OBJECTIVE: To investigate the mechanism of autophagy in regulating bacterial translocation in intestinal infection caused by hypervirulent Klebsiella pneumonia (hvKp) and explore the method of reducing translocation infection of intestinal bacteria. METHODS: Fifty C57BL/6J mice were divided into gavage group (n = 40) and control group (CO group, n = 10). The gavage group was orally administered with 200 μL/d of hvKp (colony count of 10⁹ CFU/mL) continuously for 5 days to establish a hvKp intestinal infection model. CO group was given an equal amount of normal saline. After the experiment, the mice were anesthetized with lsofluraneand euthanized with cervical dislocation under anesthesia. Peripheral venous blood of mice was collected to detect bacterial translocation by 16S rDNA sequencing, then divided into translocation group (BT+ group) and non-translocation group (BT- group). Hematoxylin-eosin (HE) staining was used to evaluate intestinal morphology. The ultrastructural changes of intestinal tissues were observed by electron microscope. The levels of intestinal oxidative stress indicators such as superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GPx) were measured. Translocation was detected by in situ hybridization. The expression of tight junction protein microtubule-associated protein 1 light chain 3-II (LC3-II) and autophagy protein Beclin-1 were measured by Western blotting. The mRNA expression of tight junction proteins ZO-1 and Claudin-2 were detected by reverse transcription-polymerase chain reaction (RT-PCR). The expression of autophagy protein and tight junction protein were observed by immunofluorescence. RESULTS: Two out of 40 mice in the gavage group died after developing aspiration pneumonia. All mice in the CO group survived. The 16S rDNA sequencing results showed that no bacteria were detected in the peripheral blood of the CO group, but bacteria were detected in the peripheral blood of 18 mice in the gavage group, with a bacterial translocation rate of 47.4%. The BT- and BT+ groups showed intestinal mucosal tissue damage, with severe damage in the BT+ group. Compared with the CO group, the level of MDA in the BT- and BT+ groups were significantly increased, while the activities of SOD and GPx were significantly decreased. Compared with the BT- group, the MDA level in the BT+ group further increased, while the SOD and GPx activities further decreased [MDA (mmol/mg): 2.98±0.11 vs. 2.48±0.11, SOD (U/mg): 62.40±5.45 vs. 73.40±4.08, GPx (U/mg): 254.72±10.80 vs. 303.55±8.57, all P < 0.01]. The results of in situ hybridization detection showed that after continuous gastric lavage for 5 days, displaced hvKp was detected in the intestinal mucosal lamina propria and liver tissue of the BT+ group. Compared with the CO group, the protein expressions of LC3-II and Beclin-1 in the BT- and BT+ groups were significantly increased. The protein expressions of LC3-II and Beclin-1 in the BT+ group were obviously lower than those in the BT- group (LC3-II/β-actin: 0.38±0.04 vs. 0.70±0.09, Beclin-1/β-actin: 0.62±0.05 vs. 0.86±0.05, both P < 0.01), and there were autophagosomes in the intestinal mucosa. These results indicated that intestinal mucosal autophagy was activated after hvKp continuous gavage. Compared with CO group, the mRNA expressions of ZO-1 and Claudin-2 in the BT- and BT+ groups were significantly decreased. Compared with the BT- group, the mRNA expressions of ZO-1 and Claudin-2 in the BT+ group was further reduced [ZO-1 mRNA (2^-ΔΔCT): 0.78±0.06 vs. 0.88±0.06, Claudin-2 mRNA (2^-ΔΔCT): 0.40±0.04 vs. 0.70±0.06, both P < 0.01]. The immunofluorescence results showed that the fluorescence intensity of LC3-II, Beclin-1, ZO-1, and Claudin-2 in the BT+ group was significantly lower than that in the BT- group. CONCLUSION HvKp can activate intestinal mucosal autophagy and reduce the damage to intestinal mucosal barrier function by down-regulating oxidative stress level, reduce the occurrence of bacterial translocation.
