Patients undergoing laparoscopic surgery experience postoperative pain especially in the abdomen, lower back, and shoulders, Relieving postoperative pain, especially with certain types of analgesic agents, may reduce postoperative morbidity and mortality. It is also important to prevent adverse events such as myocardial infarction, cardiac arrhythmia, ileus, and poor wound healing and pulmonary complications. There is evidence that the main source of pain after laparoscopic surgeries is the peritoneum . Due to CO2 insufflation constitutes the commonest means of creating the pneumoperitoneum. Co2pneumoperitoneum is known to cause systemic acidosis. Which is responsible for damaging of the mesothelial lining of the peritoneum and consequent peritoneal irritation . Moreover, the phrenic nerve could be damaged by the acidic environment The use of local anesthetics has been advocated as a method for reducing postoperative pain local anesthetic intraperitoneal administration has shown good effects on reducing postoperative pain in laparoscopic cholecystectomy and gynecological surgeries . intraperitoneal sodium bicarbonate instillation may neutralize effect of the acid milieu on peritoneal cavity and the phrenic nerve damage which consecutively will lead to a reduction of postoperative pain. Magnesium sulfate, a non-competitive NMDA antagonist, has been proven in animal and human being models to have antinociceptive properties. The antinociceptive effect of magnesium sulfate relieves chronic pain and it can also decrease the duration and intensity of postoperative pain.