In the clinical practice, the mechanical ventilation is a very important assisting method to improve the patients' breath. Whether or not the parameters set for the ventilator are correct would affect the pulmonary gas exchange. In this study, we try to build an advisory system based on the gas exchange model for mechanical ventilation using fuzzy logic. The gas exchange mathematic model can simulate the individual patient's pulmonary gas exchange, and can help doctors to learn the patient's exact situation. With the fuzzy logic algorithm, the system can generate ventilator settings respond to individual patient, and provide advice to the doctors. It was evaluated in 10 intensive care patient cases, with mathematic models fitted to the retrospective data and then used to simulate patient response to changes in therapy. Compared to the ventilator set only as part of routine clinical care, the present system could reduce the inspired oxygen fraction, reduce the respiratory work, and improve gas exchange with the model simulated outcome.
Objective To explore the application value of shear wave elastography (SWE) combined with diaphragmatic thickening fraction (DTF) and rapid shallow breathing index (RSBI) in predicting the results of weaning of patients with mechanical ventilation. Methods Fifty-two patients with severe illness who were hospitalized in this hospital from January 2022 to September 2022 were treated with mechanical ventilation. After meeting the conditions for weaning, they underwent spontaneous breathing test, and the diaphragm function of patients was evaluated by measuring DTF using ultrasound technology and shear modulus (SM) using SWE technology. According to the weaning results, they were divided into weaning success group and weaning failure group, The differences of mechanical ventilation time, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, respiratory rate, RSBI, oxygenation index, DTF, SM and other parameters between the two groups were compared. Multivariate logistic regression was used to analyze the factors affecting the withdrawal results. The receiver operator characteristic (ROC) curve was used to evaluate the predictive value of potential influencing factors on the withdrawal results. Results There were 39 cases of successful withdrawal and 13 cases of failure. There were significant differences in mechanical ventilation time, respiratory rate, RSBI, DTF and SM between the successful weaning group and the failure group (P<0.05). Through multivariate logistic regression analysis, RSBI [area under the ROC curve (AUC)=0.771, 95% confidence interval (CI) 0.589 - 0.953], DTF (AUC=0.806, 95%CI 0.661 - 0.951), SM (AUC=0.838, 95%CI 0.695 - 0.981) were independent factors that affected the results of withdrawal. The single parameter AUC was smaller than the combined index with RSBI≤70.48 times·min–1L–1, DTF≥30.0%, SM≥10.0 kPa as the cutoff value (AUC=0.937, 95%CI 0.714 - 1.0, diagnostic sensitivity, specificity and accuracy were 94.9%, 84.6% and 92.3% respectively). Conclusions SWE technology provides a new quantitative index for evaluating diaphragm function by evaluating diaphragm stiffness. Diaphragm stiffness combined with DTF and RSBI can better predict the successful withdrawal in patients with mechanical ventilation.
Since December 2019, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has gradually spread all over the world. With the implementation of class B infectious disease management policy for coronavirus disease 2019 (COVID-19), China has experienced a pandemic. For patients receiving a time-sensitive or emergency surgery, SARS-CoV-2 infection may increase the risk of postoperative pulmonary complications. An appropriate perioperative mechanical ventilation strategy, such as lung protective ventilation strategy, is particularly important for preventing postoperative pulmonary complications in patients undergoing general anesthesia. In addition, how to protect medical personnel from being infected is also the focus we need to pay attention to. This article will discuss the perioperative mechanical ventilation strategy for COVID-19 patients and the protection of medical personnel, in order to provide reference for the development of guidelines.
