Objective To investigate the application of sequential noninvasive ventilation (NIV) in weaning patients off mechanical ventilation after coronary artery bypass grafting (CABG). Methods From July 2007 to July 2009, 52 patients who underwent CABG with mechanical ventilation for no less than 24 hours and P/F Ratio lower than 150 mm Hg were divided into two groups with random number table. In the sequential NIV group (SNIV group), there were 19 patients including 16 males and 3 females whose ages were 69.26±8.10 years. In the prolonged mechanical ventilation group (PMV group), there were 33 patients including 28 males and 5 females whose ages were 70.06±7.09 years. Clinical data of these two groups were compared and the influence of NIV on the circulation and respiration of the patients were observed. Results The SNIV group weaned off mechanical ventilation earlier than the PMV group (26.46±3.66 h vs. 38.65±9.12 h, P=0.013). The SNIV group held shorter total ventilation time (29.26±21.56 h vs.54.45±86.57 h,P=0.016), ICU stay time (2.44±2.99 d vs. 4.89±7.42 d, P=0.028) and postoperative hospital time (10.82±4.31 d vs. 14.01±19.30 d, P=0.039) than the PMV group. Furthermore, the SNIV group had lower pneumonia rate (5.26% vs. 30.30%, P=0.033) and total postoperative complication rate (10.53% vs.45.45%, P=0.030) than the PMV group. However, there was no significant difference (Pgt;0.05) between the two groups in the successful weaning rate, repeated tracheal intubation rate, tracheotomy rate and mortality 30 days after operation. After NIV, SNIV group had no significant change in heart rate, central vein 〖CM(1585mm〗pressure, pulmonary arterial pressure and pulmonary arterial wedge pressure than the baseline value, while systolic pressure (129.66±19.11 mm Hg vs. 119.01±20.31 mm Hg, P=0.031), cardiacindex ［3.01±0.30 L/(min.m2) vs. 2.78±0.36 L/(min.m2), P=0.043］ and P/F Ratio (205.95±27.40 mm Hg vs. 141.33±9.98 mm Hg, P=0.001) were obviously elevated. Conclusion Sequential NIV is a effective and safe method to wean CABG patients off mechanical ventilation.
Objective To observe the effects of exogenous pulmonary surfactant (PS) on ventilation-induced lung injury (VILI) in rats, and to investigate its possible mechanisms. Methods A total of 40 Wistar rats were divided into 4 groups with randomized blocks method: control group, high tidal volume (HV) group, VILI group, and PS group, with 10 rats in each group. The control group was subjected to identical surgical procedure but was never ventilated. After 30 min of mechanical ventilation (MV) with Vt 45 ml/kg, the rats in HV group were killed immediately; rats in the VILI group were continually ventilated for up to 150 min with Vt 16 ml/kg; in the PS group, 100 mg/kg of PS administered intratracheally and with the same settings as VILI group. Mean artery pressure (MAP), blood gas analysis, lung wet to dry weight ratios (W/D), thorax-lung compliance, and cell counts in bronchoalveolar lavage fluid (BALF) were determined. Nuclear factor-κB(NF-κB) activity in lungs was measured by enzyme-linked immunosorbent assay (ELISA), interleukin-8(IL-8) in serum and BALF was determined by radioimmunoassay (RIA). Pathological examination of the lung was performed. Results Injurious ventilation significantly decreased MAP and PaO2/FiO2, but increased NF-κB activity and W/D. MAP and PaO2/FiO2 improved, but NF-κB activity, IL-8 in serum and BALF, and cell counts in BALF reduced significantly in PS group compared with those in VILI group. Histological studies showed reduced pulmonary edema and atelectasis in the PS group. Conclusion PS administered intratracheally can suppress the increased activity of NF-κB induced by VILI, exogenous PS can be used to treat VILI.
