OBJECTIVE: To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults. METHODS: This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results. RESULTS: The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m². During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m³, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m³, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m³ increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m³. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter. CONCLUSION Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.
Humans ; Female ; Adult ; Young Adult ; Air Pollutants/analysis* ; Heart Rate/physiology* ; Volatile Organic Compounds/analysis* ; Carbon Dioxide ; Particulate Matter/adverse effects* ; Environmental Pollutants

At present, the death cases of simple asphyxiant gas acute poisoning are increasing sharply. Common asphyxiant gases in death cases include nitrogen, helium, carbon dioxide, methane, propane, laughing gas, etc. Simple asphyxiant gas has no affinity for biological matrices and escapes quickly, which puts forward new requirements for autopsy procedures, selection and collection of samples, laboratory analysis and identification. This paper reviews the research and development process of death cases caused by simple asphyxiant gas acute poisoning and put forwards the collection and analysis strategy of the samples in such cases. The most valuable biological samples in such cases should be lung tissues associated with the airways, followed by brain tissue and cardiac blood. Gaseous samples from the esophageal cavity, tracheal cavity, pulmonary bronchi, gastric and cardiac areas are also recommended as valuable samples. In the case of postmortem examination, the gas should be injected into gas sample bag directly. Biological materials such as tissue and blood should be directly sealed in head-space vials and analyzed by using the headspace gas chromatography-mass spectrometry.
Carbon Dioxide/analysis* ; Autopsy ; Gas Chromatography-Mass Spectrometry ; Methane/analysis* ; Nitrogen

Objective: To explore the occupational hazards caused by three kinds of welding operations, and to provide data support for individual protection. Methods: In October 2020, the welding fumes, metal elements and welding arc generated by three welding operations of argon gas shielded welding (JS80 welding wire) , manual welding (ZS60A welding rod) and carbon dioxide shielded welding (907A flux cored wire) were collected and measured in the welding laboratory. The samples were analyze and compare in the laboratory, and the differences of the occupational hazard factors of the three welding operations were judged. Results: The concentration of welding fume produced by carbon dioxide shielded welding, manual welding (ZS60A electrode) , and argon gas shielded welding (JS80 welding wires) were 6.80 mg/m(3), 6.17 mg/m(3), and 3.13 mg/m(3), respectively. The effective irradiance of the welding arc outside the welding mask from high to low is manual welding (ZS60A electrode) , carbon dioxide shielded welding (907A flux-cored welding wire) , and argon shielded welding (JS80 welding wire) , respectively 1 010.7, 740.9, 589.5 μW/cm(2). The long-wave ultraviolet UVA intensity generated by argon shielded welding (JS80 welding wire) is the largest, which is 1 500 μW/cm(2). The content of Mn in the three welding operations is the highest, and JS80 welding wire has the highest Mn content of 128493.2 mg/kg. 907A flux cored wire has the highest Ti content, which is 24355.5mg/kg. The electrode ZS60A has the highest Cu content, which is 24422.12 mg/kg. Conclusion: The intensity of occupational hazards is different in the three kinds of welding operations, so the methods of personal protective equipment, field exposure assessment and health monitoring should be more targeted.
Air Pollutants, Occupational/analysis* ; Argon/analysis* ; Carbon Dioxide/analysis* ; Gases/analysis* ; Occupational Exposure/analysis* ; Welding/methods*

OBJECTIVES: The association between concentrations of sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), ozone (O), and emergency ambulance dispatches (EADs) for asthma was explored in the central Sichuan Basin of southwestern China for the first time. METHODS: EADs for asthma were collected from the Chengdu First-Aid Command Center. Pollutant concentrations were collected from 24 municipal environmental monitoring centers and including SO, NO, CO, daily 8-h mean concentrations of O (O-8 h), and particulate matter less than 2.5 μm in aerodynamic diameter (PM). The climatic data were collected from the Chengdu Municipal Meteorological Bureau. All data were collected from years spanning 2013-2017. A time-stratified case-crossover design was used to analyze the data. RESULTS: After controlling for temperature, relative humidity, and atmospheric pressure, IQR increases in SO (13 μg/m), NO (17 μg/m), and CO (498 μg/m) were associated with 18.8%, 11.5%, and 3.1% increases in EADs for asthma, respectively. The associations were strongest for EADs and SO, NO, and CO levels with 3-, 5-, and 1-day lags, respectively. CONCLUSIONS This study provides additional data to the limited body of literature for potential health risks arising from ambient gaseous pollutants. The results of the study suggest that increased concentrations of SO, NO, and CO were positively associated with emergency ambulance dispatches for asthma in Chengdu, China. Further studies are needed to investigate the effects of individual air pollutants on asthma.
Air Pollutants ; analysis ; toxicity ; Asthma ; chemically induced ; epidemiology ; Carbon Monoxide ; analysis ; toxicity ; China ; epidemiology ; Cities ; Cross-Over Studies ; Emergency Medical Dispatch ; statistics & numerical data ; Environmental Monitoring ; statistics & numerical data ; Humans ; Nitrogen Dioxide ; analysis ; toxicity ; Ozone ; analysis ; toxicity ; Particle Size ; Particulate Matter ; analysis ; toxicity ; Risk ; Sulfur Dioxide ; analysis ; toxicity

