The setting and adjustment of ventilator parameters need to rely on a large amount of clinical data and rich experience. This paper explored the problem of difficult decision-making of ventilator parameters due to the time-varying and sudden changes of clinical patient’s state, and proposed an expert knowledge-based strategies for ventilator parameter setting and stepless adaptive adjustment based on fuzzy control rule and neural network. Based on the method and the real-time physiological state of clinical patients, we generated a mechanical ventilation decision-making solution set with continuity and smoothness, and automatically provided explicit parameter adjustment suggestions to medical personnel. This method can solve the problems of low control precision and poor dynamic quality of the ventilator’s stepwise adjustment, handle multi-input control decision problems more rationally, and improve ventilation comfort for patients.
Hot topics on the diagnosis and antimicrobial therapy of ventilator-associated pneumonia, including clinical diagnostic criteria, evaluation of biomarkers, ventilator associated events, clinical pulmonary infection score, ventilator-associated tracheobronchitis, microbiological diagnosis and duration of therapy were discussed. The viewpoints in the guidelines of America, Europe and Japan were also reviewed.
ObjectiveTo analyze the influencing factors of ventilator-associated pneumonia (VAP) in comprehensive intensive care units (ICUs) in a certain district of Shanghai, and to provide evidence for developing targeted measures to prevent and reduce the occurrence of VAP.MethodsThe target surveillance data of 1 567 inpatients with mechanical ventilation over 48 hours in comprehensive ICUs of 5 hospitals in the district from January 2015 to December 2017 were retrospectively analyzed to determine whether VAP occurred. The data were analyzed with SPSS 21.0 software to describe the occurrence of VAP in patients and to screen the influencing factors of VAP.ResultsThere were 133 cases of VAP in the 1 567 patients, with the incidence of 8.49% and the daily incidence of 6.01‰; the incidence of VAP decreased year by year from 2015 to 2017 (χ2trend=11.111, P=0.001). The mortality rate was 12.78% in VAP patients while was 7.25% in non-VAP patients; the difference was significant (χ2=5.223, P=0.022). A total of 203 pathogenic bacteria were detected in patients with VAP, mainly Gram-negative bacteria (153 strains, accounting for 75.37%). The most common pathogen was Pseudomonas aeruginosa. The single factor analysis showed that gender, age, Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ score, the length of ICU stay, and the length of mechanical ventilation were the influencing factors of VAP (χ2=9.572, 5.237, 34.759, 48.558, 44.960, P<0.05). Multiple logistic regression analysis found that women [odds ratio (OR)=1.608, 95% confidence interval (CI) (1.104, 2.340), P=0.013], APACHE Ⅱ score >15 [OR=4.704, 95%CI (2.655, 8.335), P<0.001], the length of ICU stay >14 days [OR=2.012, 95%CI (1.188, 3.407), P=0.009], and the length of mechanical ventilation >7 days [OR=2.646, 95%CI (1.439, 4.863), P=0.002] were independent risk factors of VAP.ConclusionsNosocomial infection caused by mechanical ventilation in this area has a downward trend, and the mortality rate of patients with VAP is higher. For the patients treated with mechanical ventilation in ICU, we should actively treat the primary disease, shorten the length of ICU stay and the length of mechanical ventilation, and strictly control the indication of withdrawal, thereby reduce the occurrence of VAP.
Traditional manual testing of ventilator performance is labor-intensive, time-consuming, and prone to errors in data recording, making it difficult to meet the current demands for testing efficiency in the development and manufacturing of ventilators. Therefore, in this study we designed an automated testing system for essential performance parameters of ventilators. The system mainly comprises a ventilator airflow analyzer, an automated switch module for simulated lungs, and a test control platform. Under the control of testing software, this system can perform automated tests of critical performance parameters of ventilators and generate a final test report. To validate the effectiveness of the designed system, tests were conducted on two different brands of ventilators under four different operating conditions, comparing tidal volume, oxygen concentration, and positive end expiratory pressure accuracy using both the automated testing system and traditional manual methods. Bland-Altman statistical analysis indicated good consistency between the accuracy of automated tests and manual tests for all respiratory parameters. In terms of testing efficiency, the automated testing system required approximately one-third of the time needed for manual testing. These results demonstrate that the designed automated testing system provides a novel approach and means for quality inspection and measurement calibration of ventilators, showing broad application prospects.
