Objective Exploring the correlation between intravesical pressure (IP) and diaphragm excursion (DE) in patients with severe acute pancreatitis (SAP) and acute respiratory distress syndrome (ARDS), and evaluating its predictive value for weaning outcomes. Methods A retrospective analysis was conducted on the clinical data of 144 SAP patients with ARDS admitted between 2020 and 2023. By collecting the outcome of weaning, collect data on gender, age, acute physiology and chronic health score II (APACHE II), oxygenation index, and IP and DE before weaning and extubation for all patients. Based on weaning outcomes, divide patients into successful and failed groups, and compare the differences in various indicators between the two groups; Use binary logistic regression to analyze whether IP and DE are risk factors affecting weaning in SAP patients with ARDS, and use Pearson correlation analysis to examine the correlation between IP and DE; Use receiver operating characteristic curve (ROC curve) to analyze the predictive value of IP and DE on weaning outcomes in SAP patients with ARDS. ResultsA total of 144 SAP patients with ARDS were included, of which 108 were successfully weaned and 36 were unsuccessful. There were no statistically significant differences in gender, age, and APACHE II scores between the successful and failed groups (males: 62.96% (68/108) compared to 69.44% (25/36), age (years): 41.91 ± 8.14 compared to 42.42 ± 6.22, APACHE II score (points): 18.28 ± 2.22 compared to 18.97 ± 1.83, P>0.05). The IP of the successful group was significantly lower than that of the failed group, and the DE was significantly higher than that of the failed group [IP (mmHg): 18.45 ± 3.76 compared to 23.92 ± 5.65, DE (mm): 16.18 ± 4.23 compared to 12.28 ± 4.44, all P<0.05]. All patients showed a significant negative correlation between IP and DE (r=–0.457, P<0.001). ROC curve analysis showed that the area under the curve (AUC) of IP predicting the withdrawal outcome of SAP patients with ARDS was 0.805, with a 95% confidence interval (95%CI) of 0.724-0.885 and P<0.001. When the cutoff value was 19.5 mmHg, the sensitivity was 91.57% and the specificity was 47.54%; The AUC for predicting the withdrawal outcome of SAP patients with ARDS by DE was 0.738, with a 95%CI of 0.641-0.834 and P<0.001. When the cutoff value was 11.5 points, the sensitivity was 84.82% and the specificity was 59.38%. Conclusions There is a significant negative correlation between IP and DE in SAP combined with ARDS patients, and both have certain predictive value for weaning outcomes.
To evaluate the development prevention and treatment of pneumonic injury after operation on aged patients with abdominal infection. We analyzed 77 aged patients (＞60 y) admitted from Jan. 1991 to Dec. 1992: 38 cases of which with abdominal infection (infection group), 39 cases without abdominal infection (non-infection group). All patients were given oxygen therapy and continuous SaO2 monitoring. Results: There were 28 patients with hypoxemia (SaO2＜95%) in infection group, with an occurrence rate of 73.7%. In non-infection group (12 patients), the rate of hyoxemia was 30.8%, which has significant difference between two groups (Ｐ＜0.001). All patients with hypoxemia were given oxygen therapy and 31 patients′ SaO2 was elevated. The efficient rate was 77.5%. Other 9 patients developed ARDS, the rate was 2.5% (9/40). In the infection group 8 patients developed ARDS with an occurrence rate of 21.1%. There was one patient with ARDS in the non-infection group, the rate was 2.6%. There was significant difference between two group (Ｐ＜0.05). Conclusions: The results suggest that hypoxemia is liable to occur in aged patients with abdominal infection after operation and these patients were liable to develop ARDS. Oxygen therapy and SaO2 monitoring is the important managements to these patients in prevention of pneumonic injury.
This article introduces the basic principles of finite element analysis in biomechanics, focusing on the basic principles of a variety of finite element analysis software, and their respective characteristics. In addition, it also describes the basic stress analysis of UGNX6.0 NASTRAN analysis for artificial knee process, i.e. the choice of the type, material definition, the set of constants, finite element mesh division and the finite element results of the analysis. Finite element analysis and evaluation of the design of personalized artificial knee were carried out, so that the rationality of the geometric design of the structure of the experimental design of artificial knee has been verified.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.
