Objective:This study aimed to retrospectively analyze the impact of preoperative infection with the COVID-19 on postoperative pulmonary complications of maxillofacial surgery patients.Methods:Adult patients who underwent elective surgery under general anesthesia were included in this study.The patients were classified into three groups:control group,group infected with COVID-19 4 weeks before surgery,and group infected 4-6 weeks before surgery.The outcome measure was the postoperative pulmonary complications within 30 days.Perioperative data of all patients were collected.Logistic regression analysis was per-formed to assess the effect of infection with COVID-19 on postoperative pulmonary complications.Results:267 patients were in-cluded in this study.The incidence of postoperative pulmonary complications in control group,＜4 weeks group and 4-6 weeks group were 2.22％,11.36％,6.98％respectively.Infection with COVID-19 less than 4 weeks before surgery(OR:5.64,95％CI:1.45-21.97,P=0.006)was identified as a risk factor for postoperative pulmonary complications within 30 days.However,infection with COVID-19 during the period of 4-6 weeks did not increase the occurrence of postoperative pulmonary complications.Conclusion:Infection with COVID-19 within 4 weeks before surgery increased the risk of postoperative pulmonary complications after maxillofacial surgery.

To explore the effect of simulation technology in the training of flexible fiberoptic intubation for undergraduate students. The research subjects were 39 students majoring in dentistry at Air Force Medical University, including 22 males and 17 females with an average age of 20.62 years. The study subjects were randomly divided into two groups, with 19 in experimental group and 20 in control group. There were no significant differences in gender and age distribution. The experimental group used the flexible fiberoptic bronchoscopy to perform 5 times in endoscopic operation training module, while the control group was only familiar with flexible fiberoptic bronchoscopy without simulation training. The two groups were evaluated for their skills after training. The evaluation included the duration of placing the fiberoptic bronchoscope into the airway and the time to find the target pattern. The duration of placing and finding the target pattern were compared between two groups. The Global rating scale(GRS) was used to evaluate the proficiency of positioning, operation and direction. The students gave self-confidence feedback before and after the training, and the rating was based on the Liker five-level scale. The experimental group of students had a bronchoscopy insertion time of 18.0 (18.0, 20.0) s and a target pattern search time of 20.0 (17.0, 21.0) s, both of which were significantly faster than the control group′s times of 30 (36.0, 47.0) s and 39.0 (30.0, 41.0) s, respectively, P<0.001. The experimental and control groups′ GRS scores for task proficiency were 3.0 (3.0, 4.0) and 3.0 (3.0, 4.0), respectively, which were substantially higher than those in the control group (2.0, 1.0, 2.0) and 2.0 (1.0, 2.0) ( P<0.001). There was no statistically significant difference in confidence feedback between the two groups prior to training, according to the results of the trainees′ feedback on operational confidence. The control group had a confidence feedback score of 2.0 (1.0, 2.0) after training, while the experimental group earned a feedback score of 3.0 (2.0, 3.0), showing a substantial gain in student confidence ( P<0.001). Fiberoptic bronchoscopy intubation simulation training is excellent for novices to quickly understand this technology, increase their academic performance and confidence, and provide an effective reference for undergraduate teaching of this technology.

To explore the effect of simulation technology in the training of flexible fiberoptic intubation for undergraduate students. The research subjects were 39 students majoring in dentistry at Air Force Medical University, including 22 males and 17 females with an average age of 20.62 years. The study subjects were randomly divided into two groups, with 19 in experimental group and 20 in control group. There were no significant differences in gender and age distribution. The experimental group used the flexible fiberoptic bronchoscopy to perform 5 times in endoscopic operation training module, while the control group was only familiar with flexible fiberoptic bronchoscopy without simulation training. The two groups were evaluated for their skills after training. The evaluation included the duration of placing the fiberoptic bronchoscope into the airway and the time to find the target pattern. The duration of placing and finding the target pattern were compared between two groups. The Global rating scale(GRS) was used to evaluate the proficiency of positioning, operation and direction. The students gave self-confidence feedback before and after the training, and the rating was based on the Liker five-level scale. The experimental group of students had a bronchoscopy insertion time of 18.0 (18.0, 20.0) s and a target pattern search time of 20.0 (17.0, 21.0) s, both of which were significantly faster than the control group′s times of 30 (36.0, 47.0) s and 39.0 (30.0, 41.0) s, respectively, P<0.001. The experimental and control groups′ GRS scores for task proficiency were 3.0 (3.0, 4.0) and 3.0 (3.0, 4.0), respectively, which were substantially higher than those in the control group (2.0, 1.0, 2.0) and 2.0 (1.0, 2.0) ( P<0.001). There was no statistically significant difference in confidence feedback between the two groups prior to training, according to the results of the trainees′ feedback on operational confidence. The control group had a confidence feedback score of 2.0 (1.0, 2.0) after training, while the experimental group earned a feedback score of 3.0 (2.0, 3.0), showing a substantial gain in student confidence ( P<0.001). Fiberoptic bronchoscopy intubation simulation training is excellent for novices to quickly understand this technology, increase their academic performance and confidence, and provide an effective reference for undergraduate teaching of this technology.

Objective:This study aimed to retrospectively analyze the impact of preoperative infection with the COVID-19 on postoperative pulmonary complications of maxillofacial surgery patients.Methods:Adult patients who underwent elective surgery under general anesthesia were included in this study.The patients were classified into three groups:control group,group infected with COVID-19 4 weeks before surgery,and group infected 4-6 weeks before surgery.The outcome measure was the postoperative pulmonary complications within 30 days.Perioperative data of all patients were collected.Logistic regression analysis was per-formed to assess the effect of infection with COVID-19 on postoperative pulmonary complications.Results:267 patients were in-cluded in this study.The incidence of postoperative pulmonary complications in control group,＜4 weeks group and 4-6 weeks group were 2.22％,11.36％,6.98％respectively.Infection with COVID-19 less than 4 weeks before surgery(OR:5.64,95％CI:1.45-21.97,P=0.006)was identified as a risk factor for postoperative pulmonary complications within 30 days.However,infection with COVID-19 during the period of 4-6 weeks did not increase the occurrence of postoperative pulmonary complications.Conclusion:Infection with COVID-19 within 4 weeks before surgery increased the risk of postoperative pulmonary complications after maxillofacial surgery.

ObjectiveTo investigate the survival and differentiation of autologous bone-marrow mononuclear cell (ABM-MNCs) after transplanted to infarcted area and border area, and the effect of ABM-MNC on the cardiac function.Methods40 male big-ear Japanese rabbits were divided randomly into the transplanted group and control group with 20 animals in each group. Acute myocardial infarction model was made by ligating left anterior descending artery. 7 days later, Brdu labeled ABM-MNCs were injected into myocardium in the transplanted group, while the control rabbits were injected with saline. Six weeks later, tests of histology and immunohistochemistry were performed.ResultsViable cells labeled with Brdu can be identified in the infarcted area, and myocytes and endothelial cells labeled with Brdu can also be found in the border area, these cells demonstrated myogenic differentiation with the expression of α-actin by immunostaining. While, no cells labeled with Brdu were found in the control group. Moreover, the vessel density of the transplanted group in the borders of the infarction was higher than the control group (P<0.05), but there was no difference in infarcted area between two groups (P>0.05).At the 6 weeks after experiment, the cardiac function was improved in both groups, but there was a significant difference between two groups (P<0.05).ConclusionABM-MNCs injected into the infarcted myocardium can survive in both the infarcted and border areas, and differentiate into endothelial cells and other cells which are able to obtain the characters of myocytes, and increase the vessel density in border area, improve the cardiac function.