Animals ; Oxidative Stress ; Mice, Inbred C57BL ; Autophagy ; Intestinal Mucosa/microbiology* ; Bacterial Translocation ; Mice ; Klebsiella Infections/microbiology* ; Superoxide Dismutase/metabolism* ; Beclin-1

Objective:To investigate the computed tomography (CT)-based integrated deep learning model for qualitative and quantitative classification of hepatic portal vein.Methods:The retrospective study was conducted. The CT imaging data of 291 patients undergoing upper-abdomen enhanced CT examination in the Beijing Tsinghua Changgung Hospital of Tsinghua University from October 2017 to January 2019 were collected. There were 195 males and 96 females, aged (51±12)years. The hepatic portal vein was reconstructed using the three-dimensional reconstruction system. Three-dimensional point cloud was input to the encoder model to obtain the three-dimen-sional reconstructed vectorized representation, which was used for qualitative classification and quantitative representation classification. Measurement data with normal distribution were repre-sented as Mean± SD, and comparison between groups was conducted using the paired t test. Count data were repre-sented as percentages or absolute numbers, and comparison between groups was analyzed using the paired chi-square test. Results:(1) Three-dimensional reconstruction of portal vein and anatomical classification. Three-dimensional structure was reconstructed in the 291 patients. Classification of main hepatic portal vein showed 211 cases of Akgul type A, 29 cases of Akgul type B, 16 cases of Akgul type C, 10 cases of Akgul type D, and 25 cases of unclassifiable. (2) Prediction of qualitative classification of main hepatic portal vein. Of the 291 patient samples, 25 unclassifiable or poor quality samples were excluded, 266 samples were used for automated qualitative classification of the main portal vein by machine model. There were 211 cases of Akgul type A, 29 cases of Akgul type B, 26 cases of Akgul type C&D. The Macro-F1 of 266 patients was 61.93%±40.50% and the accuracy was 84.99%, versus 32.38%±19.81% and 61.65% of Random classifier, showing significant differ-ences between them ( t=7.85, χ2=62.89, P<0.05). (3) Quantitative representation of portal vein classification. The probabilities of quantitative classification for Akgul qualitative classification of similar samples included P@1 as 73%±45%, P@3 as 70%±37%, P@5 as 69%±35%, P@10 as 67%± 32%, mean reciprocal rank(MRR) as 80%±34%, versus 57%±50%, 58%±35%, 58%±32%, 58%± 30%, 70%±37% of the baseline model, showing significant differences between the two analytical methods ( t=5.22, 5.11, 5.00, 4.99, 3.47, P<0.05). Conclusion:The automated classification model for the hepatic portal vein structure was constructed using CT-based three-dimensional reconstruc-tion and deep learning technology, which can achieve automatic qualitative classification and quanti-tatively describe the hepatic portal vein structure.

By extracting quantitative radiomic features from regions of interest in medical images and correlating them with the biological features and heterogeneity of tumors, radiomics can provide critical information and a basis for personalized precision diagnosis and treatment. Peritumoral regions contain a wealth of microbiological information. Therefore, chest CT peritumoral radiomics, which can provide quantitative non-invasive assessment for patients with non-small cell lung cancer (NSCLC) by mining the deep heterogeneity of peritumoral regions, has broad prospects for future clinical applications. Given the rapid progress in computer and medical big data techniques, as well as the in-depth efforts in multi-center, high-quality, and large-sample data in the future, it is reasonably believed that radiomics research will be gradually normalized and reproducible. This is conducive to the translation and application of radiomics research to clinical practice, thus laying a foundation for personalized and accurate diagnosis, treatment, and follow-up for lung cancer patients.

