title: One night's CPAP withdrawal in otherwise compliant OSA patients: marked driving impairment but good awareness of increased sleepiness.
abstract: OBJECTIVE
  Obstructive sleep apnoea (OSA) patients effectively treated by and compliant with continuous positive air pressure (CPAP) occasionally miss a night's treatment. The purpose of this study was to use a real car interactive driving simulator to assess the effects of such an occurrence on the next day's driving, including the extent to which these drivers are aware of increased sleepiness.
  
  
  METHODS
  Eleven long-term compliant CPAP-treated 50-75-year-old male OSA participants completed a 2-h afternoon, simulated, realistic monotonous drive in an instrumented car, twice, following one night: (1) normal sleep with CPAP and (2) nil CPAP. Drifting out of road lane ('incidents'), subjective sleepiness every 200 s and continuous electroencephalogram (EEG) activities indicative of sleepiness and compensatory effort were monitored.
  
  
  RESULTS
  Withdrawal of CPAP markedly increased sleep disturbance and led to significantly more incidents, a shorter 'safe' driving duration, increased alpha and theta EEG power and greater subjective sleepiness. However, increased EEG beta activity indicated that more compensatory effort was being applied. Importantly, under both conditions, there was a highly significant correlation between subjective and EEG measures of sleepiness, to the extent that participants were well aware of the effects of nil CPAP.
  
  
  CONCLUSIONS
  Patients should be aware that compliance with treatment every night is crucial for safe driving.
authors: Sleep Research Centre, Loughborough University, Loughborough, Leicestershire, UK. ashleigh.filtness@monash.edu
authors: Ashleigh J
authors: AJ
authors: Filtness
authors: Louise A
authors: LA
authors: Reyner
authors: James A
authors: JA
authors: Horne
mesh_terms: D000368:Aged; D001143:Arousal; D001288:Attention; D001334:Automobile Driving; D001364:Awareness; D003198:Computer Simulation; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects* / Q000523:psychology*; D006970:Disorders of Excessive Somnolence / Q000523:psychology* / Q000628:therapy*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000523:psychology*; D012815:Signal Processing, Computer-Assisted; D020181:Sleep Apnea, Obstructive / Q000523:psychology* / Q000628:therapy*