Methods
Search Strategy
We utilised a (PICO) format to ask our clinical question: Is real time ultrasound-guided CVC placement more successful than a traditional landmark approach in the ED setting?
Patients: Our study included ED patients over the age of 18 years requiring CVC placement for any reason deemed necessary by the ED physician, with the exception of placement for the purposes of cardiopulmonary resuscitation. Intervention: Central line placement using real-time ultrasound guidance. Comparator: Central line placement by traditional anatomical landmarks. Outcome: Comparison of success rates of CVC placement between ultrasound- versus landmark-guided techniques.
Outcome Measures and Data Abstraction
Our primary outcome was the successful CVC cannulation. Secondary outcome included complications of CVC placement. Our target study design limited our review to randomised trials where participants underwent either ultrasound- or landmark-guided CVC placement.
Primary Data Analysis
CVC cannulation success rates were compared using a Forest Plot of RR (95% CI) between ultrasound- and landmark-guided techniques using Review Manager (RevMan) (computer program), Version 5.0 (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2008). Pooled treatment effects were estimated using RR for CVC success rates after intervention/comparator, with Mantel–Haenszel RR, using a random-effects model. Heterogeneity was assessed by χ and the I statistic. Manuscripts were investigated for potential bias by the following criteria: randomisation, concealment, blinding, intention-to-treat and completeness of follow-up.
Data Collection and Processing
MEDLINE with the PubMed interface was searched for articles from 1965 through November 2010 and EMBASE from 1980 to November 2010 with the Ovid Technologies interface (See online appendix A for complete MEDLINE and EMBASE search strategies). We also searched the Cochrane Central Register of Controlled Trials using the same MEDLINE search strategy and the bibliographies of the included and relevant articles and reviews. Each author reviewed the articles to ensure that they met inclusion/exclusion criteria. The authors (WV) and (AMG) both abstracted the data and this was checked for accuracy by the other authors (NM) and (RS).