摘要:目的: 評價機械通氣對胸腔內脈搏氧飽和度的影響。 方法 :以食道、氣管和降主動脈作為胸腔內脈搏氧飽和度的監測位點,將改制后的氧飽和度探頭分別固定于上述部位,并連接于同一監護儀上。純氧通氣,待上述氧飽和度容積波波形和讀數穩定,停止機械通氣30s。以錄像的方式記錄機械通氣停止前后30 s內食道、氣管和降主動脈SpO2容積波和讀數的變化。同時記錄舌SpO2。 結果 :機械通氣時,食道、氣管和降主動脈三個監測位點均可獲得異常高大的SpO2容積波;停止通氣時,異常高大的氧飽和度波形消失。食道、氣管和降主動脈脈搏容積波變異率分別為112%,74%,302%。降主動脈脈搏容積波的變異率明顯高于食道和氣管( 〖WTBX〗P ＜005)。機械通氣停止前后30s內食道、氣管和降主動脈的SpO2讀數變化無顯著差異(〖WTBX〗P ＞005)。 結論 :機械通氣對胸腔內食道、氣管和降主動脈氧飽和度讀數無影響,主要影響是脈搏容積波。且各位點間脈搏氧容積波受呼吸的影響不同。Abstract: Objective: To investigate the impact of mechanical ventilation on pulse oximetry in thoracic cavity. Methods : After dogs anesthesia induction and thoracotomy, pulse oximeters were simultaneously placed at esophagus, trachea, and descending aorta, and connected with the same monitor for SpO2 monitoring. During ventilation with 100% oxygen, the mechanical ventilator was temporarily switched off for 30 seconds after high quality PPG waveforms and SpO2 readings were obtained. SpO2 signals and readings from esophagus (SeO2), trachea (StraO2), descending aorta (SDAO2) shown on the monitoring screen were recorded by the SONY video before and after stopventilation. And StonO2 were also recorded. Results : Abnormally largeamplitude PPG waves were found in normal waves at monitoring sites of esophagus, trachea, and descending aorta in all animals during ventilation; however, they disappeared without ventilator. The variation rate in ventilationinduced PPG amplitude were 112%, 74%, 302% at esophagus, trachea and descending aorta respectively. The PPG amplitude variation rate from SDAO2 was higher than that from SeO2 and StraO2 (〖WTBX〗P ＜005). However, the SpO2 readings obtained from pulse oximetries in all sites were no significantly statistical difference within 30s before and after temporarily stopventilation (〖WTBX〗P ＞005). Conclusion : Abnormally amplitude PPG waveforms from oximetry probe placed at esophagus, trachea, and descending aorta were induced by ventilation. The Variation rate in ventilationinduced PPG amplitude was various at different monitoring sites. The SpO2 readings from esophagus, trachea, and descending aorta were not significantly contaminated by ventilation.
Pressure-support ventilation (PSV) is a form of important ventilation mode. Patient-ventilator synchrony of pressure support ventilation can be divided into inspiration-triggered and expiration-triggered ones. Whether the ventilator can track the patient's inspiration and expiration very well or not is an important evaluating item of the performance of the ventilator. The ventilator should response to the patient's inspiration effort on time and deliver the air flow to the patient under various conditions, such as different patient's lung types and inspiration effort, etc. Similarly, the ventilator should be able to response to the patient's expiration action, and to decrease the patient lung's internal pressure rapidly. Using the Active Servo Lung (ASL5000) respiratory simulation system, we evaluated the spontaneous breathing of PSV mode on E5, Servo i and Evital XL. The following parameters, the delay time before flow to the patient starts once the trigger variable signaling the start of inspiration, the lowest inspiratory airway pressure generated prior to the initiation of PSV, etc. were measured.
