title: Distal tourniquet-facilitated radial arterial cannulation in adults--a double-blinded, prospective, randomized and controlled study.
abstract: OBJECTIVE
  Relatively small radial artery may be challenging for cannulation. We investigated whether a distal tourniquet would inflate the proximal radial artery and therefore facilitate cannulation in adults.
  
  
  METHODS
  There were two stages of the study. The first was to measure the characteristics of radial artery by ultrasound imaging before and after tourniquet in volunteers. The second was a prospective, randomized, double blind study. Forty patients (American Society of Anesthesiologists I-III) who needed artery cannulation during operation were enrolled. Patients were assigned into two groups: loosen or tightened tourniquet for proximal radial artery cannulation by traditional palpation technique. The primary endpoints were the success rates and time of first attempt success by traditional palpation technique. The time of success after two to three attempts, failure rates and complications were collected.
  
  
  RESULTS
  For volunteers, the distal tourniquet significantly expanded the cross-sectional up-forward diameter (p<0.001) and the area (p<0.05), but had no effect on cross-sectional lateral-lateral diameter or circumference of proximal radial artery (p>0.05). The success rate of first attempt was higher in the tighten group (75%) than in the loosen group (15%, p<0.05), but the time for success of first attempt/two to three attempts was similar (19.33 ± 1.12/62.11 ± 37.03 sec loosen group vs. 19.07 ± 12.75/45.55 ± 8.98 sec tightened group, p>0.05). Both groups had same failure rates of 10%. No complication was observed.
  
  
  CONCLUSIONS
  Distal tourniquet could inflate the proximal radial artery and facilitate palpation of radial artery cannulation.
authors.affiliation: Department of Anesthesiology, Shanghai Jiaotong University Affiliated, Shanghai Sixth People's Hospital, Shanghai - China.
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Zhou
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Yongzhu
authors.initials: Y
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002406:Catheterization, Peripheral / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D014111:Tourniquets; D018084:Ultrasonography, Interventional / Q000379:methods*; D055815:Young Adult