Application Of M-POSSUM Scoring System In Postoperative Risk Assessment Of Patients With Gastric Cancer

BackgroundGastric cancer is one of the most common malignant tumors in China,at present,surgery is preferred for the treatment of the gastric cancer.Gastric cancer has a high morbidity and mortality after surgery,and clinical staff have paid attention to how to reduce the incidence of postoperative of morbidity and mortality.There have been many scoring systems used to predict postoperative morbidity and mortality in surgical patients,but most of them are subjected to certain limitation due to their lack of accuracy.POSSUM is a standardized predictive scoring system developed by Copeland through extensive studies of postoperative morbidity and mortality in various surgical patients.However,studies have reported that the POSSUM scoring system has an excessive perdition of mortality,so Professor Ding Lianan and others have improved the modified POSSUM scoring system(M-POSSUM).At present,most studies on the M-POSSUM scoring system have focused on predictive value of postoperative,and there are few reports about the effectiveness of the assessment of the morbidity and mortality in different risk subgroups.Therefore,it is necessary to investigate the status of the occurrence and the death of postoperative complications in patients with different risk subgroups of gastric cancer and identify the influencing factors of prognosis,and to investigate the need to improve the scoring system,so as to instruct clinical nurses to reveal high risk patients according to the score and actively interfere to make individualized treatment programs for patients to reduce the incidence of postoperative complications and death,reduce hospital stay and enhance recovery of patients after surgery.Objective:1.To explore the predictive value of the M-POSSUM scoring system in assessing the incidence of morbidity and mortality in different risk subgroups,and to further investigate whether there is a distinct M-POSSSUM scoring system cut-off point between gastric cancer with high risk of postoperative morbidity and mortality2.To investigate the incidence of postoperative complications and mortality with different risk subgroups of gastric cancer and to analyze the influencing factors and further to explore the need to improve the scoring system and to provide an evidence for clinical intervention to reduce the postoperative morbidity and mortality.MethodsA total of 260 patients underwent radical gastrectomy for gastric cancer between November 2013 and December 2015 at the general surgery unit of a tertiary hospital in Jiangsu Province,China,were analyzed retrospectively.Patients characteristics(age,gender,weight,educational background,past history,and smoking and alcohol consumption habits)and their treatment regimens(surgical type,method,intraoperation blood loss)were obtained.All patients with radical gastrectomy were assessed by M-POSSUM scoring system in 24 hours after admission and on the first postoperative day.Their length of hospital stay and postoperative morbidity and mortality were recorded(observed value).According to the formula of M-POSSUM scoring system(predicting the incidence of complications(Rl):lnR1/(1-R1)=-7.287+0.765M-POSSUM score;the formula for predicting mortality(R2):lnR2/(1-R2)=-10.000+0.681M-POSSUM score)and calculated the postoperative expected mortality and morbidity for each one,and converted to the predicted value,while the observed values were recorded and compared with expected values with Chi-square test.The actual and predictive morbidity(mortality)compliance(0:E(observe:expect)value was scored to judge the discriminant efficiency of M-POSSUM scoring system.The predictive value and optimal cut-off point of M-POSSUM scoring system in morbidity and mortality of postoperative in gastric cancer patients were assessed according to the area under the receiver operating characteristic curve(AUC).Factors impacting upon postoperative mortality and morbidity in patients with gastric cancer undergoing M-POSSUM scoring system and other factors were examined using univariate and binary logistic regression analyses.Results1.M-POSSUM score system analysis1.1 All of 260 cases completed the M-POSSUM score,M-POSSUM score was from 6 to 19(9.55 ± 2.37)score,preoperative physiological score was from 4 to 7(7.55±2.32)score,the severity of operation score was from 1 to 3(2.20±0.44).M-POSSUM scoring system in predicting the complications of 89cases(34.23%)with the actual complications 68 cases(26.15%)compared to,the difference was not statistical difference(χ2=4.024,P=0.056);M-POSSUM score for predicting death in 6 cases(2.31%)and the actual death in 2cases(0.77%),the difference was not statistically significant(x2=2.031,P=0.285).1.2 The results of study indicates that The O:E value is increasing with the increase of R1 