With the growth of offshore activities, the incidence rates of seawater drowning (SWD) induced acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) increase significantly higher than before. Pulmonary interstitial edema, alveolar septum fracture, red blood cells, and inflammatory cells infiltration can be seen under light microscope in the pathologic changes of lungs. The major clinical manifestations are continual hyoxemia and acidosis, which lead to a severe condition, a high death rate, and a poor treatment effect. Bone marrow mesenchymal stem cells are capable of self-renewal, multilineage differentiation and injured lung-homing, which are induced to differentiate into alveolar epithelial cells and pulmonary vascular endothelial cells for tissues repairing. This may be a new way to treat SWD-ALI and SW-ARDS.
Abstract: Objective To determine the effects of oxidative stress reaction on intima hyperplasia after autologous vein grafting. Methods Seventy female SpragueDawley(SD) rats were randomly divided into a control group(n=10) and an experimental group (n=60). The experimental group was then divided into six time points of one day; one, two, four, and six weeks; and two months after surgery; with 10 rats for each time point. Autologous vein grafting models were established. At each time point the designated rats were anaesthetized, and the grafts were isolated and stained with HE. The same length of external jugular vein was cut from each rat in the control group. The neointima to tunica media area ratios (I/M) were measured with acomputerized digital image analysis system. Nuclear factorkappa B (NF-κB) and copper zinc superoxide dismutase (CuZnSOD) were detected byimmunohistochemistry. The concentration of malondialdehyde (MDA) in serum was analyzed by colorimetry. Results In the control group, expression levels of NF-κB and CuZnSOD were low. In the experimental group, expression of NF-κB increased after the operation and peaked two weeks later. The plateau was sustained for about one month, and then the level of expression declined gradually, reaching the baseline at the twomonth time point. The expression of CuZnSOD increased gradually after the operation and peaked one week later, then declined to the normal level after 2-3 weeks at the plateau. In the control group, the concentration of serum MDA was 4.966±1.346 nmol/ml. In the experimental -group, the-MDA concentration increased dramatically after the operation, then-declined from its highest level at the oneday time point (21.161±2.174 nmol/ml) to the normal level at two months (6.208±2.908 nmol/ml) after the operation (P＜0.05). In the control group, I/M was 0.2096±0.0253, while in the experimental group, it was higher one week after the operation (0.6806±0.0737) and peaked at four weeks (1.4527±0.0824), falling to 1.0353±00656 at six weeks and 0.9583±0.0516 attwo months (P＜0.05) for the experimental and control groups). Conclusion Endothelial cell injury initiates an oxidative stress reaction after autologous vein grafting and augments inflammation by activating NF-κB, thus playing an important role in inducing restenosis of the grafted vein.
ObjectiveTo discuss the feasibility of establishment of animal model of "functional" bicuspid aortic valve with swine and observe its effect on the wall shear stress inside the aorta. MethodsFour common Shanghai White Swine with body weight between 50 kg to 55 kg were selected. Under general anesthesia and cardiopulmonary bypass, the aortic transverse incision approach was used, continuous suture with 6-0 polypropylene to align the left and right coronary valve leaflets to create a bicuspid valve morphology. After the operation, echocardiography was used to observe the aortic valve morphology and the hemodynamic changes of the aortic valve orifice. The effect on the wall shear stress inside the aorta was studied with 4D-Flow magnetic resonance imaging (MRI). ResultsA total of 4 swine "functional" bicuspid aortic valve models were established, with a success rate of 100.0%. Echocardiography showed that the blood flow velocity of the aortic valve orifice was faster than that before the operation (0.96 m/s vs. 1.80 m/s). 4D-Flow MRI showed abnormally increased wall shear stress and blood flow velocity in the aorta of the animal models. After the surgery, in model animals, the maximal wall shear stress inside the ascending aorta was greater than 1.36 Pa, and the maximum blood flow velocity was greater than 1.4 m/s. ConclusionEstablishment of the animal model of "functional" bicuspid aortic valve in swine is feasible, scientific and reliable. It can be used in researches on evaluating the pathophysiological changes.
Objective
To Assess the efficacy of using lung ultrasound to guide alveolar recruitment maneuver in patients with acute respiratory distress syndrome (ARDS).
Methods
Sixty patients with ARDS were randomly divided into two groups, ie, maximal oxygenation group (n=30) and lung ultrasound group (n=30). All the patients had artificial airway and needed mechanical ventilation. The patients in the two groups accepted recruitment maneuver guided by maximal oxygenation or lung ultrasound respectively. During the course of recruitment maneuver, the arterial partial pressure of oxygen (PaO2), positive end-expiratory pressure (PEEP), central venous pressure (CVP), mean arterial pressure (MAP), cardiac output (CO), and extravascular lung water index (EVLWI) were recorded and compared between both groups.
