Postoperative Pain Relief With Transversus Thoracis Muscle Plane Block After Cardiac Surgery

TTP block with initial dose of placebo (NaCl0.9%) 20 ml per catheter (total volume 40ml), followed by 20 ml per catheter every 8 hours until 72 hours from the first dose has passed.

TTP block with initial dose of ropivacaine 0.5% (5 mg / ml) 20 ml per catheter (total volume 40ml), followed by doses of ropivacaine 0.2% (2 mg / ml) 20 ml per catheter every 8 hours until 72 hours from the first dose has passed.