title: The effects of propofol or sevoflurane on the estimated cerebral perfusion pressure and zero flow pressure.
abstract: The zero flow pressure (ZFP) is the pressure at which blood flow ceases through a vascular bed. Using transcranial Doppler ultrasonography, we investigated the effects of propofol or sevoflurane on the estimated cerebral perfusion pressure (eCPP) and ZFP in the cerebral circulation. Twenty-three healthy patients undergoing nonneurosurgical procedures under general anesthesia were studied. After induction of anesthesia using propofol, the anesthesia was maintained with either propofol infusion (n = 13) or sevoflurane (n = 10). Middle cerebral artery flow velocity, noninvasive arterial blood pressure, and end-tidal carbon dioxide partial pressure were recorded awake as a baseline, and during steady-state anesthesia at normocapnia (baseline end-tidal carbon dioxide partial pressure) and hypocapnia (1 kPa below baseline). The eCPP and ZFP were calculated using an established formula. The mean arterial blood pressure decreased in both groups. The eCPP decreased significantly in the propofol group (median, from 58 to 41 mm Hg) but not in the sevoflurane group (from 60 to 62 mm Hg). Correspondingly, ZFP increased significantly in the propofol group (from 25 to 33 mm Hg) and it decreased significantly in the sevoflurane group (from 27 to 7 mm Hg). Hypocapnia did not change eCPP or ZFP in the propofol group, but it significantly decreased eCPP and increased ZFP in the sevoflurane group.
authors.affiliation: University Departments of Anesthesia and Intensive Care, Queens Medical Centre and City Hospital NHS Trust, Nottingham, United Kingdom.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Marval
authors.forename: Mandy E
authors.initials: ME
authors.lastname: Perrin
authors.forename: Sally M
authors.initials: SM
authors.lastname: Hancock
authors.forename: Ravi P
authors.initials: RP
authors.lastname: Mahajan
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005260:Female; D006801:Humans; D007427:Intracranial Pressure / Q000187:drug effects*; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D008875:Middle Aged; D015742:Propofol / Q000494:pharmacology*; D000077149:Sevoflurane; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane; D015742:Propofol
references.citation: Hancock SM, Mahajan RP, Athanassiou L. Effects of changes in end tidal carbon dioxide on estimated cerebral perfusion pressure and zero flow pressure in healthy volunteers. Anesth Analg 2003;96:847–51.
references.citation: Weyland A, Buhre W, Grund S, et al. Cerebrovascular tone rather than intracranial pressure determines the effective downstream pressure of the cerebral circulation in the absence of intracranial hypertension. J Neurosurg Anesthesiol 2000;12:210–6.
references.citation: Aaslid R, Lundar T, Lindegaard K-F, Nornes H. Estimation of cerebral perfusion pressure from arterial blood pressure and transcranial Doppler recordings. In: Miller JD, Teasdale GM, Rowan JO, et al., eds. Intracranial pressure. VI. Berlin: Springer-Verlag, 1986:226–9.
references.citation: Aaslid R, Lash SR, Bardy GH, et al. Dynamic pressure-flow velocity relationships in the human cerebral circulation. Stroke 2003;34:1645–9.
references.citation: Michel E, Zernikow B, von Twickel J, et al. Critical closing pressure in preterm neonates: towards a comprehensive model of cerebral autoregulation. Neurol Res 1995;17:149–55.
references.citation: Belfort MA, Saade GR, Yared M, et al. Change in estimated cerebral perfusion pressure after treatment with nimodipine or magnesium sulfate in patients with preeclampsia. Am J Obstet Gynecol 1999;181:402–7.
references.citation: Drummond JC, Todd MM, Scheller MS, Shapiro HM. A comparison of the direct cerebral vasodilating potencies of halothane and isoflurane in the New Zealand white rabbit. Anesthesiology 1986;65:462–7.
references.citation: Ogawa K, Yamamoto M, Mizumoto K, Hatano Y. Volatile anesthetics attenuate hypocapnia-induced constriction in isolated dog cerebral arteries. Can J Anaesth 1997;44:426–32.
references.citation: Girling KJ, Cavill G, Mahajan RP. The effects of nitrous oxide and oxygen on transient hyperemic response in human volunteers. Anesth Analg 1999;89:175–80.
references.citation: Tibble RK, Girling KJ, Mahajan RP. Comparison of the transient hyperemic response test and the static autoregulation test to assess graded impairment in cerebral autoregulation. Anesth Analg 2001;93:171–6.
references.citation: Strebel S, Lam AM, Matta B, et al. Dynamic and static cerebral autoregulation during isoflurane, desflurane, and propofol anesthesia. Anesthesiology 1995;83:66–76.
references.citation: Matta BF, Heath KJ, Tipping K, Summors AC. Direct cerebral vasodilatory effects of sevoflurane and isoflurane. Anaesthesiology 1999;91:677–80.
references.citation: Harrison JM, Girling KJ, Mahajan RP. The effects of target controlled infusion of propofol on the transient hyperaemic response and carbon dioxide reactivity in middle cerebral artery. Br J Anaesth 1999;83:839–45.
references.citation: Pinaud M, Lelausque JN, Chetanneau A, et al. The effects of propofol on cerebral hemodynamics and metabolism in patients with brain trauma. Anesthesiology 1990;73:404–9.
references.citation: Aaslid R. Transcranial Doppler examination techniques. In: Aaslid R, ed. Transcranial Doppler ultrasonography. Wien: Springer-Verlag, 1986:39–59.
references.citation: Burton AC. On the physical equilibrium of small blood vessels. Am J Physiol 1951;164:319–29.
references.citation: Dewey RC, Pieper HP, Hunt WE. Vasomotor tone, critical closing pressure and vascular bed resistance. J Neurosurg 1974;41:597–606.
references.citation: Early CB, Dewey RC, Pieper HP, Hunt WE. Dynamic pressure-flow relationships of brain blood flow in the monkey. J Neurosurg 1974;41:590–6.
references.citation: Czosnyka M, Matta BF, Smielewski P, et al. Cerebral perfusion pressure in head-injured patients: a non-invasive assessment using transcranial Doppler ultrasonography. J Neurosurg 1998;88:802–8.
references.citation: Buhre W, Heinzel FR, Grund S, et al. Extrapolation to zero-flow pressure in cerebral arteries to estimate intracranial pressure. Br J Anaesth 2003;90:291–5.
references.citation: Aaslid R, Lindegaard KF. Cerebral haemodynamics. In: Aaslid R, ed. Transcranial Doppler sonography. Wien: Springer-Verlag, 1986:65–85.
references.citation: Legarth J, Thorup E. Characteristics of Doppler blood-velocity waveforms in a cardiovascular in vitro model. I. The model and the influence of pulse rate. Scand J Clin Lab Invest 1989;49:451–7.
references.citation: Legarth J, Thorup E. Characteristics of Doppler blood-velocity waveforms in a cardiovascular in vitro model. II. The influence of peripheral resistance, perfusion pressure and blood flow. Scand J Clin Lab Invest 1989;49:459–64.
references.citation: Moppett IK, Wild MJ, Sherman RW, et al. Effects of ephedrine, dobutamine, and dopexamine on cerebral haemodynamics: transcranial Doppler studies in healthy volunteers. Br J Anaesth 2004;92:39–44.
references.citation: Bedforth NM, Girling KJ, Harrison JM, Mahajan RP. The effects of sevoflurane and nitrous oxide on middle cerebral artery blood flow velocity and transient hyperemic response. Anesth Analg 1999;89:170–4.