Objective To determine the effect of closed tracheal suction system versus open tracheal suction system on the rate of ventilator-associated pneumonia in adults. Methods We searched The Cochrane Library (Issue 1, 2007), PubMed (1966 to 2006) and CBM (1980 to 2007), and also hand searched relevant journals. Randomized controlled trials involving closed tracheal suction system versus open tracheal suction system for ventilator-associated pneumonia in adults were included. Data were extracted and the quality of trials was critical assessed by two reviewers independently. The Cochrane Collaboration’s RevMan 4.2.8 software was used for data analyses. Result Five randomized controlled trials involving 739 patients were included. Results of meta-analyses showed that compared to open tracheal suction system, closed tracheal suction system did not increase the rate of ventilator-associated pneumonia (RR 0.83, 95%CI 0.50 to 1.37) or case fatality (RR 1.05, 95%CI 0.85 to 1.31). No significant differences were observed between open tracheal suction system and closed tracheal suction system in the total number of bacteria (RR 0.83, 95%CI 0.50 to 1.37), the number of SPP colony (RR 2.87, 95%CI 0.94 to 8.74) and the number of PSE colony (RR 1.46, 95%CI 0.76 to 2.77). There was no significant difference between the two groups in the duration of ventilation and length of hospital stay. Conclusion Open or closed tracheal suction systems have similar effects on the rate of ventilator-associated pneumonia, case fatality, the number of SPP and PSE colonies, duration of ventilation and length of hospital stay. However, due to the differences in interventions and statistical power among studies included in this systematic review, further studies are needed to determine the effect of closed or open tracheal suction systems on these outcomes.
For a long time, the monitoring of ventilator-associated pneumonia (VAP) has many drawbacks, such as complex diagnostic criteria, high subjectivity, low comparability, low attributable mortality, and difficulty in automated monitoring. The U.S. Center for Disease Control and Prevention proposed a new monitoring definition of ventilator-associated event (VAE) in January 2013 to address the existing problems of VAP. VAE monitoring can better predict the adverse prognosis of patients, adopt objective diagnostic criteria, and realize automatic monitoring. However, VAE surveillance also has some shortcomings: poor identification of VAP patients, lack of sufficient evidence of preventive strategies so far, inconclusive application in neonates and children groups, as easy to be interfered with as VAP. The applicability of VAE in China, its risk factors and preventive strategies need to be further studied.
Objective To evaluate the effects of inhalation combined intravenous antibiotics for the treatment of ventilator-associated pneumonia. Methods A computerized search was performed through Cochrane library, Joanna Briggs Institute Library, PubMed, MEDLINE, CINAHL, CBM, CNKI and Wangfang medical network about inhalation combined intravenous antibiotics therapy in ventilator-associated pneumonia in the literatures. The data extracting and quality assessment were performed by three researchers. The meta-analysis was performed by RevMan 5.3 software. Results Thirteen studies was included for analysis. The results showed that the cure rate was higher in the experimental group compared with the control group with significant difference (RR=1.16, 95%CI 1.07 to 1.56,P=0.000 5). There were no significant differences in the mortality (RR=1.04, 95%CI 0.82 to 1.32,P=0.74) or the incidence of kidney damage (RR=0.79, 95%CI 0.51 to 1.22,P=0.29). The difference in pathogenic bacteria removal was statistically significant (RR=1.38, 95%CI 1.09 to 1.74,P=0.007). The negative conversion rate of respiratory secretions was higher in the experimental group. Conclusion Inhalation combined intravenous antibiotics can improve the cure rate of patients with ventilator-associated pneumonia, clear pathogenic bacteria effectively, and is worthy of recommendation for clinical use.
