Obstructive sleep apnoea and daytime driver sleepiness

Transcription

1 Obstructive sleep apnoea and daytime driver sleepiness Dr Ashleigh Filtness CRICOS No J

2 Obstructive Sleep Apnoea (OSA) Repeated collapse of the airway during sleep blocking air flow. At least 5 an hour, some up to 60 an hour Most common in Middle aged men Collar >43cm BMI 28 Symptoms Daytime sleepiness (feeling un-rested after sleep) Loud snoring Holding breath during sleep Gasping for air

3 Treatment

4 UK law OSAand Driving Group 1 licence holders (car/motorcycle) diagnosed with sleep apnoea must stop driving until the symptoms have been controlled and confirmed by medical opinion.

5 Research Evidence supports OSA return to driving Post-treatment, the incidence of road traffic collisions for this group is substantially reduced. (Yamamoto et al. 2000; George 2001; Tregear et al. 2010;) Post-treatment performance at driving simulator tasks improve. (Orth et al. 2005; Mazzaet al. 2006) However, not in all studies (Vakulinet al. 2011)

6 Aim To investigate the impact of modest sleep restrictionand treatment withdrawal on driving ability in long term treated OSA. 1. Sleep restriction (5h) with CPAP treatment 2. Normal length of sleep ( 7h) without CPAP treatment 6

7 Vulnerability to sleep restriction

8 Participants 39 participants male (19 with OSA), age 50 75y OSA Control Age 63.8 (1.7) 66.6 (1.3) BMI 34.5 (1.4) 25.5 (0.4) ESS 5.3 (0.7) 4.7 (0.6) Usual sleep 7h 40min (8.1 min) 7h 48 min (10.1 min) Treatment duration 1y Average 7.5y (5.7) NA

9 Methodology -Driving Simulator 30 min practice drive Repeated measure counterbalanced design Normal nights sleep (8 h) Sleep restriction to (5 h) 9

10 Simulated road Monotonous dual carriageway 2 h duration starting at 2pm Occasional slow moving vehicles to overtake

11 Measures Prior sleep was verified using actigraphy

12 Measures Driving incidents: all four wheels out of the driving lane. Subjective sleepiness: KarolinskaSleepiness Scale (KSS) every 200 seconds. EEG: Spectral analysis in the alpha and theta, 4 11Hz range, and beta, Hz range

13 Results Driving incidents Significant group by condition interaction F(1,37) = 9.4, p < 0.05 Significant main effect of condition F(1,37) = 20.8, p < Significant main effect of time on task F(1.7,63) = 15.0, p < 0.001

14 Results -Time to first driving incident Significant group by condition interaction F(1,37) = 4.2, p < 0.05 Significant main effect of condition F(1,37) = 4.0, p < 0.05

15 Results -KSS Significant main effect of condition F(1,37) = 19.9, p < Significant main effect of driving time F(1.9,72.1) = 70.0, p < 0.001

16 Results EEG alpha and theta Significant group by time interaction F(1.7, 64.2) = 4.27, p < 0.05 Significant main effect of time F(1.7, 64.2) = 35.0, p < 0.001

17 Results EEG -beta Significant group by time interaction F(1.8,65.6) = 4.9, p< 0.05 t(37) = 2.0, p < 0.05

18 Discussion Sleep restriction No significant difference between driving performance after a normal nights sleep. Treated OSApatients show greater vulnerability to sleep restriction More incidents Shorter safe driving time.

19 Discussion Sleep Restriction Despite performance decrements no significant difference in subjective sleepiness groups when sleep deprived. Time on task following sleep restriction affected EEG activity differently for OSAcompared with control participants particularly during second half of drive Alpha and theta Beta activity

20 Vulnerability to CPAPwithdrawal

21 Participants 11 male participants with OSAage 50 75y OSA Age 65.6 (2.3) BMI 33.1 (1.8) ESS 5.2 (0.7) Usual sleep Treatment duration 7h 45min (3.6 min) 1y Average 7.7y (5.8)

22 Methodology -Driving Simulator 30 min practice drive Repeated measure design Normal nights sleep (with CPAP) Normal nights sleep (no CPAP) Monotonous dual carriageway 2 h duration starting at 2pm Occasional slow moving vehicles to overtake 22

23 Measures Prior sleep was verified using actigraphy Driving incidents: all four wheels out of the driving lane. Subjective sleepiness: Karolinska Sleepiness Scale (KSS) every 200 seconds. EEG: Spectral analysis in the alpha and theta, 4 11Hz range, and beta, Hz range

24 Sleep quality SDI = number of wake minutes / assumed length of sleep Significant difference in SDI [t (10) = 3.510, p <0.05]

