Perioperative Intravenous Nimodipine Trial

The role of perioperative IV administration of nimodipine, an L-type calcium channel antagonist which is capable of crossing the blood-brain barrier, on peri-operative opioid and anesthetics requirements, pain intensity, opioid-related side effects and early postoperative bowel mobility in patients undergoing surgical treatment for bowel cancer with open radical colectomy remains scarcely explored. A prospective double-blind, randomized controlled trial investigating the effect of perioperative IV administration of nimodipine in patients undergoing open colectomy for cancer treatment is therefore conducted.

Inclusion Criteria: * Patients scheduled for open surgical treatment of bowel cancer at the General Hospital of Patra Exclusion Criteria: * Age \< 18 years, \> 75 years * American Society of Anesthesiologists (ASA) physical status \> III * Allergy to nimodipine * Inability to provide informed consent * Known severe renal insufficiency * Known severe bradyarrhythmia * Daily opioid consumption the last 7 days before surgery * Pain intensity assessed using the Numerical Rating Scale (NRS; 0-10), with scores greater than 5 reported on more than half of the days during the past month.