Pulmonary blast injury has become the main type of trauma in modern warfare, characterized by externally mild injuries but internally severe injuries, rapid disease progression, and a high rate of early death. The injury is complicated in clinical practice, often with multiple and compound injuries. Currently, there is a lack of effective protective materials, accurate injury detection instrument and portable monitoring and transportation equipment, standardized clinical treatment guidelines in various medical centers, and evidence-based guidelines at home and abroad, resulting in a high mortality in clinlcal practice. Therefore, the Trauma Branch of Chinese Medical Association and the Editorial Committee of Chinese Journal of Trauma organized military and civilian experts in related fields such as thoracic surgery and traumatic surgery to jointly develop the Clinical treatment guideline for pulmonary blast injury ( version 2023) by combining evidence for effectiveness and clinical first-line treatment experience. This guideline provided 16 recommended opinions surrounding definition, characteristics, pre-hospital diagnosis and treatment, and in-hospital treatment of pulmonary blast injury, hoping to provide a basis for the clinical treatment in hospitals at different levels.

Objective    To explore and analyze the risk factors for arrhythmia in patients after heart valve replacement. Methods    A retrospective analysis of 213 patients undergoing cardiac valve replacement surgery under cardiopulmonary bypass in our hospital from August 2017 to August 2019 was performed, including 97 males and 116 females, with an average age of 53.4±10.5 year and cardiac function classification (NYHA) grade of Ⅱ-Ⅳ. According to the occurrence of postoperative arrhythmia, the patients were divided into a non-postoperative arrhythmia group and a postoperative arrhythmia group. The clinical data of the two groups were compared, and the influencing factors for arrhythmia after heart valve replacement were analyzed by logistic regression analysis. Results    There were 96 (45%) patients with new arrhythmia after heart valve replacement surgery, and the most common type of arrhythmia was atrial fibrillation (45 patients, 18.44%). Preoperative arrhythmia rate, atrial fibrillation operation rate, postoperative minimum blood potassium value, blood magnesium value in the postoperative arrhythmia group were significantly lower than those in the non-postoperative arrhythmia group (P<0.05); hypoxemia incidence, hyperglycemia incidence, acidosis incidence, fever incidence probability were significantly higher than those in the non-postoperative arrhythmia group (P<0.05). The independent risk factors for postoperative arrhythmia were the lowest postoperative serum potassium value (OR=0.305, 95%CI 0.114-0.817), serum magnesium value (OR=0.021, 95%CI 0.002-0.218), and hypoxemia (OR=2.490, 95%CI 1.045-5.930). Conclusion    Taking precautions before surgery, improving hypoxemia after surgery, maintaining electrolyte balance and acid-base balance, monitoring blood sugar, detecting arrhythmia as soon as possible and dealing with it in time can shorten the ICU stay time, reduce the occurrence of complications, and improve the prognosis of patients.

OBJECTIVEAccurate segmentation of lung fields in chest radiographs (CXR) is very useful for automatic analysis of CXR. In this work, we propose to use dense matching of local features and label fusion to automatically segment the lung fields in CXR.

METHODSFor an input CXR, the dense Scale Invariant Feature Transform (SIFT) descriptors and raw image patches were extracted as the local features for each pixel. The nearest neighbors of the local features were then quickly searched by dense matching directly from the whole feature dataset of the reference images. The dense matching included three steps: limited random initialization, propagation of nearest neighbor field, and limited random search, with iteration of the last two steps for several times. The label image patches for each pixel were extracted according to the nearest neighbor field and weighted by the matching similarity. Finally, the weighted label patches were rearranged as the label class probability image of the input CXR, from which thresholds were obtained for segmentation of the lung fields.

RESULTSThe Jaccard index of the proposed method reached 95.5% on the public JSRT dataset.

CONCLUSIONA high accuracy and robustness can be obtained by adopting dense matching of local features and label fusion to segment the lung fields in CXR, and the result is better than that of current segmentation method.

