Ventilation Index Research Articles

Acute temperature effects on metabolic rate, ventilation, diffusive water exchange, osmoregulation, and acid–base status in the Pacific hagfish (Eptatretus stoutii)

The Pacific hagfish (Eptatretus stoutii) is a representative of the most basal extant craniates, and is a marine osmoconformer with an extremely low metabolic rate (MO2 = 475µmolO2/kg/h at 12°C). We investigated potential physiological trade-offs associated with compensatory changes in gill ventilation and perfusion when 12°C-acclimated hagfish were acutely exposed to 7°C or 17°C, as reflected in diffusive unidirectional water flux ([Formula: see text], measured with tritiated water: 3H2O), net ammonia flux (Jamm), and plasma ion and acid-base status. [Formula: see text] was high (~ 1.4L/kg/h at 12°C) in comparison to marine teleosts and elasmobranchs. MO2 increased linearly with temperature (R2 = 0.991), and was more sensitive (Q10 = 3.22) in the 12-7°C range than either Jamm (1.86) or [Formula: see text] (1.35), but the pattern reversed from 12 to 17°C (Q10s: MO2 = 2.77, Jamm = 2.88, [Formula: see text] = 4.01). Heart rate, ventilatory index (a proxy for total ventilation), and coughing frequency also increased but with different patterns. At 17°C, plasma [Ca2+] and [Mg2+] decreased, although osmolality increased, associated with elevations in plasma [Na+] and [Cl-]. Blood pH and PCO2 were unaffected by acute temperature changes while [HCO3-] increased. Hyperoxia (PO2 > 300Torr) attenuated the increase in [Formula: see text] at 17°C, did not affect Jamm, and had diverse effects on plasma ion and acid-base status. Our results suggest a clear osmorespiratory compromise occurring for the diffusive water fluxes as a result of acute temperature changes in this osmoconformer.

Design-based natural ventilation evaluation in early stage for high performance buildings

Natural ventilation has been recognized as one of the most promising passive strategies to reduce building energy consumption as well as to improve indoor air quality and thermal comfort level. However, a lack of agreement on evaluation index for natural ventilation in early design stage is noticeable. The target of this paper was to develop a natural ventilation evaluation index for early-stage design. The study began by reviewing current practices of natural ventilation evaluation and identifying the problems of current indices. A Design-Based Natural Ventilation Potential was then proposed as the evaluation index of natural ventilation, especially for the early design stage. The proposed evaluation index covered both indoor air quality and thermal environment aspects for natural ventilation and take early stage design information into consideration, such as urban context and environment. The evaluation index was employed in a case study of an office building to illustrate the advantage of this index comparing to other evaluation indices. As a conclusion, the Design-Based Natural Ventilation Potential can provide more design-oriented result of natural ventilation evaluation in early design stage, which as a result will lead to a better urban built environment by enhancing the possibility of high performance naturally ventilated buildings.

Multicenter Validation of the Vasoactive-Ventilation-Renal Score as a Predictor of Prolonged Mechanical Ventilation After Neonatal Cardiac Surgery*