Objective We investigated the effect of supplementation with alanyl-glutamine dipeptide on insulin resistance and outcome in patients with chronic obstructive pulmonary disease (COPD) and respiratory failure. Methods A prospective, randomized, open and controlled trial was conducted. Patients with COPD and respiratory failure were recruited between Jan 2005 to Feb 2006 and randomly assigned to a trial group (n=14) with glutamine dipeptide supplmented parenteral nutrition and a control group (n=16) with isocaloric, isonitrogenic parenteral nutrition. On the third day and fifth day of nutrition treatment, blood glucose was clamped at level of 4.4 to 6.1 mmol/L by intravenously bumped insulin. Blood gas, blood glucose level, insulin dosage were recorded everyday. The outcomes were mortality, length of stay (LOS) in hospital and in ICU, mechanical ventilation times and the costs of ICU and hospital.Results Thirty patients successfully completed the trial. There was no difference in blood gas between two groups, but PaO2 increased gradually. Compared with control group, blood glucose level had trend to decrease in trial group. The average insul in consumption decreased significantly in trial group on the fifth day. There was no statistical difference between two groups in mortality, length of stay in hospital and the costs of hospital. But compared with control group, length of stay in ICU and mechanical ventilation days had trend to decrease in trial group. Conclusion Alanyl-glutamine dipeptide do not improve pulmonary function of patients with COPD and respiratory failure. However, alanyl-glutamine dipeptide attenuated insul in resistance and stabilized blood glucose. This trial does not confirm alanyl-glutamine di peptide can improve outcome in critically ill patients with COPD and respiratory failure between two groups in mortality at the end of 30 days, length of stay in hospital and the costs of hospital. But the length of stay in ICU and the duration of mechanical ventilation does decrease, but not significantly, in the trial group.
ObjectiveTo estimate whether alpha 1-antitrypsin (AAT) can reduce ventilator-induced lung injury (VILI) in acute respiratory distress syndrome (ARDS) rats after mechanical ventilation.MethodsThe rats were randomly divided into 3 groups: a sham (S) group, a mechanical ventilation (V) group and a mechanical ventilation/AAT (VA) group. The rats in the S group only received anesthesia, and the rats in the V and VA groups received endotoxin to simulate ARDS followed by mechanical ventilation for 4 hours. At the beginning of ventilation, the rats in the V group received saline, and the rats in the VA group received AAT. The PaO2/FiO2 ratio and the lung wet/dry (W/D) weight ratio were tested. The total protein and neutrophil elastase concentrations and the neutrophil and macrophage counts in bronchoalveolar lavage fluid (BALF) were tested. Proinflammatory factors in BALF and intercellular cell adhesion molecule-1 (ICAM-1) and microphage inflammatoryprotein-2 (MIP-2) in the serum were also detected. Furthermore, the oxidative stress response was detected, and histological injury and apoptosis were evaluated.ResultsCompared with the S group, PaO2/FiO2 was significantly decreased in the V group and the VA group, the protein concentration in the BALF and the lung W/D weight ratio were significantly increased, the concentration of inflammatory factors in BALF and peripheral blood was significantly increased, and inflammatory cells in BALF also increased. Meanwhile, malondialdehyde (MDA) concentration, myeloperoxidase (MPO) and nicotinamide adeninedinucleotide phosphate (NADPH) activity increased significantly. The V group and VA group were severely damaged, and the number of apoptotic cells increased significantly. Compared with the V group, the PaO2/FiO2 in the VA group significantly increased; the W/D weight ratio and the BALF protein concentration decreased; the number of macrophages and neutrophils in the BALF, and the concentration of elastase significantly decreased; tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in BALF decreased, IL-10 increased; ICAM-1 and MIP-2 in peripheral blood decreased. At the same time, the MDA concentration, MPO and NADPH activities in the VA group were significantly lower than those in the V group; the tissue damage was significantly reduced, and the number of apoptosis was significantly reduced. In addition, compared with the V group, the expression of Bax, gelsolin and cleaved caspase-3 decreased in the VA group, but the expression of Bcl-2 was increased (all P<0.05).ConclusionsAAT can relieve VILI in ARDS rats. The protection conferred by AAT may be associated with the anti-inflammatory, antioxidative stress response and antiapoptotic effect of AAT.
ObjectiveTo explore the clinical significance of prone position in the treatment of patients with acute respiratory distress syndrome (ARDS) caused by pulmonary contusion.MethodsA retrospective analysis was conducted on pulmonary contusion patients in the Intensive Care Medicine (ICU) from January 2017 to April 2021. The patients were divided into a prone position group (n=121) and a control group (n=117) after screening. The patients' basic conditions, occurrence of ARDS (P/F<150 mm Hg), changes in vital signs, laboratory examinations, lung compliance and other changes after treatment, mechanical ventilation time, staying in ICU, complications, and mortality were recorded and conpared between the two groups.ResultsWhen ARDS [oxygenation index (P/F)<150 mm Hg] occurred, compared with 1 day later, the P/F [(125.7±15.3) vs. (209.5±22.4) mm Hg , P<0.05] and lung compliance [(64.6±4.8) vs. (76.0±5.4) mL/cm H2O, P<0.05] increased in the prone position group. Compare with the control group after 1 day of treatment ARDS (P/F<150 mm Hg), P/F [(209.5±22.4) vs. (126.1±19.5) mm Hg, P<0.05] and lung compliance [(76.0±5.4) vs. (63.5±5.5) mL/cm H2O, P<0.05] increased in the prone position group (P<0.05). Compare with the control group, the prone position group had shortened mechanical ventilation time and ICU stay time, less atelectasis, lower mortality (P<0.05), lower occurrence of pneumothorax (P>0.05).ConclusionProne position treatment for patients with pulmonary contusion after ARDS (P/F<150 mm Hg) can correct hypoxemia faster, improve lung compliance, reduce atelectasis, shorten mechanical ventilation time and stay time of ICU, and reduce mortality, hence it has clinical value.