ObjectiveTo investigate the risk factors associated with failure of weaning from invasive mechanical ventilation in gerontal patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MethodsA retrospective study was conducted on 76 patients aged 65 years and older with AECOPD who received invasive mechanical ventilation and met the weaning criteria from July 2012 to June 2014. The subjects who passed the spontaneously breathing trial (SBT) and did not need mechanical ventilation within 48 h were enrolled into a weaning success group. The subjects who did not pass the SBT or needed mechanical ventilation again within 48 h were enrolled into a weaning failure group. The risk factors associated with failure of weaning were studied by univariate and multivariate Logistic regression analysis. ResultsThere were 53 subjects in the weaning success group and 23 in the weaning failure group. The incidences of sepsis, multiple organ dysfunction syndrome (MODS), fungal infection, hypoproteinemia, duration for mechanical ventilation > 14 d, the prevalences of aeropleura, cardiac failure, diabetes, coronary heart disease and hepatic insufficiency were higher in the weaning failure group than those in the weaning success group (P < 0.05). Logistic analysis revealed that MODS (OR=8.070), duration for mechanical ventilation > 14 d (OR=17.760), cardiac failure (OR=4.597) and diabetes (OR=13.937) were risk factors of weaning failure (P < 0.05). ConclusionMODS, duration for mechanical ventilation > 14 d, cardiac failure and diabetes were associated with the failure of weaning from invasive mechanical ventilation in gerontal patients with AECOPD.
ObjectiveTo investigate the prognostic value of high mobility group protein 1 (HMGB1) in patients with ventilator-associated pneumonia (VAP). MethodsA total 118 VAP patients admitted between March 2013 and March 2015 were recruited in the study. The patients were divided into a death group and a survival group according to 28-day death. Baseline data, HMGB1, C-reactive protein (CRP), clinical pulmonary infection score (CPIS), acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) and sepsis-related organ failure assessment (SOFA) scores were collected on 1st day (d1), 4th day (d4), and 7th day (d7) after VAP diagnosis. The possible prognostic factors were analyzed by univariate and logistic multivariate analysis. ResultsThere were 87 cases in the survival group and 31 cases in the death group. Age, female proportion, body mass index, HMGB1 (d1, d4, d7), APACHEⅡ (d1, d4, d7) and SOFA (d1, d4, d7) scores were all higher in the death group than those in the survival group (all P < 0.05). HMGB1 (d4, P=0.031), APACHEⅡ (d4, P=0.018), SOFA (d4, P=0.048), HMGB1(d7, P=0.087), APACHEⅡ(d7, P=0.073) and SOFA (d7, P=0.049) were closely correlated with 28-day mortality caused by VAP. Multivariate analysis revealed that HMGB1 (d4, HR=1.43, 95%CI 1.07 to 1.78, P=0.021), SOFA (d4, HR=1.15, 95%CI 1.06 to 1.21, P=0.019) and HMGB1 (d7, HR=1.27, 95%CI 1.18 to 1.40, P=0.003) were independent predictors of death in the VAP patients. ROC curve revealed HMGB1 (d4, d7) and SOFA (d4) with area under ROC curve of 0.951, 0.867 and 0.699. ConclusionIndividual HMGB1 level can be used as a good predictor of the short-outcomes of VAP.
ObjectiveTo systematically review the efficacy of closed and open tracheal suction system on the prevention of ventilator-associated pneumonia.MethodsThe Cochrane Library, CNKI, WanFang Data, Airiti Library, PubMed, CINAHL and Proquest databases were electronically searched to collect randomized controlled trials (RCTs) on closed and open tracheal suction system on the prevention of ventilator-associated pneumonia. Two reviewers independently screened literature, extracted data, and assessed the risk bias of included studies. Then, meta-analysis was performed by RevMan 5.3 software.ResultsA total of 11 RCTs involving 1 187 patients were included. The results of meta-analysis showed that compared with open tracheal suction system, closed tracheal suction system was associated with a reduced incidence of ventilator-associated pneumonia (RR=0.55, 95%CI 0.44 to 0.67, P<0.000 01), late-onset ventilator-associated pneumonia (RR=0.47, 95%CI 0.28 to 0.80, P=0.005), length of stay in intensive care unit (MD=?0.85, 95%CI ?1.66 to ?0.04, P=0.04) and rate of microbial colonization (RR=0.69, 95%CI 0.56 to 0.86, P=0.000 9). However, there were no significant differences between two groups in time to ventilator-associated pneumonia development (MD=0.96, 95%CI ?0.21 to 2.12, P=0.11), length of mechanical ventilation (MD=?2.24, 95%CI ?4.54 to 0.06, P=0.06), and rate of mortality (RR=0.88, 95%CI 0.73 to 1.05, P=0.15).ConclusionsCurrent evidence shows that compared with open tracheal suction system, closed tracheal suction system can reduce the incidence of ventilator-associated pneumonia and late-onset ventilator-associated pneumonia, shorten the hospital stay in intensive care unit, and reduce rate of microbial colonization. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.