BACKGROUND: Beyond its current function as a rescue therapy in acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) may be applied in ARDS patients with less severe hypoxemia to facilitate lung protective ventilation. The purpose of this study was to evaluate the efficacy of extended ECMO use in ARDS patients. METHODS: This study reviewed 223 adult patients who had been admitted to the intensive care units of 11 hospitals in Korea and subsequently treated using ECMO. Among them, the 62 who required ECMO for ARDS were analyzed. The patients were divided into two groups according to pre-ECMO arterial blood gas: an extended group (n=14) and a conventional group (n=48). RESULTS: Baseline characteristics were not different between the groups. The median arterial carbon dioxide tension/fraction of inspired oxygen (FiO2) ratio was higher (97 vs. 61, p<0.001) while the median FiO2 was lower (0.8 vs. 1.0, p<0.001) in the extended compared to the conventional group. The 60-day mortality was 21% in the extended group and 54% in the conventional group (p=0.03). Multivariate analysis indicated that the extended use of ECMO was independently associated with reduced 60-day mortality (odds ratio, 0.10; 95% confidence interval, 0.02–0.64; p=0.02). Lower median peak inspiratory pressure and median dynamic driving pressure were observed in the extended group 24 hours after ECMO support. CONCLUSION: Extended indications of ECMO implementation coupled with protective ventilator settings may improve the clinical outcome of patients with ARDS.
Adult ; Anoxia ; Carbon Dioxide ; Extracorporeal Membrane Oxygenation ; Humans ; Intensive Care Units ; Korea ; Lung ; Mortality ; Multicenter Studies as Topic ; Multivariate Analysis ; Oxygen ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Retrospective Studies ; Ventilation ; Ventilators, Mechanical

OBJECTIVETo study the clinical effect and safety of bubble nasal continuous positive airway pressure (BNCPAP) versus conventional nasal continuous positive airway pressure (nCPAP) in respiratory support for preterm infants with neonatal respiratory distress syndrome (NRDS).

METHODSA retrospective analysis was performed for the clinical data of 130 preterm infants with NRDS. Among them, 69 underwent BNCPAP and 61 underwent nCPAP. The two groups were compared in terms of mortality rate, duration of respiratory support, use of pulmonary surfactant (PS), and treatment failure rate, and the incidence rates of bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP), as well as the changes in blood gas pH, partial pressure of oxygen, and partial pressure of carbon dioxide. The safety was evaluated for both groups.

RESULTSThere were no significant differences between the BNCPAP group and the nCPAP group in sex distribution, gestational age, birth weight, Apgar score at 1 and 5 minutes after birth, delivery mode, and the severity of NRDS (P>0.05). No infants in the BNCPAP group died, and one infant in the nCPAP group died; there was no significant difference in the mortality rate between the two groups (P>0.05). There were also no significant differences between the two groups in the duration of noninvasive ventilation, treatment failure rate, the incidence rates of BPD and ROP, and the percentage of infants with a need for use or reuse of PS (P>0.05). After 8-12 hours of ventilation, there were no significant differences between the two groups in the changes in blood gas pH and oxygenation index (P>0.05), while the BNCPAP group had a significantly greater reduction in partial pressure of carbon dioxide than the nCPAP group (P<0.05). There were no significant differences between the two groups in the incidence rates of pneumothorax, nasal septal injury, and nasal mucosal injury (P>0.05).

CONCLUSIONSBNCPAP and nCPAP have similar clinical effect and safety in respiratory support for preterm infants with NRDS.

