title: Acceptance, effectiveness and safety of continuous positive airway pressure in acute stroke: a pilot study.
abstract: OBJECTIVE
  To evaluate the acceptance, effectiveness in preventing upper airways obstruction, and haemodynamic effects of continuous positive airway pressure (CPAP) in acute stroke.
  
  
  METHODS
  Twelve patients (4 M, and 8 F; mean (SD), 75.2 (5.5) years) within 48 h of acute stroke onset underwent: (1) sleep studies (1st night: auto-CPAP mode; 2nd night: diagnostic); (2) nocturnal non-invasive blood pressure studies (1st night during CPAP; 2nd night during spontaneous breathing (SB)); and (3) daytime cerebral blood flow velocity measurement in middle cerebral artery (FV) with transcranial Doppler during SB and with CPAP (5, 10, 15 cm H(2)O).
  
  
  RESULTS
  Ninety percent, 60% and 50% of stroke patients had a respiratory disturbance index (RDI) of >or=5, >or=10 and >or=15 events per hour, respectively (18.2 (11.3)). CPAP acceptance was 84%; 42% used CPAP more than 6h and 42% between 1-3h with a mean use of CPAP of 5.2h (4.0). Compared to SB, CPAP reduced, though not significantly, RDI, time with SaO(2)<90%, mean blood pressure and mean blood pressure dips (10 mm Hg)/h. Compared with SB, any level of CPAP progressively and significantly reduced systolic and mean FV; drop in diastolic FV was significant at CPAP10 and CPAP15. The partial pressure of end-tidal CO(2) was significantly lowered by all levels of CPAP.
  
  
  CONCLUSIONS
  According to this pilot study, CPAP is reasonably well tolerated by patients with acute stroke for at least one night. Despite its possible beneficial effect on obstructive sleep-disordered breathing and blood pressure variability, CPAP use in acute stroke should be still considered with caution due to possible harmful haemodynamic effects at higher pressures.
authors.affiliation: Unità Operativa di Pneumologia, Endoscopia Toracica e UTSIR, Ospedale San Donato ASL8, Via Pietro Nenni, 20, 52100, Arezzo, Italy. raffaele_scala@hotmail.com
authors.forename: Raffaele
authors.initials: R
authors.lastname: Scala
authors.forename: Peter M
authors.initials: PM
authors.lastname: Turkington
authors.forename: Peter
authors.initials: P
authors.lastname: Wanklyn
authors.forename: John
authors.initials: J
authors.lastname: Bamford
authors.forename: Mark W
authors.initials: MW
authors.lastname: Elliott
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001783:Blood Flow Velocity; D001794:Blood Pressure; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D010865:Pilot Projects; D011446:Prospective Studies; D012891:Sleep Apnea Syndromes / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D020521:Stroke / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D017585:Ultrasonography, Doppler, Transcranial