We sought to validate the Vasoactive-Ventilation-Renal score, a novel disease severity index, as a predictor of outcome in a multicenter cohort of neonates who underwent cardiac surgery. Retrospective chart review. Seven tertiary-care referral centers. Neonates defined as age less than or equal to 30 days at the time of cardiac surgery. Ventilation index, Vasoactive-Inotrope Score, serum lactate, and Vasoactive-Ventilation-Renal score were recorded for three postoperative time points: ICU admission, 6 hours, and 12 hours. Peak values, defined as the highest of the three measurements, were also noted. Vasoactive-Ventilation-Renal was calculated as follows: ventilation index + Vasoactive-Inotrope Score + Δ creatinine (change in creatinine from baseline × 10). Primary outcome was prolonged duration of mechanical ventilation, defined as greater than 96 hours. Receiver operative characteristic curves were generated, and abilities of variables to correctly classify prolonged duration of mechanical ventilation were compared using area under the curve values. Multivariable logistic regression modeling was also performed. We reviewed 275 neonates. Median age at surgery was 7 days (25th-75th percentile, 5-12 d), 86 (31%) had single ventricle anatomy, and 183 (67%) were classified as Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Category 4 or 5. Prolonged duration of mechanical ventilation occurred in 89 patients (32%). At each postoperative time point, the area under the curve for prolonged duration of mechanical ventilation was significantly greater for the Vasoactive-Ventilation-Renal score as compared to the ventilation index, Vasoactive-Inotrope Score, and serum lactate, with an area under the curve for peak Vasoactive-Ventilation-Renal score of 0.82 (95% CI, 0.77-0.88). On multivariable analysis, peak Vasoactive-Ventilation-Renal score was independently associated with prolonged duration of mechanical ventilation, odds ratio (per 1 unit increase): 1.08 (95% CI, 1.04-1.12). In this multicenter cohort of neonates who underwent cardiac surgery, the Vasoactive-Ventilation-Renal score was a reliable predictor of postoperative outcome and outperformed more traditional measures of disease complexity and severity.

Acute Respiratory Failure in Pediatric Hematopoietic Cell Transplantation: A Multicenter Study.

Acute respiratory failure is common in pediatric hematopoietic cell transplant recipients and has a high mortality. However, respiratory prognostic markers have not been adequately evaluated for this population. Our objectives are to assess respiratory support strategies and indices of oxygenation and ventilation in pediatric allogeneic hematopoietic cell transplant patients receiving invasive mechanical ventilation and investigate how these strategies are associated with mortality. Retrospective, multicenter investigation. Twelve U.S. pediatric centers. Pediatric allogeneic hematopoietic cell transplant recipients with respiratory failure. None. Two-hundred twenty-two subjects were identified. PICU mortality was 60.4%. Nonsurvivors had higher peak oxygenation index (38.3 [21.3-57.6] vs 15.0 [7.0-30.7]; p < 0.0001) and oxygen saturation index (24.7 [13.8-38.7] vs 10.3 [4.6-21.6]; p < 0.0001), greater days with FIO2 greater than or equal to 0.6 (2.4 [1.0-8.5] vs 0.8 [0.3-1.6]; p < 0.0001), and more days with oxygenation index greater than 18 (1.4 [0-6.0] vs 0 [0-0.3]; p < 0.0001) and oxygen saturation index greater than 11 (2.0 [0.5-8.8] vs 0 [0-1.0]; p < 0.0001). Nonsurvivors had higher maximum peak inspiratory pressures (36.0 cm H2O [32.0-41.0 cm H2O] vs 30.0 cm H2O [27.0-35.0 cm H2O]; p < 0.0001) and more days with peak inspiratory pressure greater than 31 cm H2O (1.0 d [0-4.0 d] vs 0 d [0-1.0 d]; p < 0.0001). Tidal volume per kilogram was not different between survivors and nonsurvivors. In this cohort of pediatric hematopoietic cell transplant recipients with respiratory failure in the PICU, impaired oxygenation and use of elevated ventilator pressures were common and associated with increased mortality.

Impacts of Saharan Dust on Atlantic Regional Climate and Implications for Tropical Cyclones

AbstractThe radiative and microphysical properties of Saharan dust are believed to impact the Atlantic regional climate and tropical cyclones (TCs), but the detailed mechanism remains uncertain. In this study, atmosphere-only simulations are performed from 2002 to 2006 using the Community Atmospheric Model, version 5.1, with and without dust emission from the Sahara Desert. The Saharan dust exhibits noticeable impacts on the regional longwave and shortwave radiation, cloud formation, and the convective systems over West Africa and the tropical Atlantic. The African easterly jet and West African monsoon are modulated by dust, leading to northward shifts of the intertropical convergence zone and the TC genesis region. The dust events induce positive midlevel moisture and entropy deficit anomalies, enhancing the TC genesis. On the other hand, the increased vertical wind shear and decreased low-level vorticity and potential intensity by dust inhibit TC formation in the genesis region. The ventilation index shows a decrease in the intensification region and an increase in the genesis region by dust, corresponding to favorable and unfavorable TC activities, respectively. The comparison of nondust scenarios in 2005 and 2006 shows more favorable TC conditions in 2005 characterized by higher specific humidity and potential intensity, but lower ventilation index, wind shear, and entropy deficit. Those are attributable to the observed warmer sea surface temperature (SST) in 2005, in which dust effects can be embedded. Our results imply significant dust perturbations on the radiative budget, hydrological cycle, and large-scale environments relevant to TC activity over the Atlantic.

