title: Real-time two-dimensional ultrasound guidance for central venous cannulation: a meta-analysis.
abstract: BACKGROUND
  Use of ultrasound-guided techniques to facilitate central venous cannulation (CVC) may reduce the risk of misplacement and complications. A meta-analysis was conducted to compare real-time two-dimensional ultrasound (RTUS) guidance technique with anatomical landmark technique for CVC to determine whether RTUS has any advantages.
  
  
  METHODS
  Randomized studies comparing outcomes in patients undergoing CVC with either RTUS or landmark technique were retrieved from PubMed, ISI Web of Knowledge, EMBASE, and OVID EBM Reviews from their inception to March 2012.
  
  
  RESULTS
  Twenty-six studies involving 4,185 CVC procedures met the inclusion criteria. Compared with landmark technique, patients with RTUS had a pooled relative risk (RR) of 0.18 (95% CI: 0.10-0.32) for cannulation failure, 0.25 (95% CI: 0.15-0.42) for arterial puncture, 0.30 (95% CI: 0.19-0.46) for hematoma, 0.21 (95% CI: 0.06-0.73) for pneumothorax, and 0.10 (95% CI: 0.02-0.54) for hemothorax from random-effects models. However, RTUS did not show a reduction in the risk of cannulation failure (RR = 0.26, 95% CI: 0.03-2.55), arterial puncture (RR = 0.34, 95% CI: 0.05-2.60), hematoma (RR = 0.13, 95% CI: 0.01-2.42), pneumothorax (RR = 0.40, 95% CI: 0.02-9.61), and hemothorax (RR = 0.40, 95% CI: 0.02-9.61) in children or infants when the limited data were analyzed.
  
  
  CONCLUSIONS
  Among adults receiving CVC, RTUS was associated with decreased risks of cannulation failure, arterial puncture, hematoma, and hemothorax. Additional data of randomized studies are necessary to evaluate these outcomes in pediatric patients.
authors.affiliation: Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Shao-yong
authors.initials: SY
authors.lastname: Wu
authors.forename: Quan
authors.initials: Q
authors.lastname: Ling
authors.forename: Long-hui
authors.initials: LH
authors.lastname: Cao
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Mei-xi
authors.initials: MX
authors.lastname: Xu
authors.forename: Wei-an
authors.initials: WA
authors.lastname: Zeng
mesh_terms: D000328:Adult; D001158:Arteries / Q000293:injuries; D002405:Catheterization, Central Venous / Q000009:adverse effects / Q000379:methods*; D002648:Child; D006406:Hematoma / Q000517:prevention & control; D006491:Hemothorax / Q000517:prevention & control; D006801:Humans; D019300:Medical Errors / Q000517:prevention & control / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000453:epidemiology; D017594:Publication Bias; D016032:Randomized Controlled Trials as Topic; D017211:Treatment Failure; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000379:methods*