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.
ObjectiveTo analyze the clinical characteristics and related prognostic factors of post-renal transplantation pneumonia.MethodsThe clinical data of 89 patients with post-renal transplantation pneumonia in Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital from 1st January 2014 to 31st December 2015 were collected in the study. Kaplan-Meier method was used to calculate overall survival. Cox analysis was used to analyze the related prognostic factors.ResultsPost-renal transplantation pneumonia occurred mainly within 6 months after renal transplantation. The prominent clinical manifestations were cough (95.5%), fever (56.1%), and dyspnea (12.3%). The mortality of post-renal transplantation pneumonia was 11.2% and all death occurred within 5 months after transplantation. The overall survival rate significantly decreased in the patients with C-reactive protein (CRP) ≥40 mg/L (P<0.001), procalcitonin ≥1 ng/ml (P=0.002), brain natriuretic peptide >100 pg/ml (P<0.001), platelet ≤100×109/L (P<0.001), or those with occurrence time of pneumonia <180 days (P=0.013). Platelet ≤100×109/L could increase the risk of death by 66.6 times (RR=0.015, P=0.006), and CRP ≥ 40 mg/L could increase the risk of death by 20 times (RR=0.05, P=0.029).ConclusionsPost-renal transplantation pneumonia has prominent clinical characteristics. Platelet ≤100×109/L or CRP ≥40 mg/L can increase the risk of death and can be used as an independent prognoctic factor of post-renal transplatation pneumonia.
Forced oscillation technique (FOT) is an active method to test pulmonary function, which can derive the mechanical characteristics of the respiratory system with liner system identification theory by pushing in an oscillation air signal and measuring the changes of output pressure and flow. A pulmonary function determination system was developed based on the FOT in this paper. Several critical technologies of this determination system were analyzed, including the selection criteria of oscillation air generator, pressure and flow sensor, the signal design of oscillation air generator, and the synchronous sampling of pressure and flow data. A software program on LabVIEW platform was set up to control the determination system and get the measuring data. The performance of sensors and oscillation air generator was verified. According to the frequency response curve of the pressure, the amplitude of driving signal to the oscillation air generator was corrected at the frequency range between 4~40 Hz. A simulation experiment was carried out to measure the respiratory impedance of the active model lung ASL5000 and the results were close to the setting values of the model lung. The experiment testified that the pulmonary function determination system based on FOT had performance good enough to provide a tool for the in-depth research of the mechanical properties of the respiratory system.
Objective To investigate HCV genotypes in HCV patients in West China Hospital of Sichuan University, and to analyze the major genotypes and clinical characteristics. Methods From March 2011 to September 2016, 4 520 HCV patients who were successfully genotyped HCV genotypes were enrolled in West China Hospital of Sichuan University. The genotypes distributions and the characteristics of laboratory characteristics of liver function, the viral loading were all analyzed. In addition, the genotypes in HCC patients, liver cirrhosis, HBC/HCV co-infection were also analyzed. Results HCV genotypes of HCV patients were divided into five genotypes of 1, 2, 3, 4, 6 and 23 subtypes, including predominant genotypes/subtypes 1b, 1*, 3b, 2a, 3a and 6a, accounting for 66.42%, 8.01%, 6.57%, 4.54%, 4.29%, and 3.41%, respectively. Subtype 1b was the predominant subtype for both sex. In male patients, the levels of ALT were highest in 6a subtype, while in female, the levels of ALT were highest in 3a subtype. For the 94 liver cirrhosis patients, 42 patients were 1b subtypes; as for the 6 HCC patients, 1b and 3b subtypes were the only detected. Conclusion HCV genotypes/subtypes of HCV patients in West China Hospital of Sichuan University have unique characteristics of distribution, while the predominant genotype/subtypes are 1b,1*, 3b, 2a, 3a, 6a.
Correlation between nonlinear subharmonic scattering of ultrasound contrast agent microbubbles and ambient pressure is expected to be used for local brain tissue pressure monitoring. Although high-frequency ultrasound has achieved high-resolution imaging of intracranial microvessels, the research on high-frequency subharmonic scattering characteristics of microbubbles is insufficient at present, which restricts the research progress of estimating local brain tissue pressure based on high-frequency subharmonic scattering of microbubbles. Therefore, under the excitation of 10 MHz high-frequency ultrasound, the effects of different acoustic pressures and ambient pressures on the high-frequency subharmonic scattering characteristics of three different ultrasound contrast agents including SonoVue, Sonazoid and Huashengxian were investigated in this in vitro study. Results showed that the subharmonic scattering amplitudes of the three microbubbles increased with the increase of ambient pressure at the peak negative acoustic pressures of 696, 766 and 817 kPa, and there was a favorable linear correlation between subharmonic amplitude and ambient pressure. Under the above three acoustic pressures, the highest correlation coefficient of SonoVue was 0.948 (P = 0.03), the highest sensitivity of pressure measurement was 0.248 dB/mm Hg and the minimum root mean square error (RMSE) was 2.64 mm Hg. Sonazoid's highest correlation coefficient was 0.982 (P < 0.01), the highest sensitivity of pressure measurement was 0.052 dB/mm Hg and the minimum RMSE was 1.51 mm Hg. The highest correlation coefficient of Huashengxian was 0.969 (P = 0.02), the highest sensitivity of pressure measurement was 0.098 dB/mm Hg and the minimum RMSE was 2.00 mm Hg. The above in vitro experimental results indicate that by selecting ultrasound contrast agent microbubbles and optimizing acoustic pressure, the correlation between high-frequency subharmonic scattering of microbubbles and ambient pressure can be improved, the sensitivity of pressure measurement can be upgraded, and the measurement error can be reduced to meet the clinical demand for local brain tissue pressure measurement, which provided an important experimental basis for subsequent research in vivo.
