摘要:目的: 评价机械通气对胸腔内脉搏氧饱和度的影响。 方法 :以食道、气管和降主动脉作为胸腔内脉搏氧饱和度的监测位点,将改制后的氧饱和度探头分别固定于上述部位,并连接于同一监护仪上。纯氧通气,待上述氧饱和度容积波波形和读数稳定,停止机械通气30s。以录像的方式记录机械通气停止前后30 s内食道、气管和降主动脉SpO2容积波和读数的变化。同时记录舌SpO2。 结果 :机械通气时,食道、气管和降主动脉三个监测位点均可获得异常高大的SpO2容积波;停止通气时,异常高大的氧饱和度波形消失。食道、气管和降主动脉脉搏容积波变异率分别为112%,74%,302%。降主动脉脉搏容积波的变异率明显高于食道和气管( 〖WTBX〗P ＜005)。机械通气停止前后30s内食道、气管和降主动脉的SpO2读数变化无显著差异(〖WTBX〗P ＞005)。 结论 :机械通气对胸腔内食道、气管和降主动脉氧饱和度读数无影响,主要影响是脉搏容积波。且各位点间脉搏氧容积波受呼吸的影响不同。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.
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.
It is difficult to select the appropriate ventilation mode in clinical mechanical ventilation. This paper presents a nonlinear multi-compartment lung model to solve the difficulty. The purpose is to optimize respiratory airflow patterns and get the minimum of the work of inspiratory phrase and lung volume acceleration, minimum of the elastic potential energy and rapidity of airflow rate changes of expiratory phrase. Sigmoidal function is used to smooth the respiratory function of nonlinear equations. The equations are established to solve nonlinear boundary conditions BVP, and finally the problem was solved with gradient descent method. Experimental results showed that lung volume and the rate of airflow after optimization had good sensitivity and convergence speed. The results provide a theoretical basis for the development of multivariable controller monitoring critically ill mechanically ventilated patients.
ObjectiveTo evaluate the effects of home mechanical ventilation (HMV) for stable chronic obstructive pulmonary disease (COPD) patients with respiratory failure in Tongzhou district of Beijing city. MethodsTwenty stable COPD patients with respiratory failure were included in the study.During the one-year follow-up period,4 patients died and 1 withdrew and 15 patients finished the follow-up.The patients was followed up by telephone each month and guided in drug administration,HMV,and rehabilitation therapy.At the beginning of the study and one year later,the patients were interviewed and accessed on the general data,nutritional status,COPD assessment test (CAT),Borg dyspnea and respiratory fatigue score,Hamilton depression scale,Hamilton anxiety scale,and arterial blood gas analysis. ResultsAt the end of one-year follow-up,nutrition index,CAT,Borg dyspnea and respiratory fatigue score,Hamilton depression scale,Hamilton anxiety scale,pH,and PaO2 did not change significantly (P>0.05),while PaCO2 decreased significantly compared with those at the beginning of the study (P<0.05).Compared with the past year,the times of hospitalization due to acute exacerbation of COPD was significantly reduced during the follow-up year (P<0.05). ConclusionHMV can ameliorate carbon dioxide retention and reduce times of hospitalization due to acute exacerbation of COPD for COPD patients with respiratory failure.
