Effect of paracetamol in gastrointestinal cancer surgery

Intervention 1: Intervention group: every 6 hours up to a maximum weight based on grams (total dose 24 h 4 grams) Paracetamol IV to receive. If a patient requires drug for pain or analgesic PRN 0.5mg/kg, up to a maximum ceiling of 35 mg to receive. Intervention 2: Control group: patients, 0.5mg/kg every 6 hours, up to a maximum of 50 mg analgesic receives and the need for additional drug fixed dose of 35 mg intravenously has analgesic.;Treatment - Drugs;Treatment - Drugs;Intervention group: every 6 hours up to a maximum weight based on grams (total dose 24 h 4 grams) Paracetamol IV to receive. If a patient requires drug for pain or analgesic PRN 0.5mg/kg, up to a maximum ceiling of 35 mg to receive.;Control group: patients, 0.5mg/kg every 6 hours, up to a maximum of 50 mg analgesic receives and the need for additional drug fixed dose of 35 mg intravenously has analgesic. Primary outcome(s): Reduce pain. Timepoint: Three days after surgery. Method of measurement: VAS. Study Design: Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Other design features: This study was double blinded.At sampling time Patient and information collector were not aware of which group they would be and patients randomly divided in 2 groups, base on their folder numbers. The study designer was inform about drugs administration.