This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kolbitsch, C. Articles by Benzer, A. Search for Related Content PubMed PubMed Citation Articles by Kolbitsch, C. Articles by Benzer, A. Related Collections Neuroanesthesia Monitoring (Non-cardiac)

---

NEUROSURGICAL ANESTHESIA

The Impact of Hypercapnia on Systolic Cerebrospinal Fluid Peak Velocity in the Aqueduct of Sylvius

Christian Kolbitsch, MD DEAA^*, Ingo H. Lorenz, MD^*, Christoph Hörmann, MD^*, Michael F. Schocke, MD, Christian Kremser, PhD, Patrizia L. Moser, MD, Karl P. Pfeiffer, PhD, and Arnulf Benzer, MD DEAA^*

Departments of *Anaesthesia and Intensive Care Medicine, Magnetic Resonance Imaging, Pathology, and Biostatistics and Documentation, University of Innsbruck, Austria

Address correspondence and reprint requests to C. Kolbitsch, MD, DEAA, Department of Anaesthesia and Intensive Care Medicine, University of Innsbruck, A-6020 Innsbruck, Anichstr. 35, Austria. Address e-mail to christian.kolbitsch{at}uibk.ac.at

Phase-contrast magnetic resonance imaging measurements of systolic cerebrospinal fluid peak velocity (CSFVPeak) in the aqueduct of Sylvius have been shown to be sensitive enough to detect even minor changes in cerebral compliance. Clinically relevant changes in cerebral compliance can be caused by changes in cerebral blood volume (CBV). Changes in arterial carbon dioxide partial pressure, which correlate well with end-tidal carbon dioxide concentration (ETCO₂), cause changes in CBV. In this study, we investigated the effect of hypercapnia-induced changes in CBV on systolic CSFVPeak in anesthetized patients (n = 8). Hypercapnia (ETCO₂ = 60 mm Hg) increased systolic CSFVPeak in the aqueduct of Sylvius as compared with normocapnia (ETCO₂ = 40 mm Hg) (hypercapnia: -5.67 ± 0.74 cm/s versus normocapnia: -3.54 ± 0.98 cm/s). In addition to the already known decrease in systolic CSFVPeak, changes in cerebral compliance can also prompt an increase in systolic CSFVPeak.

IMPLICATIONS: Magnetic resonance imaging measurements of systolic cerebrospinal fluid peak velocity (CSFVPeak) in the aqueduct of Sylvius are sensitive enough to detect even minor changes in cerebral compliance. We investigated the effect of hypercapnia-induced changes in cerebral blood volume on systolic CSFVPeak in anesthetized patients. Hypercapnia (end-tidal carbon dioxide concentration = 60 mm Hg) increased systolic CSFVPeak.