost-reduction of £973 (95% CI: -£1,983; £1,508) over

14 years

Guest J Thorax online April O8 10.1136/thx.2007.086454

Effect of CPAP in non sleepy OSA

27

• Parallel gp study

• CPAP vs Sham

Baseline mean

• n=29 vs 25

• ESS 8 vs 6

• BMI 29 vs 29

• AHI 57 vs 57

• 6 weeks Rx

Barbe Ann Intern Med. 2001;134:1015

No benefit

found..

Positional therapy and OSA

16 pats with positional OSA

Time supine fell 42.8 ±26 to 5.8 ±7.2 %

AHI fell 26.7 ± 17 to 6.0 ±3.0

ESS 9.4 ±5 to 6.6 ±5

Used device for 74% nights 8.0± 2.0h/n

Good compliance at 3 months – results persisted

Heinzer Sleep 2012:13;425

Weight reduction and OSA

25 pat (17m) 44y; 154kg; BMI 52.7

Lap band

Mean weight loss 44.7kg (50% excess weight loss)

AHI fell from 61.6 ±34 to 13.4 ± 13

ESS from 13 ±7 to 3.8 ±3

Improved depression, T2DM, metabolic syndrome

Int J Obesity 2005;29:1048

For Pete ?

30

• Long term implications for untreated sleep

apnea in an asymptomatic patient are

unknown

• Is he really asymptomatic ?

•? Trial of CPAP

•? MWT (NB occupation)

• Treat cardio vascular risk factors

• Lose weight

• If he’s really asymptomatic observe only

• Control of snoring

http://www.austroads.com.au/

In summary: driving and sleep If the patient has sleep apnea (RDI>10) and (or) is

sleepy (ESS ≥ 16) and or has had sleepiness driving or

crashes due to sleepiness –

Must use CPAP (and have improved sleepiness)

You must be happy the patient is adhering (ESS; download)

You should fill in an F7312 and the patient should submit

You have legal protection in reporting the patient if you believe non

compliance or a risk driving

Refer if worries

If the patient holds a commercial license and meets

above condition

Should be referred to a sleep physician