Surfactant replacement therapy in combination with different non-invasive ventilation techniques in spontaneously-breathing, surfactant-depleted adult rabbits.

Nasal intermittent positive pressure ventilation (NIPPV) holds great potential as a primary ventilation support method for Respiratory Distress Syndrome (RDS). The use of NIPPV may also be of great value combined with minimally invasive surfactant delivery. Our aim was to implement an in vivo model of RDS, which can be managed with different non-invasive ventilation (NIV) strategies, including non-synchronized NIPPV, synchronized NIPPV (SNIPPV), and nasal continuous positive airway pressure (NCPAP). Forty-two surfactant-depleted adult rabbits were allocated in six different groups: three groups of animals were treated with only NIV for three hours (NIPPV, SNIPPV, and NCPAP groups), while three other groups were treated with surfactant (SF) followed by NIV (NIPPV+SF, SNIPPV+SF, and NCPAP+SF groups). Arterial gas exchange, ventilation indices, and dynamic compliance were assessed. Post-mortem the lungs were sampled for histological evaluation. Surfactant depletion was successfully achieved by repeated broncho-alveolar lavages (BALs). After BALs, all animals developed a moderate respiratory distress, which could not be reverted by merely applying NIV. Conversely, surfactant administration followed by NIV induced a rapid improvement of arterial oxygenation in all surfactant-treated groups. Breath synchronization was associated with a significantly better response in terms of gas exchange and dynamic compliance compared to non-synchronized NIPPV, showing also the lowest injury scores after histological assessment. The proposed in vivo model of surfactant deficiency was successfully managed with NCPAP, NIPPV, or SNIPPV; this model resembles a moderate respiratory distress and it is suitable for the preclinical testing of less invasive surfactant administration techniques.

A statistical examination of the effects of stratospheric sulfate geoengineering on tropical storm genesis

Abstract. The thermodynamics of the ocean and atmosphere partly determine variability in tropical cyclone (TC) number and intensity and are readily accessible from climate model output, but an accurate description of TC variability requires much higher spatial and temporal resolution than the models used in the GeoMIP (Geoengineering Model Intercomparison Project) experiments provide. The genesis potential index (GPI) and ventilation index (VI) are combinations of dynamic and thermodynamic variables that provide proxies for TC activity under different climate states. Here we use five CMIP5 models that have run the RCP4.5 experiment and the GeoMIP stratospheric aerosol injection (SAI) G4 experiment to calculate the two TC indices over the 2020 to 2069 period across the six ocean basins that generate TCs. GPI is consistently and significantly lower under G4 than RCP4.5 in five out of six ocean basins, but it increases under G4 in the South Pacific. The models project potential intensity and relative humidity to be the dominant variables affecting GPI. Changes in vertical wind shear are significant, but it is correlated with relative humidity, though with different relations across both models and ocean basins. We find that tropopause temperature is not a useful addition to sea surface temperature (SST) in projecting TC genesis, perhaps because the earth system models (ESMs) vary in their simulation of the various upper-tropospheric changes induced by the aerosol injection.

