Effects Of Ventilation Research Articles

Ventilation Strategies for Mitigating Indoor Air Pollutants in High-Rise Residential Buildings: A Case Study in Dubai

This study investigates the effectiveness of different ventilation methods in reducing indoor air pollutants in newly constructed residential buildings, focusing on indoor air quality (IAQ) in Dubai. The paper highlights the growing concern for IAQ in response to residents’ increasing awareness of their well-being and environmental sustainability. The study examines the concentrations of formaldehyde (HCHO), volatile organic compounds (VOCs), and total volatile organic compounds (TVOC) in bedrooms and living rooms before and after implementing various ventilation methods during the construction phase. The findings indicate that mechanical exhaust ventilation, mainly through bathroom and kitchen exhaust fans, was highly effective in reducing HCHO levels. Combining kitchen and bathroom exhaust fans demonstrated the most significant reduction in HCHO concentrations. Similarly, reductions in VOCs, such as ethylbenzene, toluene, and xylene, were observed with different ventilation methods. Natural ventilation also proved effective in reducing pollutant concentrations. The results emphasize the importance of implementing appropriate ventilation strategies to improve IAQ in residential buildings. However, the study acknowledges the limitations of a single-location measurement and recommends further research to validate the findings across different building types and locations. Additionally, long-term studies are necessary to assess the sustained effects of ventilation methods on IAQ. The study highlights the significance of addressing IAQ concerns in residential buildings and suggests potential research directions to explore other ventilation strategies and their energy efficiency implications. Ultimately, this research contributes to developing healthier and sustainable living environments by promoting effective ventilation strategies to mitigate indoor air pollutants.

Effect of CPAP therapy on the reperfusion lung injury after transluminal balloon angioplasty of the pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension

Aim. To evaluate the effect of non-invasive ventilation (NIV) in CPAP (continuous positive airway pressure) mode on the development of reperfusion pulmonary edema after percutaneous balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH).Materials and methods. The study included 70 patients with CTEPH who underwent the first stage of BPA. Prevention of reperfusion edema was carried out using NIV in the CPAP mode starting from the early postoperative period in combination with oxygen and diuretic therapy (as nedeed). The presence and severity of pulmonary edema was assessed based on clinical signs and data from computed tomography or chest radiography.Results. Patients after BPA were on CPAP therapy: average pressure: 10.0±0,7 hPa. During 1st day, the average time of use was: 990±417 minutes. Prolongation of CPAP therapy >1 day occurred in 26 (37%) patients. Depending on the severity of reperfusion edema to the lungs, patients were divided into 2 groups: group 1 (grade 1, n=42) and group 2 (grade 3-4, n=12). During the observation period, there were no cases of severe reperfusion edema (grade 5), and no cases required the use of invasive ventilation or extracorporeal membrane oxygenation. No complications of CPAP therapy were recorded. The number of PA segments and ΔPFG did not differ, but the PEPSI index was higher in group 2: 41,9 [16,0; 57,9] vs 80.5 [52,5; 111,25], p=0,0146. The number of days before discharge after BPA in patients of group 2 was higher: 4.0 [3,9; 5,5] vs 7,0 [4,6; 10,0] days, p=0,013. Despite the development of reperfusion edema, before discharge the SpO2 values in group 2 were comparable to the baseline: 93,0 [89,9; 94,2] vs 93,0 [89,7; 94,4]Conclusion. Preventive use of NIV in the CPAP mode, starting from the early postoperative period, is safe and makes it possible to achieve optimal clinical results in patients even with moderate and severe lung reperfusion edema after large volumes of surgical intervention.

Doxapram for the prevention and treatment of apnea in preterm infants.

Doxapram for the prevention and treatment of apnea in preterm infants.

Real-Time Digital Feedback Device and Simulated Newborn Ventilation Quality.

