Application of flipped classroom based on WeChat and TBL in basic surgery teaching / 中华医学教育探索杂志

There are many problems existing in the basic teaching of traditional surgery, such as much more content, difficult operation, fewer learning hours, more passive acceptance while less active learning and so on. Flipped class based on the WeChat and team-based learning (TBL) is based on the on-line and off-line class. We can use WeChat group and subscription to issue relevant learning materials, learning tasks and test before class. Also, we can summarize and explain incisively by discussion after field operation in class, and answer and test in the way of WeChat discussion after class. Finally, the three-dimensional hybrid teaching will be condensed and sublimated by brand competition based on the basis of surgery, achieving knowledge transfer before class, knowledge internalization in class, knowledge consolida-tion after class and brand competition sublimation, in order to improve the teaching effect of surgical basis.

Establishment of risk prediction model and risk score for in-hospital mortality after adult rheumatic heart valve surgery / 中华胸心血管外科杂志

Objective To establish a surgical risk prediction model for in-hospital mortality of adult rheumatic heart disease.Methods The study sample comprised of 3 889 patients with adult (is, or older than 18 years) rheumatic heart valve surgery only.All patients were divided into three subgroups according to the surgery site of left atrioventricular valve: mitral valve surgery group;aortic valve surgery group;and mitral and aortic valve surgery group.The data was splited into development(60％) and validation(40％) data sets, and then the risk model was developed by using a logistic regression model according to the data in development data set.Model calibration was analyzed by Hosmer-Lemeshow goodness-of-fit statistic, and model discrimination was tested by calculating the area under the receiver operating characteristic(ROC) curve.Risk score was finally set up according to the coefficient β and rank of variables in logistic regression model.Results The general in-hospital mortality of the whole group is 4.2％ (165/3 889).We established a risk prediction model and found seven risk factors: heart function in NYHA functional class ≥ Ⅱ grade (OR =3.36, 95％ CI: 2.42-4.67) , preoperative creatinine ＞ 110 mmoL/L (OR =2.69, 95％ CI: 1.51-4.79) , history of previous chest pain(OR =2.33, 95％ CI: 1.07-5.11) , surgical status(OR =2.32, 95 ％ CI: 0.94-5.73) , previous history of hypertension (OR =2.24, 95 ％ CI: 1.19-4.23), preoperative critical state (OR =2.14, 95％ CI: 1.27-3.60) and age ＞ 50 years (OR =1.57, 95 ％ CI: 1.18-2.09).Our risk model showed good calibration and discriminative power for the development data set, validation data set, and three subgroup in which Hosmer-Leme-show test' s P value were greater than 0.05 and the area under the ROC curve were greater than 0.70.Scoring methods: age 51-60years: 1 point, age 61-70 yeas: 2 points, age ＞70 years: 3 points;history of hypertension: 1 point;creatinine ＞ 110 umol/L: 4 points;NYHA class stage Ⅱ : 2 points, NYHA class stage Ⅲ: 4 points;NYHA class stage Ⅳ: 6 points;history of previous chest pain: 1point;preoperative critical condition: 2 points;urgent surgery: 2 points: emergency surgery: 4 points.Conclusion We have created a new risk prediction model and risk score, which can accurately predicts outcomes in patients undergoing heart valve surgery for our center.Furthermore, our risk model can also enable benchmarking and comparisons between multicenter in a meaningful way in the future.

Risk factors for prolonged mechanical ventilation after adult double valve replacement surgery / 中华胸心血管外科杂志

Objective During last decades,mechanical ventilation has been an important support in the postoperative management of patients undergoing cardiac surgery.However,a considerable number of patients need mechanical ventilation for a prolonged period after cardiac surgery,and this is associated with increased mortality and morbidity.The study was designed to determine the pre-and perioperative predictors of prolonged mechanical ventilation (PMV) in adult patients undergoing double valve surgery.Methods The retrospective study considered of 2026 adult patients who underwent double valve replacement surgery at Changhai Heart Center from January 1990 to December 2010.PMV is considered as mechanical ventilation period of ＞ 48 hours at postoperative hospital stay here.Results PMV occurred in 11.35 ％ of patients.The total hospital mortality was 4％.The hospital mortality of patients who had undergone double valve replacement surgery required PMV was significantly higher than control (33.5％ vs 0.2％,P ＜ 0.01).And so as comorbidities.Age more than 60 years (OR =1.943),diabetes(OR =1.757),preoperative active endocarditis (OR =3.167),New York Heart Association class higher than 3 (OR =2.464),preoperative critical state(OR =2.556),ejection fraction less than 0.50 (OR =2.026),creatinine greater than 110 μmol/L (OR =2.740),cardiopulmonary bypass time longer than 180 min (OR =3.529) and perioperative intra-aortic balloon pump(OR =18.350) were independent predictors of PMV in our patients.Conclusion PMV is associated with significant comorbidities and increased hospital mortality.Strategies to delineate the patients at risk and to modify these risk factors by prophylactic measures should probably lead to a lower incidence of prolonged mechanical ventilation for adult patients undergoing double valve replacement surgery.