OBJECTIVE To clarify whether the thera-peutic effect of escitalopram on depression patients is cor-related with traditional Chinese medicine syndrome types,and to provide a basis for more accurate drug applica-tion.METHODS A total of 235 depression patients were recruited and classified according to traditional Chinese medicine syndrome differentiation into 5 types:liver and qi stagnation(45),liver stagnation and fire transformation(43),liver qi stagnation and spleen deficiency(79),heart and spleen deficiency(20),and liver and kidney deficiency(38).All patients were treated with escitalopram(10 mg·d-1)for eight weeks.The Montgomery Depression Rating Scale(MADRS)and the 17 Hamilton Depression Rating Scale(HAMD-17)were used to score before treatment and 2,4,and 8 weeks after treatment,respectively.RESULTS Compared with before treatment,the MADRS and HAMD-17 scores and remission rates of each syn-drome type significantly improved with increasing medica-tion duration.The MADRS score relief rate of liver and kidney deficiency type was the most significant(69.3%),significantly higher than the other four syndrome types(47.5%-52.6%,P<0.05);The remission rate of HAMD-17 score was significantly higher than that of heart and spleen deficiency(50.7%vs.28.5%,P＜0.05).The remis-sion rate of HAMD-17 score in liver and qi stagnation type(52.2%)was significantly higher than that in liver stagnation and spleen deficiency type(37.0%,P＜0.01)and heart spleen deficiency type(28.5%,P＜0.05).CON-CLUSION Escitalopram may have a more significant therapeutic effect on patients with liver and kidney defi-ciency and liver stagnation depression.This study pro-vides a new approach for the more effective and accu-rate application of traditional Chinese medicine syndrome differentiation in the selection of clinical antidepressants.

Objective:To analyze the possible causes of arrhythmia in patients receiving continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA).Methods:A retrospective cohort study was conducted. All patients underwent RCA-CRRT treatment from January 1, 2020 to October 31, 2020 in the intensive care unit (ICU) of Tianjin Third Central Hospital were enrolled. The patients were divided into arrhythmia group and non-arrhythmia group according to whether arrhythmia occurred. The gender, age, acute physiology and chronic health evaluationⅡ(APACHEⅡ) score, catheterization site, underlying diseases, electrocardiogram (ECG), electrolytes [total calcium, serum free calcium (iCa 2+), phosphorus, magnesium, potassium] and blood gas analysis (pH value, HCO 3-) of patients in the two groups were recorded. The changes of ECG were observed, the differences in electrolyte and blood gas analysis indexes between the two groups of patients at different time points (before CRRT, 24, 48, 72 hours after CRRT, and when arrhythmia occurred) were compared. Results:A total of 86 RCA-CRRT patients were enrolled, of which 12 cases (13.95%) had arrhythmia, and the remaining 74 cases (86.05%) had no arrhythmia. The average time for the occurrence of arrhythmia in the 12 patients was (44.00±16.82) hours. There was no significant ST-segment change in the ECG when the arrhythmia occurred compared with that before CRRT, the total calcium level was significantly higher than that before CRRT (mmol/L: 2.48±0.40 vs. 2.13±0.35, P < 0.05), the blood magnesium level was significantly lower than that before CRRT (mmol/L: 0.73±0.20 vs. 0.95±0.25, P < 0.05). There was no significant difference in iCa 2+, blood phosphorus, blood potassium, pH value and HCO 3- between before CRRT and when arrhythmia occurred. Over time, the total calcium levels in the two groups increased, and there was a statistical difference between the 48 hours after CRRT and before CRRT (mmol/L: 2.48±0.33 vs. 2.13±0.35 in the arrhythmia group, and 2.30±0.22 vs. 2.15±0.48 in non-arrhythmia group, both P < 0.05). The linear change trend of iCa 2+, pH value and HCO 3- was not obvious in the two groups. The blood phosphorus and blood magnesium levels in the two groups decreased. The blood potassium in the arrhythmia group decreased, however, the blood potassium level in non-arrhythmia group did not change significantly. The total calcium level in the arrhythmia group was significantly higher than that in the non-arrhythmia group at 72 hours after CRRT (mmol/L: 2.69±0.35 vs. 2.45±0.23, P < 0.05); however, there was no significant difference in serum iCa 2+, phosphorus, magnesium, potassium, pH value and HCO 3- between the two groups. Conclusion:Patients receiving RCA-CRRT were less likely to develop arrhythmia, the causes may be related to the accumulation of citric acid and electrolyte disturbances such as calcium, phosphorus, and magnesium.

