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

Aim: 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.