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find Keyword "Positive" 27 results
  • Design and validation of an automated testing system for essential performance parameters of ventilators

    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.

    Release date:2025-02-21 03:20 Export PDF Favorites Scan
  • Effects of Positive End-Expiratory Pressure Ventilation via Different Tidal Volume on Dogs with Oleic Acid-Induced Acute Lung Injury

    Objective To investigate the effects of mechanical ventilation( MV) via different tidal volume ( VT) in combination with positive end expiratory pressure( PEEP) on dogs with acute lung injury( ALI) . Methods Dog model of oleic acid-induced ALI was established. And after that animals were randomized into different MV groups ( included low VT group, VT =6 mL/kg; and high VT group, VT =20 mL/kg) and ventilated for 6 h with a PEEP of 10 cmH2O. Arterial blood gas wasmeasured before, during and after ALI model was established ( at 1 h,2 h, 4 h and 6 h during MV) . The albumin concentration in BALF and pathological change of the lung tissue were evaluated in order to determine the lung injury while animals were sacrificed after 6 h MV. Results ALI model was successfully established ( 2. 50 ±0. 80) hours after oleic acid injection. Arterial pH decreased much severer in the low VT group than the high VT group( P lt;0. 01) . PaO2 and SaO2 in ventilation groups decreased after modeling but increased after MV, and PaO2 and SaO2 were significantly higher in the low VT group than the high VT group after 6 h MV( P lt;0. 05) . PaCO2 fluctuated less in the high VT group, while it increased significantly in the low VT group after MV( P lt; 0. 01) . Oxygenation index( PaO2 /FiO2 ) was lowered after modeling( P lt; 0. 01) , decreased to about 190 mm Hg after 1 h MV. And PaO2 /FiO2 in low VT group was significantly higher than the high VT group after 6 h MV( P lt; 0. 05) . BALF albumin concentration and the lung injury score in the low VT group were both significantly lower than the high VT group( both P lt; 0. 05) . Conclusions Ventilation with PEEP could improve the oxygenation of ALI dogs, and low VT ventilation improves the oxygenation better than high VT. Otherwise, low VT could induce hypercapnia and ameliorate lung injury caused by high VT MV.

    Release date:2016-09-14 11:22 Export PDF Favorites Scan
  • Analysis on the formation of antibodies to COVID-19 inactivated vaccine for critical care workers in Sichuan Province

    ObjectiveTo investigate the antibody concentration and immune status of intensive care medical staff after vaccination against COVID-19. Methods From October 1, 2021 to February 28, 2022, the serial numbers of 47 hospitals were randomly selected by cluster stratified random sampling method. Blood samples were collected from 192 medical staff in intensive care department who had received inactivated novel coronavirus vaccine in 7 hospitals. The antibody concentration was determined by chemiluminescence method to find the antibody rule. Logistic regression analysis was used to determine the related factors affecting the production of antibodies. ResultsTotal antibody concentration of 192 blood samples was 23.25 (5.09, 270.22), IgG concentration was 0.94 (0.15, 4.48), IgM concentration was 0.05 (0.03, 0.12). Logistic regression analysis showed that the total antibody concentration might be related to gender and age, and the IgG concentration was significantly related to whether the third injection was administered. One hundred and twenty-seven people received 2 doses of inactivated vaccine, and the positive rate of IgG was the highest within 1 to 2 months, and decreased significantly after 3 months. The positive rate of IgG antibody was 95.4% within 60 days after receiving 3 doses of vaccine, 70% within 1 month after receiving the third dose of vaccine, and 100.0% within 1 to 2 months (P<0.05). The total antibody positive rate was 96.3% in people aged 17 to 35 years and 73.3% in people aged 36 to 58 years, showing statistical difference (P<0.05). The total antibody production rate of those who received the third dose of vaccine was 100.0%, and no severe case of COVID-19 occurred during the sampling period. Conclusions After the first, second, and third doses of COVID-19 vaccine, the total antibody concentration of the virus gradually increases to 100.0%, indicating initial immunity. However, the antibody concentration decreased gradually after 3 months of inoculation. The concentration of IgG in women is higher than that in men, and the concentration of antibody in young people is higher than that in middle-aged and elderly people during the same period.