Objective:To investigate the clinical effect of setting proportional pressure support (PPS) parameters by target tidal volume (VT) method.Methods:The study was conducted retrospectively on acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients admitted to Tianjin Third Central Hospital from January 2016 to December 2020. According to the PPS parameter setting method, the patients were divided into the airway blocking group and target VT group. The baseline characteristics, initial setting values of flow assist (FA) and volume assist (VA), respiratory system parameters, and clinical outcomes were collected and compared between the two groups.Results:Fifty-nine patients were enrolled, 29 patients in the airway blocking group, and 30 in the target VT group. There was no statistically significant difference in baseline characteristics, compliance, resistance, and initial settings of FA and VA between the two groups. Compared with the target VT group, the respiratory rate (RR), mean arterial pressure (MAP), VT, and arterial partial pressure of oxygen (PaO 2) recorded 1 hour after the initial setting of the PPS parameters in the airway block method group were significantly reduced [RR (times/minute): 21.0 (18.5, 22.5) vs. 23.0 (21.0, 25.0), MAP (mmHg, 1 mmHg = 0.133 kPa): 84.0 (79.0, 90.5) vs. 90.0 (87.0, 96.2), VT (mL): 305.24±41.07 vs. 330.87±46.84, PaO 2 (mmHg): 68.0 (66.0, 73.5) vs. 74.0 (69.8, 82.5), all P < 0.05], while arterial partial pressure of carbon dioxide (PaCO 2) and oral closure pressure (P0.1) were both increased significantly [PaCO 2 (mmHg): 41.0 (39.0, 46.0) vs. 37.5 (35.0, 42.2), P0.1 (cmH 2O, 1 cmH 2O = 0.098 kPa): 1.42±0.78 vs. 0.90±0.67, both P < 0.05]. Compared with airway blocking group, the duration of weaning, ICU stay, and hospital stay in the target VT group were significantly shorter [duration of weaning (hours): 42.0 (24.0, 70.5) vs. 64.0 (30.5, 97.5), ICU stay: 10.00±3.38 to 13.28±5.41, hospital stay (days): 12.07±3.40 vs. 15.41±5.60, all P < 0.05]. There was no statistically significant difference in the invasive mechanical ventilation time, weaning failure rate, ICU mortality and in-hospital mortality between the two groups. Conclusion:This study suggested that the target TV method has the advantages of practicality, safety, convenience, and rapid to set PPS parameters than the airway block method, which shortens the duration of weaning and ICU stay, and has a good clinical prospect.