Acute responses to sprint-interval and continuous exercise in adults with and without exercise-induced bronchoconstriction

ABSTRACTThe purpose was to compare the airway response to sprint interval exercise (SIE) and continuous exercise (CE) in active adults with exercise-induced bronchoconstriction (EIBC), and to compare ventilatory and oxygen delivery responses between adults with and without EIBC. Adults with EIBC (n = 8, 22.3 ± 3.0 years) and adults without EIBC (n = 8, 22.3 ± 3.0 years) completed a SIE (4 × 30 s sprints separated by 4.5 min of active recovery) and CE (20 min at 65% peak power output) session. Lung function was assessed at baseline, during exercise, and up to 20 min post-exercise. Ventilatory parameters and tissue saturation index (TSI) were recorded continuously throughout the sessions. The decline in forced expiratory volume in 1 s was similar following SIE (−8.6 ± 12.6%) and CE (−9.0 ± 9.3%) in adults with EIBC. There were no significant differences in any of the ventilatory parameters or in TSI during SIE or CE between those with and without EIBC. These findings suggest that SIE and CE affect airway responsiveness to a similar extent. Future research using a lower intensity CE protocol in an inactive sample of adults with EIBC is needed.

Lower Distending Pressure Improves Respiratory Mechanics in Congenital Diaphragmatic Hernia Complicated by Persistent Pulmonary Hypertension

To investigate the effects of distending pressures on respiratory mechanics and pulmonary circulation in newborn infants with congenital diaphragmatic hernia (CDH) and persistent pulmonary hypertension (PPHN). In total, 17 consecutive infants of ≥37 weeks of gestational age with CDH and PPHN were included in this prospective, randomized, crossover pilot study. Infants were assigned randomly to receive 2 or 5 cmH2O of positive end-expiratory pressure (PEEP) for 1 hour in a crossover design. The difference between peak inspiratory pressure and PEEP was kept constant. Respiratory mechanics, lung function, and hemodynamic variables assessed by Doppler echocardiography were measured after each study period. At 2 cmH2O of PEEP, tidal volume and minute ventilation were greater (P < .05), and respiratory system compliance was 30% greater (P < .05) than at 5 cmH2O. PaCO2 and ventilation index were lower at 2 cmH2O than at 5 cmH2O (P < .05). Although preductal peripheral oxygen saturation was similar at both PEEP levels, postductal peripheral oxygen saturation was lower (median [range]: 81% [65-95] vs 91% [71-100]) and fraction of inspired oxygen was greater (35% [21-70] vs 25% [21-60]) at 5 cmH2O. End-diastolic left ventricle diameter, left atrium/aortic root ratio, and pulmonary blood flow velocities in the left pulmonary artery were lower at 5 cmH2O. After surgical repair, lower distending pressures result in better respiratory mechanics in infants with mild-to-moderate CDH. We speculate that hypoplastic lungs in CDH are prone to overdistension, with poor tolerance to elevation of distending pressure.

Social Determinants and Risk Factors for Tuberculosis Patients: A Case Control Study at Health Services Applying Directly Observed Treatment Shortcourse (DOTS) in Bandar Lampung, Indonesia

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Influence of xenon on pulmonary mechanics and lung aeration in patients with healthy lungs

BackgroundThe anaesthetic xenon shows potent organ-protective properties. Due to high density and dynamic viscosity, peak inspiratory pressure (Pmax) increases during xenon application. Thus, barotrauma may counteract organ protection. Accordingly, we investigated the influence of xenon on lung mechanics and lung aeration in patients with normal and reduced thoracic wall compliance. MethodsAfter registration and ethical approval, 20 patients free of pulmonary disease undergoing routine xenon-based anaesthesia were mechanically ventilated. The primary outcome variable transpulmonary pressure (Ptp) was determined from plateau pressure and intraoesophageal pressure before and after xenon wash-in. We recorded Pmax, and calculated airway resistance (RAW), and static (Cstat) and dynamic (Cdyn) respiratory compliances. Finally, lung aeration was quantified by electrical impedance tomography-derived centre of ventilation index (CVI) and global inhomogeneity index (GI) in the awake state, before and during xenon. ResultsXenon increased Pmax [20.8 (SD 3) vs 22.6 (3) cm H2O, P<0.001] and RAW [0.9 (0.2) vs 1.4 (0.3) cm H2O litre−1 s, P<0.001], without affecting Ptp [1.5 (4) vs 2.0 (4) cm H2O, P=0.15]. While Cstat remained unchanged, Cdyn was reduced [33.9 (7) vs 31.2 (6) ml (cm H2O)−1, P<0.001). A ventral tidal volume shift after anaesthesia induction [CVI 0.53 (0.03) vs 0.59 (0.04), P<0.001] was unaltered during xenon [CVI 0.59 (0.04), P=0.29]. Homogeneity of lung aeration was also unchanged during xenon [GI 0.37 (0.03) vs 0.37 (0.03), P=0.99]. There were no clinically meaningful differential BMI-related effects. ConclusionsXenon increases calculated airway resistance and peak inspiratory pressure without affecting transpulmonary pressure, independent of BMI. Clinical trial registrationNCT02682758.

