Objective To systematically evaluate the efficacy of home noninvasive positive pressure ventilation (HNPPV) on patients with severe stable chronic obstructive pulmonary disease in China. Methods Systematic literature search was performed in Chinese BioMedical Literature Database, WanFang Data, VIP Database, Chinese National knowledge Infrastructure databases from inception to January 2018. All randomized controlled trials (RCTs) that reported comparison of the efficacy of HNPPV on patients with severe stable chronic obstructive pulmonary disease were included. All related data were extracted. Meta-analysis was conducted using the statistical software RevMan 5.3 on the basis of strict quality evaluation. Results A total of 767 patients from 14 studies were included in this meta-analysis. The combined results showed that, compared with the control group, HNPPV could significantly reduce the mortality (relative risk 0.51, 95%CI 0.33 – 0.78, P=0.002) and PaCO2 ［weighted mean difference (MD) –10.78, 95%CI –13.17 – –8.39, P<0.000 01］ of patients, improve the levels of PaO2 (MD 7.84, 95%CI 5.81 – 9.87, P<0.000 01), FEV1 (MD 0.13, 95%CI 0.08 – 0.18, P<0.000 01), and the quality of life (MD –6.27, 95% CI –9.04 – –3.51, P<0.000 01). Conclusion HNPPV can reduce the mortality of patients, improve the gas exchange, pulmonary function and the quality of life, but more large sample, high-quality, and multicenter RCT studies are needed.
Objective To analyze the risk factors of treatment failure by noninvasive positive pressure ventilation (NPPV) in patients with acute respiratory failure (ARF) due to acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and explore the best time that NPPV be replaced by invasive ventilation when NPPV failure occurs. Methods The data of patients with ARF due to AECOPD who were treated with NPPV from January 2013 to December 2015 were retrospectively collected. The patients were divided into two groups: the NPPV success group and the NPPV failure group (individuals who required endotracheal intubation or tracheotomy at any time). The Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ score was analyzed; the Glasgow Coma Scale score, respiratory rate (RR), pH value, partial pressure of oxygen (PaO2), PaO2/fraction of inspired oxygen (FiO2) ratio, and partial pressure of carbon dioxide were also analyzed at admission, after 2 hours of NPPV, and after 24 hours of NPPV. Results A total of 185 patients with ARF due to AECOPD were included. NPPV failed in 35.1% of the patients (65/185). Multivariate analysis identified the following factors to be independently associated with NPPV failure: APACHEⅡscore≥30 [odds ratio (OR)=20.603, 95% confidence interval (CI) (5.309, 80.525), P<0.001], RR at admission≥35 per minute [OR=3.723, 95%CI (1.197, 11.037), P=0.020], pH value after 2 hours of NPPV<7.25 [OR=2.517, 95%CI (0.905, 7.028), P=0.070], PaO2 after 2 hours of NPPV<60 mm Hg (1 mm Hg=0.133 kPa) [OR=3.915, 95%CI (1.374, 11.508), P=0.010], and PaO2/FiO2 after 2 hours of NPPV<200 mm Hg [OR=4.024, 95%CI (1.542, 11.004), P=0.010]. Conclusion When patients with ARF due to AECOPD have a higher severity score, have a rapid RR at admission, or fail to improve in terms of pH and oxygenation after 2 hours of NPPV, the risk of NPPV failure is higher.