Objective To investigate the therapeutic effects of biphasic positive airway pressure (Bilevel) ventilation and volume ventilation plus [VV+，including volume control plus (VC+) and volume support (VS)] on respiratory failure in patients with chronic obstructive pulmonary disease (COPD).Methods 63 patients with COPD complicated by acute respiratory failure were intubated and underwent mechanical ventilation for at least 24 hours.At the first patients were underwent assist-control (A/C) ventilation for 2 to 4 hours to obtain the suitable basic ventilatory parameters.Meanwhile，the hemodynamics and oxygen dynamic parameters were measured.Then the patients were randomly allocated to three groups with 21 patients in each group and the ventilation mode was switched to Bilevel，VC+ and A/C mode correspondingly.The setting parameter was identical in three modes.In the process of weaning，patients in Bilevel group were ventilated with Bilevel and pressure support ventilation (PSV) mode at each pressure level，and subdivided into Bilevel and PSV 1 group accordingly.In VC+ group，the mode was switched to VS and PSV mode and subdivided into VC+ group and PSV 2 group,respectively.Every mode was run for 30 minutes while the ventilation function，blood gas exchange and lung mechanics index were measured.Results In the initial stage，the airway peak pressure (PIP) of Bilevel and VC+ mode obviously decreased，and the respiratory compliance was higher compared to the A/C mode. The effectiveness of Bilevel and A/C was equivalent in improving alveolar ventilation and oxygenation.The difference in the change of circulation function and blood gas between the two groups were not significant (Pgt;0.05).In the process of weaning，the effectiveness of Bilevel and VV+ was equal to PSV.The changes of breathing mode and blood gas between the two groups had no significant differences.Conclusions Bilevel and VV+ mode ventilation can be used in the whole mechanical ventilation for acute respiratory failure due to COPD with lower PIP，higher respiratory compliance compared to A/C model and similar performance as PSV during mechanical ventilation withdrawn.
ObjectiveTo systematically evaluate the efficacy and safety of probiotics for prevention of ventilator-associated pneumonia (VAP).MethodsThe Web of Science, Pubmed, OVID, Cochrane Library, CNKI, EMbase, Sciencedirect, Chinese biomedical database, and Wanfang database before August 2017 were searched, and the relevant data resources were also searched by hand to collect randomized controlled trials (RCTs) of probiotics for prevention of VAP. The quality of the included studies was evaluated using a modified version of the Jadad scale. Meta-analysis was performed with RevMan 5.3 software.ResultsA total of 16 RCTs were included. The use of probiotics can reduce the incidence of VAP [RR=0.71, 95%CI (0.62, 0.80), P<0.000 01], ICU days [MD=–3.28, 95%CI (–6.15, –0.41), P=0.03] and total duration of antibiotics [MD=–2.47, 95%CI (–4.89, –0.04), P=0.05], but can not reduce the mortality of ICU [RR=0.99, 95%CI (0.74, 1.32), P=0.94], hospital mortality [RR=0.77, 95%CI (0.58, 1.01), P=0.06], 28-day mortality [RR=1.01, 95%CI (0.69, 1.47), P=0.97], 90-day mortality [RR=1.00, 95%CI (0.72, 1.37), P=0.99], hospital stays [MD=–0.68, 95%CI (–3.88, 2.52), P=0.68], duration of mechanical ventilation [MD=–2.17, 95%CI (–4.78, 0.44), P=0.10], or the incidence of diarrhea [RR=0.96, 95%CI (0.80, 1.14), P=0.62]. No serious adverse events were reported in all included RCTs.ConclusionsThe use of probiotics can reduce the incidence of VAP, but it has no effect on the mortality, hospital stay, duration of mechanical ventilation or the incidence of diarrhea. However, considering the heterogeneity of research designs, we need more rigorous, large sample randomized controlled studies to increase the strength of evidence.
