Background & Objective: Postoperative nausea and vomiting is the most common complication of anesthesia with an approximate prevalence of 30% up to 70% (in high risk patients). In recent years several articles have investigated the effects of antiemetic and anesthetic drugs on postoperative nausea and vomiting, but the nonpharmacological methods, which are cost-effective and have no side effects, are rare. Since it is essential for patients to be on fast before surgeries which require general anesthesia, occurrence of dehydration and extra cellular fluid volume deficit and subsequently nausea and vomiting are expected and anticipated. Thus in this study the effect of preoperative intravenous fluid on postoperative nausea and vomiting was explored.

  Methods: This clinical trial study was performed in two experimental and control groups, with 30 subjects in each. Experimental group were given a 1- liter bolus of intravenous normal saline preoperatively in addition to routine IV fluid. Finally the incidence of postoperative nausea and vomiting was observed and compared between two groups.

  Results : According to statistical tests, the differences between age, preoperative and postoperative NPO duration, use of antiemetics and the duration of hospitalization in two groups were statistically significant but the differences between other demographic variables and the volume of intraoperative intravenous fluid received during the surgery were not. Results showed that experimental group had significantly lower incidence of nausea and vomiting (20% and 10% respectively) in comparison with control group (50%). According to chi-square test, the rate of postoperative nausea and vomiting was significantly different in two groups. (p=0.015 and p=0.001 respectively) Also, preoperative NPO duration had significant relationship with postoperative vomiting (p= 0.05).

  Conclusion: Regarding the positive effect of intravenous fluid therapy on postoperative nausea and vomiting as a cost effective and harmless method in surgery, its use is recommended.