The effects of local anaesthesia with bupivacaine and botulinum toxin-A after thoracotomy on stress hormone levels

To investigate the effects of local and systemic analgesics on stress hormone levels, which increase after thoracotomy. Materials and methods: Sixty-three male rats were divided into 9 groups (n = 7). In the control animals, only a blood sample was taken. In the thoracotomy group, a retractor was inserted for 1 h. In the local anaesthesia group, intercostal nerve block was performed with bupivacaine or botulinum toxin-A. In the systemic analgesia group, blockade was performed with bupivacaine and diclofenac sodium was given intraperitoneally. Blood samples were taken twice 4 h and 24 h after thoracotomy. Results: At 4 h, stress hormone levels were significantly higher in all groups compared to the control (P < 0.05). In the systemic analgesia group, cortisol level was lower than in the thoracotomy group (P < 0.05), and lactate dehydrogenase level was lower than in the thoracotomy and bupivacaine groups (P < 0.05). At 24 h, all stress hormones except glucose were significantly higher in all groups compared to the control (P < 0.05). Norepinephrine level was significantly lower in the systemic analgesia group as compared with the thoracotomy group (P < 0.05). Conclusion: Our study showed that analgesic therapy alone may be insufficient to lower stress hormone levels, which increase after thoracotomy.