对意外或自主拔管患者的研究显示，接受完全机械通气患者的23％和开始撤机过程患者的69％并不需要重新插管，这表明机械通气患者的撤机存在被延迟的倾向，致使患者承受不必要的痛苦，增加了并发症的发生率和医疗费用。撤机过程所耗费的时间占机械通气整个时间的40％~50％ 。Esteban等的研究证明：延长通气时间增加病死率。在美国，机械通气的费用约2 000美元／d，延长通气者占总机械通气患者的6％，但却消耗ICU资源的37％。我国的撤机现状与之类似，日益增多的撤机困难患者占用各ICU的有限资源，成为医疗费用和床位周转的沉重负担。机械通气撤离的研究亟待加强。
Objective To investigate the clinical characteristics, risk factors and perioperative outcome of prolonged mechanical ventilation (PMV) in elderly patients undergoing coronary artery bypass grafting (CABG). Methods The data of elderly patients receiving CABG in the Nanjing First Hospital from January 2013 to June 2019 were collected. All patients were divided into a control group and a PMV group according to whether ventilation time≥24 h.The clinical characteristics and risk factors of PMV were compared between the two groups. Variables were 1∶1 balanced through propensity score matching (PSM) and perioperative outcomes of two groups was analyzed. Results Finally 956 patients were collected, including 187 in the PMV group and 769 in the control group. There were 586 males and 370 females aged 70-94 (74.3±3.5) years. Compared with the control group, the PMV group had higher rates of smoking, preoperative renal impairment, intraoperative blood transfusion and intra-aortic balloon pump (IABP) implantation, worse cardiac function, lower glomerular filtration rate and ejection fraction, larger left atrial diameter, longer cardiopulmonary bypass time and aortic cross-clamping time (P<0.05). There was no statistical difference in other clinical data between the two groups (P>0.05). Binary multivariate logistic regression analysis showed that females, smoking, chronic obstructive pulmonary disease, left ventricular ejection fraction≤56.0%, cardiopulmonary bypass time>106.0 min, IABP implantation and intraoperative blood transfusion were independent risk factors for PMV in elderly patients. After PSM, there were 146 patients in the control group and the PMV group, respectively. The PMV group had longer ICU stay and length of hospital stay and more drainage volume compared with the control group (all P<0.05). There was no statistical difference in perioperative mortality or other complications between the two groups (all P>0.05). ConclusionThere are a lot of factors associated with PMV of the elderly patients undergoing on-pump CABG. In order to establish a complete and formal PMV prediction model, clinicians can make a further step of assessment according to perioperative elements, and improve the prognosis of such patients.
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 compare the sequential efficacy of high-flow nasal cannula oxygen therapy (HFNC) with non-invasive mechanical ventilation (NIV). Methods Randomized controlled trials comparing the efficacy of NIV sequential invasive mechanical ventilation with HFNC were included in the Chinese Journal Full-text Database, VIP Journal database, Wanfang Database, Chinese Biomedical Literature Database, PubMed, Cochrane Library and Embase. Meta-analysis was performed using RevMan5.4 software. Results A total of 2404 subjects were included in 19 studies. Meta-analysis results showed that compared with NIV, HFNC had a statistically significant difference in reducing patients' re-intubation rate in invasive mechanical ventilation sequence [relative risk (RR)=0.65, 95% confidence interval (CI) 0.50 - 0.86, Z=3.10, P=0.002]. HFNC showed statistically significant difference compared with NIV in reducing lung infection rate (RR=0.40, 95%CI 0.21 - 0.79, Z=2.67, P=0.008). HFNC was significantly different from NIV in terms of length of stay in Intensive Care Unit (ICU) (MD=–5.77, 95%CI –7.64 - –3.90, Z=6.05, P<0.00001). HFNC was significantly different from NIV in improving 24 h oxygenation index (MD=13.16, 95%CI 8.77 - 17.55, Z=5.87, P<0.00001). There was no significant difference in ICU mortality between HFNC and NIV (RR=0.70, 95%CI 0.45 - 1.08, Z=1.61, P=0.11). Conclusion Compared with NIV, sequential application of HFNC in invasive mechanical ventilation can improve the reintubation rate and pulmonary infection rate to a certain extent, reduce the length of ICU stay and improve the 24 h oxygenation index, while there is no difference in ICU mortality, which is worthy of clinical application.
