Subcutaneous emphysema causing inefficient ultrasound guidance during central vein cannulation

The Challenges of Ultrasound-guided Thoracic Paravertebral Blocks in Rib Fracture Patients

Thoracic paravertebral blocks (TPVBs) provide an effective pain relief modality in conditions where thoracic epidurals are contraindicated. Historically, TPVBs were placed relying solely on the landmark-based technique, but the availability of ultrasound imaging makes it a valuable and practical tool during the placement of these blocks. TPVBs also provide numerous advantages over thoracic epidurals, namely, minimal hypotension, absence of urinary retention, lack of motor weakness, and remote risk of an epidural hematoma. Utilization of both landmark-based and ultrasound-guided techniques may increase the successful placement of a TPVB. This article reviews relevant sonoanatomy as it pertains to TPVBs. However, certain patient-related issues, including pneumothoraces, surgical emphysema, body habitus, and transverse process fractures, all may make imaging with ultrasound challenging. The changes noted on ultrasound imaging as a result of these issues will be further described in this review.