Objective:To establish a model that can predict weaning failure from ventilation through hemodynamic and fluid balance parameters.Methods:A retrospective analysis was conducted. The patients who underwent invasive mechanical ventilation for more than 24 hours and having spontaneous breathing test admitted to intensive care unit (ICU) of Tianjin Third Central Hospital from January 1st, 2017 to December 31st, 2018 were enrolled. The information was collected, which included the baseline data, hemodynamic parameters by pulse indicator continuous cardiac output (PiCCO) monitoring, B-type natriuretic peptide (BNP), urinary output, fluid balance in first 24 hours when patients admitted to ICU, and hemodynamic parameters by PiCCO monitoring, BNP, urinary output, fluid balance, diuretic usage, noradrenalin usage within 24 hours before weaning as well as usage of continuous renal replacement therapy (CRRT) during mechanical ventilation. According to weaning success or failure, the patients were divided into weaning success group and weaning failure group, and the statistical differences between the two groups were calculated. Variables with statistical significance within 24 hours before weaning were included in the multivariate Logistic regression analysis to establish weaning failure prediction model and find out the possible risk factors of weaning failure.Results:A total of 159 patients were included in this study, which included 138 patients in the weaning success group and 21 patients in the weaning failure group. There were no statistical differences in all hemodynamic parameters by PiCCO monitoring, BNP, urinary output, fluid balance within 24 hours into ICU between two groups. There were statistical differences in BNP ( χ2 = 9.262, P = 0.026), central venous pressure (CVP; χ2 = 7.948, P = 0.047), maximum rate of the increase in pressure (dPmx; χ2 = 10.486, P = 0.015), urinary output ( χ2 = 8.921, P = 0.030), fluid balance ( χ2 = 9.172, P = 0.027) within 24 hours before weaning between two groups. In addition, variable about cardiac index (CI; χ2 = 7.789, P = 0.051) was included into multivariate Logistic regression model to improve the prediction model and enhance the accuracy of model. Finally, variables included in the multivariate Logistic regression model were BNP, CVP, CI, dPmx, urinary output, fluid balance volume, and the accuracy of the weaning failure prediction model was 92.9%, the sensitivity was 100%, and the specificity was 76.8%. When the model was adjusted by variables of age and noradrenalin usage, the accuracy of model to predict failure of weaning was 94.2%, the sensitivity was 100%, the specificity was 81.2%. Conclusion:Weaning failure prediction model based on hemodynamic parameters by PiCCO monitoring and variables about liquid balance has high accuracy and can guide clinical weaning.

Objective:To assess the impact of not inflated lung tissue (NILT) volume on the prognosis of patients with moderate-to-severe acute respiratory distress syndrome (ARDS).Methods:The clinical data of 131 patients with moderate-to-severe ARDS admitted to the intensive care unit (ICU) of Tianjin Third Central Hospital from March 2016 to June 2019 were collected. The basic data of patients, including gender, age, body mass index (BMI), causes of ARDS, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, sequential organ failure assessment (SOFA) score and oxygenation index (PaO 2/FiO 2), were collected. The CT imaging data of patients on the 1st and 7th day in the ICU were collected. According to the CT value, they were divided into hyperventilated areas (-1 000 to -900 HU), normal ventilation areas (-899 to -500 HU), poorly ventilated areas (-499 to -100 HU), and atelectasis area (-99 to 100 HU). The total lung volume and the percentage of NILT to the total lung volume (NILT%) were calculate. At the same time, duration of mechanical ventilation, length of ICU stay, total length of hospital stay were collected. According to the 28-day follow-up, they were divided into survival group and death group. Multivariate Logistic regression analysis was used to determine the risk factors for 28-day death in ARDS patients. The receiver operating characteristic (ROC) curve was drawn, the area under ROC curve (AUC) and 95% confidence interval (95% CI) were calculated to determine the accuracy of NILT% in predicting the 28-day prognosis of ARDS patients, and the NILT% threshold was used for subgroup analysis of patients. Results:Among the 131 patients with moderate-to-severe ARDS, patients were excluded for more than 48 hours after ARDS diagnosis, repeated admission to ICU due to ARDS, the ICU duration less than 7 days, death within 72 hours of admission, chronic interstitial lung disease or congestive heart failure, no chest CT examination within 7 days of admission to ICU, and no specimen collection within 2 hours of admission to ICU. Finally, a total of 53 patients were enrolled in the analysis. Of the 53 patients, 31 patients survived and 22 patients