title: Ultrasound Guidance Facilitates Radial Artery Catheterization: A Meta-analysis With Trial Sequential Analysis of Randomized Controlled Trials.
abstract: BACKGROUND
  Potential benefits and possible risks associated with ultrasound guidance compared with traditional palpation for radial artery catheterization are not fully understood.
  
  
  METHODS
  We searched PubMed, Embase, and the Cochrane Library through July 2015 to identify randomized controlled trials that evaluated ultrasound guidance compared with traditional palpation for radial artery catheterization. Primary outcome was first-attempt failure. Secondary outcomes included mean attempts to success, mean time to success, and hematoma complications. A random-effects model was used to estimate relative risks (RRs) with 95% CIs.
  
  
  RESULTS
  Twelve trials used dynamic two-dimensional (2-D) ultrasound guidance (N = 1,992) and two used Doppler ultrasound guidance (N = 666). Compared with traditional palpation, dynamic 2-D ultrasound guidance was associated with a reduced first-attempt failure (RR, 0.68; 95% CI, 0.52-0.87). Trial sequential analysis showed that the cumulative z curve crossed the trial sequential monitoring boundary for benefit establishing sufficient and conclusive evidence. Dynamic 2-D ultrasound guidance further reduced mean attempts to success, mean time to success, and hematoma complications. No evidence of publication bias was detected. Compared with traditional palpation, Doppler ultrasound guidance had no benefit on first-attempt failure (RR, 1.00; 95% CI, 0.87-1.15), which was confirmed by trial sequential analysis as the cumulative z curve entered the futility area.
  
  
  CONCLUSIONS
  The use of dynamic 2-D ultrasound guidance for radial artery catheterization decreases first-attempt failure, mean attempts to success, mean time to success, and the occurrence of hematoma complications. Dynamic 2-D ultrasound guidance is recommended as an adjunct to aid radial arterial catheterization.
authors.affiliation: Department of Anesthesiology, Drum Tower Hospital, Medical College of Nanjing University, Nanjing, China.
authors.forename: Wan-Jie
authors.initials: WJ
authors.lastname: Gu
authors.affiliation: Department of Orthopaedic Surgery, the First Affiliated Hospital, Chongqing Medical University, Chongqing, China.
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Wu
authors.affiliation: Department of Anesthesiology, General Hospital of Jinan Military Command, Jinan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Drum Tower Hospital, Medical College of Nanjing University, Nanjing, China. Electronic address: mazhengliang1964@nju.edu.cn.
authors.forename: Zheng-Liang
authors.initials: ZL
authors.lastname: Ma
authors.affiliation: Department of Anesthesiology, Drum Tower Hospital, Medical College of Nanjing University, Nanjing, China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Gu
mesh_terms: D002406:Catheterization, Peripheral; D006801:Humans; D017534:Radial Artery; D016032:Randomized Controlled Trials as Topic; D018084:Ultrasonography, Interventional
keywords: catherizations; meta-analysis; ultrasound