ObjectiveTo analyze hepatitis B virus (HBV) genotype distribution and drug-resistant mutations in West China Hospital of Sichuan University, providing basis for hepatitis B individualized treatment.MethodsA total of 786 chronic hepatitis B patients admitted to West China Hospital of Sichuan University from January 2016 to December 2018 were enrolled in the study. Genotype and drug-resistant mutations were analyzed by Sanger sequencing, and statistical analysis was conducted by χ2 test.ResultsThree genotypes (B, C and D) were identified in 786 samples, 489 (62.2%) in genotype B, 291 (37.0%) in genotype C , and 6 (0.8%) in genotype D. The distribution differences of B and C genotypes in age and ethnic groups were statistically significant (P<0.05). Among them, 627 cases had drug-resistant mutations, with a drug-resistant mutation rate of 79.8%. A total of 262 cases (33.3%) were resistant to lamivudine and tibivudine, 102 cases (13.0%) were resistant to lamivudine, tibivudine and entecavir; 83 cases (10.6%) were resistant to adefovir dipivoxil. No tenofovir resistant strains were detected in 786 samples. There were statistically significant differences in drug resistance between B and C genotypes (χ2=14.356, P<0.01). The most common single mutation was M204I [179 cases (22.8%)], followed by 46 cases (5.9%) of A181V/T associated with adefovir dipivoxil resistance. The most common mixed mutation was L180M+M204V/I in 83 cases (10.6%), and another 102 cases (13.0%) showed M250V and/or V173L and/or T184A/G/S/I and/or S202G/I with L180M+M204V/I.ConclusionsHBV genotypes in West China Hospital of Sichuan University are mainly B and C, and the situation of drug resistance is severe and the mutation pattern is complex. Therefore, detecting HBV genotype and drug resistance mutation is necessary, which may develop better clinical treatments.
ObjectiveTo investigate the influencing factors of unplanned readmission in patients with chronic obstructive pulmonary disease (COPD) within 1 year, construct a risk prediction model and evaluate its effect. MethodsClinical data of 403 inpatients with COPD were continuously collected from January 2023 to May 2023, including 170 cases in the readmission group and 233 cases in the non readmission group. LASSO regression was applied to screen the optimized variables and multivariate logistic regression analyses were applied to explore the risk factors of unplanned readmission in patients with COPD within 1 year. After that a nomogram prediction model was constructed and evaluated its discrimination, calibration, and clinical applicability. ResultsThe incidence of unplanned readmission in patients with COPD within 1 year was 42.2%. Respiratory failure, number of acute exacerbation in the last year, creatinine and white blood cell count were risk factors for unplanned admission of patients with COPD within one year (P<0.05). Creatinine, white blood cell count, the number of acute exacerbation in the last year, the course of disease, concomitant respiratory failure and high uric acid were included in the nomogram model, the area under curve (AUC) and its 95% confidential interval (CI) of the nomogram model was 0.687 (0.636 - 0.739), with the sensitivity, specificity, and accuracy were 0.824, 0.742 and 0.603, respectively. The AUC of the nomogram after re-sampling 1 000 times was 0.687 (0.634 - 0.739). The calibration curve showed a high degree of three line overlap and the clinical decision curve showed that the nomogram model provided better net benefits than the treat-all tactics or the treat-none tactics with threshold probabilities of 15.0% - 55.0%. ConclusionThe nomogram model constructed based on creatinine, white blood cell count, the number of acute exacerbation in the last year, the course of disease, concomitant respiratory failure and high uric acid has good predictive value for unplanned readmission in patients with COPD within 1 year.
Objective To analyze the genetic variation characteristics of circulating tumor DNA (ctDNA) in patients with advanced lung cancer, aiming to provide valuable information for clinical decision-making. Methods In this retrospective study, a total of 468 patients with advanced-stage lung cancer were enrolled at West China Hospital, Sichuan University, from February 2017 to November 2019. Peripheral blood from each patient was collected for next generation sequencing (NGS) based on Illumina NextSeq550 platform, using a 23-gene targeted panel. Results Totally, 74.57% of patients were found to have at least one genetic alteration in plasma ctDNA, and drug-sensitive or drug-resistance information was obtained in 68.19% of patients. Frequently mutated genes included EGFR (47.01%), ROS1 (7.91%), ALK (7.69%), and HER2 (6.41%). EGFR mutation was more common in non-smokers (P<0.05), while KRAS mutation tended to occur more frequently in males (P<0.01) and smokers (P<0.01). EGFR 19DEL (28.88%), T790M (25.07%), and L858R (23.43%) were the most common types of EGFR mutations, and some rare potential drug-resistant mutations like K806R, S768I and L861Q, were also detected. Patients with brain metastasis had a relatively lower positive rate (69.23%). EGFR mutations were associated with bone metastasis (P<0.001), PIK3CA and KRAS mutations were enriched in liver metastasis (P<0.01 and P<0.001, respectively), while FGFR1 and HER2 mutations were more common in adrenal metastasis (P<0.01 and P<0.05, respectively). Third-generation EGFR tyrosine kinase inhibitor significantly increased the detection rate of FGFR1 genetic alterations in patient ctDNA when administered as second-line therapy (P<0.01). Conclusions The mutation profile and positive rate of plasma ctDNA are closely associated with smoking history, sex and metastatic sites. Comprehensive plasma ctDNA profiling using NGS technology demonstrates clinical utility by revealing therapeutically sensitive or resistant alterations in over half of the advanced-stage lung cancer patients, thereby informing personalized treatment strategies.