Blood Gas Analysis ; Carbon Dioxide ; analysis ; blood ; Continuous Positive Airway Pressure ; methods ; Female ; Gestational Age ; Humans ; Infant, Newborn ; Infant, Premature ; blood ; Male ; Oxygen ; analysis ; blood ; Pneumothorax ; therapy ; Respiratory Distress Syndrome, Newborn ; blood ; therapy ; Retrospective Studies ; Treatment Failure

OBJECTIVE: This study aimed to identify the effects of serum potassium and lactate on neurologic outcomes in out-of-hospital post-cardiac arrest adult patients. METHODS: This study was a single center, retrospective observational study. We recruited out-of-hospital post-cardiac arrest adult patients admitted to an intensive care unit from 2011 to 2017. Primary outcome was good neurologic outcome at discharge. To evaluate the prognostic impact of serum potassium and lactate, univariate and multivariate logistic regression analyses were performed. RESULTS: A total of 57 patients were included in this study. The number of patients with good neurologic outcome was 19 (33.3%). In the univariate analysis, good neurologic outcome patients showed a higher smoking rate, shorter pre-hospital transportation time, higher rate of percutaneous coronary intervention, and lower severity score (all p < 0.05). The good neurologic outcome patients also presented higher pH, lower partial pressure of carbon dioxide, and lower potassium regarding laboratory findings on the first hospital day (all p < 0.05). In the multivariate analysis, the independent factors favoring good neurologic outcome were pre-hospital transportation time (adjusted odds ratio [aOR], 0.82; 95% confidence interval [CI], 0.69–0.97; P=0.019) and lower partial pressure of carbon dioxide on the first hospital day (aOR, 0.95; 95% CI, 0.91–0.99; P=0.034). CONCLUSION: Serum potassium and lactate were not significantly associated with good neurologic outcome in out-of-hospital post-cardiac arrest adult patients. The prognostic factors for good neurologic outcome were pre-hospital transportation time and initial partial pressure of carbon dioxide.
Adult* ; Carbon Dioxide ; Cardiopulmonary Resuscitation ; Heart Arrest ; Humans ; Hydrogen-Ion Concentration ; Intensive Care Units ; Lactic Acid* ; Logistic Models ; Multivariate Analysis ; Observational Study ; Odds Ratio ; Partial Pressure ; Percutaneous Coronary Intervention ; Potassium* ; Prognosis ; Retrospective Studies ; Smoke ; Smoking ; Transportation

OBJECTIVE: This study examined the initial partial pressure of carbon dioxide (PCO₂) as a possible indicator of prehospital ventilation and its association with prehospital i-gel in out-of-hospital cardiac arrest (OHCA) patients. METHODS: The demographics and arrest parameters, including i-gel insertion and initial arterial blood gas analysis, of OHCA patients who visited the emergency department were analyzed retrospectively. Linear regression analysis was performed to examine the association between i-gel insertion and the initial PCO₂. RESULTS: A total of 106 patients were investigated. Fifty-six patients had prehospital i-gel insertion and 50 patients did not have a prehospital advanced airway. The initial PCO₂ was higher in the i-gel group than the no advanced airway group (105.2 mmHg [77.5–134.9] vs. 87.5 mmHg [56.8–115.3], P=0.03). Prehospital i-gel insertion was associated with a higher initial PCO₂ level (βcoefficient, 20.3; 95% confidence interval, 2.6–37.9; P=0.03). CONCLUSION: Prehospital insertion of i-gel was associated with higher initial PCO₂ values in OHCA patients compared to no advanced airway.
Airway Management ; Blood Gas Analysis ; Carbon Dioxide ; Cardiopulmonary Resuscitation ; Demography ; Emergency Medical Services ; Emergency Service, Hospital ; Heart Arrest ; Humans ; Linear Models ; Out-of-Hospital Cardiac Arrest* ; Partial Pressure ; Retrospective Studies ; Ventilation

