Thoracic paravertebral blockade (TPVB) can be effective in many clinical settings. However, many clinicians are reluctant to use this technique due to its adverse effects such as pneumothorax. The aim of this study was estimate the appropriate depth and width for safe needle positioning.

The depth from skin to the paravertebral space (PVS) and the width from the spinous process (SP) to the PVS and the lateral tip of the transverse process (LTTP) were measured in all available sections from 84 patients examined by chest computed tomography (CT). The correlation between age, gender, body mass index (BMI) and each measured value was analyzed.

All 828 sections from the 84 patients aged between 19 and 65 years old were evaluated. The minimum and maximum values of the mean depth from the skin to PVS were 40.3-52.4 mm in men and 41.2-55.9 mm in women. The minimum and maximum values of the mean width from the SP to LTTP were 29.2-34.6 mm in men and 23.7-31.0 mm in women. At every thoracic level, the depth to PVS was similar in both genders but the width from the SP to the NEP in men was significantly higher than in women. Weight significantly influenced the width from the SP to LTTP in men but height and BMI did not. Also weight and BMI significantly influenced the depth from skin to PVS in almost all of the thoracic region at both sex, but height did not influence the depth from skin to PVS in both sex.

We report clinically useful estimates that may be used to help avoid side effects such as pneumothorax and achieve a successful thoracic paravertebral blockade.