對意外或自主拔管患者的研究顯示，接受完全機械通氣患者的23％和開始撤機過程患者的69％并不需要重新插管，這表明機械通氣患者的撤機存在被延遲的傾向，致使患者承受不必要的痛苦，增加了并發癥的發生率和醫療費用。撤機過程所耗費的時間占機械通氣整個時間的40％~50％ 。Esteban等的研究證明：延長通氣時間增加病死率。在美國，機械通氣的費用約2 000美元／d，延長通氣者占總機械通氣患者的6％，但卻消耗ICU資源的37％。我國的撤機現狀與之類似，日益增多的撤機困難患者占用各ICU的有限資源，成為醫療費用和床位周轉的沉重負擔。機械通氣撤離的研究亟待加強。
Post operational recovery from cardiac surgery can be affected by many factors, including preoperative, intraoperative, and postoperative factors. Prolonged mechanical ventilation (PMV) , one of the major complications, has been widely accepted as a measure to evaluate the performance and outcomes of cardiac surgeries. Great progress has been made in the studies of risk factors contributing to PMV following cardiac surgeries in recent years. However, no clear and effective measures and approaches are available yet to prevent PMV. In this review, the authors try to summarize the risk factors that are associated with PMV throughout the perioperative period of cardiac surgery, as well as possible interventions when applicable.
Objective To investigate the risk factors of prolonged postoperative mechanical ventilation for adult patients with atrioventricular septal defect (AVSD). Methods We retrospectively analyzed the clinical data of 76 patients with AVSD aged more than 18 years in our hospital from January 1, 2011 to December 31, 2017. The patients ventilated longer than 24 hours were described as a prolonged ventilation group (n=27) and the others as a normal group (n=49). There were 9 males and 18 females aged 32.22±9.64 years in the prolonged ventilation group, and 16 males and 33 females aged 35.98±11.34 years in the normal group. Perioperative variables between the two groups were compared and selected, and then analyzed by logistic regression analysis. Results The result of univariate analysis showed that there was a statistical difference in weight, preoperative pulmonary artery systolic pressure, duration of cardiopulmonary bypass, the level of postoperative platelet, hemoglobin, blood glucose, lactic acid and serum creatinine, postoperative maximum heart rate and postoperative infection rate between the prolonged ventilated group and the normal group. Multivarable logistic regression showed that preoperative pulmonary artery hypertension (OR=1.056, 95%CI 1.005 to 1.110, P=0.030), prolonged duration of cardiopulmonary bypass (OR=1.036, 95%CI 1.007 to 1.066, P=0.016) and the low postoperative hemoglobin level (OR=0.874, 95%CI 0.786 to 0.973, P=0.014) were the risk factors of prolonged postoperative mechanical ventilation. Conclusion Preoperative pulmonary artery hypertension, long duration of cardiopulmonary bypass and postoperative anaemia are the risk factors associated with prolonged postoperative mechanical ventilation.
Objective To explore the feasibility of ultrasound diagnosis of diaphragmatic paralysis in patients with ventilation after congenital heart disease surgery. Methods There were 542 patients with congenital heart disease after surgery, difficult to be weaned off the ventilator or suspected diaphragmatic paralysis of the patients, respectively, in the ventilator continous positive pressure breathing (CPAP) mode and completely independent breathing state, whose ultrasound examination of diaphragm function was conducted to determine the presence of diaphragmatic paralysis in our hospital between January 1, 2013 and April 30, 2016. There were 327 males and 215 females at age of 14±32 months. The results of ultrasound diagnosis between ventilator CPAP mode and completely spontaneous breathing mode were compared. Results Five hundred and forty-two patients underwent ultrasound diaphragmatic examination. The results of bedside ultrasound were completely diagnosed: in completely spontaneous breathing, 82 patients who were diagnosed as diaphragmatic paralysis, including 39 on the right, 25 on the left, 18 on both sides; in CPAP mode, 82 patients who were diagnosed as diaphragmatic paralysis, 38 on the right, left 25, bilateral 19. Using ultrasound in CPAP mode to diagnose diaphragmatic paralysis after congenital heart disease surgery, compared with the completely spontaneous breathing state, the sensitivity was 100.0% and the specificity was 99.9%. Conclusion It is accurate and feasible to diagnose the presence of diaphragmatic paralysis in patients with ventilation after congenital heart disease surgery.
