Sleep and Breathing

, Volume 17, Issue 1, pp 289–296 | Cite as

The effect of continuous positive airway pressure on total cerebral blood flow in healthy awake volunteers

  • Theresia I. YiallourouEmail author
  • Céline Odier
  • Raphael Heinzer
  • Lorenz Hirt
  • Bryn A. Martin
  • Nikolaos Stergiopulos
  • José Haba-Rubio
Original Article



Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no widespread accepted protocol. We studied the physiologic influence of CPAP on CBF using a method integrating arterial diameter and flow velocity (FV) measurements obtained for each vessel supplying blood to the brain.


FV and lumen diameter of the left and right internal carotid, vertebral, and middle cerebral arteries were measured using duplex Doppler ultrasound with and without CPAP at 15 cm H2O, applied in a random order. Transcutaneous carbon dioxide (PtcCO2), heart rate (HR), blood pressure (BP), and oxygen saturation were monitored. Results were compared with a theoretical prediction of CBF change based on the effect of partial pressure of carbon dioxide on CBF.


Data were obtained from 23 healthy volunteers (mean ± SD; 12 male, age 25.1 ± 2.6 years, body mass index 21.8 ± 2.0 kg/m2). The mean experimental and theoretical CBF decrease under CPAP was 12.5 % (p < 0.001) and 11.9 % (p < 0.001), respectively. The difference between experimental and theoretical CBF reduction was not statistically significant (3.84 ± 79 ml/min, p = 0.40). There was a significant reduction in PtcCO2 with CPAP (p = <0.001) and a significant increase in mean BP (p = 0.0017). No significant change was observed in SaO2 (p = 0.21) and HR (p = 0.62).


Duplex Doppler ultrasound measurements of arterial diameter and FV allow for a noninvasive bedside estimation of CBF. CPAP at 15 cm H2O significantly decreased CBF in healthy awake volunteers. This effect appeared to be mediated predominately through the hypocapnic vasoconstriction coinciding with PCO2 level reduction. The results suggest that CPAP should be used cautiously in patients with unstable cerebral hemodynamics.


Continuous positive airway pressure Cerebral blood flow PCO2 Ultrasound 



The authors are indebted to all volunteers whose participation made this study possible. This study was funded by the Swiss National Science Foundation Grant 205321_132695/1.


