Real-Time Ultrasound Guidance as Compared With Landmark Technique for Subclavian Central Venous Cannulation: A Systematic Review and Meta-Analysis With Trial Sequential Analysis

Objectives: We conducted a systematic review and meta-analysis to assess the effectiveness of real-time dynamic ultrasound-guided subclavian vein cannulation as compared to landmark technique in adult patients. Data sources: PubMed and EMBASE until June 1, 2022, with the EMBASE search restricted to the last 5 years. Study selection: We included randomized controlled trials (RCTs) comparing the two techniques (real-time ultrasound-guided vs landmark) for subclavian vein cannulation. The primary outcomes were overall success rate and complication rate, whereas secondary outcomes included success at first attempt, number of attempts, and access time. Data extraction: Independent extraction by two authors according to prespecified criteria. Data synthesis: After screening, six RCTs were included. Two further RCTs using a static ultrasound-guided approach and one prospective study were included in the sensitivity analyses. The results are presented in the form of risk ratio (RR) or mean difference (MD) with 95% CI. Real-time ultrasound guidance increased the overall success rate for subclavian vein cannulation as compared to landmark technique (RR = 1.14; [95% CI 1.06-1.23]; p = 0.0007; I2 = 55%; low certainty) and complication rates (RR = 0.32; [95% CI 0.22-0.47]; p < 0.00001; I2 = 0%; low certainty). Furthermore, ultrasound guidance increased the success rate at first attempt (RR = 1.32; [95% CI 1.14-1.54]; p = 0.0003; I2 = 0%; low certainty), reduced the total number of attempts (MD = -0.45 [95% CI -0.57 to -0.34]; p < 0.00001; I2 = 0%; low certainty), and access time (MD = -10.14 s; [95% CI -17.34 to -2.94]; p = 0.006; I2 = 77%; low certainty). The Trial Sequential Analyses on the investigated outcomes showed that the results were robust. The evidence for all outcomes was considered to be of low certainty. Conclusions: Real-time ultrasound-guided subclavian vein cannulation is safer and more efficient than a landmark approach. The findings seem robust although the evidence of low certainty.