Sleep apnea: the essentials

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Elaine Cain
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1 Sleep apnea: the essentials Simon Bowler Director Medicine Mater Adult Hospital Mater Private Hospital Queensland Sleep

2 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

3 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?

4 How common is sleep apnoea? 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

5 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 factors Male gender Nasal obstruction: Alcohol / sedatives reduce muscle tone & reduce compensatory increases in dilator activity Post menopausal

6 Etiological /exacerbating factors Male gender Nasal obstruction: Alcohol / sedatives reduce muscle tone & reduce compensatory increases in dilator activity Post menopausal status: Genetics: eg receding jaw resp response Reduced sleep time.. Increased sub mucosal tissue: Obesity (NB neck circumference), Acromegaly Tonsillar enlargement Supine sleep

7 Which snorers should have a sleep study? No study Study No daytime somnolence ESS 10 Normotensive No observed apneas Neck circum < 40cm No cardiovascular pathology No high risk occupation ESS>10 Hypertensive Observed apneas Neck circum 40cm Cardiovascular pathology High risk occupation

8 Lancet 1981;317:862

9 Pete s PSG 9

10 Peter s PSG Tot sleep Sleep effic. Arousal index 354 min 90% 30.8/hr 5.7% time S a O2<90%.. RDI Supine 52.9 /h Non supine 24.7/h Tot RDI 32.5/h 10

11 Assessing sleep apnea severity Respiratory Disturbance Index events/hr normal mild moderate severe RDI >35 Plus modifying factors Pete s RDI 32.5 Extent/duration hypoxic episodes Duration apnoeas / hypopnea Fragmentation of sleep - loss of cycling 11

12 Treatment based on AHI AHI Pete s RDI Mild Moderate Severe General meas: Wt reduction 2. attention to nasal patency 3.± avoid supine sleep (If less sleepy; intolerant CPAP) MAS ± MAS ± CPAP (If sleepy++; marked supine or REM effects or hypoxia). CPAP

13 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

14 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

15 CARDIOVASCULAR DISEASE 15

16 Sleep apnea and CV disease Metabolic syndrome Sleep apnea? Cardiovascular events 16

17 Fatal events OSA CPAP and CV outcomes Non Fatal events Months Marin Lancet 2005; 365: 1046 Months 17

18 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:

19 Meta analysis of CPAP and Syst BP CPAP produces small but significant drop in BP Fava C Chest 2013 Online /chest

Consequences of OSA Insulin resistance Sympathetic dysfunction T2 Diabetes Lipid metabolism Inflammation Oxidative stress Endothelial dysfunction Coagulation abnormalities Metabolic dysregulation

20 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

21 Sleep and driving 21

22 CPAP and driving skills: reaction time OSA pre CPAP OSA post CPAP N L x 2 Mazza ERJ :

23 CPAP + number of MVA s n= 210 age 52± 11y BMI 35±10 RDI 54±29 OSA No OSA George Thorax 2001;56:508 23

24 For Pete? An asymptomatic patient What to do Will CPAP make him feel better? 24

25 Treatment based on AHI AHI Pete s RDI Mild Moderate Severe General meas: Wt reduction 2. attention to nasal patency 3.± avoid supine sleep (If less sleepy; intolerant CPAP) MAS ± MAS ± CPAP (If sleepy++; marked supine or REM effects or hypoxia). CPAP

26 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 O /thx

27 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:

28 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

29 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

30 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

33 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

Diagnosis and Treatment

Sleep Apnea: Diagnosis and Treatment Sleep Apnea Sleep Apnea is Common Dangerous Easily recognized Treatable Types of Sleep Disordered Breathing Apnea Cessation of airflow > 10 seconds Hypopnea Decreased