Simulation of the human biological lung is a crucial method for medical professionals to learn and practice the use of new pulmonary interventional diagnostic and therapeutic devices. The study on ventilation effects of the simulation under positive pressure ventilation mode provide valuable guidance for clinical ventilation treatment. This study focused on establishing an electrical simulation ventilation model, which aims to address the complexities in parameter configuration and slow display of air pressure and airflow waveforms in simulating the human biological lung under positive pressure ventilation mode. A simulated ventilation experiment was conducted under pressure-regulated volume control (PRVC) positive pressure ventilation mode, and the resulting ventilation waveform was compared with that of normal adults. The experimental findings indicated that the average error of the main reference index moisture value was 9.8% under PRVC positive pressure ventilation mode, effectively simulating the ventilatory effect observed in normal adults. So the established electrical simulation ventilation model is feasible, and provides a foundation for further research on the simulation of human biological lung positive pressure ventilation experimental platform.
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.
Monitoring airway impedance has significant clinical value in accurately assessing and diagnosing pulmonary function diseases at an early stage. To address the issue of large oscillator size and high power consumption in current pulmonary function devices, this study adopts a new strategy of expiration-driven oscillation. A lightweight and low-power airway impedance monitoring system with integrated sensing, control circuitry, and dynamic feedback system, providing visual feedback on the system’s status, was developed. The respiratory impedance measurement experiments and statistical comparisons indicated that the system could achieve stable measurement of airway impedance at 5 Hz. The frequency spectrum curves of respiratory impedance (R and X) showed consistent trends with those obtained from the clinical pulmonary function instrument, specifically the impulse oscillometry system (IOS). The differences between them were all less than 1.1 cm H2O·s/L. Additionally, there was a significant statistical difference in the respiratory impedance R5 between the exercise and rest groups, which suggests that the system can measure the variability of airway resistance parameters during exercise. Therefore, the impedance monitoring system developed in this study supports subjects in performing handheld, continuous measurements of dynamic changes in airway impedance over an extended period of time. This research provides a foundation for further developing low-power, portable, and even wearable devices for dynamic monitoring of pulmonary function.
ObjectiveTo evaluate the effect of driving pressure-guided lung protective ventilation strategy on lung function in adult patients under elective cardiac surgery with cardiopulmonary bypass.MethodsIn this randomized controlled trial, 106 patients scheduled for elective valve surgery via median sternal incision under cardiopulmonary bypass from July to October 2020 at West China Hospital of Sichuan University were included in final analysis. Patients were divided into two groups randomly. Both groups received volume-controlled ventilation. A protective ventilation group (a control group, n=53) underwent traditional lung protective ventilation strategy with positive end-expiratory pressure (PEEP) of 5 cm H2O and received conventional protective ventilation with tidal volume of 7 mL/kg of predicted body weight and PEEP of 5 cm H2O, and recruitment maneuver. An individualized PEEP group (a driving pressure group, n=53) received the same tidal volume and recruitment, but with individualized PEEP which produced the lowest driving pressure. The primary outcome was oxygen index (OI) after ICU admission in 30 minutes, and the secondary outcomes were the incidence of OI below 300 mm Hg, the severity of OI descending scale (the Berlin definition), the incidence of pulmonary complications at 7 days after surgery and surgeons’ satisfaction on ventilation.ResultsThere was a statistical difference in OI after ICU admission in 30 minutes between the two groups (273.5±75.5 mm Hg vs. 358.0±65.3 mm Hg, P=0.00). The driving pressure group had lower incidence of postoperative OI<300 mm Hg (16.9% vs. 49.0%, OR=0.21, 95%CI 0.08-0.52, P=0.00) and less severity of OI classification than the control group (P=0.00). The incidence of pulmonary complications at 7 days after surgery was comparable between the driving pressure group and the control group (28.3% vs. 33.9%, OR=0.76, 95%CI 0.33-1.75, P=0.48). The atelectasis rate was lower in the driving pressure group (1.0% vs. 15.0%, OR=0.10, 95%CI 0.01-0.89, P=0.01).ConclusionApplication of driving pressure-guided ventilation is associated with a higher OI and less lung injury after ICU admission compared with the conventional protective ventilation in patients having valve surgery.