    Release date:2023-08-16 02:13 Export PDF Favorites Scan
  • Evaluation of the Effect of Positive Implication in the Operating Room

    ObjectiveTo explore the effect of positive implication in the operating room on the patient's mental. MethodsA total of 160 patients who received the routine laparoscopic appendectomy surgery from January 2011 to October 2012 were treated with positive implications and conventional appease routine psychological care and the fear, pain, depression and anxiety, and other indicators of the two groups were compared. ResultsThe fear scores in the control group patients were significantly higher than that in the observation group (P<0.05). The patient's perceived pain in the control group was higher than that in the observation group (P<0.05); after nursing intervention, the anxiety and depression levels in the two groups decreased significantly; the observation group had significantly higher satisfaction for the entire course of medical treatment (P<0.05). ConclusionThe positive implication in the operating room can effectively alleviate the patient's fear, anxiety, depression and perceived pain and so on and can contribute to the effect of operation and rehabilitation of the patients.

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  • Effect of positive lymph node ratio on prognosis of patients with non-small cell lung cancer

    Objctive To explore the effect of positive lymph nodes ratio (LNR) on prognosis of patients with non-small cell lung cancer (NSCLC). Methods Clinical data of 432 NSCLC patients undergoing radical surgery for lung cancer and systemic lymph node dissection in our hospital from January 2010-2013 were retrospectively analyzed. There were 316 males and 116 females with age of 39-84 (57.59±9.16) years. Among 432 patients, 229 (53.0%) were classified as N0 based on pathological staging of lymph nodes, 104 (24.1%) as N1 and 99 (22.9%) as N2. Kaplan-Meier curve and COX multi-factor regression model were used to evaluate the correlation between the clinical data and patients' survival. Results Five lymph nodes on average (range, 1-52) were removed in each patient. Kaplan-Meier survival curves showed that the higher the staging of positive lymph nodes was, the shorter the patients' overall survival and disease-free survival were (P<0.001). Survival analysis showed that the LNR was closely associated with disease-free survival and overall survival (P<0.001). COX multivariate analysis revealed that the LNR staging was an independent risk factor of prognosis of NSCLC. Conclusion LNR is an independent prognostic factor of NSCLC, and can be used to improve lymph node staging in standards for NSCLC staging in the future.

    Release date:2017-01-22 10:15 Export PDF Favorites Scan
  • Impact of Positive End-expiratory Pressure on Respiratory Mechanics and Hemodynamics in Concomitant Acute Lung Injury and Intra-abdominal Hypertension

    ObjectiveTo evaluate the effect of positive end-expiratory pressure (PEEP) on respiratory function and hemodynamics in acute lung injury (ALI) with intra-abdominal hypertension (IAH). MethodsSix pigs were anesthetized and received mechanical ventilation (MV). Volume controlled ventilation was set with tidal volumn(VT) of 8 mL/kg,respiratory rate(RR) of 16 bpm,inspired oxygen concentration (FiO2) of 0.40,and PEEP of 5 cm H2O. ALI was induced by repeated lung lavage with diluted hydrochloric acid (pH<2.5) until PaO2/FiO2 declined to 150 mm Hg or less to established ALI model. Intra-abdominal hypertension was induced by an nitrogen inflator to reach intra-abdominal pressure of 20 mm Hg. Respiratory parameters and hemodynamics were continuously recorded at different PEEP levels(5,10,15,and 20 cm H2O). Every level was maintained for one hour. ResultsPaO2/FiO2 in PEEP5,10,15 and 20 were 90±11,102±10,172±23 and 200±34 mm Hg respectively. PaO2/FiO2 in PEEP15 and 20 were significantly higher than those in PEEP5 and 10 (P<0.05). Chest wall compliance (Ccw) in PEEP5,15 and 20 were 26±3,76±15 and 85±14 mL/cm H2O respectively. Ccw in PEEP15 and 20 were significantly higher than those in PEEP5 (P<0.05). There was no significant difference in lung compliance (CL) in different PEEP levels (P>0.05). Plateau pressure(Pplat) in PEEP5,10,15 and 20 were 30±3,31±2,36±2 and 38±4 cm H2O respectively. Pplat in PEEP15 and 20 were significantly higher than those in PEEP5 and 10 (P<0.05). There was no significant difference in Pplat between PEEP15 and 20 (P>0.05). Heart rate (HR) in PEEP5,15 and 20 were 113±17,147±30,and 160±30 beat/min respectively. HR in PEEP15 and 20 were significantly higher than those in PEEP5 (P<0.05). There was no significant difference in HR between PEEP15 and 20 (P>0.05).Cardiac index (CI) in PEEP5 and 20 were 4.5±0.6 and 3.5±0.6 L·min-1·m-2 respectively. CI in PEEP20 was significantly lower than that in PEEP5 (P<0.05). There was no significant difference in CI in PEEP5,10 or 15(P>0.05). Central venous pressure(CVP) in PEEP5,15 and 20 were 12±2,17±2,and 18±3 mm Hg respectively. CVP in PEEP15 and 20 were significantly higher than those in PEEP5 (P<0.05). There was no significant difference in CVP between PEEP15 and 20 (P>0.05). There were no significant differences in MAP,SVRI,ITBVI,GEDI,PVPI,or EVLWI between different PEEP levels. ConclusionConcomitant ALI and IAH can induce great impairments in respiratory physiology. When PEEP is gradually increased,oxygenation and the respiratory function are improved without significant secondary hemodynamic disturbances.