died. The 28-day mortality was 41.5%. Compared with the survival group, patients in the death group were older (years old: 65.32±11.29 vs. 55.77±14.23), and had a higher SOFA score (11.68±3.82 vs. 8.39±2.23) with significant differences (both P < 0.05), while there were no significant differences in gender, BMI, ARDS cause, APACHE Ⅱ score and PaO 2/FiO 2 between the two groups. There was no significant difference in CT value, total lung volume and NILT% between the two groups at 1st day after admission to ICU; NILT% on day 7 after admission to ICU in the death group was significantly higher than that in the survival group [(28.95±8.40)% vs. (20.35±5.91)%, P < 0.01], but there was no significant difference in CT value and total lung volume between the two groups. Multivariate Logistic regression analysis showed that the 28-day prognosis of ARDS was related to age, SOFA score and NILT% independently [age: odds ratio ( OR) = 0.892, 95% CI was 0.808-0.984, P = 0.023; SOFA score: OR = 0.574, 95% CI was 0.387-0.852, P = 0.006; NILT%: OR = 0.841, 95% CI was 0.730-0.968, P = 0.016]. ROC curve analysis showed that 7-day NILT% could predict the 28-day prognosis of patients with moderate-to-severe ARDS, and AUC was 0.810 (95% CI was 0.678-0.952, P < 0.01). The NILT% threshold was 15.50%, sensitivity was 95.5%, specificity was 80.6%, positive predictive value was 85.7%, and negative predictive value was 74.6%. According to the 7-day NILT% threshold, a subgroup analysis of patients was performed, and 7-day NILT% > 15.50% was defined as a high-risk clinical prognosis, and ≤ 15.50% was a low-risk. Compared with low-risk patients ( n = 7), the duration of mechanical ventilation, the length of ICU stay and total length of hospital stay in high-risk patients ( n = 46) were significantly prolonged [duration of mechanical ventilation (days): 9.37±6.14 vs. 4.43±1.72, length of ICU stay (days): 12.11±5.85 vs. 7.57±1.13, total length of hospital stay (days): 18.39±5.87 vs. 11.29±2.22, all P < 0.05]. Conclusion:The 7-day NILT% > 15.50% of patients with moderate-to-severe ARDS after ICU admission is related to poor prognosis.

Objective To evaluate the diagnostic value of contrast-enhanced ultrasound in acute kidney injury (AKI) caused by sepsis. Methods The sepsis patients admitted to intensive care unit of Tianjin Third Central Hospital from January 2015 to June 2017 were enrolled. All of the patients were completed the 6-hour Bundle treatment and the bilateral renal contrast-enhanced ultrasound within 24 hours, and the peak signal intensity (PSI), peak intensity time (PIT), wash internal rate (WIR) and renal function parameters were measured at the same time. The patients were divided into AKI 24 hours group and non-AKI 24 hours group according to Kidney Disease: Improving Global Outcomes (KDIGO)-AKI diagnostic criteria, and the parameters differences were compared between the two groups. The receiver operating characteristic (ROC) curve were used to analyze the diagnostic value of the parameters. Renal function of the non-AKI group patients was measured again 7 days after hospital admission, and patients were divided into AKI 7 days group and non-AKI 7 days group, and the related parameters of the two groups measured within 24 hours were compared. Results ① Ninety-six patients were enrolled, with 39 cases of AKI occurred within 24 hours after admission, and with an incidence of 40.6%. Contrast-enhanced ultrasound showed that the time-intensity curve (TIC) of non-AKI patients manifested as a slow down after rapid rise to the peak, but the AKI patients showed as slow rise to the peak and more slow decrease. Compared with non-AKI 24 hours group, AKI 24 hours group performance as PSI weakened, PIT extended and WIR decreased [PSI (dB): 114.41±19.38 vs. 141.24±24.65, PIT (s): 22.86±4.29 vs. 17.39±3.68, WIR (dB/s): 5.53±4.17 vs. 7.85±1.84, all 1 < 0.01]. ROC curve analysis showed that area under the ROC curve (AUC) of WIR, PIT, PSI was 0.85, 0.84, 0.82 respectively (all 1 < 0.01), the cut-off value of WIR was 7.18 dB/S, the sensitivity, specificity and accuracy were 82.05%, 80.70% and 81.25% respectively; the cut-off value of PIT was 18.45 s, the sensitivity, specificity and accuracy were 74.35%, 73.68% and 73.95% respectively;the cut-off values of PSI was 121.21 dB, the sensitivity, specificity and accuracy were 71.79%, 87.72% and 81.25% respectively. ② The incidence of AKI within 7 days in non-AKI patients was 26.3% (15/57). There were significant differences in PIT, WIR and PSI between AKI 7 days group and non-AKI 7 days group [PSI (dB): 124.97±26.64 vs. 147.02±21.51, PIT (s): 20.61±3.27 vs. 16.24±3.13, WIR (dB/s): 6.81±1.76 vs. 8.22±1.75, all 1 < 0.05]. However, there was no significant difference in serum creatinine (SCr), blood urea nitrogen (BUN) and creatinine clearance rate (CCr). Conclusion Compared to SCr and BUN, contrast-enhanced ultrasound parameters can early response to renal dysfunction, and contribute to early diagnosis of sepsis induced AKI.