Objective To investigate the changes of blood oxygen saturation and heart rate after urgently going to high‐alti‐tude area ,so as to provide a reference for medical rescue in high‐altitude area .Methods Subjects left from the plain area with an al‐titude of 400 m .Blood oxygen saturation and heart rate were measured before departure and after reaching 4 300 m altitude region . Then the subjects were taken to the destination with an altitude of 3 200 m ,at which they received a dynamic continuous monitoring of blood oxygen saturation /heart rate at the 1st day ,2nd day ,3rd day ,4th day ,5th day ,6th day ,7th day after arrival .After adapting to the environment in 3 200 m altitude area for 1 week ,subjects were taken to the 4 300 m altitude region ,at which they were re‐measured blood oxygen saturation and heart rate .Results After entering the areas of 4 300 m altitude and 3 200 m altitude ,the blood oxygen saturation was significantly decreased compared with that in plain area (P< 0 .05) .The blood oxygen saturation at the 6th and 7th day after entering 3 200 m altitude area was statistically different when compared with that at the 1st day(P< 0 .05) . The blood oxygen saturation had statistical difference between reaching at 4 300 m altitude area for the first time and re‐entering 4 300 m altitude area ,while the heart rate had no statistical difference (P> 0 .05) .Conclusion The arterial oxygen saturation was de‐creased with the increase of altitude ;the people living in plain areas can preliminarily adapt to the environment at 6th day after reaching 3 200 m altitude regions ;people can better adapt to the high‐altitude environment by shortly living in lower‐altitude areas before re‐entering high‐altitude areas .

Objective The purpose of this study was to investigate the early outcome of radiofrequency ablation for the treatment of atri-al fibrillation (AF) during concomitant mitral valve replace procedures. Methods From January 2013 to September 2014,43 patients with mitral valvular disease with atrial fibrillation were enrolled in this study. The cases were classified into underwent mitral valve replace surgery concomitant with atrial fibrillation radiofrequency ablation ( RFA group) or underwent only mitral valve replace surgery ( control group) . Re-sults There was no perioperative death and stroke. RFA group’ s time of Cardiopulmonary bypass was more longer than control group. The comparison between RFA and control groups revealed no differences in terms of bleeding,24 hours’ Pleural fluid volume,the mechanical ven-tilation time and time in intensive care unit. One week after the operation,20 cases (87%) in RAF group were sinus rhythm while it was 6 cases(30%) in control group. After a follow-up of one month,RAF group had 78% remaind sinus rhythm while it was 25% in control group. Conclusion Radiofrequency ablation for the treatment of atrial fibrillation ( AF) during concomitant mitral valve replace is safe and effective.

Objective To observe hypoxia-induced pulmonary arterial endothelial-to-mesenchymal transition and investigate the role of transforming growth factor β1 (TGF-β1) in the process. Methods Pulmonary arterial cells improved by adherence method were cultured in normoxia (containing 21%O2,5%CO2 and 74%N2) or hypoxia (containing 1%O2,5%CO2 and 94%N2) for 1,4,or 7 days,respectively. Endothelial-to-mesenchymal transition was confirmed with morphological observation and expression of α-smooth muscle actin (α-SMA) by immunocytochemistry. Expression of TGF-β1 was evaluated by RT-PCR and Western blot,and α-SMA by Western blot. Results Hypoxia-induced paving-stone-like pulmonary arterial endothelial cells transdifferentiating to polygonal cells with high-expression of α-SMA. TGF-β1 expression was increased significantly after 7 days of hypoxia. TGF-β1 stimulating alone increasedα-SMA expression of pulmonary arterial en-dothelial cells;while,SD-208,inhibitor of TGF-β1,abolished the above effect. Conclusion Hypoxia can induce endothelial-to-mesenchymal transition. And TGF-β1 plays an important role in the process.