A novel targeted personalized ventilation system based on the shooting concept

Thermal comfort and energy saving has drawn widespread attention in recent years, and personalized ventilation (PV) is a theoretical air supply method designed for both comfort and energy savings. This study introduces a targeted personalized ventilation (TPV) system formed by a multi-tuyere apparatus and based on the concept of targeted ventilation. Corresponding targeted ventilation indices are introduced to evaluate regional thermal comfort, and the effectiveness of the ventilation systems is presented. Turbulence model selection is conducted by comparing computational fluid dynamics (CFD) and experimental data to determine the practical effect of the TPV.The TPV provides air supply to the controlled area and thus improves the utilization ratio of the flow field. The air supply through the coupled tuyeres results in a uniform flow field with air speeds very close to 0.3 m/s. Compared with other PV systems, the velocity target value of the TPV system proposed in this paper is 40.5% lower, and the energy-saving rate reaches 52.9%. The effects of the TPVs were verified in a full-scale experiment.

Association between oxygenation and ventilation indices with the time on invasive mechanical ventilation in infants

BackgroundInvasive mechanical ventilation (IMV) is a common practice in pediatric intensive care unit (PICU). However, the role of oxygenation (OI) and ventilation (VI) indices regarding the time on IMV has not been fully understood. Basic proceduresThe study was conducted with infants up to 24 months of age, hospitalized in PICU for two consecutive years. The values of ventilatory parameters, OI, VI, and blood gas of infants, collected in the first seven days in IMV, were associated with the time on IMV. IMV was classified into: short (≤seven days) and long time (>seven days). The comparison was made from the first to the seventh day. Alpha=0.05. Main findingsOf 142 infants [mean age=7.51±6.33 months], 59 (41.5%) remained on IMV for a short time and 83 (58.5%) for a long time. Differences in PaO2 values were found on the second day, and PaO2/FiO2 ratio on the second, third and fourth days, with higher values in the short-term IMV. For FiO2 from the second to the fifth day; Pinsp from the first to the seventh day; PEEP from the second to the sixth day; mechanical respiratory frequency from the second to the seventh day, PaCO2 on the second day; Paw from the first to the seventh day, OI from the second to the sixth day, and VI from the first to the seventh day, the values were higher in the long-term IMV. ConclusionsThe OI and VI can be considered as potential predictors of long-term IMV, along with other markers obtained during the IMV.

Basic anthropometric parameters and ventilatory function indices among current cigarette smokers