Results
The PaO2 in lung ultrasound group was higher than that in maximal oxygenation group (P=0.04). The PEEP was higher in lung ultrasound group but without significant difference (P=0.910). There was no significant difference of the other outcomes (CVP, MAP, CO, EVLWI) between the two groups (all P>0.05).
Conclusion
Lung ultrasound is an effective means that has good repeatability and security for guiding recruitment maneuver in patients with ARDS.
Acute respiratory distress syndrome (ARDS) is a serious threat to human life and health disease, with acute onset and high mortality. The current diagnosis of the disease depends on blood gas analysis results, while calculating the oxygenation index. However, blood gas analysis is an invasive operation, and can’t continuously monitor the development of the disease. In response to the above problems, in this study, we proposed a new algorithm for identifying the severity of ARDS disease. Based on a variety of non-invasive physiological parameters of patients, combined with feature selection techniques, this paper sorts the importance of various physiological parameters. The cross-validation technique was used to evaluate the identification performance. The classification results of four supervised learning algorithms using neural network, logistic regression, AdaBoost and Bagging were compared under different feature subsets. The optimal feature subset and classification algorithm are comprehensively selected by the sensitivity, specificity, accuracy and area under curve (AUC) of different algorithms under different feature subsets. We use four supervised learning algorithms to distinguish the severity of ARDS (P/F ≤ 300). The performance of the algorithm is evaluated according to AUC. When AdaBoost uses 20 features, AUC = 0.832 1, the accuracy is 74.82%, and the optimal AUC is obtained. The performance of the algorithm is evaluated according to the number of features. When using 2 features, Bagging has AUC = 0.819 4 and the accuracy is 73.01%. Compared with traditional methods, this method has the advantage of continuously monitoring the development of patients with ARDS and providing medical staff with auxiliary diagnosis suggestions.
ObjectiveTo evaluate the effects of N-acetylcysteine (NAC) on lung tissue of Wistar rats, which were tracheally instilled fine particulate matter (PM2.5).MethodsForty-eight male Wistar rats were randomly divided into six groups: two control groups [they were blank group (C1), fake treatment group (C2) separately], four treatment groups [they were PM2.5 group (P), low-dose NAC group (L), medium-dose NAC group (M), high-dose NAC group (H) separately]. C1 received no treatments at all. C2 was instilled with sterile water (1 ml/kg) tracheally once a week for four times. P was instilled equivoluminal PM2.5 suspension (7.5 mg/kg) tracheally once a week for four times. The NAC groups received gavage (10 ml/kg) of different dosage of NAC (125, 250, 500 mg/kg) for six days. At the seventh day, the NAC groups were instilled PM2.5 suspension (7.5 mg/kg) tracheally. The procedures were repeated for three times in the NAC groups. Twenty-four hours later after four weeks or after the last instilling, all rats were sacrificed. Lung tissue was stained by hematoxylin-eosin (HE) staining, and histopathological changes of lung tissue were observed by optical microscope. The levels of C-reactive protein (CRP) as well as tumor necrosis factor-α (TNF-α) of serum, TNF-α of bronchoalveolar lavage fluid (BALF), TNF-α as well as interleukin-1β (IL-1β) of homogenates of lung tissue were detected by enzyme-linked immunosorbent assay. The activity of lactate dehydrogenase (LDH) as well as the levels of malondialhyde (MDA) of serum and BALF were detected by standard colorimetric method.ResultsHE staining showed that the normal structure of lung were destroyed in the groups dealed with PM2.5 and NAC could alleviate these changes. Higher dosage of NAC seemed to provide more powerful protections. Structure of the lung in C1 as well as C2 were nearly normal. The levels of CRP as well as TNF-α of serum, TNF-α of BALF, TNF-α as well as IL-1β of homogenates of lung tissue in the groups of P, L, M, H were higher than that in the groups of C1, C2 (all P<0.05). The levels of CRP as well as TNF-α of serum, TNF-α of BALF, TNF-α as well as IL-1β of homogenates of lung tissue in the groups of L, M, H which groups received NAC treatments were lower than that in P group. More, the groups seemed to have lower levels of CRP, TNF-α, IL-1β when higher dosage of NAC were given. The activity of LDH as well as the levels of MDA of serum, and BALF in the groups of P, L, M, H were higher than that in the groups of C1, C2 (all P<0.05). The activity of LDH as well as the levels of MDA of serum and BALF in the groups of L, M, H which groups received NAC treatments were lower than that in P group (all P<0.05). ConlusionTo some extent, NAC demonstrate antagonistic effects on oxidative stress and inflammatory injury on rats’ lung brought by PM2.5.