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  • Use of Reactance to Assess Airway Obstruction in Severe COPD Patients and Effect of Noninvasive ventilation

    Objective To assess the effect of continuous positive airway pressure ( CPAP) on expiratory flow limitation in severe chronic obstructive pulmonary disease ( COPD) patients during noninvasive ventilation by oscillatory reactance ( Xrs ) . Methods Eight patients with stable COPD and chronic hypercapnic respiratory failure( type II) received noninvasive ventilation with a traditional CPAP ventilator through a nasal mask were enrolled. The CPAP were successively set as 4, 8 and 12 cm H2O respectively. The forecd oscillation( 5 Hz, 2 cm H2O) was imposed into the mask and the flow and nasal pressure were measured at the airway opening. The difference between inspiratory and expiratory Xrs( ΔXrs)were calculated for each breathing cycle and average ΔXrs was calculated at different pressure levels according to the established algorithm. Meanwhile, the oesophageal pressure was also measured by a balloontipped catheter and transpulmonary pressure was calculated. The breathing cycles above were analyzed subsequently and classified as expiratory flow-limited( EFL) and non-EFL breath. In addition, flow and nasal pressure when breathing naturally( CPAP = 0 cmH2O) was also collected for each patient and the EFL breath cycles was identified as baseline. Then, the percentage of EFL breathing cycles and ΔXrs were calculated for each CPAP level and their relationship was analyzed. The threshold value of ΔXrs with maximum sensitivity and specificity to detect EFL and the optimal CPAP to suppress the development of EFL were computed. Results ①CPAP increased from4 to 8 and 12 cm H2O resulted in fall of mean values of ΔXrs from2. 67 to 1. 62 and 1. 31 cm H2O· s- 1 · L- 1 , respectively( ΔXrs at CPAP 0 cm H2O was not detected) , and the decrease of ΔXrs when CPAP up to 8 cm H2O from 4 cm H2 O was significant ( Z = - 2. 68, P = 0. 01) . ②CPAP significantly suppressed the development of EFL, when CPAP increased from0 cm H2O to 4,8 and12 cmH2O resulted in decrease in the percentage of breathing cycle from 29. 8% to 9. 9% , 8. 1% and 4. 4%, respectively(  2 = 15. 6, P = 0. 01) . ③ ΔXrs was related to the degree of EFL and the mean value of ΔXrs in EFL breathing cycles was significantly higher than that in non-EFL’s. When ΔXrs decreased to 1. 83 cm H2O· s- 1 · L- 1, the majority of breath showed non-EFL, with a sensitivity of 94% and specificity of 97% for detecting EFL, respectively. Conclusions ΔXrs is an indicator of the occurrence of EFL. Appropriate CPAP to render the value of ΔXrs equal to or slightly less than 1. 83 cm H2O·s - 1 ·L- 1 may effectively suppress the development of EFL in severe COPD patients during noninvasive ventilation.

    Release date:2016-09-14 11:23 Export PDF Favorites Scan
  • Application of Positive End-expiratory Pressure in Patients with Acute Respiratory Distress Syndrome Complicated with Intra-abdominal Hypertension

    ObjectiveTo investigate different levels of positive end-expiratory pressure (PEEP) on respiratory function and hemodynamics in patients with acute respiratory distress syndrome (ARDS) complicated with intra-abdominal hypertension(IAH). MethodsThirty patients with moderate ARDS admitted in ICU between January 2012 and December 2014 were recruited in the study. They were divided into three groups according to intra-abdominal pressure (IAP),including 10 patients with normal abdominal pressure as a normal IAP group,10 patients with IAP of 12-15 mm Hg as an IAPⅠ group,and 10 patients with IAP of 16-20 mm Hg as an IAPⅡ group. The optimal level of PEEP was titrated according to the best oxygenation methods. The changes of oxygenation index (OI),respiratory mechanics and hemodynamics before and after the optimal level of PEEP were monitored and compared in all groups. The 28-day mortality and ICU stay were also compared. ResultsThe OI after titration was significantly improved compared to baseline in all groups (all P<0.01). The OI after titration in the IAPⅡ group was significantly higher than that in other two groups (all P<0.05). The static lung compliance (Cst) after titration significantly improved than baseline in all groups(all P<0.05),but no significant difference was revealed among three groups (all P>0.05). In the IAPⅡ group,the levels of PEEP,IAP,blood lactate,heart rate and airway plateau pressure after titration were significantly increased than baseline but higher than those in other two groups(all P<0.05),while the level of mean arterial pressure was significantly decreased and significantly lower than those in other two groups(all P<0.01). Meanwhile,the ICU stay was longest in the IAPⅡ group (P<0.01). There was no significant difference in 28-day mortality among three groups(all P>0.05). ConclusionsPEEP can significantly improve oxygenation in patients with ARDS complicated with IAH. The higher the IAP is,the higher the PEEP level is required. However the higher PEEP will significantly increase IAP which will cause adverse impacts on hemodynamics and can not improve the prognosis.