Mechanical ventilation is an importmant life-sustaining treatment for patients with acute respiratory distress syndrome. Its clinical outcomes depend on patients’ characteristics of lung recruitment. Estimation of lung recruitment characteristics is valuable for the determination of ventilatory maneurvers and ventilator parameters. There is no easily-used, bedside method to assess lung recruitment characteristics. The present paper proposed a method to estimate lung recruitment characteristics from the static pressure-volume curve of lungs. The method was evaluated by comparing with published experimental data. Results of lung recruitment derived from the presented method were in high agreement with the published data, suggesting that the proposed method is capable to estimate lung recruitment characteristics. Since some advanced ventilators are capable to measure the static pressure-volume curve automatedly, the presented method is potential to be used at bedside, and it is helpful for clinicians to individualize ventilatory manuevers and the correpsonding ventilator parameters.
ObjectiveTo investigate the association of preoperative serum uric acid (UA) levels with postoperative prolonged mechanical ventilation (PMV) in patients undergoing mechanical heart valve replacement.MethodsClinical data of 311 patients undergoing mechanical heart valve replacement in The First Affiliated Hospital of Anhui Medical University from January 2017 to December 2017 were retrospectively analyzed. There were 164 males at age of 55.6±11.4 years and 147 females at age of 54.2±9.8 years. The patients were divided into a PMV group (>48 h) and a control group according to whether the duration of PMV was longer than 48 hours. Spearman's rank correlation coefficient and logistic regression analysis were conducted to evaluate the relationship between preoperative UA and postoperative PMV. The predictive value of UA for PMV was undertaken using the receiver operating characteristic (ROC) curve..ResultsAmong 311 patients, 38 (12.2%) developed postoperative PMV. Preoperative serum UA level mean values were 6.11±1.94 mg/dl, while the mean UA concentration in the PMV group was significantly higher than that in the control group (7.48±2.24 mg/dl vs. 5.92±1.82 mg/dl, P<0.001). Rank correlation analysis showed that UA was positively correlated with postoperative PMV (rs=0.205, P<0.001). Multivariate logistic regression analysis demonstrated that preoperative elevated UA was associated independently with postoperative PMV with odds ratio (OR)=1.44 and confidence interval (CI) 1.15–1.81 (P=0.002). The area under the ROC curve of UA predicting PMV was 0.72, 95% CI0.635–0.806, 6.40 mg/dl was the optimal cut-off value, and the sensitivity and specificity was 76.3% and 63.0% at this time, respectively.ConclusionPreoperative elevated serum UA is an independent risk factor for postoperative PMV in patients undergoing mechanical heart valve replacement and has a good predictive value.
Objective To develop and validate a nomogram for predicting the risk of weaning failure in elderly patients with severe pneumonia undergoing mechanical ventilation. Methods A retrospective analysis was conducted on the clinical data of 330 elderly patients with severe pneumonia undergoing mechanical ventilation who were hospitalized in our hospital from July 2021 to July 2023. According to their weaning outcomes, they were divided into a successful group (n=213 ) and a failure group (n=117). Univariate analysis and multivariate non-conditional logistic regression analysis were used to explore the factors influencing the weaning failure of mechanical ventilation in elderly patients with severe pneumonia. Results Univariate analysis showed that there were significant differences in age, smoking status, chronic obstructive pulmonary disease, ventilation time, albumin, D-dimer, and oxygenation index levels between the two groups (all P<0.05). Multivariate logistic regression analysis revealed that age ≥65 years, smoking, presence of chronic obstructive pulmonary disease, ventilation time ≥7 days, D-dimer ≥2 000 μg/L, and reduced oxygenation index were risk factors for weaning failure in the elderly patients with severe pneumonia. The nomogram model constructed based on these factors had an area under ROC curve of 0.970 (95%CI 0.952 - 0.989), and the calibration curve demonstrated good agreement between predicted and observed values. Conclusions Age, smoking status, chronic obstructive pulmonary disease, ventilation time, D-dimer, and oxygenation index are influencing factors for weaning failure in elderly patients with severe pneumonia receiving mechanical ventilation. The nomogram model constructed based on these factors exhibits good discrimination and accuracy.