ObjectiveTo investigate the effect of recruitment maneuver (RM) following fibrobronchoscopy in invasively mechanically ventilated (IMV) patients with excessive airway secretions or foreign body aspiration. MethodsFrom September 2012 to July 2014, 200 eligible patients were randomly assigned to intervention group (n=100) and control group (n=100) . Airway clearance by fibrobronchoscopy was conducted in both the two groups, but RM was subsequently performed only in the intervention group. Outcome measurements included oxygenation index, partial pressure of carbon dioxide (PaCO2), heart rate (HR), air way resistance (Raw) and dynamic lung compliance (Cdyn) before and 2 hours after treatment, and duration of IMV and Intensive Care Unit (ICU) stay were also analyzed. ResultsAfter treatment with fibrobronchoscopy, oxygenation index [intervention vs. control: (291.14±38.49) vs. (241.39± 35.62) mm Hg (1 mm Hg=0.133 kPa)], PaCO2 [(41.65±7.73) vs. (38.87±7.97) mm Hg] and Cdyn [(48.94±11.21) vs. (39.59±10.98) mL/cm H2O (1 cm H2O=0.098 kPa) ] were significantly increased, while HR [(95.41±20.59) , vs. (106.47±19.11) beats/min] and Raw [(17.87±8.32) vs. (23.98±7.88) cm H2O/(L·s)] were significantly decreased in both groups (P ＜ 0.01) . Duration of IMV and ICU stay in the intervention group were (15.72±6.42) and (19.85±8.12) days respectively, while in the control group were (20.49±7.21) and (27.87±10.33) days. Compared with the control group, patients in the intervention group had lower Raw, duration of IMV and ICU stay, and higher Cdyn, oxygenation index, and PaCO2 (P ＜ 0.01) , but no significant difference was found in HR (P ＞ 0.05) . ConclusionIn mechanically ventilated patients with excessive airway secretion or foreign body aspiration, recruitment maneuver following fibrobronchoscopy is of great clinical importance, due to the decrease of the duration of mechanical ventilation and ICU stay by re-inflating the collapsing alveoli, improving pulmonary ventilation and gas exchange, lung compliance and diffusion capacity.
Objective To investigate the predictive value of mechanical power (MP) in the weaning outcome of adaptive mechanical ventilation plus intelligent trigger (AMV+IntelliCycle, simply called AMV) mode for acute respiratory distress syndrome (ARDS) patients. Methods From November 2019 to March 2021, patients with mild to moderate ARDS who were treated with invasive mechanical ventilation in the intensive care unit of the First Affiliated Hospital of Jinzhou Medical University were divided into successful weaning group and failed weaning group according to the outcome of weaning. All patients were treated with AMV mode during the trial. The MP, oral closure pressure (P0.1), respiratory rate (RR) and tidal volume (VT) of the two groups were compared 30 min and 2 h after spontaneous breathing trial (SBT). The correlation between 30 min and 2 h MP and shallow rapid respiratory index (RSBI) was analyzed by Pearson correlation. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of 30 min MP in ARDS patients with AMV mode weaning failure. Results Sixty-eight patients were included in the study, 49 of them were successfully removed and 19 of them failed. There was no statistical significance in age, gender, body mass index, oxygenation index, acute physiology and chronic health evaluation Ⅱ score, reasons for mechanical ventilation (respiratory failure, sepsis, intracranial lesions, and others) between the two groups (all P>0.05). The MP, P0.1 and RR at SBT 30 min and 2 h of the successful weaning group was lower than those of the failed weaning group (all P<0.05), but the VT of the successful weaning group was higher than the failed weaning group (all P<0.05). There was a significant relation between the MP at SBT 30 min and 2 h and RSBI (r value was 0.640 and 0.702 respectively, both P<0.05). The area under ROC curve of MP was 0.674, 95% confidence interval was 0.531 - 0.817, P value was 0.027, sensitivity was 71.73%, specificity was 91.49%, positive predictive value was 0.789, negative predictive value was 0.878, optimal cutoff value was 16.500. The results showed that 30 min MP had a good predictive value for the failure of weaning in AMV mode in ARDS patients. Conclusion MP can be used as an accurate index to predict the outcome of weaning in ARDS patients with AMV mode.