pulse pressure variation based intraoperative fluid therapy versus traditional fluid therapy for colonic cancer patients undergoing mass resection and anastomosis for maintaining adequate hydration without complications.

All Patients will be assigned randomly by using computerized program to one of the two equal groups. Patients will be (forty five patients per group):

Group A ;( control group) Forty five patients will do elective open colonic mass resection and anastomosis. Infusion of 6 ml/kg/hr. Ringer's solution.

Group B; Forty five patients will do elective open colonic mass resection and anastomosis. Infusion of 2 ml/kg/hr. Ringer's solution guided by pulse pressure variation.

Intraoperative fluid volume, hemodynamics, serum lactate and intestinal edema will be measured after induction of anesthesia and every hour till the end of the operation, length of the hospital stay, first time to gastrointestinal motion and postoperative complications are recorded.

Inclusion Criteria:

• American Society of Anesthesiologists physical status (ASA-PS) I and II Patients.
• Patients scheduled for elective open colonic mass resection and anastomosis.

Exclusion Criteria:

• Serious cardiac arrhythmia.
• Peripheral artery disease.
• An ejection fraction below 30%.
• A pulmonary pathology.

participant eligibility is based on self-representation of gender identity