Background: Ventilatory function indices [forced vital capacity (FVC), expiratory volume in 1 (FEV1), and FEV1/FVC] are a function of the basic anthropometric parameters (weight and height). Cigarette smoking is an important confounder in the relationship between ventilatory function indices and basic anthropometric parameters. Aim: To determine the relationship between anthropometric parameters and ventilatory function among male adult cigarette smokers. Materials and Methods: This is a community-based cross-sectional study incorporating 200 male participants (150 cigarette smokers and 50 non-smokers) who met inclusion criteria using stratified random sampling technique. Participants were drawn from local governments that constituted Sokoto metropolis. Subsequently, participants had a questionnaire adapted from European Community Respiratory Health Survey administered to collect demographic, clinical and cigarette smoking data. Ventilatory function test was performed using Clement Clarke One Flow Spirometer, version 1.3 Revision 0 (Clement Clarke International, Edinburgh, UK). The highest value of each ventilatory function indices (FEV1, FVC, FEV1/FVC) was chosen for analysis. Data were summarized, and statistical tests were applied using the software Statistical Package for Social Sciences, version 19 (IBM SPSS Inc., Chicago, IL, USA). Result: The majority of study participants among cigarette smokers and control were young, single and had a form of formal education. There was no significant difference in the mean of anthropometric indices [weight, height, body mass index (BMI)] of participants (cigarette smokers) and control (non-cigarette smokers). Twenty-nine (58%) non-cigarette smokers were overweight/obese as against 35 (23.3%) participants among cigarette smokers observed to be equally overweight/obese. Mean values of the ventilatory function indices except FVC were low among study participants as compared with control. Furthermore, the mean FEV1/FVC between participants (75.60 ± 7.53) and control (82.48 ± 6.11) was statistically significant (P = 0.001). A significant correlation between anthropometric parameters (height and BMI) and ventilatory function indices (FEV1 and FVC) was observed among study participants and control. Conclusion: Ventilatory function indices are associated with anthropometric parameters among cigarette smokers. Although, BMI did not significantly affect decline in ventilatory function indices among cigarette smokers, an inverse relationship was observed between them.

Use of Conventional Ultrafiltration in Patients with Pulmonary Hypertensive Mitral Valve Disease Undergoing Valve Surgery

Adverse effects of cardiopulmonary bypass on blood and lungs are encountered more severelyin pulmonary hypertensive patients undergoing mitral valve surgery. Aim of this study is to identify the favorable effects of conventional ultrafiltration on postoperative pulmonary functions, hemodynamics, morbidity or mortality in pulmonary hypertensive patients undergoing mitral valve surgery. 40 patients with severe pulmonary hypertension who underwent mitral valve surgery were included in study. Patients were divided into two groups according to whether conventional ultrafiltration was applied or not. Demographic data, preoperative transthoracic echocardiography, respiratory functions, complete blood count, biochemical parameters, alterations in pulmonary functions, bleeding, use of inotropic agents and blood products, intubation time, mortality, morbidity, length of intensive care unit and hospital stay, were evaluated. Intubation time (7.97±2.77 vs. 10.12±2.95; p 0.05) and inotropic agents (14 vs. 18; p>0.05) were less than the control group. Increase of pulmonary compliance, cardiac index, oxygen index, decrease of alveolar-arterial oxygen pressure difference and ventilation index were significant in both groups. Hematocrit (28.07±3.18 vs. 26.96±2.51; p>0.05) and white blood cell (13.56±2.37 vs. 13.03±2.51; p>0.05) were higher in the study. No morbidity and mortality were presentin both groups. Conventional ultrafiltration decreased the intubation time, intensive care unit stay, hospital stay, bleeding, use of blood products and inotropic agents. Favorable effects were also detected on pulmonary compliance, cardiac index, oxygen index, alveolar-arterial oxygen pressure difference and ventilation index. Studies with larger patient population, application of conventional and modified ultrafiltration together may give significant results for pulmonary functions.

Predictive capability of End Tidal carbon dioxide and its correlation with arterial carbon dioxide in mechanically ventilated children

