OBJECTIVE: To evaluate the toxic side effects of intraperitoneal chemotherapy for gastric cancer and to discuss its management. METHODS: A total of 156 patients with gastric cancer were randomly grouped. They were divided into three groups: immediate intraoperative hypotonic warm intraperitoneal chemotherapy combined with early postoperative intraperitoneal chemotherapy (treatment group), immediate intraoperative hypotonic warm intraperitoneal chemotherapy alone (control group 1), and no intraperitoneal chemotherapy group (control group 2). RESULTS: The incidence of chemical peritonitis, gastrointestinal reactions, bone marrow suppression and abnormal liver function was significantly higher in the treatment group than in the two control groups. CONCLUSION: The prevention and treatment of chemical peritonitis in the application of immediate intraoperative hypotonic warm intraperitoneal chemotherapy combined with early postoperative intraperitoneal chemotherapy should not be neglected. Intraperitoneal chemotherapy as a selective regional chemotherapy has obvious pharmacokinetic advantages compared with peripheral intravenous chemotherapy. Therefore, it has been more and more widely used in the treatment of gastric cancer, and has achieved encouraging efficacy. Many scholars have studied and elaborated on the toxic side effects and safety of intraperitoneal chemotherapy for gastric cancer. Most scholars believe that intraperitoneal chemotherapy is relatively safe, and there is no significant difference in the incidence of postoperative complications and toxic side effects relative to those who have not undergone any chemotherapy [1, 2]. The literature reports that although warm intraperitoneal chemotherapy has certain effects on the human body, they are within the controllable range and its clinical application is safe and reliable [3]. In this study, we evaluated two aspects of the safety of abdominal chemotherapy and the toxic side effects of abdominal chemotherapy. 1. Clinical data (1) General data: we studied 156 cases of gastric cancer patients who met the enrollment criteria admitted to our hospital during 1999.1~2001.2. There were 106 males and 50 females, aged 25-75 years. Among them, 134 cases (85.90%) underwent radical gastric cancer surgery and 22 cases (14.10%) underwent palliative gastrectomy and lymphatic metastasis resection. (2) Grouping: randomly grouped: (i) 52 cases in the immediate intraoperative hypotonic warm abdominal chemotherapy combined with early postoperative abdominal chemotherapy group (treatment group), of which 36 were male and 16 were female, and 45 cases (86.54%) underwent radical resection; (ii) 49 cases in the immediate intraoperative warm abdominal chemotherapy group (control group 1), of which 32 were male and 17 were female, and 40 cases (81.63%) underwent radical resection; (iii) no abdominal chemotherapy (3) The group without intraoperative warm intraperitoneal chemotherapy (control group 2) consisted of 55 cases, including 38 males and 17 females, and 49 cases (89.10%) underwent radical resection. In all three groups, six courses of conventional intravenous chemotherapy were started at about one month after surgery. 2. Results (1) Observation of the safety of abdominal chemotherapy. From the study data, we can see that: (1) the incidence of chemical peritonitis in the treatment group was higher than that in control group 1 (P<0.05) and significantly higher than that in control group 2 (P<0.01); (2) there was no significant difference in the incidence of chemical peritonitis between the two control groups (P>0. 05); (3) there was no statistical difference in the four aspects of incisional infection and dehiscence, anastomotic leakage, abdominal abscess and adhesive bowel obstruction between the three groups (P>0. 05). There was no statistical difference (P>0. 05). (2) Observation of toxic side effects of intraperitoneal chemotherapy. From the data of the four groups, we can see that: (1) the incidence of gastrointestinal reactions in the treatment group was significantly higher than that in the two control groups (P<0.01); (2) the incidence of bone marrow suppression and liver function abnormalities in the treatment group was higher than that in the two control groups (P<0.05), while the incidence of renal function abnormalities was not statistically different (P>0. 05); (3) there was no significant difference between the two control groups in these four aspects (P>0. 05). 05). 3. Discussion In terms of the safety of peritoneal chemotherapy by analyzing the study data we found that (1) the incidence of chemical peritonitis was significantly higher in the treatment group relative to control group 1 and control group 2, which was different from that reported in the literature. In contrast, there was no statistically significant difference between the two control groups compared to each other. This may be caused by the application of intraoperative chemotherapy alone with 5-FU in this study, while postoperative chemotherapy was combined with cisplatin. We observed the most pronounced symptoms of peritoneal irritation in patients when cisplatin was applied on the first day of postoperative chemotherapy. Therefore, the addition of a small amount of lidocaine to cisplatin on the first day of chemotherapy was more effective in relieving peritoneal irritation in our patients. Even so, 6 patients failed to complete the next 4 days of peritoneal chemotherapy due to severe symptoms. In addition, 2 patients still had severe peritoneal irritation after the 5-day course of chemotherapy, which lasted for a long time and caused more pain to the patients. Therefore, we believe that the prevention and management of chemical peritonitis during the application of intraperitoneal chemotherapy is something that all physicians need to pay attention to. We appreciate that the amount of fluid perfused into the peritoneal cavity should be appropriately increased to achieve dilution when applying cisplatin, and 400 ml of saline added with lidocaine should be dripped into the peritoneal cavity in advance during application, which can prevent chemical peritonitis more effectively. However, too much fluid can cause abdominal distension in patients, and the total amount of fluid we apply is usually 1000-1200 ml. up to 1800 ml, whichever the patient can tolerate. In case of severe chemical peritonitis, the peritoneal irritation leads to more peritoneal exudation, and the patient tends to eat poorly at this time, so we should pay attention to the amount of rehydration, maintain the water-electrolyte and acid-base balance, and strengthen nutritional support. Preferably, TPN should be applied.(2) There was no statistical difference between the three groups when comparing the four aspects of incisional infection and dehiscence, anastomotic leak, abdominal abscess, and adhesive bowel obstruction. This is consistent with most of the literature reports. Regarding the toxic side effects of abdominal chemotherapy by analyzing the study data we found that (1) the incidence of gastrointestinal reactions, bone marrow suppression and liver function abnormalities were higher in the treatment group than in the two control groups, while the incidence of renal function abnormalities was not statistically different. (2) There were no significant differences between the two control groups in these four areas. Our statistical indications for GI reactions were wide, including nausea, vomiting, diarrhea and loss of appetite. Most of the GI reactions resolved spontaneously after the end of abdominal chemotherapy. Irreversible bone marrow suppression and hepatic impairment have not been observed. Since these side effects are relatively easy to manage, we believe that although the incidence of intraoperative combined postoperative intraperitoneal chemotherapy side effects is higher than that of the two control groups, it does not affect the implementation of this treatment. In order to improve the safety of laparoscopic chemotherapy and reduce the impact of laparoscopic chemotherapy side effects on patients, we appreciate that the following issues should be noted: (1) patients should be free of cardiopulmonary diseases that affect surgery; (2) patients should have normal liver and kidney function and normal blood count; (3) the perioperative period should pay attention to the correction of factors that affect recovery from surgery, such as anemia and hypoproteinemia; (4) the water-electrolyte and acid-base (4) to correct the disorders of water-electrolyte and acid-base balance, paying special attention to the prevention and control of hypokalemia; (5) to attach great importance to the anastomosis technique, the suture of the anastomosis must be satisfactory, and those who are not satisfied cannot apply laparoscopic chemotherapy; (6) poor general condition, over age, complicated surgery, and heavy contamination of the abdominal cavity are not suitable for laparoscopic chemotherapy; (7) early postoperative supplementation of protein and vitamins is desirable, and TPN therapy is given when necessary.