Patients were randomized to receive via a thoracic epidural catheter either a ) bupivacaine 0.25 % ( 10 mL ) and saline 0.9 % ( 2 mL ) as a bolus followed by an infusion of bupivacaine 0.25 % ( 5 mL/hr ) or b ) bupivacaine 0.25 % ( 10 mL ) and morphine 0.1 % ( 2 mL ) as a bolus followed by an infusion of bupivacaine 0.25 % plus morphine 0.025 % ( 5 mL/hr ) .