Objective To assess the risk factors associated with extubation failure in patients who had successfully passed a spontaneous breathing trial.Methods Patients receiving invasive mechanical ventilation for over 48 h were enrolled in the study，they were admitted into Emergency ICU of Zhongshan Hospital during May 2006 and Oct.2007.A spontaneous breathing trial was conducted by a pressure support of 7 cm H2O for 30 min.Clinical data were prospectively recorded for the patient receiving full ventilatory support before and after the spontaneous breathing trial.Regarding the extubation outcome，patients were divived into extubation success group and extubation failure group.Results A total of 58 patients with a mean（±SD） age of 69.4±12.7 years passed spontaneous breathing trial and were extubated.Extubation failure occurred in 11 patients（19%）.The univariate analysis indicated the following associations with extubation failure：elderly patients（78.1±7.9 years vs 67.4±15.1years，Plt;0.05），higher rapid shallow breathing index（RSBI） value（83±12 breaths·min-1·L-1 vs 68±19 breaths·min-1·L-1，Plt;0.05）and excessive respiratory tract secretions（54.5％ vs 21.3％，Plt;0.05）.Conclusion Among routinely measured clinical variables，elderly patients，higher RSBI value and amount of respiratory tract secretions were the valuable index for predicting extubation failure despite a successful spontaneous breathing trial.
Objective To explore the oxygen therapy effects of high-flow T-tube oxygen therapy on neurointensive care patients who have undergone tracheostomy and are undergoing mechanical ventilation while meeting the criteria for weaning from mechanical ventilation, especially in terms of controlling airway temperature and humidity, promoting mucus dilution, and reducing postoperative complications. MethodsCollected data from 50 neurointensive care patients who underwent tracheostomy and were on mechanical ventilation, meeting the criteria for weaning from mechanical ventilation, treated at West China Hospital of Sichuan University from September 2019 to September 2021. The three groups of patients had different weaning methods: a high-flow T-tube for weaning, a heat and moisture exchanger (artificial nose) for weaning, and a high-flow tracheal joint for weaning. The vital signs, dyspnea and blood gas analysis before and three days after weaning were collected. The primary outcomes were mechanical sputum excretion, postural drainage, phlegm-resolving drugs use, airway-related events (artificial airway blockage, artificial nose blockage, lung infection), stay in ICU (days), and death in ICU. Results Among the 50 patients, 28 were males and 22 were females. There were no significant differences in age, weight, height, gender, finger pulse oxygen saturation, heart rate, APACHEII score, sequential organ failure assessment, or Glasgow coma scale among the three groups (P>0.05). There was no statistical difference in the number of 72-hour mechanical sputum excretion or the use of phlegm-resolving drugs in the three groups (P=0.113, P=1.00). Conclusion The use of high-flow T-tube oxygen therapy in neurointensive care patients who have undergone tracheostomy, are on mechanical ventilation, and meet the criteria for weaning from mechanical ventilation can effectively control airway temperature and humidity, promote mucus dilution for better drainage, thereby reducing post-tracheostomy complications.