Objective To research ischemic postconditioning on heart function after myocardial ischemia-reperfusion(I/R),and the protective mechanisms. Methods Thirty-two rats were divided into four groups:I/R group ( n = 8 ) , ischemic postconditioning group (n=8),myocardial ischemic postconditioning+ NSC-74859 (STAT3 inhibitor) group(n=8),and control group(n=8). Establish a model of rat to observe changes of the heart rate,LVSP,+dp/dtmax,-dp/dtmax,coronary flow and myocardial enzyme spectrum in each group un-der different conditions. Results Compared with ischemia-reperfusion group,heart rate of the reperfusion period,CK and LDH of coronary ef-fluent in the ischemic postconditioning group were obviously lower,while left ventricular systolic pressure,change of intraventricular pressure, and coronary effluent volume increased obviously. And after inhibition of STAT3 expression,this protective effect decreased significantly. Con-clusion Ischemic postconditioning can provide potent cardioprotective effect in which STAT3 mediates the cardioprotective effects.

Objective To investigate the relationship between the expression of the survivin gene and CpC methylation in exon 1 of the survivin gene in CA tissue, and to study the expression of survivin protein in CA tissue and its modulation mechanism. Methods Tissue samples were obtained from the CA lesions of 30 patients, normal cervix of 10 female controls, and normal foreskin of 10 male controls. Immunohistochemistry was carried out to detect the expression of survivin protein in these specimens, RT-PCR to measure the mRNA expression of survivin, and methylation specific PCR (MSP) to analyze the methylation status of CpG island in the survivin gene exon 1. Results The positivity rate of survivin protein and mRNA was 90% (27/30) and 93.3% (28/30) in CA tissue specimens, respectively, 5% (1/20) and 5% (1/20) in control tissue specimens, respectively; there was a significant difference between the two groups of specimens in both the parameters (x2 = 35.187, 38.437, both P < 0.01). The demethylation of CpG island in the survivin gene exon 1 was observed in 86.7% (26/30) of the CA tissue specimens and in 15% (3/20) of the control tissue specimens (x2 = 10.865, P < 0.01). There was a positive correlation between the demethylation status of CpG island in exon 1 and the mRNA expression of survivin gene (x2 = 13.929, P = 0.014). Conclusions The expression of survivin protein in CA tissues might be associated with the demethylation of CpG island in exon 1 of the survivin gene, and may play a certain role in the development of CA.

By analyzing the status of Cardiovascular Surgery advanced students,we discussed the characteristics and problems of clinical teaching for advanced students of Cardiovascular Surgery.Strategies of clinical teaching for advanced students of cardiovascular surgery are explored to improve the quality of clinical teaching.

Objective To evaluate the efficiency of emergency surgery to consecutive 258 infants suffering with critical congenital heart diseases (CHD). Methods From January 2006 and February 2009,emergency surgery was performed within 24 h after definite diagnosis on 258 children with critical congenital heart diseases,including 150 males (58.1%) and 108 females (41.9%),with a mean age of (7.5?4.3) months (ranging from 6 d to 11 months),at a mean weight of (5.5?3.3) kg (ranging from 2.1 to 9.5 kg). Complications such as refractory pneumonia,heart failure,repeated episodes of hypoxic spells,kidney dysfunction,liver dysfunction,severe anaemia or growth retardation were found in 233 infants (90.2%). Totally 246 (95.3%) of them were operated on CPB with heart arrested,and 12 (4.7%) with patent ductus arteriosus and operated off pump. Results This group of patients had a stage-one corrective rate of 92.3%,and a total curative rate of 96.9%. In infants operated with heart arrested and with heart beating,the duration of cardiopulmonary bypass was 105.00?38.71 min and (71.89?27.78) min respectively,postoperative ventilation duration was (16.5?9.3) h,intensive care unit (ICU) staying duration was (98.5?33.6) h. After operation,low cardiac output syndrome occourred with a rate of 6.9% and severe complications of major organs with a rate of 12.9%. Of 8 (3.1%) dead infants,7 were diagnosed with complicated CHD. Five died of low cardiac output syndrome,1 of arrhythmia,1 of respiratory failure and 1 of arrhythmic heart. Conclusion Emergency surgical treatment should be performed as soon as definite diagnosis for critical infants with congenital heart disease. Heart failure,respiratory failure,liver dysfunction,severe anaemia and infection are not contraindications to surgical treatment. However,complex anomalies and younger age are considered to be the most risk factors for surgery of infants with CHD.