Effective bag-valve-mask ventilation is critical for reducing perinatal asphyxia-related neonatal deaths; however, providers often fail to achieve and maintain effective ventilation. The Augmented Infant Resuscitator (AIR) attaches to bag-valve-masks and provides visual feedback on air leaks, blocked airways, harsh breaths, and improper ventilatory rates. We evaluated the effect of this real-time-digital feedback on ventilation quality and the effective determination of airway integrity in a randomized controlled study in Uganda and the United States. Birth attendants trained in newborn resuscitation were randomized to receive either real-time AIR device feedback (intervention) or no feedback (control) during ventilation exercises. Intervention-arm participants received a 2-minute orientation on interpreting AIR feedback using a single-page iconography chart. All participants were randomly assigned to 3 blinded ventilation scenarios on identical-appearing manikins with airways that were either normal, significantly leaking air, or obstructed. We enrolled 270 birth attendants: 77.8% from Uganda and 22.2% from the United States. Birth attendants receiving AIR feedback achieved effective ventilation 2.0 times faster: intervention mean 13.8s (95% confidence interval 10.6-17.1) versus 27.9s (21.6-34.3) for controls (P < .001). The duration of effective ventilation was 1.5 times longer: intervention mean 72.1s (66.7-77.5) versus 47.9s (41.6-54.2) for controls (P < .001). AIR feedback was associated with significantly more accurate and faster airway condition assessment (intervention mean 43.7s [40.5-47.0] versus 55.6s [51.6-59.6]). Providers receiving real-time-digital AIR device feedback achieved effective ventilation significantly faster, maintained it longer, and determined airway condition faster and more accurately than providers in the control group.

P010 Delivery of volume assured pressure support (VAPS) through tracheostomy in paediatric patients

Abstract INTRODUCTION Volume assured pressure support (VAPS) allows the ventilator to deliver a constant pre-set tidal volume or alveolar ventilation by automatically adjusting the inspiratory pressures within a set range, providing targeted pressure support. Data on its use in children are limited. We describe a series of four children effectively and safely ventilated using VAPS mode through tracheostomy. METHODS Retrospective review of patient notes. PROGRESS TO DATE Four paediatric patients were identified in our cohort who were successfully and safely ventilated using the VAPS mode through tracheostomy. The patients were between 6-14 years of age inclusive, with four differing underlying disease processes – Prader-Willi syndrome, congenital central hypoventilation syndrome, Guillain-Barré syndrome and Moebius-type syndrome. INTENDED OUTCOME AND IMPACT Whilst there have been previous paediatric case reports and case series which have demonstrated efficacy of VAPS mode used non-invasively, the use of VAPS mode to provide effective and safe ventilation through tracheostomy in children has been described in only one recent case series. The advantages of its use over conventional bilevel positive airway pressure support include its ability to compensate for changes in tidal volume, which can occur with changes in lung compliance and during different stages of sleep. This case series highlights safe and effective use of VAPS mode in children with tracheostomy.

Airway Pressure Release Ventilation in COVID-19-Associated Acute Respiratory Distress Syndrome-A Multicenter Propensity Score-Matched Analysis.

Background: There are limited and partially contradictory data on the effects of airway pressure release ventilation (APRV) in COVID-19-associated acute respiratory distress syndrome (CARDS). Therefore, we analyzed the clinical outcome, complications, and longitudinal course of ventilation parameters and laboratory values in patients with CARDS, who were mechanically ventilated using APRV. Methods: Respective data from 4 intensive care units (ICUs) were collected and compared to a matched cohort of patients receiving conventional low tidal volume ventilation (LTV). Propensity score matching was performed based on age, sex, blood gas analysis, and APACHE II score at admission, as well as the implementation of prone positioning. Findings: Forty patients with CARDS, who were mechanically ventilated using APRV, and 40 patients receiving LTV were matched. No significant differences were detected for tidal volumes per predicted body weight, peak pressure values, and blood gas analyses on admission, 6 h post admission as well as on day 3 and day 7. Regarding ICU survival, no significant difference was identified between APRV patients (40%) and LTV patients (42%). Median duration of mechanical ventilation and duration of ICU treatment were comparable in both groups. Similar complication rates with respect to ventilator-associated pneumonia, septic shock, thromboembolic events, barotrauma, as well as the necessity for hemodialysis were detected for both groups. Clinical characteristics that were associated with increased mortality in a Cox proportional hazards regression analysis included age (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.04-1.1; P < .001), severe acute respiratory distress syndrome (HR 2.62, 95% CI 1.02-6.7; P = .046) and the occurrence of septic shock (HR 17.18, 95% CI 2.06-143.2; P = .009), but not the ventilation mode. Interpretation: Intensive care unit survival, duration of mechanical ventilation, and ICU treatment as well as ventilation-associated complication rates were equivalent using APRV compared to conventional LTV in patients with CARDS.