25 Results Driving incidents Significant group main effect of treatment withdrawal F(1,20) = 12.33, p < 0.05

26 Results -Time to first driving incident Significant reduction in time to first incident t(10) = 3.8, p < 0.05

27 Safe driving time

28 Results -KSS Significant main effect of condition F(1,10) = 24.12, p < 0.05 Significant drive time by condition interaction F(3,30) = 5.03, p < 0.05

29 Results KSSand EEG (alpha and theta)

30 Results KSSand EEG (alpha and theta Significant correlation between KSSand EEG R 2 = 0.77, p < 0.05

31 Discussion CPAPwithdrawal Increase in SDI although total sleep time remains similar CPAPwithdrawal for one night impairs driving performance Overall number of incidents Time to first incident

32 Discussion CPAPwithdrawal Increased subjective sleepiness Aware of the withdrawal Although performance is impaired, insight into sleepiness is apparent.

33 Conclusions CPAP treated OSA patients are more susceptible to the effects of sleep restriction Why? Missing only 1 night of treatment could be critical Patient education Control group were also affected

34 Publications Filtness, A.J., Reyner, L.A., Horne, J.A. (2011) Moderate sleep restriction in treated older male OSA participants: greater impairment during monotonous driving compared with controls. Sleep Medicine 12 (9) Filtness, A. J., Reyner, L. A., & Horne, J. A. (2012). One night s CPAP withdrawal in otherwise compliant OSA patients: marked driving impairment but good awareness of increased sleepiness. Sleep and Breathing 16(3) Filtness, A. J., Reyner, L. A., & Horne, J. A. (2012). Driver sleepiness -comparisons between young and older men during a monotonous afternoon simulated drive. Biological Psychology 89 (3)

35 Acknowledgements Dr Louise Reyner and Prof. Jim Horne, Loughborough University Dr Andrew Hall and Dr Chris Hanning, Leicester General Hospital

36 Dr Missy Rudin-Brown Dr Mike Lenné Dr Paul Salmon

37

38 Origins of CARRS-Q Centre for Accident Research & Road Safety Queensland (CARRS-Q) was established in 1996 as joint initiative of: QUT Motor Accident Insurance Commission (MAIC) Based in the School of Psychology & Counselling, Faculty of Health Primary role is to undertake research and training to improve safety on Queensland roads and in the workplace

39 Research Themes CARRS-Q currently has approximately 90 staff and students researching 6 themes: Regulation and Enforcement School and Community Injury Prevention Vulnerable Road Users Occupational Safety Road Safety Infrastructure Intelligent Transport Systems

40 School and Community Injury Issues addressed: Prevention School-based education programs Community-based education programs Non-enforceable high-risk behaviours e.g. fatigue Research projects include: Understanding sleep in carers (dementia and older adults) Postpartum fatigue: Effects on safety-sensitive tasks Motivations to drive when sleepy Proxy definitions of sleep related crashes

41 Regulation and Enforcement Issues addressed: Drink Driving Drug Driving Speeding Aggressive Driving Unlicensed Driving Research projects include: Development of a brief computer based intervention for first time drink driving offenders Design and evaluation of anti-speeding messages to target high risk road users' attitudes and behaviours The road safety implications of unlicensed driving

42 Vulnerable Road Users Issued addressed: Motorcycle riders Pedestrians Cyclists Research projects include: Development and evaluation of a motorcycle training intervention Compendium of best practices on motorcycle and scooter safety Delineating injury patterns and safety behaviours among cyclist groups

43 Occupational Safety Issues addressed: Work-related driver safety Fleet safety Workplace Health and Safety Policy Previous research projects include: Safety in the heavy vehicle industry Development and evaluation of an OH&S framework for work related driving Developing driving risk assessment tools to improve fleet safety

44 Road Safety Infrastructure Issues addressed: Transportation planning Safety analysis methodologies (e.g., black spot identification) Research projects include: Evaluation of High Risk Crash Prediction Methods Speed Camera Evaluation Effects of speeding and headway related signs on driver behaviour

45 Intelligent Transport Systems Issues addressed: Use of Technology and Information Systems Simulation of future ITS Research projects include: Predicting vigilance impairment in drivers and operators functioning under monotonous contexts Integrating driver and traffic simulation to assess invehicle and road-based level crossing safety interventions Development and evaluation of a novel Driver Training Assessment Tool

46 Advanced Driving Simulator

47 Advanced Driving Simulator Officially unveiled in 2010 ; $1.5 million Holden Calais, 8 computers, 3 projectors, mobile platform in 3 dimensions Replicates real-time traffic conditions Many projects driver, road conditions, rail projects

48 CARRS-Q Vision The CARRS-Q vision is to decrease the local, national and international burden of trauma-related harm

49 Questions? CRICOS No J