Back ground:End-tidal carbon dioxide (ETCO2) is a surrogate, non-invasive measurement of arterial carbon dioxide (PaCO2); however, its clinical applicability in the intensive care unit setting remains unclear in pediatric population. Objectives:This study aims at assessing the effect of severity of lung disease and correlation between ETCO2 and PaCO2 Materials and methods: This was a prospective, nonrandomised study carried in pediatric intensive care unit of a tertiary care unit on 104 children requiring mechanical ventilation. Simultaneous ETCO2 and PaCO2 recording were taken, data on ventilator parameters recorded. Severity of lung disease was estimated by alveolar- arteriolar oxygen gradient, ventilation index and PaO2/FiO2 ratio. The PaCO2 and ETCO2 difference and its variability were studied. Results:208 samples were analysed where the mean PaCO2 value 28.9±9.7 mmhg was higher than mean ETCO2 value of 27.8±9.6 mmHg. The mean difference between PACO2 and ETCO2 was 1.6±3.23 mmHg. There was significant level of correlation between PACO2 and ETCO2 ( r=0.941, r2 = 0.886 , 95% CI= 0.95-0.97) for mild to moderate lung disease than severe lung disease. Systemic diseases, Ventilator index and alveolar arterial oxygen gradient did not have any significant correlation with the PACO2 and ETCO2 difference in our study. Conclusion: Significant correlation was found between the PaCO2 and ETCO2 value irrespective of the disease conditionand ETCO2 can be validated to predict PACO2.

THE IMPACT OF RESPIRATORY MUSCLE FATIGUE ON THE QUALITY AND EFFICIENCY OF RESCUE ACTION

INTRODUCTION The lifeguard is the person in charge of safety in water environments. After a rescue, it is possible that he has to execute a CPR. The European Resuscitation Council (ERC) as well as theAmerican Heart Association are currently encouraging a quality CPR performance. The lifeguard may be obliged to carry out a CPR during a long period of time as the response of the Emergency Medical Service takes 5–8 min on average and it can even reach 20 min. The normal respiratory muscle effort at maximal swimming intensity requires a significant fraction of cardiac output and causes leg blood flow to fall. The main objective of this paper was to determine respiratory muscle fatigue (RMF) level in swimming with different intensity on quality and efficiency rescu action in the water. MATERIAL AND METHODS The study involved eleven lifeguards male (9) and female (2); age: (24.25±1.5); body height( 176,27±7,88) and body mass (75.81±11,01)form University School of Physical Education, Cracow. Two tests were conducted: the first test involved the execution of 5 min of CPR (rested), and the second one in performing water rescue and subsequent CPR (exhausted) for 5 minutes. The quality of the CPR at rest and at fatigue condition was compared. The recording instrument was the Ambu Defib Trainer W (Wireless).The time and precision of the simulated water rescue was also registered. Two spirometry tests were performed the first test was set before swimming and the second after (exhausted). Maximal respiratory pressures (PImax, PEmax) were evaluated before and directly after swimming in different intensity.The quality of the respiratory muscle fatigue at rest and at fatigue condition was compared. The recording instrument was portable MicroLoop spirometer. RESULTS After e simulated water rescue significantly increase parameters such as: ventilation minute volume rested (3,06±22,10) exhausted (4,23 ±22,10. P &lt; .001); ventilation rate rested (3.60±34.80) exhausted (4,80 ±34.80. P &lt; .001); and stomach inflation rested (2,0±20,47) exhausted (5.80 ±20.47. P &lt; .001). The greatest variation in the results of the respiratory muscle fatigue both before and after swimming with different intensity was observed only in two parameters: maximal ventilation index (MVV) and peak exhaust flow (PEF). CONCLUSIONS The accumulated fatigue during a simulated water rescue performed by lifeguards reduces the quality of compression depth and pause between compressions. The following respiratory parameters were found to have the strongest effect on the swimming: during maximum exercise intensity and FEV 1 (-0.77) rested and FEV 1 (-0.57) exhausted and FVC (-0.79) rested and FVC (-0.70) exhausted.

Experimental evaluation of thermal comfort, ventilation performance indices and exposure to airborne contaminant in an airborne infection isolation room equipped with a displacement air distribution system

This study is focused on determining the convenience of the use of displacement ventilation strategy in airborne infection isolation rooms (AIIRs). Thermal comfort of the occupants of the chamber, ventilation and contaminant performance indices and the exposure of the health worker (HW) to the contaminants exhaled by the confined patient (P) are considered in a typical AIIR set up with two thermal breathing manikins and a radiant wall simulating an external wall. Three air renewal rates are tested to determine their influence in the studied variables. Results show that ventilation performance, contaminants and general comfort indices for both manikins perform well in the cases studied. Lockup phenomenon associated with displacement ventilation occurs above P but it has a low influence on contaminant exposure of HW because of the influence of the convective boundary layer of HW. The influence of the radiant wall could lock the air path near the exhaust grille.