Can windcatcher's natural ventilation beat the chill? A view from heat loss and thermal discomfort

Windcatchers provide effective low-energy ventilation and summer passive cooling in temperate climates. However, their use in winter is limited due to significant ventilation heat loss and potential discomfort. Limited research has been conducted on quantifying windcatcher heat loss in cold climates, particularly through field studies. This study aims to evaluate the applicability of windcatchers in low-temperature conditions, with a focus on ventilation heat loss and thermal discomfort. Field experiments were conducted in Nottingham, UK, during an icy period. A 3D-printed prototype windcatcher and a test room were built and tested in such weather conditions. A Computational Fluid Dynamics (CFD) model validated against the field experimental data was employed to investigate the windcatcher's performance in a typical UK primary school classroom. The field experimental results indicate that the indoor airflow patterns are dynamic and continuously change with varying external wind conditions. Using static boundary conditions for ventilation analysis is inadequate, as it may lead to inaccurate predictions due to observed fluctuations and irregular airflow patterns. CFD modelling revealed significant over-ventilation in the classroom at external wind speeds of 3 m/s, despite being previously deemed as “satisfactory”, “adequate”, or “sufficient” ventilation. At wind speeds of 3 m/s or higher, the over-ventilation can cause a minimum 941.4 W heat loss, adding 4.7 kWh heating load and £1.6 electricity cost for a typical-sized single classroom during a 5-h occupied period. The research findings highlighted that control strategies should be introduced to reduce over-ventilation. Integrating heat recovery or thermal storage can enhance winter thermal conditions.

Elucidating the Impacts of Various Atmospheric Ventilation Conditions on Local and Transboundary Ozone Pollution Patterns: A Case Study of Beijing, China

AbstractThe ventilation condition in the atmospheric boundary layer, which varies with the synoptic pattern, is a crucial factor affecting the transport and dispersion of air pollutants. In this study, taking Beijing as an example, local ozone (O3) accumulation and the transboundary O3 pollution (TOP) patterns during the warm season were explored under different boundary layer ventilation conditions by using integrated objective weather classification, non‐negative matrix factorization, and backward trajectory model. Results show that local sources are a major contributor to O3 pollution in the whole of Beijing, accounting for ∼73.36% of the O3 concentration on average. The local accumulation is mainly facilitated by poor ventilation conditions with weak wind speeds (&lt;3 m/s) under favorable photochemical reaction conditions and abundant precursors, resulting in local O3 events. In contrast, the occurrence of synoptic patterns associated with TOP is more frequent, so the TOP contribution cannot be ignored, especially for the northern regions, where it may exceed 50%. Horizontal wind vector variations play a marked role in driving the TOP, affecting not only the location of the source region and transport pathway but also the transport distance and volume. In addition, a strong nocturnal low‐level jet (LLJ) results in horizontal transport and a temporary rise in O3 concentration, while a daytime LLJ stimulates a peak in O3 concentration over the downwind area, lagging by about 1 hr. Our findings provide new perspectives on the effects of boundary layer ventilation on the regulation of O3 pollution, as well as other air pollutants.