Objective To investigate the effect of different appropriate modes of weaning from mechanical ventilation (MV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods Patients with AECOPD and mechanically ventilated by orotracheal intubation, suitable for continuous positive airway pressure+proportional pressure support (CPAP+PPS) and CPAP+assisted spontaneous breath (ASB) ventilation mode for weaning from MV, admitted to intensive care unit (ICU) of Tianjin Third Central Hospital form January 1st, 2016 to December 31st, 2017 were enrolled. When the patients recovered to spontaneous respiration and down regulation of ventilator support frequency to 10 bpm, they were taken ventilator weaning in CPAP+PPS and CPAP+ASB mode according to the random number table method, respectively. Basic characteristics, ventilator parameters, the incidence of high man-machine confrontation (man-machine confrontation index > 10%) and clinical outcomes (ventilator weaning time, which was defined as the time from randomization to successful weaning from MV, ventilator weaning failure times, the duration of MV, the length of ICU stay and the length of hospital stay) were compared between the two groups. Results Eighty-seven AECOPD patients were selected, 44 in CPAP+ASB group and 43 in CPAP+PPS group. There was no significant difference in gender, age, acute physiology and chronic health evaluation Ⅱ(APACHEⅡ), sequential organ failure score (SOFA), Glasgow coma score (GCS), Charsen index and the highest arterial blood carbon dioxide partial pressure (PaCO2), the lowest arterial oxygen partial pressure (PaO2) and tidal volume (VT) at the time of onset between the two groups. Compared with CPAP+ASB group, incidence of high man-machine confrontation was significantly decreased in CPAP+PPS group [9.30% (4/43) vs. 27.27% (12/44), P =0.027], and the airway occlusion pressure (P0.1) was significantly decreased [cmH2O (1 cmH2O = 0.098 kPa): 2.21±0.83 vs. 2.63±0.94, P = 0.032], and the failure rate of the first spontaneous breathing trial (SBT) was significantly decreased [6.98% (3/43) vs. 22.73% (10/44), P = 0.039], ventilator weaning time, the length of ICU stay and the length of hospital stay were significantly shortened [ventilator weaning time (hours): 12.73±14.23 vs. 50.64±38.11, the length of ICU stay (hours): 254.53±108.06 vs. 344.93±124.95, the length of hospital stay (days): 18.53±7.59 vs. 26.64±11.22, all P < 0.05]. However, there was no significant difference in PaCO2, duration of MV, ICU mortality and hospital mortality between the two groups. Conclusion Compared with CPAP+ASB ventilation mode, CPAP+PPS ventilation mode can reduce respiratory muscle load, promote respiratory function recovery, and reduce the occurrence of man-machine confrontation, which is beneficial to AECOPD patients taking ventilator weaning, and can significantly shorten the ventilator weaning time of patients and further shorten the hospitalization time.