Severe eating disorders characterized by repetitive episodes of purging and vomiting can occasionally trigger acute kidney injury. However, interstitial nephritis induced by episodes of repeated vomiting has rarely been reported, and the pathophysiology of this entity remains unknown. A 26-year-old man was admitted to our hospital because of known hypokalemia. His serum electrolyte profile showed: sodium 133 mEq/L, potassium 2.6 mEq/L, chloride 72 mEq/L, total carbon dioxide 50 mEq/L, blood urea nitrogen/creatinine ratio (BUN/Cr) 21.9/1.98 mg/dL, and magnesium 2.0 mg/dL. Arterial blood gas analysis showed: pH 7.557, partial pressure of carbon dioxide 65.8 mmHg, and bicarbonate 58.5 mEq/L. His urinary potassium concentration was 73.2 mEq/L, and Cr was 111 mg/dL. Renal biopsy revealed acute tubular necrosis and tubulointerstitial nephritis with a few shrunken glomeruli. Repeated psychogenic vomiting may precipitate acute kidney injury and interstitial nephritis secondary to volume depletion and hypokalemia. Serum electrolyte levels and renal function should be carefully monitored in patients diagnosed with eating disorders to prevent tubular ischemia and interstitial nephritis.
Acute Kidney Injury ; Adult ; Anorexia Nervosa* ; Anorexia* ; Biopsy ; Blood Gas Analysis ; Carbon Dioxide ; Eating ; Humans ; Hydrogen-Ion Concentration ; Hypokalemia ; Ischemia ; Magnesium ; Male* ; Necrosis ; Nephritis, Interstitial* ; Partial Pressure ; Potassium ; Sodium ; Urea ; Vomiting

OBJECTIVE: To evaluate the prognostic value of the difference between peripheral venous and arterial partial pressure of carbon dioxide in patients with septic shock following early resuscitation. METHODS: This prospective study was conducted among the patients with septic shock treated in our department during the period from May, 2017 to May, 2018. Peripheral venous, peripheral arterial and central venous blood samples were collected simultaneously and analyzed immediately at bedside after 6-h bundle treatment. Arterial blood lactate concentration (Lac) and the arterial (PaCO), peripheral venous (PpvCO) and central venous partial pressure of carbon dioxide (PcvCO) were recorded. The differences between PpvCO and PaCO (Ppv-aCO) and between PcvCO and PaCO (Pcv-aCO) were calculated. Pearson correlation analysis was used to test the agreement between Pcv-aCO and Ppv-aCO. Multivariable logistic regression analysis was performed to analyze the possible risk factors for 28-day mortality, and the receiver-operating characteristic curve (ROC) was plotted to assess the prognostic values of these factors for 28-day mortality. RESULTS: A total of 62 patients were enrolled in this study, among who 35 survived and 27 died during the 28-day period. Compared with the survivor group, the patients died within 28 days showed significantly higher Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score (24.2±6.0 20.5±4.9, =0.011), sequential organ failure assessment (SOFA) score (14.9±4.7 12.2±4.5, =0.027), PcvaCO (5.5±1.6 7.1±1.7, < 0.001), PpvaCO (7.1±1.8 10.0±2.7, < 0.001), and arterial lactate level (3.3±1.2 4.2±1.3, =0.003) after 6-h bundle treatment. Pearson correlation analysis showed that Ppv-aCO was significantly correlated with Pcv-aCO (=0.897, R= 0.805, < 0.001). Multiple logistic regression analysis identified Ppv-aCO (β=0.625, =0.001, OR=1.869, 95% CI: 1.311-2.664) and lactate level (β=0.584, =0.041, OR=1.794, 95%CI: 1.024-3.415) as the independent risk factors for 28-day mortality. The maximum area under the ROC (AUC) of Ppv-aCO was 0.814 (95%CI: 0.696- 0.931, < 0.001), and at the best cut- off value of 9.05 mmHg, Ppv-aCO had a sensitivity of 70.4% and a specificity of 88.6% for predicting 28-day mortality. The AUC of lactate level was 0.732 (95%CI: 0.607-0.858, =0.002), and its sensitivity for predicting 28-day mortality was 70.4% and the specificity was 74.3% at the best cut-off value of 3.45 mmol/L; The AUC of Pcv-aCO was 0.766 (95%CI: 0.642-0.891, < 0.001), and its sensitivity was 66.7% and the specificity was 80.0% at the best cut-off value of 7.05 mmHg. CONCLUSIONS A high Ppv-aCO after early resuscitation of septic shock is associated with poor outcomes. Ppv-aCO is well correlated with Pcv-aCO and can be used as an independent indicator for predicting 28-day mortality in patients with septic shock.
APACHE ; Carbon Dioxide ; Cardiopulmonary Resuscitation ; Humans ; Lactic Acid ; blood ; Organ Dysfunction Scores ; Partial Pressure ; Pilot Projects ; Prognosis ; Prospective Studies ; ROC Curve ; Regression Analysis ; Shock, Septic ; blood ; mortality