Physiological effects of lung-protective ventilation in patients with lung fibrosis and usual interstitial pneumonia pattern versus primary ARDS: a matched-control study

BackgroundAlthough patients with interstitial pneumonia pattern (ILD-UIP) and acute exacerbation (AE) leading to severe acute respiratory failure may require invasive mechanical ventilation (MV), physiological data on lung mechanics during MV are lacking. We aimed at describing the physiological effect of lung-protective ventilation in patients with AE-ILD-UIP compared with primary ARDS.MethodsPartitioned lung and chest wall mechanics were assessed in a series of AE-ILD-UIP patients matched 1:1 with primary ARDS as controls (based on BMI and PaO2/FiO2 ratio). Three PEEP levels (zero = ZEEP, 4–8 cmH2O = PEEPLOW, and titrated to achieve positive end-expiratory transpulmonary pressure PL,EE = PEEPTITRATED) were used for measurements.ResultsTen AE-ILD-UIP patients and 10 matched ARDS were included. In AE-ILD-UIP median PL,EE at ZEEP was − 4.3 [− 7.6– − 2.3] cmH2O and lung elastance (EL) 44 [40–51] cmH2O/L. At PEEPLOW, PL,EE remained negative and EL did not change (p = 0.995) versus ZEEP. At PEEPTITRATED, PL,EE increased to 0.8 [0.3–1.5] cmH2O and EL to 49 [43–59] (p = 0.004 and p < 0.001 compared to ZEEP and PEEPLOW, respectively). ΔPL decreased at PEEPLOW (p = 0.018) and increased at PEEPTITRATED (p = 0.003). In matched ARDS control PEEP titration to obtain a positive PL,EE did not result in significant changes in EL and ΔPL.ConclusionsIn mechanically ventilated AE-ILD-UIP patients, differently than in patients with primary ARDS, PEEP titrated to obtain a positive PL,EE significantly worsened lung mechanics.

Investigation on indoor airflow and contaminant dispersion of diffuse ceiling ventilation in heating and cooling modes

This paper systematically investigates the indoor airflow and contaminant dispersion of diffuse ceiling ventilation (DCV) for space heating and cooling. A numerical model of the office with DCV is built and validated. The indoor thermal comfort and air quality (IAQ) under different cases are analyzed. Simultaneously, different indices are employed to determine the influence of exhaust positions and air change rates on the system. The results indicate that DCV can provide a satisfying thermal environment both in heating and cooling modes, and there is no reverse flow from the room to the plenum. Besides, the visualizations of indoor airflow, temperature distributions, and mean age of air (MAA) show the different characteristics during heating and cooling. The ranges of contaminant removal effectiveness (CRE) and temperature effectiveness (TE) are 0.87–1.00 and 0.79–1.55 for heating, respectively. For cooling, they are 0.96–1.23 (CRE) and 0.92–1.06 (TE), respectively. Although the TE for heating is slightly higher than that of cooling, the CO2 concentrations and CRE manifest that DCV performs better for space cooling. Moreover, the results show that the exhaust positions influence TE more than CRE, especially for heating. Within the measured air change rates, it is found that the increase of air change per hour (ACH) can aid to the ventilation effectiveness of DCV. Meanwhile, the linear regression equations between ACHs and MAA are obtained. This research is helpful to reveal the flow mechanisms of DCV and guides the design and operation of the system.

Radon transport to indoor air in groundwater plants as a by-effect of different water treatments

Radon released from groundwater into indoor air is the main radiation safety problem for water treatment plants. This study investigated the release of radon from different water treatment processes and the effect of ventilation on the indoor radon concentration at six waterworks. In addition to various aeration processes, groundwater pretreatments, such as activated carbon and pre-ozonation, were demonstrated to be associated with the indoor radon concentration. This study revealed that accurate assessment of radon exposure at water treatment plants is very difficult because of the large and sudden temporal variations in the radon concentration and smaller local variations that follow the steps of the water treatment process and ventilation. Based on the study, concrete proposals are also presented for improving radiation safety and the reliability of measurements.