ObjectiveProlonged mechanical ventilation (PMV) is a prognostic marker for short-term adverse outcomes in patients after lung transplantation.The risk of prolonged mechanical ventilation after lung transplantation is still not clear. The study to identify the risk factors of prolonged mechanical ventilation (PMV) after lung transplantation.Methods This retrospective observational study recruited patients who underwent lung transplantation in Wuxi People’s Hospital from January 2020 to December 2022. Relevant information was collected from patients and donors, including recipient data (gender, age, BMI, blood type, comorbidities), donor data (age, BMI, time of endotracheal intubation, oxygenation index, history of smoking, and any comorbidity with multidrug-resistant bacterial infections), and surgical data (surgical mode, incision type, operation time, cold ischemia time of the donor lung, intraoperative bleeding, and ECMO support), and postoperative data (multi-resistant bacterial lung infection, multi-resistant bacterial bloodstream infection, and mean arterial pressure on postoperative admission to the monitoring unit). Patients with a duration of mechanical ventilation ≤72 hours were allocated to the non-prolonged mechanical ventilation group, and patients with a duration of mechanical ventilation>72 hours were allocated to the prolonged mechanical ventilation group. LASSO regression analysis was applied to screen risk factors., and a clinical prediction model for the risk of prolonged mechanical ventilation after lung.ResultsPatients who met the inclusion criteria were divided into the training set and the validation set. There were 307 cases in the training set group and 138 cases in the validation set group. The basic characteristics of the training set and the validation set were compared. There were statistically significant differences in the recipient’s BMI, donor’s gender, CRKP of the donor lung swab, whether the recipient had pulmonary infection before the operation, the type of transplantation, the cold ischemia time of the donor lung, whether ECMO was used during the operation, the duration of ECMO assistance, CRKP of sputum, and the CRE index of the recipient's anal test (P<0.05). 2. The results of the multivariate logistic regression model showed that female recipients, preoperative mechanical ventilation in recipients, preoperative pulmonary infection in recipients, intraoperative application of ECMO, and the detection of multi-drug resistant Acinetobacter baumannii, multi-drug resistant Klebsiella pneumoniae and maltoclomonas aeruginosa in postoperative sputum were independent risk factors for prolonged mechanical ventilation after lung transplantation. The AUC of the clinical prediction model in the training set and the validation set was 0.838 and 0.828 respectively, suggesting that the prediction model has good discrimination. In the decision curves of the training set and the validation set, the threshold probabilities of the curves in the range of 0.05-0.98 and 0.02-0.85 were higher than the two extreme lines, indicating that the model has certain clinical validity.ConclusionsFemale patients, Preoperative pulmonary infection, preoperative mechanical ventilation,blood type B, blood type O, application of ECMO assistance, multi-resistant Acinetobacter baumannii infection, multi-resistant Klebsiella pneumoniae infection, and multi-resistant Stenotrophomonas maltophilia infection are independent risk factors for PMV (prolonged mechanical ventilation) after lung transplantation.
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.
ObjectiveTo investigate the correlation between compliance of clinical respiratory bundle and duration of mechanical ventilation. MethodsThe data of patients who admitted to intensive care unit (ICU)of Cancer Hospital Chinese Academy of Medical Sciences between June 2013 and December 2014 were retrospectively reviewed and analyzed.The patients with respiratory insufficiency who ventilated more than 48 hours were included into the study. ResultsFifty-five patients were enrolled into the final analysis.There were 43 males and 12 females with a mean age of 63.47±12.49 years.The mean sequential organ failure assessment (SOFA)score was 2.8±2.2,and the mean simplified acute physiology score 3 (SAPS3)was 51±14 on ICU admission.The mean duration of mechanical ventilation of all 55 patients was 7.3±5.5 days.The compliance of low tidal volume strategy was 23.6%(13/55).No significant difference was found on duration of mechanical ventilation between the patients who was compliant with low tidal volume strategy and the patients who was not compliant (7.31±7.02 days vs. 7.31±5.07 day,P=0.444).A negative correlation between compliance of protocolized sedation strategy and duration of mechanical ventilation was found by Bivariate spearman correlation analysis (r2=0.312,P<0.001).A negative correlation between compliance of spontaneous awakening trial strategy and duration of mechanical ventilation (r2=0.337,P<0.001)and a negative correlation between compliance of spontaneous breathing trial strategy and duration of mechanical ventilation (r2=0.280,P<0.001)were also found by Bivariate spearman correlation analysis.Multiple linear regression analysis showed that only spontaneous awakening trial strategy was correlated with duration of mechanical ventilation(B=-0.623,P<0.001). ConclusionThe more compliance with clinical respiratory bundle,especially with spontaneous awakening trial strategy,the shorter of duration of mechanical ventilation.The effect of low tidal volume strategy on the duration of mechanical ventilation needs further studies.
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.
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。
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.