Low-dose buprenorphine to prevent remifentanil-induced hyperalgesia after major lung resection: a prospective, randomised, controlled, double-blinded study

INTERVENTION: All patients will receive remifentanil based general anaesthesia (target‐controlled infusion [TCI] system), supplemented with oxygen and desflurane. Patients will then be randomised to: 1. Buprenorphine group: intra‐ and post‐operative infusion of 25 µg/h of buprenorphine for 24 hours 2. Morphine group: intra‐ and post‐operative infusion of 834 µg/h of morphine for 24 hours Follow‐up will occur until 30 days after hospital discharge. CONDITION: Post‐operative remifentanil‐induced hyperalgesia ; Skin and Connective Tissue Diseases ; Disturbances of skin sensation PRIMARY OUTCOME: Post‐operative morphine consumption (PCA). SECONDARY OUTCOME: 1. Morphine titration at the end of the surgery; 2. Visual Analogue Scale (VAS) at rest and during coughing at 24 and 48 hours; 3. Hyperalgesic area at 24 and 48 hours (Quantitative Sensory Testing); 4. Length of post‐operative hospitalisation; 5. Incidence of post‐thoracotomy pain after one month from surgery INCLUSION CRITERIA: 1. Adult patients (American Society of Anaesthesiologists [ASA] grade I ‐ III) undergoing major lung resections 2. Aged greater than 18 years, either sex