Usually, to avoid PDPH, a small gauge needle is used. This is performed at the angle of the rib where the intercostal nerves pass round the chest wall beneath the inferior border of the ribs. There is a risk of pneumothorax. Multiple blocks are necessary and the high blood levels are reached. This is a particularly useful technique for pain relief in patients with chest injuries.
Local anaesthetic is introduced through the catheter into the pleural space.
Analgesia occurs due to diffusion of local anaesthetic to the intercostal nerves, sympathetic chain and direct action on pleural nerve endings. The results of several studies have varied from moderate to excellent analgesia to no analgesia and further work on defining the exact role of interpleural analgesia is currently underway. Physical Methods Commonly used physical agents include applications of cold, massage, movement, TENS, and rest or immobilization. This has been used with varying degrees of success in the management of postoperative pain. Preparing patients in order to understand their responsibilities in pain management is important.