    Release date:2016-10-02 04:55 Export PDF Favorites Scan
  • The effect of family positive behavioral support on emotional and behavioral problems in preschool children with epilepsy

    ObjectiveTo investigate the effect of positive family behavior support on emotional and behavioral problems in preschool children with epilepsy. Methods A total of 80 preschool epileptic children and their parents who were admitted to the Department of Neurology of our hospital from October 2022 to February 2023 were selected as the research objects, and were divided into experimental group and control group with 40 cases each by random number table method. The control group received neurology routine nursing, and the experimental group received positive family behavior support intervention based on the control group. The scores of family intimacy and adaptability scale, strengths and difficulties questionnaire, medication compliance and quality of life of epilepsy children were compared before and after intervention between the two groups. ResultsAfter intervention, the scores of strength and difficulty questionnaire in experimental group were lower than those in control group (P<0.05), and the scores of family intimacy and adaptability scale, quality of life and medication compliance in experimental group were higher than those in control group (all P<0.05). ConclusionThe application of positive family behavior support program can reduce the occurrence of emotional behavior problems, improve family closeness and adaptability, improve medication compliance, and improve the quality of life of preschool children with epilepsy.

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  • Level of blood pressure and hypertension prevalence and influencing factors in middle-aged population with positive family history of hypertension

    ObjectiveTo investigate the blood pressure level and prevalence of hypertension in middle-aged people with positive family history of hypertension in Chengdu area, compare the differences between middle-aged people with positive family history of hypertension and middle-aged people with negative family history of hypertension, and explore the influencing factors of hypertension in middle-aged people with positive family history of hypertension.MethodsFrom September 2013 to March 2014, the stratified sampling method was used to survey 3 096 middle-aged people aged 40-59 years in Chengdu. Their height, weight, blood pressure, blood glucose, and blood lipids were measured. Questionnaire surveys were conducted using a uniformly designed questionnaire. The blood pressure levels and hypertension prevalences were compared between people with and without positive family history of hypertension. The influencing factors of hypertension in middle-aged people with positive family history of hypertension were analyzed using multiple logistic regression.ResultsThere were significant differences between the middle-aged people with positive family history of hypertension and the ones with negative family history of hypertension in systolic blood pressure [(137.4±22.4) vs. (118.0±11.3) mm Hg (1 mm Hg=0.133 kPa), P<0.001], diastolic blood pressure [(84.1±12.2) vs. (73.9±7.7) mm Hg, P<0.001], and prevalence of hypertension (28.6% vs. 22.2%, P<0.001). Ageing [odds ratio (OR)=1.107, 95% confidence interval (CI) (1.071, 1.144), P<0.001], monthly personal income ≥3 000 yuan [OR=1.566, 95%CI (1.003, 2.445), P=0.048], and abdominal obesity [OR=1.658, 95%CI (1.091, 2.520), P=0.018] were the risk factors for hypertension in middle-aged males with positive family history. Ageing [OR=2.257, 95%CI (1.202, 4.025), P=0.026] and overweight or obesity [OR=2.365, 95%CI (1.653, 3.385), P<0.001] were the risk factors, and physical exercise [OR=0.529, 95%CI (0.304, 0.918), P=0.024] was the protective factor for hypertension in middle-aged females with positive family history.ConclusionsThe prevalence of hypertension is high in middle-aged population with positive family history of hypertension in Chengdu and is significantly higher than that in the ones with negative family history of hypertension. Strengthening health education on hypertension-related knowledge, and reasonably controlling waist circumference and body weight may have positive significance in preventing or delaying the occurrence of hypertension in people with positive family history of hypertension.

    Release date:2019-09-06 03:51 Export PDF Favorites Scan
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