  1. 1.
    Buda AJ, Pinsky MR, Ingels NB Jr, Daughters GT 2nd, Stinson EB, Alderman EL (1979) Effect of intrathoracic pressure on left ventricular performance. N Engl J Med 301(9):453–459. doi: 10.1056/NEJM197908303010901 PubMedCrossRefGoogle Scholar
  2. 2.
    Becker H, Grote L, Ploch T, Schneider H, Stammnitz A, Peter JH, Podszus T (1995) Intrathoracic pressure changes and cardiovascular effects induced by nCPAP and nBiPAP in sleep apnoea patients. J Sleep Res 4(S1):125–129PubMedCrossRefGoogle Scholar
  3. 3.
    Markwalder TM, Grolimund P, Seiler RW, Roth F, Aaslid R (1984) Dependency of blood flow velocity in the middle cerebral artery on end-tidal carbon dioxide partial pressure–a transcranial ultrasound Doppler study. J Cereb Blood Flow Metab 4(3):368–372PubMedCrossRefGoogle Scholar
  4. 4.
    Valdueza JM, Draganski B, Hoffmann O, Dirnagl U, Einhaupl KM (1999) Analysis of CO2 vasomotor reactivity and vessel diameter changes by simultaneous venous and arterial Doppler recordings. Stroke 30(1):81–86PubMedCrossRefGoogle Scholar
  5. 5.
    Eicke BM, Buss E, Bahr RR, Hajak G, Paulus W (1999) Influence of acetazolamide and CO2 on extracranial flow volume and intracranial blood flow velocity. Stroke 30(1):76–80PubMedCrossRefGoogle Scholar
  6. 6.
    Bowie RA, O'Connor PJ, Hardman JG, Mahajan RP (2001) The effect of continuous positive airway pressure on cerebral blood flow velocity in awake volunteers. Anesth Analg 92(2):415–417PubMedCrossRefGoogle Scholar
  7. 7.
    Scala R, Turkington PM, Wanklyn P, Bamford J, Elliott MW (2003) Effects of incremental levels of continuous positive airway pressure on cerebral blood flow velocity in healthy adult humans. Clin Sci (Lond) 104(6):633–639. doi: 10.1042/CS20020305 CrossRefGoogle Scholar
  8. 8.
    Haring HP, Hormann C, Schalow S, Benzer A (1994) Continuous positive airway pressure breathing increases cerebral blood flow velocity in humans. Anesth Analg 79(5):883–885PubMedCrossRefGoogle Scholar
  9. 9.
    Klingelhofer J, Hajak G, Sander D, Schulz-Varszegi M, Ruther E, Conrad B (1992) Assessment of intracranial hemodynamics in sleep apnea syndrome. Stroke 23(10):1427–1433PubMedCrossRefGoogle Scholar
  10. 10.
    Netzer N, Werner P, Jochums I, Lehmann M, Strohl KP (1998) Blood flow of the middle cerebral artery with sleep-disordered breathing: correlation with obstructive hypopneas. Stroke 29(1):87–93PubMedCrossRefGoogle Scholar
  11. 11.
    Schoning M, Walter J, Scheel P (1994) Estimation of cerebral blood flow through color duplex sonography of the carotid and vertebral arteries in healthy adults. Stroke: A Journal of Cerebral Circulation 25(1):17–22CrossRefGoogle Scholar
  12. 12.
    Harloff A, Strecker C, Reinhard M, Kollum M, Handke M, Olschewski M, Weiller C, Hetzel A (2006) Combined measurement of carotid stiffness and intima-media thickness improves prediction of complex aortic plaques in patients with ischemic stroke. Stroke 37(11):2708–2712PubMedCrossRefGoogle Scholar
  13. 13.
    Tominaga S, Strandgaard S, Uemura K, Ito K, Kutsuzawa T (1976) Cerebrovascular CO2 reactivity in normotensive and hypertensive man. Stroke 7(5):507–510PubMedCrossRefGoogle Scholar
  14. 14.
    Leguy CA, Bosboom EM, Hoeks AP, van de Vosse FN (2009) Model-based assessment of dynamic arterial blood volume flow from ultrasound measurements. Med Biol Eng Comput 47(6):641–648. doi: 10.1007/s11517-009-0473-9 PubMedCrossRefGoogle Scholar
  15. 15.
    Kety SS, Schmidt CF (1948) The effects of altered arterial tensions of carbon dioxide and oxygen on cerebral blood flow and cerebral oxygen consumption of normal young men. J Clin Invest 27(4):484–492PubMedCrossRefGoogle Scholar
  16. 16.
    Harper AM, Glass HI (1965) Effect of alterations in arterial carbon dioxide tension on blood flow through cerebral cortex at normal and low arterial blood pressures. J Neurol Neurosur Ps 28(5):449–452CrossRefGoogle Scholar
  17. 17.
    Grubb RL Jr, Raichle ME, Eichling JO, Ter-Pogossian MM (1974) The effects of changes in PaCO2 on cerebral blood volume, blood flow, and vascular mean transit time. Stroke 5(5):630–639PubMedCrossRefGoogle Scholar
  18. 18.
    Wang Q, Paulson OB, Lassen NA (1992) Effect of nitric-oxide blockade by N-G-nitro-l-arginine on cerebral blood-flow response to changes in carbon-dioxide tension. J Cerebr Blood F Met 12(6):947–953CrossRefGoogle Scholar
  19. 19.
    Eng C, Lam A, Mayberg T, Mathison T, Lee C (1992) The influence of propofol with and without nitrous-oxide on cerebral blood-flow velocity and Co2 reactivity in man. Stroke 23(3):456–456Google Scholar
  20. 20.
