Ultrasound study versus chest radiography for central venous catheter tip confirmation: A randomized clinical trial

Objective Proper positioning of central venous catheter (CVC) tips is essential to ensure procedural safety and effectiveness, preventing complications such as arrhythmia, cardiac tamponade, and vascular perforation. This study aimed to compare the first-attempt success rate and accuracy of bedside ultrasonography using transthoracic echocardiography with SonoVue contrast against chest radiography for confirming CVC tip placement. Methods A randomized, controlled, parallel-design clinical trial was conducted at Hospital São Paulo, Federal University of São Paulo (UNIFESP), between July 2020 and January 2021. Patients aged ≥18 years requiring CVC insertion were eligible. Participants were randomly assigned (1:1 ratio) to either ultrasonography (tip confirmation using transthoracic echocardiography with the bubble test) or chest radiography (standard anteroposterior radiograph) for catheter tip confirmation. All venous punctures were performed under real-time ultrasound guidance by experienced vascular surgeons (>5 years' experience). The primary outcome was first-attempt success rate (correct tip positioning without adjustment). Secondary outcomes included diagnostic accuracy of tip positioning, total procedure time, and procedure-related complications (pneumothorax, arterial puncture, and hematoma). Results A total of 35 participants were enrolled (20 in ultrasonography group and 15 in the chest radiography group), representing 43.8% of the planned sample (n = 80) due to COVID-19 pandemic recruitment challenges. First-attempt success rates were similar between the groups (ultrasonography 85% vs radiography 80%, P = .704). Correct final tip positioning was achieved in 95% of the ultrasonography group and 87% of the radiography group ( P = .381). The ultrasonography bubble test showed 95% concordance with radiographic confirmation. The mean procedure time was nonsignificantly longer in the ultrasonography group (25.4 ± 8.2 minutes vs 22.1 ± 7.5 minutes, P = .231). No pneumothorax occurred in either group; one arterial puncture (5%) occurred in the ultrasonography group, resolving spontaneously. Conclusions This underpowered study (n = 35 vs planned n=80) demonstrated the feasibility of bedside ultrasonography using transthoracic echocardiography for CVC tip confirmation, with no statistically significant differences in success rates or complications compared with chest radiography. However, nonsignificant findings cannot be interpreted as evidence of equivalence given insufficient statistical power. The technique eliminates radiation exposure and may offer logistical benefits in specific clinical contexts. Larger, adequately powered multicenter trials with formal economic evaluations are required to establish noninferiority before ultrasonography can be recommended as a routine replacement for chest radiography in standard practice.