Objective To compare the effects of high and low positive end-expiratory pressure( PEEP) levels on mortality and risk of barotrauma in patients with acute respiratory distress syndrome ( ARDS) . Methods Randomized controlled trials ( RCTs) were recruited from PubMed( 1966-2008. 9) ,EMBASE( 1980-2008. 9) , Cochrane Database ( Issue 2, 2008) , Chinese Cochrane Centre Database and CBMdisc ( 1978-2008. 9) . Related published and unpublished data and attached references were hand searched. All RCTs about ventilation with PEEP for patients with ARDS were included, then a systematic review were performed. Results Five eligible trials were enrolled in the systematic review. According to ventilation strategy, all trials were divided into subgroup A( low tidal volumes + high PEEP vs traditional tidal volumes + low PEEP) and subgroup B( low tidal volumes + high PEEP vs low tidal volumes + low PEEP) . In subgroup A, high PEEP was associated with a lower mortality[ RR 0. 59, 95%CI( 0. 43, 0. 82) ] and a lower prevalence of barotraumas [ RR 0. 24, 95% CI( 0. 09, 0. 70) ] in patients with ARDS. In subgroup B, the difference in mortality[ RR 0. 97, 95%CI( 0. 83, 1. 13) ] and barotraumas[ RR 1. 13, 95% CI( 0. 78, 1. 63) ]were not significant. Conclusions As compared with conventional ventilation, low tidal volumes and high PEEP ventilation strategy is associated with improved survival and a lower prevalence of barotraumas in patients with ARDS. It is necessary to further confirm the role of sole high PEEP in the ventilation strategy.
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.
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.
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.
ObjectiveTo explore the effects of drug management skill training on lightening the family burden of schizophrenic patients in their recovery period. MethodsBetween December 2011 and December 2013, 101 patients with schizophrenia were randomly divided into experimental group (n=56) and control group (n=45). The experimental group was given drug management skill training, while the control group only received routine follow-up. The course of the research was six months. Both groups were assessed by the positive and negative syndrome scale on patients' psychological symptoms, and family burden scale of diseases was used to assess the burden of the family. ResultsCompared with the controls, patients in the experimental group improved more in their positive symptoms (t=2.692, P=0.008), negative symptoms (t=2.729, P=0.008), general psychopathology symptoms (t=3.231, P=0.002) and the whole psychiatric symptoms (t=3.870, P<0.001). Moreover, the degree of patients' symptom improvement was positively correlated with the degree of family burden lightening (r=0.44, P<0.001). ConclusionFor patients with schizophrenia, reasonable drug management skill training can effectively improve patients' medication compliance, promote treatment effect and lighten family burden.
Objective To explore the positive rate of scanning laser ophthalmoscope in the retromode (RM-SLO) in different types of diabetic macular edema (DME), and to analyze its correlation with foveal thickness (CMT) and macular volume. MethodsFrom March to May 2021, 40 patients (65 eyes) were diagnosed as DME by fundus examination combined with optical coherence tomography (OCT) in Affiliated Eye Hospital of Wenzhou Medical University at Hangzhou were included in the study. All eyes underwent best corrected visual acuity (BCVA), OCT and RM-SLO fundus imaging examinations, 47 eyes underwent fluorescein fundus angiography (FFA) examination. RM-SLO fundus imaging examinations were performed with Mirante SLO, including retro mode illumination deviated right (RMDR) and retro mode illumination deviated left (RMDL). If one or more of the RMDR and RMDL of the examined patient can identify macular edema, RM-SLO was considered to be able to identify macular edema. The macular volume at CMT and 6 mm from the fovea was measured by OCT software. DME were divided into 3 types based on OCT images: diffuse retinal thinkening (DRT) type; cystoid macular edema(CME) type; serous retinal detachment (SRD) type, focal leakage type, diffuse leakage type and diffuse cystic leakage type. The consistency of RMDR and RMDL in the diagnosis of DME in RM-SLO fundus imaging was evaluated, as well as their positive rate in different classifications of DME. The correlation between the detection of macular edema by RM-SLO and the DME type, CMT and foveal volume, and the correlation between BCVA and edema type, CMT and macular volume were analyzed. ResultsAmong 65 eyes, the positive rates of RMDR and RMDL fundus imaging to detect DME were 46 (70.77%, 46/65) and 48 (73.85%, 48/65), respectively. There was good consistency in identifying DME (Kappa value=0.770; P＜0.001). The positive rates of RMDR and RMDL fundus imaging DRT, CME and SRD type of DME were 42.11% (8/19), 57.89% (11/19), 77.78% (28/36), 77.78% (28/36), 100.00% (10/10), 90.00% (9/10), respectively. In the FFA classification of them, the positive rates of focal leakage, diffuse leakage and diffuse cystic leakage were 68.75% (11/16), 62.50% (10/16), 68.00% (17/25), 76.00% (19/25), 100.00% (6/6), 100.00% (6/6), respectively. The results of Spearman correlation analysis showed that whether RM-SLO could identify DME was associated with CMT and OCT classification (r=0.310, 0.365; P=0.120, 0.003); there was no correlation between FFA classification and macular volume (r=0.113, 0.117; P=0.449, 0.352). BCVA was correlated with CMT and macular volume (r=0.307, 0.269; P=0.013, 0.030), however, there was no significant correlation with OCT type, angiographic type (r=0.051, 0.175; P=0.684, 0.240). ConclusionThe diagnostic agreement of DME are good between RMDR, RMDL of RM-SLO image. DME of DRT type and patients with smaller CMT in OCT are difficult to identified by RM-SLO fundus imaging.