Central venous cannulation: are routine chest radiographs necessary after B-mode and colour Doppler sonography check?

BACKGROUND: After the insertion of a central venous catheter, a chest radiograph is usually obtained to ensure correct positioning of the catheter tip.

OBJECTIVE: To determine in a paediatric population whether B-mode and colour Doppler sonography after central venous access is useful to evaluate catheter position, thus obviating the need for a postprocedural radiograph.

MATERIALS AND METHODS: A prospective study of 107 consecutive central venous access procedures placed in a paediatric intensive care unit was performed. At the end of the procedure, B-mode and colour Doppler sonography were used to assess catheter position and check for complications. A postprocedural chest radiograph was obtained in all patients.

RESULTS: In 96 patients postprocedural B-mode and colour Doppler sonography showed colour Doppler signals within the vena cava. Among the 11 patients predicted to have a potential complication, there was one pneumothorax and ten malpositions. Chest radiography showed a total of 13 complications-1 pneumothorax and 12 malpositions. The concordance between colour Doppler sonography and chest radiography was 98.1% in the detection of catheter position; sonography had a sensitivity of 84.6% and a specificity of 100%.

CONCLUSIONS: The close concordance between B-mode and colour Doppler sonography and chest radiography justifies the more frequent use of sonography to evaluate catheter position because ionizing radiation is eliminated. Chest radiography may then be performed only when there is suspected inappropriate catheter tip position after sonography.