Sleep apnea: the essentials

Sleep apnea: the essentials Simon Bowler Director Medicine Mater Adult Hospital Mater Private Hospital Queensland Sleep Sleep Apnea  Most OSA is s...
Author: Elaine Cain
14 downloads 2 Views 2MB Size
Sleep apnea: the essentials Simon Bowler Director Medicine Mater Adult Hospital Mater Private Hospital

Queensland Sleep

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?

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.. Wisconsin Sleep Cohort Study NEJM 1996;328:1230

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

Etiological /exacerbating factorsMale gender Nasal obstruction:

Alcohol / sedatives reduce muscle tone & reduce compensatory increases in dilator activity

Increased sub mucosal tissue: Obesity (NB neck circumference), Acromegaly Tonsillar enlargement

Post menopausal status: Genetics: eg receding jaw  resp response

Reduced sleep time..

Supine sleep

Which snorers should have a sleep study? No study No daytime somnolence ESS ≤ 10 Normotensive

Study ESS>10 Hypertensive

No observed apneas

Observed apneas

Neck circum < 40cm

Neck circum ≥ 40cm

No cardiovascular pathology

No high risk occupation

Cardiovascular pathology

High risk occupation

Lancet 1981;317:862

Pete’s PSG

9

Peter’s PSG Tot sleep Sleep effic. Arousal index

354 min 90% 30.8/hr

5.7% time SaO235

Pete’s RDI 32.5 Plus modifying factors

 Extent/duration hypoxic episodes  Duration apnoeas / hypopnea

 Fragmentation of sleep - loss of cycling 11

Treatment based on AHI Pete’s RDI

AHI Mild 0

10

Moderate 15

Severe

20

30

1. General meas: Wt reduction 2. attention to nasal patency 3.± avoid supine sleep (If less sleepy; intolerant CPAP) MAS

± MAS

CPAP

± CPAP (If sleepy++; marked supine or REM effects or hypoxia)

….

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, workrelated 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 Metabolic syndrome

Sleep apnea

?

Cardiovascular events

16

Fatal events

OSA CPAP and CV outcomes Non Fatal events

Months

Marin Lancet 2005; 365: 1046

Months

17

Outcomes: MI / CVA vs normals • Severe untreated OSA had x3 the chance of a heart attack or stroke compared with normal or treated severe OSA

Caveats •not a randomised study • differences between CPAP / no CPAP groups not excluded • no account of subsequent Rx or compliance

Marin Lancet 2005; 365: 1046 18

Meta analysis of CPAP and Syst BP

CPAP produces small but significant drop in BP Fava C Chest 2013 Online 10.1378/chest.13-1414

Consequences of OSA          

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

20

Sleep and driving

21

CPAP and driving skills: reaction time OSA pre CPAP NL x 2 OSA post CPAP

Mazza ERJ 2006 28: 1020

22

CPAP + number of MVA’s n= 210 age 52± 11y BMI 35±10 RDI 54±29

OSA George Thorax 2001;56:508

No OSA

23

For Pete ? • An asymptomatic patient • What to do • Will CPAP make him feel better?

24

Treatment based on AHI Pete’s RDI

AHI Mild 0

10

Moderate 15

Severe

20

30

1. General meas: Wt reduction 2. attention to nasal patency 3.± avoid supine sleep (If less sleepy; intolerant CPAP) MAS

± MAS

CPAP

± CPAP (If sleepy++; marked supine or REM effects or hypoxia)

….

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 • 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 No benefit found.. Barbe Ann Intern Med. 2001;134:1015

27

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 ? • 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 • Control of snoring

only

30

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