Sequential inspiratory muscle exercise-noninvasive positive pressure ventilation alleviates oxidative stress in COPD by mediating SOCS5/JAK2/STAT3 pathway

BackgroundPulmonary rehabilitation training is of great significance for the prognosis of chronic obstructive pulmonary disease (COPD) patients. The purpose of this study was to investigate the therapeutic effect and pathway of a new sequential noninvasive positive pressure ventilation (NIPPV) + inspiratory muscle training (IMT) therapy.MethodsA total of 100 COPD patients were enrolled and randomly divided into oxygen therapy (OT), NIPPV, IMT and sequential (NIPPV + IMT) group. Lung function, exercise endurance, quality of life, and dyspnea symptoms were examined and recorded. Then, reactive oxygen species (ROS), malonaldehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) levels were detected by enzyme-linked immunoassay, and suppressor of cytokine signaling 5 (SOCS5)/janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway expression changes were detected by quantitative real time-polymerase chain reaction (qRT-PCR) and western blot. A mouse model of COPD was then established to further verify the effects of SOCS5/JAK2/STAT3 pathways on lung function and oxidative stress.ResultsAfter 8 weeks of treatment, NIPPV, IMT or sequential (NIPPV + IMT) significantly improved exercise endurance, quality of life and dyspnea, reduced oxidative stress, promoted SOCS5 expression and inhibited the activation of JAK2/STAT3 pathway, and no significant effect was observed on lung function of COPD patients. Notably, sequential (NIPPV + IMT) showed better therapeutic outcomes than either IMT or NIPPV alone. Moreover, results at the animal level showed that overexpression of SOCS5 significantly reduced pulmonary inflammatory infiltration, pathological changes and oxidative stress levels in COPD mice, enhanced lung function, and inhibited the activation of JAK2/STAT3 pathway.ConclusionOur results elucidated that sequential (NIPPV + IMT) significantly relieved COPD development by regulating SOCS5/JAK2/STAT3 signaling-mediated oxidative stress.

Experimental evaluation of airflow guiding components for wind-driven single-sided natural ventilation: A comparative study in a test chamber

Single-sided ventilation is a frequently employed ventilation strategy in contemporary structures, yet its effectiveness is often mediocre, underscoring the need for solutions to enhance its performance. To evaluate the effect of louvres and guide vanes on the effective ventilation rate, 21 different louvre configurations and four guide vane designs were compared with a plain opening for single-sided ventilation in a full-scale experimental test chamber under three different magnitudes of local wind velocity. Ventilation rates were measured using the tracer gas decay method with 12 NDIR CO2 sensors. The findings, obtained under specific test conditions, indicate that deeper openings result in a decline in ventilation rate performance. It was observed that wider guide vanes lead to higher ventilation rates, suggesting their potential to enhance SSV performance. The results reveal that, in most cases, louvres contribute to a decline in the system's performance. However, the ventilation rate is influenced by the angle and number of louvres, with optimal performance observed at specific angles and fewer louvres. These findings provide valuable insights for optimizing the design of airflow-guiding components in wind-driven single-sided ventilation systems, enabling the development of more efficient and customized solutions for natural ventilation in buildings.

Optimum window-opening control for naturally ventilated buildings with phase change materials in the hot and humid climate of Indonesia

This study aims to determine the optimum window-opening control that maximizes annual thermal comfort using ventilative cooling, i.e., night and comfort ventilation, in naturally ventilated buildings where phase change materials (PCMs) are used. A thermal energy simulation (TES) coupled with an airflow network model was constructed to evaluate the comfort ventilation and thermal storage effects of the PCMs by controlling the window-opening patterns. The EnergyPlus-based coupled TES model was validated by comparing with the field measurement results of a full-scale experimental building in Indonesia. The root-mean-square errors of the temperature and air speeds at the center of the target building ranged from 0.2 to 0.5 °C and 0.1–0.2 m/s, respectively. The accuracy of the coupled TES was similar to that of computational fluid dynamics coupled with the heat balance analysis, which can simulate the spatial distributions of temperature and air speeds. The annual simulation results showed that prioritizing the thermal storage effect of the PCMs in the morning and comfort ventilation in the afternoon increases the thermal comfort period. For the optimum window-opening control to maximize thermal comfort in the hot and humid climate, an indoor temperature of 27 °C can be considered a criterion to open the windows for comfort ventilation in addition to night ventilation for the thermal storage effect. When this criterion was applied, the thermal comfort period in the room with PCMs increased to 83.3 %. Accordingly, the reduction in electricity consumption for space cooling was 41 % less than that in a control room without PCMs.