ObjectiveTo monitor the diaphragm function of mechanical ventilated patients in the intensive care unit. MethodsA prospective study was conducted on mechanical ventilation patients who had been evaluated by ventilation weaning screening test and planning to underwent spontaneous breathing trial between May 2013 and November 2013. A newly designed multi-function esophageal electrode was used to record the phrenic nerve conduction time (PNCT),diaphragm compound muscle action potential (CMAP) and twitch transdiaphragmatic pressure (TwPdi) elicited by bilateral anterolateral magnetic phrenic nerve stimulation. Results14 patients were recruited in this study. 1 case exited because of intolerance of repetitive magnetic stimulation,2 cases had no diaphragmatic electromyographic signals nor twitch signals,1 case had diaphragmatic electromyographic signal but could not be elicited by magnetic stimulation,1 case had no available TwPdi value with PNCT of 7.2 ms and CMAP of 1.26 mV. In the rest 9 cases,the PNCT,CMAP and TwPdi were (8.5±1.5)ms,(1.01±0.35)mV,(11.2±4.7)cm H2O,respectively. ConclusionNewly designed multi-function esophageal electrode catheter combined with bilateral anterolateral magnetic phrenic nerve stimulation can be used for non-volitional comprehensive assessment of diaphragm in critically ill patients,but not suitable for all subjects.
ObjectiveTo explore the effects of inhibition of paxillin phosphorylation on ventilation associated lung injury. MethodsSixty healthy male SD rats were randomly divided into four groups, namely a control group, a protective ventilation group, a high tidal volume ventilation group, and an inhibitor group. The rats in the control group received only tracheotomy and breathe naturally. The rats in the protective ventilation group received protective ventilation for 2 hours. The rats in the high tidal volume ventilation group and the inhibitor group received high tidal volume ventilation for 2 hours. The rats in the inhibitor group additionally received intraperitoneal injection of tyrosine protein kinase inhibitor PP2 before ventilation. All rats were sacrificed and the specimens of lung tissue were collected. The pathological changes of lungs were observed under light microscope and estimated by the diffuse alveolar damage (DAD) score system. The activity of myeloperoxidase (MPO) and the lungs wet/dry (W/D) weight ratio were measured. The expression of tumor necrosis factor-α(TNF-α) in BALF was detected by ELISA. Evans blue (EB) method was used to detect the pulmonary vascular permeability. The expression levels of phosphorylated paxillin (p-paxillin) and paxillin in lung tissue were measured by Western blot. Apoptosis in situ was detected by TUNEL. ResultsThere were significant differences in the W/D ratio, the EB extravasation, DAD score, the MPO activity and the TNF-αexpression in BALF between the high tidal volume ventilation group and the inhibitor group (P < 0.05). The apoptosis rate of each group was sorted from high to low as the high tidal volume ventilation group, the inhibitor group, the protective ventilation group, and the control group. The expression level of p-paxillin was the highest in the high tidal volume ventilation group which was significantly different from other groups (all P < 0.05). There was no significant difference in the expression of paxillin in the protective ventilation group, the high tidal volume ventilation group and the inhibitor group (P > 0.05). ConclusionInhibition of paxillin phosphorylation can significantly alleviate mechanical ventilation associated lung injury.
ObjectiveTo explore the development and application of a novel ventilator alarm management model in critically ill patients receiving invasive mechanical ventilation (MV) in the intensive care unit (ICU) using machine learning (ML) and Internet of Medical Things (IoMT). The study aims to identify alarms’ intervention requirements. MethodsA retrospective cohort study and ML analysis were conducted, including adult patients receiving invasive MV in the ICU at West China Hospital from February 10, 2024, to July 22, 2024. A total of 76 ventilator alarm-related parameters were collected through the IoMT system. Feature selection was performed using a stratified approach, and six ML algorithms were applied: Gaussian Naive Bayes, K-Nearest Neighbors, Linear Discriminant Analysis, Support Vector Machine, Categorical Boosting (CatBoost), and Logistic Regression. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC-ROC). ResultsA total of 107 patients and their associated ventilator alarm records were included. Thirteen highly relevant features were selected from the 76 parameters for model training through stratified feature selection. The CatBoost model demonstrated the best predictive performance, with an AUC-ROC of 0.984 7 and an accuracy of 0.912 3 in the training set. External validation of the CatBoost model yielded an AUC-ROC of 0.805 4. ConclusionThe CatBoost-based ML model successfully constructed in this study has high accuracy and reliability in predicting the ventilator alarms in ICU patients, providing an effective tool for ventilator alarm management. The CatBoost-based ML method exhibited remarkable efficacy in predicting the necessity of ventilator intervention in critically ill ICU patients. Further large-scale multicenter studies are recommended to validate its clinical application value and promote model optimization and implementation.