Objective To explore the effects of enteral tube feeding on moderate AECOPD patients who underwent noninvasive positive pressure ventilation ( NPPV) . Methods Sixty moderate AECOPD patients with NPPV admitted from January 2009 to April 2011 were recruited for the study. They were randomly divided into an enteral tube feeding group (n=30) received enteral tube feeding therapy, and an oral feeding group (n=30) received oral feeding therapy. Everyday nutrition intake and accumulative total nutrition intake in 7 days, plasma level of prealbumin and transferrin, success rate of weaning, duration of mechanical ventilation, length of ICU stay, rate of trachea cannula, and mortality rate in 28 days were compared between the two groups. Results Compared with the oral feeding group, the everyday nutrition intake and accumulative total nutrition intake in 7 days obviously increased (Plt;0.05) , while the plasma prealbumin [ ( 258.4 ±16.5) mg/L vs. (146.7±21.6) mg/L] and transferrin [ ( 2.8 ±0.6) g/L vs. ( 1.7 ±0.3) g/L] also increased significantly after 7 days in the enteral tube feeding group( Plt;0.05) . The success rate of weaning ( 83.3% vs. 70.0%) , the duration of mechanical ventilation [ 5. 6( 3. 2-8. 6) days vs. 8. 4( 4. 1-12. 3) days] , the length of ICU stay [ 9. 2( 7. 4-11. 8) days vs. 13. 6( 8.3-17. 2) days] , the rate of trachea cannula ( 16. 6% vs. 30. 0% ) , the mortality rate in 28 days ( 3. 3% vs. 10. 0% ) all had significant differences between the enteral tube feeding group and the oral feeding group. Conclusions For moderate AECOPD patients with NPPV, enteral tube feeding can obviously improve the condition of nutrition and increase the success rate of weaning, shorten the mechanical ventilation time and the mean stay in ICU, decrease the rate of trachea cannula and mortality rate in 28 days. Thus enteral tube feeding should be preferred for moderate AECOPD patients with NPPV.
Objective To determine the efficacy and prognosis of noninvasive positive pressure ventilation (NPPV) in exacerbations of chronic obstructive pulmonary disease (COPD). Methods Trials were located through electronic searches of MEDLINE, EMBASE, Springer, and Foreign Journals Integration System (from the start date to March 2008). We also checked the bibliographies of retrieved articles. Statistical analysis was performed with The Cochrane Collaboration’s software RevMan 4.2.10. Results A total of 19 trials involving 1 236 patients were included. Results showed that: (1) NPPV vs. conventional therapy: NPPV was superior to conventional therapy in terms of intubation rate (RR 0.36, 95%CI 0.27 to 0.49), failure rate (RR 0.62, 95%CI 0.43 to 0.90), and mortality (RR 0.49, 95%CI 0.34 to 0.69). The length of hospital stay was shorter in the NPPV group compared with the conventional group (WMD – 3.83, 95%CI – 5.78 to – 1.89), but the length of ICU stay was similar. The changes of PaO2, PaCO2, and pH were much more obvious in the NPPV group compared with the conventional group. The change of respiratory rate was more significant in the NPPV group compared with the conventional group (WMD – 3.75, 95%CI – 5.48 to – 2.03). At discharge and follow-up, there were no significant differences in FEV1, pH, PaCO2, PaO2, and vital capacity between the two groups. (2) NPPV vs. invasive ventilation: the mortality was similar between the two groups. The incidence of complications was lower in the NPPV group compared with the invasive group (RR 0.38, 95%CI 0.20 to 0.73). The length of ICU stay, duration of mechanical ventilation, and weaning time were shorter in the NPPV group than those of the invasive group. At discharge and follow-up, clinical conditions were similar between the two groups. Conclusion The limited current evidence showed that NPPV was superior to conventional therapy in improving intubation rate, mortality, short term of blood-gas change, the change of respiratory rate; and superior to invasive ventilation in the length of hospital stay and the incidence of complication. There were no difference among them in discharge and follow-up.