    Henriksen L (1986) Brain luxury perfusion during cardiopulmonary bypass in humans—a study of the cerebral blood-flow response to changes in Co2, O-2, and blood pressure. J Cerebr Blood F Met 6(3):366–378CrossRefGoogle Scholar
  21. 21.
    Reivich M (1964) Arterial Pco2 and cerebral hemodynamics. Am J Physiol 206:25–35PubMedGoogle Scholar
  22. 22.
    Kontos HA (1989) Validity of cerebral arterial blood flow calculations from velocity measurements. Stroke 20(1):1–3PubMedCrossRefGoogle Scholar
  23. 23.
    Scala R, Turkington PM, Wanklyn P, Bamford J, Elliott MW (2009) Acceptance, effectiveness and safety of continuous positive airway pressure in acute stroke: a pilot study. Respir Med 103(1):59–66. doi: 10.1016/j.rmed.2008.08.002 PubMedCrossRefGoogle Scholar
  24. 24.
    Schmidt JF, Waldemar G, Vorstrup S, Andersen AR, Gjerris F, Paulson OB (1990) Computerized analysis of cerebral blood flow autoregulation in humans: validation of a method for pharmacologic studies. J Cardiovasc Pharmacol 15(6):983–988PubMedCrossRefGoogle Scholar
  25. 25.
    Guyton AC (1991) Textbook of medical physiology, 8th edn. Saunders, PhiladelphiaGoogle Scholar
  26. 26.
    Stroobant N, Vingerhoets G (2000) Transcranial Doppler ultrasonography monitoring of cerebral hemodynamics during performance of cognitive tasks: a review. Neuropsychol Rev 10(4):213–231PubMedCrossRefGoogle Scholar
  27. 27.
    Droste DW, Ludemann P, Anders F, Kemeny V, Thomas M, Krauss JK, Ringelstein EB (1999) Middle cerebral artery blood flow velocity, end-tidal pCO(2) and blood pressure in patients with obstructive sleep apnea and in healthy subjects during continuous positive airway pressure breathing. Neurol Res 21(8):737–741PubMedGoogle Scholar
  28. 28.
    Navalesi P, Fanfulla F, Frigerio P, Gregoretti G, Nava S (2000) Physiologic evaluation of noninvasive mechanical ventilation delivered with three types of masks in patients with chronic hypercapnic respiratory failure. Crit Care Med 28(6):1785–1790PubMedCrossRefGoogle Scholar
  29. 29.
    Bakker JP, Neill AM, Campbell AJ (2011) Nasal versus oronasal continuous positive airway pressure masks for obstructive sleep apnea: a pilot investigation of pressure requirement, residual disease, and leak. Sleep Breath. doi: 10.1007/s11325-011-0564-3
  30. 30.
    Wasserman A, Patterson JL (1961) Cerebral vascular response to reduction in arterial carbon dioxide tension. J Clin Investig 40(7):1297–1303PubMedCrossRefGoogle Scholar
  31. 31.
    White JC, Brooks JR, Goldthwait JC, Adams RD (1943) Changes in brain volume and blood content after experimental concussion. Ann Surg 118(4):619–633PubMedCrossRefGoogle Scholar
  32. 32.
    Lambertsen CJ, Owen SG, Wendel H, Stroud MW, Lurie AA, Lochner W, Clark GF (1959) Respiratory and cerebral circulatory control during exercise At.21 and 2.0 atmospheres inspired Po2. J Appl Physiol 14(6):966–982PubMedGoogle Scholar
  33. 33.
    Alexander SC, Cohen PJ, Wollman H, Smith TC, Reivich M, Vandermolen RA (1965) Cerebral carbohydrate metabolism during hypocarbia in man: studies during nitrous oxide anesthesia. Anesthesiology 26:624–632PubMedCrossRefGoogle Scholar
  34. 34.
    Pierce EC, Linde HW, Deutsch S, Chase PE, Price HL, Lambertsen CJ, Dripps RD (1962) Cerebral circulation and metabolism during thiopental anesthesia and hyperventilation in man. J Clin Investig 41(8):1664–1671PubMedCrossRefGoogle Scholar
  35. 35.
    James IM, Millar RA, Purves MJ (1969) Observations on extrinsic neural control of cerebral blood flow in baboon. Circ Res 25(1):77–93PubMedCrossRefGoogle Scholar
  36. 36.
    Smith AL, Neufeld GR, Ominsky AJ, Wollman H (1971) Effect of arterial Co2 tension on cerebral blood flow, mean transit time, and vascular volume. Journal of Applied Physiology 31(5):701–707PubMedGoogle Scholar
  37. 37.
    Raichle ME, Posner JB, Plum F (1970) Cerebral blood flow during and after hyperventilation. Arch Neurol-Chicago 23(5):394–403PubMedCrossRefGoogle Scholar
  38. 38.
    Fujishima M, Scheinberg P, Busto R, Reinmuth OM (1971) The relation between cerebral oxygen consumption and cerebral vascular reactivity to carbon dioxide. Stroke 2(3):251–257PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Theresia I. Yiallourou
    • 1
    Email author
  • Céline Odier
    • 2
  • Raphael Heinzer
    • 3
  • Lorenz Hirt
    • 2
  • Bryn A. Martin
    • 1
  • Nikolaos Stergiopulos
    • 1
  • José Haba-Rubio
    • 3
  1. 1.Ecole Polytechnique Fédérale de Lausanne (EPFL)Laboratory of Hemodynamics and Cardiovascular Technology (LHTC)LausanneSwitzerland
  2. 2.Neurosciences DepartmentCentre Hospitalier Universitaire Vaudois Lausanne(CHUV)LausanneSwitzerland
  3. 3.CHUVCenter for Investigation and Research in Sleep (CIRS)LausanneSwitzerland

Personalised recommendations