title: Reproducibility of Brachial Vascular Changes with Alterations in End-Tidal Carbon Dioxide.
abstract: The purpose of this study was to examine the reproducibility of the peripheral vascular response to hypercapnia. Healthy college-aged men (n = 7) and women (n = 10) underwent an iso-oxic 10-mm Hg increase in PetCO2 for 12 min. Brachial artery diameter changes were measured using ultrasound imaging. Two tests were completed on day 1 with 15 min of rest between tests. Tests were repeated on day 2. Paired t-tests, Bland-Altman plots and intra-class correlations (ICCs) determined reproducibility. There were no significant differences in peak dilation within day (5.33 ± 3.73% vs. 4.52 ± 2.49%, p = 0.378). The within-day ICC was poor (0.213). Within-day time-to-peak dilation did not significantly differ (660.0 ± 231.8 s vs. 602.7 ± 259.9 s, p = 0.379), and the ICC was fair (0.416, p = 0.113). Between-day peak dilation did not significantly differ (5.24 ± 3.84% vs. 4.71 ± 3.17%, p = 0.123), and the ICC was fair (0.419). Hypercapnia-induced brachial artery dilation is similar within day and between days. The ICC for peak dilation suggests the methodology is not reproducible.
authors.affiliation: Department of Health and Exercise Rehabilitation Sciences, Winona State University, Winona, Minnesota, USA.
authors.forename: Justin R
authors.initials: JR
authors.lastname: Geijer
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Evanoff
authors.affiliation: Department of Pediatrics, University of Minnesota, and University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, USA; Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Kelly
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Chernin
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Stoltman
authors.affiliation: School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, USA; Department of Pediatrics, University of Minnesota, and University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, USA. Electronic address: denge001@umn.edu.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Dengel
mesh_terms: D000328:Adult; D001916:Brachial Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D008297:Male; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide
keywords: Hypercapnia; Ultrasound; Vasodilation