ObjectiveTo investigate whether noninvasive positive pressure ventilation (NIV) will improve preoxygenation in critically ill patients in intensive care unit (ICU) before intubation, when compared with bag-valve-mask (BVM).MethodsThis was a single-centered, prospective and randomized study. The patients in the study were those who required tracheal intubation in the ICU of the First Affiliated Hospital of Guangzhou Medical University and Guangzhou Institute of Respiratory Health from June 2015 to June 2017. These critically ill patients were provided with BVM or NIV assisted preoxygenation randomly. The data of the NIV group and the control group were compared and the application values of NIV in preoxygenation of critically ill patients were evaluated.ResultsA total of 106 patients participated in this study, including 75 males and 31 females and with an average age of (65.0±12.6) years. The patients were classified either into the control group (BVM assisted preoxygenation, n=53), or the NIV group (NIV assisted pre-oxygenation, n=53). The causes of intubation in the control group and the NIV group were as follows: pneumonia [40 patients (75.5%) vs. 39 patients (73.6%)], chronic obstructive pulmonary disease [12 patients (22.6%) vs. 11 patients (20.8%)], and other disease [1 patient (1.9%) vs. 3 patients (5.7%)], which showed no significant difference between the two groups. The scores of the Acute Physiology and Chronic Health Evaluation System Ⅱ of the control group and the NIV group were 20 (17, 26) vs. 20 (16, 26), P=0.86, which also showed no significant difference. The oxygen saturation of the pulse (SpO2) before preoxygenation were similar in both the control group and the NIV group 92% (85%, 98%) vs. 91% (85%, 98%), P=0.87. After preoxygenation, SpO2 was significantly higher in the NIV group than in the control group 99% (96%, 100%) vs. 96% (90%, 99%), P=0.001. For the subgroup of patients with SpO2 less than 90% before preoxygenation, the respective SpO2 in the control group and the NIV group were 83% (73%, 85%) vs. 81% (75%, 86%), P=0.75; after preoxygenation, SpO2 in the NIV group was significantly higher than in the control group 99% (96%, 100%) vs. 94%(90%, 99%), P=0.000. For the subgroup of patients with SpO2 of 90% or more before preoxygenation, the respective SpO2 in the control group and the NIV group were similar 95.5% (92%, 99%) vs. 96% (94%, 99%), P=0.52; and continued to be similar after preoxygenation 98% (95%, 100%) vs. 99% (96%, 100%), P=0.1. The duration of mechanical ventilation of the control group and the NIV group was 17 (10, 23)d vs. 19 (11, 26)d (P=0.86). The 28 days survival rate of the control group and the NIV group was 73.6% vs. 71.7% (P=0.34). The mortality rate in the control group and NIV group were 31.3% and 31.7% (P=0.66).ConclusionsWhen compared with the use of BVM, NIV assisted preoxygenation is effective and safe for critically ill patients. Critically ill patients with severe hypoxemia will benefit more from NIV assisted preoxygenation.
Objective To evaluate the effect of auto adjusted triggering mechanism on the triggering balance of sensitivity and anti-interference in non invasive ventilator field. Methods Taking the breathing simulator as the experimental platform, for the same ventilator, the experiments of "automatic adjustment mode" and "manual adjustment mode" were carried out in a self-control manner, comparing the sensitivity and anti-interference indexes of the experimental group and the control group in the triggering stage. The results were statistically analyzed. Results In case of large air leakage, for ventilator of "A40", the group of "automatic adjustment mode" presented auto-triggered cycle and the group of "manual adjustment mode" (the inspiratory trigger sensitivity was adjusted to 5 to 9 L/min) could provide breathing assistance ventilation. While for ventilator of "VENT", both the group of "automatic adjustment mode" and the group of "manual adjustment mode" (the inspiratory trigger sensitivity was adjusted to 1 to 8 arbitrary unit) appear auto-triggered cycle. In case of medium air leakage, for ventilator of "A40", the trigger delay time, trigger pressure and trigger work of the "manual