The effect of monrustet on the exhalation of nitric oxide and inflammatory cytokines in patients with asthma combined with OSAHS

Objective:To study the effect of monrustet on fractional exhaled nitric oxide and inflammatory cytokines in the elderly with bronchial asthma combined obstructive sleep apnea hypopnea syndrome.Method:150 cases diagnosed as asthma were enrolled in this study. The patients were divided into bronchial asthma combined with OSAHS (n=72)and bronchial asthma (n=78). According to the different treatment methods , patients were divided into observation group and control group. Two groups were given common treatment with inhaled corticosteroids, and the observation group was taken orally montrast 10mg/night additionally. The fractional exhaled nitric oxide was detected before and after treatment. Serum were collected for detection of tumor necrosis factor alpha (TNR-α), Creactive protein (CRP) and interleukin 6 (IL-6), according to the sleep monitoring results, the sleep apnea low ventilation index (AHI) was calculated, and the changes of FeNO level,CRP,TNR-α,IL-6 and AHI were analyzed in the two groups.Result:Before treatment, the gender, age, degree of disease, FeNO level,TNR-α, CRP,IL-6 and AHI differences were not statistically significant in the two groups (P>0.05).After treatment, both groups of FeNO, TNR-α,CRP,IL-6 and AHI decreased before treatment (P < 0.05).The observation group was lower than the control group, and the difference was statistically significant (FeNO level, AHIP< 0.01,TNR-α, CRP,IL-6 P< 0.05).Conclusion::Montelukast can reduce the FeNO level, the expression of TNR-α, CRP, and IL-6 of patients of bronchial asthma combined with OSAHS. Further improvement of the patient's condition, and provide reference value for the clinical medicine of patients with asthma.

Impact of four different recumbencies on the distribution of ventilation in conscious or anaesthetized spontaneously breathing beagle dogs: An electrical impedance tomography study.

The aim was to examine the effects of recumbency and anaesthesia on distribution of ventilation in beagle dogs using Electrical Impedance Tomography (EIT). Nine healthy beagle dogs, aging 3.7±1.7 (mean±SD) years and weighing 16.3±1.6 kg, received a series of treatments in a fixed order on a single occasion. Conscious dogs were positioned in right lateral recumbency (RLR) and equipped with 32 EIT electrodes around the thorax. Following five minutes of equilibration, two minutes of EIT recordings were made in each recumbency in the following order: RLR, dorsal (DR), left (LLR) and sternal (SR). The dogs were then positioned in RLR, premedicated (medetomidine 0.01, midazolam 0.1, butorphanol 0.1 mg kg-1 iv) and pre-oxygenated. Fifteen minutes later anaesthesia was induced with 1 mg kg-1 propofol iv and maintained with propofol infusion (0.1–0.2 mg kg-1 minute-1 iv). After induction, the animals were intubated and allowed to breathe spontaneously (FIO2 = 1). Recordings of EIT were performed again in four recumbencies similarly to conscious state. Centre of ventilation (COV) and global inhomogeneity (GI) index were calculated from the functional EIT images. Repeated-measures ANOVA and Bonferroni tests were used for statistical analysis (p < 0.05). None of the variables changed in the conscious state. During anaesthesia left-to-right COV increased from 46.8±2.8% in DR to 49.8±2.9% in SR indicating a right shift, and ventral-to-dorsal COV increased from 49.8±1.7% in DR to 51.8±1.1% in LLR indicating a dorsal shift in distribution of ventilation. Recumbency affected distribution of ventilation in anaesthetized but not in conscious dogs. This can be related to loss of respiratory muscle tone (e.g. diaphragm) and changes in thoracic shape. Changing position of thoraco-abdominal organs under the EIT belt should be considered as alternative explanation of these findings.