title: Clinical and microcirculatory effects of transcutaneous CO2 therapy in intermittent claudication. Randomized double-blind clinical trial with a parallel design.
abstract: BACKGROUND
  This randomized, double blind trial determined the short and long-term clinical and hemodynamic vasodilator effects induced by percutaneous applications of natural CO2 gas in patients with moderate Fontaine stage II.
  
  
  METHODS
  62 patients with intermittent claudication (100-500 meters) were randomized to 18 consecutive days of CO2 treatment or placebo (air). The gas fluids were applied at a constant temperature of 30 degrees C on pre-humidified skin. The effects of the treatment were evaluated by total distance walked (primary criterion) and hemodynamic and microcirculatory findings. Patients also answered a quality of life questionnaire.
  
  
  RESULTS
  The Strandness test showed a significant increase in total distance walked (+ 131 meters, 66%; p = 0.001) and pain-free distance (+ 81 meters, 73%; p = 0.02) after 18 days of CO2 treatment. The improvement was maintained 3 and 12 months later. The systolic pressure index (ABI) increased by 37% (p = 0.001) 1 minute after treadmill walking and ABI recovery time decreased significantly by 38% (p = 0.002). Microcirculatory findings showed an increase in systolic pressure of the great toe (13%; p < 0.0001), in baseline pO2 (20%; p = 0.01) and in vasomotion (78%; p = 0.001) in the treatment group. The improvement in total walking distance was correlated with the increase in ABI and peripheral cutaneous oxygenation. Patients' subjective assessments corroborated the benefits. No significant change was observed in the placebo group.
  
  
  CONCLUSIONS
  This study demonstrates that 18 consecutive days of percutaneous CO2 treatment significantly increases walking distance in patients with moderate intermittent claudication. This effect, which was associated with an increase in peripheral systolic pressure and pO2, is evidence of a better ability to withstand effort.
authors.affiliation: Service therapeutique et Hydrologie Med., Faculté de Médicine, Clermont-Ferrand, France. regine.fabry@u-clermont.fr
authors.forename: R
authors.initials: R
authors.lastname: Fabry
authors.forename: P
authors.initials: P
authors.lastname: Monnet
authors.forename: J
authors.initials: J
authors.lastname: Schmidt
authors.forename: J-R
authors.initials: JR
authors.lastname: Lusson
authors.forename: P-H
authors.initials: PH
authors.lastname: Carpentier
authors.forename: J-C
authors.initials: JC
authors.lastname: Baguet
authors.forename: C
authors.initials: C
authors.lastname: Dubray
mesh_terms: D000279:Administration, Cutaneous; D000368:Aged; D000842:Ankle / Q000098:blood supply; D001494:Baths; D001794:Blood Pressure / Q000187:drug effects; D001916:Brachial Artery / Q000187:drug effects / Q000503:physiopathology; D002245:Carbon Dioxide / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D007866:Leg / Q000098:blood supply*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011788:Quality of Life; D020127:Recovery of Function; D012039:Regional Blood Flow / Q000187:drug effects; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage*; D016138:Walking
chemical_list: D014665:Vasodilator Agents; D002245:Carbon Dioxide; D010100:Oxygen