adjustment mode" group (the inspiratory trigger sensitivity was adjusted to 3 to 5 L/min) were significantly less than those of the "automatic adjustment mode" group, and the trigger delay time, trigger work of the "manual adjustment mode" group (the inspiratory trigger sensitivity was adjusted to 8 to 9 L/min) were significantly higher than those of the "automatic adjustment mode" group; While for ventilator of "VENT", compared with the inspiratory trigger sensitivity of the "automatic adjustment mode" group and the "manual adjustment mode" group (the inspiratory trigger sensitivity was adjusted to 4 arbitrary unit), the trigger delay time, trigger pressure and trigger work were not statistically significant. In case of small air leakage, for ventilator of "A40", the trigger delay time and trigger work of the "manual adjustment mode" group (the inspiratory trigger sensitivity was adjusted to 2 to 6 L/min) were significantly less than those in the "automatic adjustment mode" group, and the trigger pressure of "manual adjustment mode" group (the inspiratory trigger sensitivity was adjusted to 2 to 5 L/min and 7 L/min) was significantly lower than that of "automatic adjustment mode" group. While for ventilator of "VENT", the trigger delay time, trigger pressure and trigger work of the "manual adjustment" group (the inspiratory trigger sensitivity was adjusted to 1 to 2 arbitrary unit) were less than those of the experimental group, and they were statistically significant. Conclusions In case of large air leakage, ventilator of "VENT" can not provide breathing assistance ventilation no matter which inspiratory trigger mode. While ventilator of "A40" should be used the "manual adjustment mode", and adjust the inspiratory trigger sensitivity to the less sensitive arbitrary unit to increase its performance of anti-interference. In case of medium air leakage, for both ventilator of "A40" and ventilator of "VENT", it is better to use "automatic adjustment" mode for breathing assistance ventilation. In case of small air leakage, for both ventilator of "A40" and ventilator of "VENT", it is better to use "manual adjustment" mode for breathing assistance ventilation and we should adjust the inspiratory trigger sensitivity to the higher sensitive arbitrary without auto-triggered cycle.
This paper aims to propose a noninvasive radiotherapy patient positioning system based on structured light surface imaging, and evaluate its clinical feasibility. First, structured light sensors were used to obtain the panoramic point clouds during radiotherapy positioning in real time. The fusion of different point clouds and coordinate transformation were realized based on optical calibration and pose estimation, and the body surface was segmented referring to the preset region of interest (ROI). Then, the global-local registration of cross-source point cloud was achieved based on algorithms such as random sample consensus (RANSAC) and iterative closest point (ICP), to calculate 6 degrees of freedom (DoF) positioning deviation and provide guidance for the correction of couch shifts. The evaluation of the system was carried out based on a rigid adult phantom and volunteers’ body, which included positioning error, correlation analysis, and receiver operating characteristic (ROC) analysis. Using Cone Beam CT (CBCT) as the gold standard, the maximum translation and rotation errors of this system were (1.5 ± 0.9) mm along Vrt direction (chest) and (0.7 ± 0.3) ° along Pitch direction (head and neck). The Pearson correlation coefficient between results of system outputs and CBCT verification distributed in an interval of [0.80, 0.84]. Results of ROC analysis showed that the translational and rotational AUC values were 0.82 and 0.85, respectively. In the 4D freedom accuracy test on the human body of volunteers, the maximum translation and rotation errors were (2.6 ± 1.1) mm (Vrt direction, chest and abdomen) and (0.8 ± 0.4)° (Rtn direction, chest and abdomen) respectively. In summary, the positioning system based on structured light body surface imaging proposed in this article can ensure positioning accuracy without surface markers and additional doses, and is feasible for clinical application.
