This randomized, double-blinded, controlled study aims to investigate the effect of transversus thoracis muscle plane block (TTP), using repeated boluses of ropivacaine via catheter, on postoperative pain and oxycodone consumption after elective cardiac surgery with sternotomy. Altogether 120 eligible patients, sixty per group, will be recruited into the study, after informed consent at the discretion of the principal investigator.~All patients will receive 20 mg of temazepam orally as a premedication one hour before anaesthesia. General anaesthesia will be induced with propofol and sufentanil 0.5 μg/kg. Anaesthesia will be maintained with inhalational anaesthetic sevoflurane and sufentanil 0.005 μg ˖ kg-1 ˖ min-1 intravenous infusion. Opioids other than sufentanil will not be used before or during anaesthesia.~After inclusion for the study, the patient will be randomized to one of the two study groups (G1 and G2). At the end of the surgery, when sternal wound is secured, bilateral TTP block with ultrasound guidance is performed to both groups. G1 group will receive an initial dose of 20ml placebo (NaCl 0,9%) per catheter bilaterally (total volume 40ml), followed by 20ml doses of placebo per catheter every 8 hours until 72 hours from the first dose and G2 group will receive initial dose of 20ml ropivacain 0,5% per catheter bilaterally (total volume 40ml) followed by doses of ropivacain 0,2% 20ml per catheter every 8 hours until 72 hours from the first dose has passed.~All the patients will receive a patient-controlled analgesia (PCA) pump for added pain relief. After the setting of two TTP catheters, PCA pump will be attached to intravenous line and activated. Oxycodone PCA is used with 3 mg dose and lockout interval of 10 minutes. No continuous background infusion will be used during the postoperative period. When the patient is weaned from ventilator in the ICU, they are encouraged to use PCA for postoperative pain whenever necessary. If the patient is assessed to suffer from pain and is unable to use the PCA device, they will be assisted by the ICU nurse. The total duration of PCA oxycodone treatment will be 3 days (72 hours). No oral opioids or ketamine will be used. Each patients will be given 1000mg paracetamol intravenous infusion at the time of awakening and thereafter every 8 hours during TTP and PCA treatments.~During recovery, the patient assess the amount of their pain using numerical rating scale (NRS, range 0-10). If the patient is sedated and/or under mechanical ventilation, behavioral pain scale (BPS) will be used to estimate the amount of pain in the ICU.
This study aims to investigate the effect of transversus thoracis muscle plane block (TTP), using repeated boluses of ropivacaine via catheter, on postoperative pain and oxycodone consumption after elective cardiac surgery with sternotomy.