Portable ultrasound for difficult central venous access.

Central venous catheterization can be difficult and can cause serious complications. Ultrasound-guided venous access is increasingly used but reports concern only routine cases. We performed a prospective observational study in 'difficult' or 'failed' procedures to assess the usefulness of ultrasound guidance. We used the technique in 33 patients; 23 had previous failed attempts or had suffered complications from such attempts. Ultrasound provided an anatomical reason for failure in 16 patients. Ten other patients were expected to be difficult before catheterization. Ultrasound identified a suitable site for catheterization in all 33 patients. Real-time ultrasound was used to successfully catheterize 22 patients. In nine patients, a surface landmark technique was used, which failed in three patients. In these three patients, ultrasound guidance allowed successful cannulation. Ultrasound guidance is a useful technique to aid central venous access when difficulties or complications have been encountered or anticipated.