Building Ventilation: The Consequences for Personal Exposure

Ventilation is central to human civilization. Without it, the indoor environment rapidly becomes uncomfortable or dangerous, but too much ventilation can be expensive. We spend much of our time indoors, where we are exposed to pollutants and can be infected by airborne diseases. Ventilation removes pollution and bioaerosols from indoor sources but also brings in pollution from outdoors. To determine an appropriate level of ventilation and an appropriate way of providing it, one must understand that the needs for ventilation extend beyond simple thermal comfort; the quality of indoor air is at least as important. An effective ventilation system will remove unwanted contaminants, whether generated within the space by activities or by the simple act of breathing, and ensure that the ventilation system does not itself introduce or spread contaminants from elsewhere. This review explores how ventilation flows in buildings influence personal exposure to indoor pollutants and the spread of airborne diseases.

Effect of mechanical ventilation under intubation on respiratory tract change of bacterial count and alteration of bacterial flora

Background: The most common ‘second strike’ in mechanically ventilated patients is a pulmonary infection caused by the ease with which bacteria can invade and colonize the lungs due to mechanical ventilation. At the same time, metastasis of lower airway microbiota may have significant implications in developing intubation mechanical ventilation lung inflammation. Thus, we establish a rat model of tracheal intubation with mechanical ventilation and explore the effects of mechanical ventilation on lung injury and microbiological changes in rats. To provide a reference for preventing and treating bacterial flora imbalance and pulmonary infection injury caused by mechanical ventilation of tracheal intubation. Methods: Sprague-Dawley rats were randomly divided into Control, Mechanical ventilation under intubation (1, 3, 6 h) groups, and Spontaneously breathing under intubation (1, 3, 6 h). Lung histopathological injury scores were evaluated. 16SrDNA sequencing was performed to explore respiratory microbiota changes, especially, changes of bacterial count and alteration of bacterial flora. Results: Compared to groups C and SV, critical pathological changes in pulmonary lesions occurred in the MV group after 6 h (p < 0.05). The Alpha diversity and Beta diversity of lower respiratory tract microbiota in MV6, SV6, and C groups were statistically significant (p < 0.05). The main dominant bacterial phyla in the respiratory tract of rats were Proteobacteria, Firmicutes, Bacteroidetes, and Cyanobacteria. Acinetobacter radioresistens in group C was significant, Megaonas in group MV6 was significantly increased, and Parvibacter in group SV6 was significantly increased. Anaerobic, biofilm formation, and Gram-negative bacteria-related functional genes were altered during mechanical ventilation with endotracheal intubation. Conclusion: Mechanical ventilation under intubation may cause dysregulation of lower respiratory microbiota in rats.

Investigation of the effectiveness of prone ventilation in patients followed up for acute respiratory distress syndrome in the intensive care unit.

Prone positioning has been found to improve oxygenation in most patients with acute respiratory distress syndrome (ARDS). The study aimed to investigate the effectiveness of the prone position in patients with ARDS. The prone position is one of the ventilator techniques included in recent guidelines for acute respiratory distress syndrome. This study was a retrospective evaluation of the records of 100 ARDS patients who were administered prone position mechanical ventilation in our intensive care unit. All patients were placed in the prone position for a total of 12 hours per day at 4-hour intervals (supine-prone) while admitted to the intensive care unit. This study included 100 participants. These patients were divided into two groups as survivors [(n=38, 16 females, 22 males, median age: 60 (24-86)] and non-survivors [(n=62, 19 females, 43 males, median age: 64 (21-93)], according to their intensive care follow-ups. Acute physiology and chronic health evaluation (APACHE) II score, the sequential organ failure assessmentscore (SOFA), and inflammation markers were statistically significantly higher in the non-survivor group. Between the two groups, there was no statistically significant difference in terms of fundamental characteristics. In the sub-group evaluation of the subjects in patients with ARDS with and without novel coronavirus disease 2019 (COVID-19) groups, the patients in the COVID-19 (+) group were older, had shorter hospital stays, had higher APACHE II and SOFA scores, and higher rates of cardiovascular disease and sepsis. Applying prone-position mechanical ventilation in the cohorts of our patients with ARDS resulted in a demonstrable significant improvement in the oxygenation levels of our patients.

