Please confirm that an ethics committee approval has been applied for or granted: Not relevant (see information at the bottom of this page)

Application for ESRA Abstract Prizes: I apply as an Anesthesiologist (Aged 35 years old or less)

Background and Aims The presence of a pleural effusion can present challenges during the performance of paravertebral block (PVB) under ultrasound (US). PVB is a regional anaesthetic technique used in thoracic surgery for perioperative and postoperative analgesia. In our centre, we have performed PVB in patients with pleural effusions undergoing pleural drainage and diagnostic video-assisted thoracoscopic surgery. In doing so, we have discovered that the US image of the chest is altered in these patients. We wish to demonstrate this finding as it affects the performance of a successful PVB.

Methods Patients with a pleural effusion undergoing thoracic surgery underwent a US-guided PVB in sagittal orientation with a 12MHz linear transducer. Images were taken before and after PVB injection of local anaesthetic (LA).

Results On US imaging, the presence of a pleural effusion has the appearance of the paravertebral space on first inspection: a dark hypoechoic space bounded by ‘bright’ pleural borders. In one patient this was confirmed by inadvertent aspiration of pleural fluid. On closer inspection, the paravertebral space is more superficial and hyperechoic than normally anticipated. The injection of LA injection into the true paravertebral space renders the borders more prominent.

• Download figure
• Open in new tab
• Download powerpoint

Abstract #36405 Figure 1

US sagittal view of PVB anatomy comparing normal (A) with pleural effusion (B)

Conclusions We demonstrate that a pleural effusion may be mistakenly identified as the paravertebral space when performing an US-guided PVB. The true paravertebral space is more superficial and becomes more prominent after injection into the space. Misidentification of the space may result in suboptimal block efficacy, limitation of local anaesthetic spread, inadvertent needling of effusion, haemothorax and infection.