ObjectiveTo investigate the application value of noninvasive ventilation (NIV) performed in patients with unplanned extubation (UE) in intensive care unit (ICU).MethodsThis was a retrospective analysis. The clinical data, application of NIV, reintubation rate and prognosis of UE patients in the ICU of this hospital from January 2014 to December 2018 were reviewed, and the patients were assigned to the control group or the NIV group according to the application of NIV after UE. The data between the two groups were compared and the application effects of NIV in UE patients were evaluated.ResultsA total of 66 UE patients were enrolled in this study, including 44 males and 22 females and with an average age of (64.2±16.1) years. Out of them, 41 patients (62.1%) used nasal catheter or mask for oxygenation as the control group, 25 patients (37.9%) used NIV as the NIV group. The Acute Physiology andChronic Health EvaluationⅡ score of the control group and the NIV group were (18.6±7.7) vs. (14.8±6.3), P=0.043. The causes of respiratory failure in the control group and the NIV group were as follows: pneumonia 16 patients (39.0%) vs. 7 patients (28.0%), postoperative respiratory failure 7 patients (17.1%) vs. 8 patients (32.0%), chronic obstructive pulmonary disease 8 patients (19.5%) vs. 6 patients (24.0%), others 5 patients (12.2%) vs. 4 patients (16.0%), heart failure 3 patients (7.3%) vs. 0 patients (0%), nervous system diseases 2 (4.9%) vs. 0 patients (0%), which showed no significant difference between the two groups. Mechanical ventilation time before UE were (12.5±19.8) vs (12.7±15.2) d (P=0.966), PaO2 of the control group and the NIV group before UE was (114.9±37.4) vs. (114.4±46.3)mm Hg (P=0.964), and oxygenation index was (267.1±82.0) vs. (257.4±80.0)mm Hg (P=0.614). Reintubation rate was 65.9% in the control group and 24.0% in the NIV group (P=0.001). The duration of mechanical ventilation was (23.9±26.0) vs. (21.8±26.0)d (P=0.754), the length of stay in ICU was (34.4±36.6) vs. (28.5±25.8)d (P=0.48). The total mortality rate in this study was 19.7%. The mortality rate in the control group and NIV group were 22.0% and 16.0% (P=0.555).ConclusionPatients with UE in ICU may consider using NIV to avoid reintubation.
Without artificial airway though oral, nasal or airway incision, the bi-level positive airway pressure (Bi-PAP) has been widely employed for respiratory patients. In an effort to investigate the therapeutic effects and measures for the respiratory patients under the noninvasive Bi-PAP ventilation, a therapy system model was designed for virtual ventilation experiments. In this system model, it includes a sub-model of noninvasive Bi-PAP respirator, a sub-model of respiratory patient, and a sub-model of the breath circuit and mask. And based on the Matlab Simulink, a simulation platform for the noninvasive Bi-PAP therapy system was developed to conduct the virtual experiments in simulated respiratory patient with no spontaneous breathing (NSB), chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). The simulated outputs such as the respiratory flows, pressures, volumes, etc, were collected and compared to the outputs which were obtained in the physical experiments with the active servo lung. By statistically analyzed with SPSS, the results demonstrated that there was no significant difference (P > 0.1) and was in high similarity (R > 0.7) between the data collected in simulations and physical experiments. The therapy system model of noninvasive Bi-PAP is probably applied for simulating the practical clinical experiment, and maybe conveniently applied to study the technology of noninvasive Bi-PAP for clinicians.
ObjectiveTo investigate the feasibility of electroencephalography (EEG) power spectrum analysis monitoring noninvasive intracranial pressure (ICP). MethodsBetween September 2008 and May 2009, the EEG signals were recorded in 62 patients (70 cases/times) with central nervous system (CNS). By using self-designed software, EEG power spectrum analysis was conducted and pressure index (PI) was calculated automatically. ICP was measured by lumbar puncture (LP). ResultsThe mean ICP was (239.74±116.25) mm H2O (70-500 mm H2O, 1 mm H2O=0.009 8 kPa), and 52.9% of patients had increased ICP. The mean PI was 0.29±0.20 (0.02-0.85). The Spearman rank test showed that there was a significant negative correlation between PI and ICP (rs=-0.849, P<0.01). The data from the patients with diffuse lesions of CNS and focal lesions were analyzed separately; the results showed there were significant negative correlations between PI and ICP in both groups (rs=-0.815, -0.912; P<0.01). ConclusionThe PI obtained from EEG analysis is correlated with ICP. Analysis of specific parameters from EEG power spectrum might reflect the ICP. Further research should be carried out.