Post-COVID ventilation design: Infection risk-based target ventilation rates and point source ventilation effectiveness

Post-COVID ventilation design: Infection risk-based target ventilation rates and point source ventilation effectiveness

A study of comparison of outcomes of positive pressure ventilation and face mask oxygen on arterial blood gas parameters in children with congestive heart failure

Aims and objective. To compare the effects of Positive Pressure Ventilation (PPV) and Face Mask oxygen on arterial blood gas (ABG) parameters in children with congestive heart failure. Materials and methods. A prospective, randomized, single-blind, cross-sectional study was undertaken in eastern India’s Dr. B.C. Roy Post Graduate Institute of Pediatric Sciences PICU. From December 2014 to June 2016, single-blind randomization was used to diagnose congestive heart failure in children aged 3 months to 12 years. Results. Patients receiving face mask oxygen had a mean pH of 7.2150, while those receiving NIV had a mean pH of 7.2740 (P value = 0.012, &lt;0.05). After 6 hours, the pH improved more in the NIV group (mean pH = 7.3023) than the face mask oxygen group (mean pH = 7.2503), P value = 0.003 (&lt;0.05). The group receiving face mask oxygen had a mean pCO2 of 54.93 at the start of the study, while the NIV group had 52.83 (P value = 0.395, &gt;0.05). The baseline pCO2 values of the two groups were similar. After 1-2 hours of investigation, the face mask oxygen group had a mean pCO2 of 53.50, whereas the NIV group had 47.77, with a P value of 0.008 (&lt;0.05). After 4-6 hours, the face mask oxygen group had a mean pCO2 of 50.90, while the NIV group had 46.77, with a P value of 0.001 (&lt;0.05). Conclusion. After 6 hours of therapy, NIV improved mean pH more than face mask oxygen. NIV ventilation improved pCO2 readings more than face mask oxygen after 2 hours. The mean pCO2 drop over 4-6 hours in the NIV group was greater than in the face mask oxygen group.

Effect of Heating, Ventilation, and Air Conditioning (HVAC) System on Indoor Air Quality in a Medical Facility

Indoor Air Quality (IAQ) refers to the stationary air within an inhabited or occupied structure. Previously, there were fewer studies on indoor air quality in medical facilities in Malaysia especially in Terengganu. Most indoor air quality issues are caused by insufficient Heating, Ventilation, and Air Conditioning (HVAC) systems, which regulate three parameters. The purpose of this study is to assess the indoor air quality of a medical facility and determine if it complies with the Industry Code of Practice 2010 (ICOP 2010) and ASHRAE 170-2017. In this investigation, a total of 3 locations namely Administration Office, Surgical Outpatient Department (SOPD) waiting area and Ophthalmology Consultation Room in Hospital Sultanah Nur Zahirah (HSNZ) were evaluated. Walkthrough inspections were done at the locations before data collection to determine the IAQ. Two IAQ meters, notably VelociCalc and Testo, were used to collect data to assess the temperature, relative humidity, and air flow of the selected locations. Samples were taken every 2 hours for each location from 8 a.m. to 5 p.m. The data then were analysed. All three locations' temperatures were lower than ICOP 2010's acceptable limit (23-26°C), but still within ASHRAE 170-207's 21-24°C range, except for the SOPD waiting room. All three locations met ICOP 2010 and ASHRAE 170-207 relative humidity standards. Meanwhile, only the SOPD waiting room had an appropriate air flow of 0.16-0.17m/s per ICOP 2010. The study also revealed that there was a correlation between the number of occupancies and the performance of HVAC system with the indoor air quality level.