Intercostal nerve blocks
, Thoracic epidural, Opioids in the epidural space, and transcutaneous electrical nerve stimulation, can produce adequate analgesia but have their limitations along with possible side effects.
We conclude that using clonidine as an adjunct to bupivacaine for continuous paravertebral intercostal nerve block improves pain relief after thoracotomy, but hypotension and sedation are adverse effects interfering with its clinical application.
Paravertebral intercostal nerve block is a technically simple and quick procedure (3), especially for low-risk patients.
In this study we evaluated the efficacy of clonidine as an adjuvant to bupivacaine for paravertebral intercostal nerve block among patients undergoing thoracotomy, by measuring analgesia, sedation, pulmonary function and associated side-effects.
We found that continuous paravertebral intercostal nerve block with bupivacaine and clonidine provided significantly better pain relief at rest and on coughing when compared with bupivacaine alone.
Tschernko added 2 [micro]g/kg of clonidine to bupivacaine for paravertebral intercostal nerve block and found that this afforded better and more prolonged pain relief than plain bupivacaine, as measured by VAS scores, additional analgesic requirements and improved arterial oxygenation (11).
Systemically absorbed clonidine may have contributed to this and it offsets one of the main advantages of paravertebral intercostal nerve block compared with thoracic epidural analgesia, namely a lower incidence of hypotension.
Continuous intercostal nerve block for pain relief after thoracotomy.