Real‐Time Ultrasound Central Line Placement to Replace Postprocedural Chest X‐Ray: Is Post–Central Line Placement Chest X‐Ray Still Considered the Gold Standard?

Background:

Central line placement is a common ICU procedure that aids in hemodynamic monitoring, as well as delivery of medical treatment and nutritional support. In the United States alone, more than 5 million central venous catheters are placed every year. Complications are experienced in 5%–19% of cases. The current standard to detect postprocedural complications and to confirm proper line position is by chest radiography. This study compared the effectiveness of using ultrasound to the current standard, chest radiography, in the identification of proper central line placement and in ruling out pneumothorax.

Methods:

This was a prospective pilot study consisting of 23 central venous catheter insertions using dynamic ultrasonographic guidance. Intravascular guide‐wire positions were assessed by observing for target sign (guide wire floating in the center of the vessel on cross‐sectional view). Central line position/malposition was evaluated by observing the guide wire's target sign while it was inside the catheter. The presence of pneumothorax was assessed by observing for sliding lung (to‐and‐fro movement synchronous with respiration between 2 hyperechogenic lines created by the chest wall and the aerated lung), comet tail artifact (hyperechoic reverberation artifacts that extend from the pleural interface to the distal edge of the ultrasound image), and lung point sign (image where the sliding lung and the tip of the pneumothorax are visualized). Postprocedural AP chest X‐rays were done. Elapsed time between the X‐ray and confirmation was recorded.

Results:

Ultrasonography was able to rule out pneumothorax with a specificity of 100% (1‐sided 95% Cl: 86.7%) when compared with chest radiography. Specificity could not be estimated because there were no false positives and no true negatives. In this limited study, ultrasonography has also demonstrated 100% accuracy for confirming proper line position. The median time between procedure completion and chest radiography was 37 minutes (95% Cl: 23, 60 minutes). The median time from procedure completion to when the chest radiograph report was called to the floor and the catheter was used was 90 minutes (95% Cl: 52, 155 minutes).

Conclusions:

Ultrasound was proven beneficial for vascular localization and cannulation during central line placement. Ultrasonography demonstrated 100% accuracy for confirming line position and detecting pneumothorax. Moreover, we learned there was a significant time delay between central line placement and postprocedural radiographic confirmation in comparison with the near‐instantaneous confirmation for ultrasonography. These findings suggest that real‐time ultrasonographic guidance may be better than the gold standard in evaluating central line position.

Author Disclosure:

D. De Leon, Carilion Clinic, employee; S. Aziz, Carilion Clinic, employee.