and R2.The observed value of M-POSSUM is closest to expected value(0:E)while R1 is between 61%and 91%and R2 is between 61%and 100%.By calculation,the use of M-POSSUM scoring system in predicting the postoperative complications,with 10 points as the boundary value,AUROC area is the biggest that the risk of postoperative complications increased when M-POSSUM score is greater than 10;the use of M-POSSUM scoring system in predicting the mortality after surgery,with 12 points as the boundary value,the largest area is AUROC;and when the M-POSSUM score is greater than 12,the risk of postoperative mortality increases in patients with gastric cancer.2.Mono-factor analysis2.1 The mono-factor analysis(n=260)indicated that age、cardiovascular system、respiratory system、abnormal liver function、endocrine system(preoperative hyperglycemia)、nutritional status、operation time、volume of intraoperation blood loss(P<0.05)in the M-POSSUM scoring system and at the same time BMI、ASA classification、nutritional risk、surgery approach(P<0.05)as the factors of outside of the M-POSSUM scoring system were significant factors affecting postoperative morbidity of gastric cancer patients.2.2 The mono-factor analysis(n=260)indicated that age、respiratory system、endocrine system(preoperative hyperglycemia)、nutritional status、volume of intraoperation blood loss(P<0.05)in the M-POSSUM scoring system and meanwhile BMI、nutritional risk、complications(abdominal infection、pulmonary infection、anastomotic leakage)(P<0.05)as the factors of outside of the M-POSSUM scoring system were significant factors affecting postoperative mortality of gastric cancer patients.3.Multi-factor analysis3.1 The influencing factors of P<0.05 were taken as independent variable in the mono-factor analysis of postoperative morbidity,and with postoperative morbidity as the dependent variable.The results of binary logistic regression analysis showed that respiratory system(β=1.783,P<0.01)、nutritional status(β=1.285,P<0.01)and volume of intraoperation blood loss(β=2.606,P<0.01)in the M-POSSUM scoring system and nutritional risk(β=2.852,P<0.01)as the factors of outside of the M-POSSUM scoring system have greatly affected the postoperative morbidity in gastric cancer patients.3.2 The influencing factors of P<0.05 were taken as independent variable in the mono-factor analysis of postoperative mortality,and with postoperative mortality as the dependent variable.Binary logistic regression model showed that nutritional status(β=1.487,P<0.01)and endocrine system(preoperative hyperglycemia)(β=1.767,P<0.01)in the M-POSSUM scoring system and nutritional risk(β=1.823,P<0.01)、complications(abdominal infection(β=2.017,P<0.01)anastomotic leakage(β=1.783,P<0.01))as the factors of outside of the M-POSSUM scoring system were influencing factors of the postoperative mortality in patients with gastric cancer.Conclusions1.This study discovered that the M-POSSUM scoring system has a favourable predictive value for morbidity and mortality postoperative in patients with gastric cancer,when R1 is between 61%and 90%and R2 is between 61%and 100%and M-POSSUM scoring system in predicting the postoperative morbidity and mortality of the best;Thus,10 and 12 of the M-POSSUM is to distinguish between patients with postoperative morbidity and high mortality risk.2.The study indicates that the main factors influencing the occurrence of postoperative morbidity and mortality of M-POSSUM scoring system with gastric cancer patients were respiratory system(preoperative pulmonary function),nutritional status,and the blood loss of the operation.Meanwhile,the factors affecting the postoperative morbidity and mortality of gastric cancer outside of M-POSSUM scoring system was preoperative nutritional status,furthermore,abdominal infection、anastomotic leakage as a factor outside of the M-POSSUM scoring system is also an important factor influencing postoperative mortality in patients with gastric cancer which can not be scored by M-POSSUM scoring system,thus,M-POSSUM scoring system still need to be further improved.3.In clinical practice,on the basis of the M-POSSUM score,the following measures are recommended for high risk patients.①Prevention first:preoperative improvement of pulmonary function,nutritional support is provided to patients with nutritional risks to improve nutritional status,monitoring blood glucose levels,control blood loss bleeding of intraoperative and prevention of abdominal infection and anastomotic leakage of postoperative② Early identification:medical staff should based on the M-POSSUM scoring system and pay more attention to observe situation changes and to identify the potential critical patients.③Predictive nursing:In terms of patients situation to implement predictive individualized nursing,so as to promote the rehabilitation and reduce the suffering of patients and to improve the prognosis.