Quantifying hospital environmental ventilation using carbon dioxide monitoring - a multicentre study.

The COVID-19 pandemic has highlighted the importance of environmental ventilation in reducing airborne pathogen transmission. Carbon dioxide monitoring is recommended in the community to ensure adequate ventilation. Dynamic measurements of ventilation quantifying human exhaled waste gas accumulation are not conducted routinely in hospitals. Instead, environmental ventilation is allocated using static hourly air change rates. These vary according to the degree of perceived hazard, with the highest change rates reserved for locations where aerosol-generating procedures are performed, where medical/anaesthetic gases are used and where a small number of high-risk infective or immunocompromised patients may be isolated to reduce cross-infection. We aimed to quantify the quality and distribution of ventilation in hospital by measuring carbon dioxide levels in a two-phased prospective observational study. First, under controlled conditions, we validated our method and the relationship between human occupancy, ventilation and carbon dioxide levels using non-dispersive infrared carbon dioxide monitors. We then assessed ventilation quality in patient-occupied (clinical) and staff break and office (non-clinical) areas across two hospitals in Scotland. We selected acute medical and respiratory wards in which patients with COVID-19 are cared for routinely, as well as ICUs and operating theatres where aerosol-generating procedures  are performed routinely. Between November and December 2022, 127,680 carbon dioxide measurements were obtained across 32 areas over 8 weeks. Carbon dioxide levels breached the 800 ppm threshold for 14% of the time in non-clinical areas vs. 7% in clinical areas (p < 0.001). In non-clinical areas, carbon dioxide levels were > 800 ppm for 20% of the time in both ICUs and wards, vs. 1% in operating theatres (p < 0.001). In clinical areas, carbon dioxide was > 800 ppm for 16% of the time in wards, vs. 0% in ICUs and operating theatres (p < 0.001). We conclude that staff break, office and clinical areas on acute medical and respiratory wards frequently had inadequate ventilation, potentially increasing the risks of airborne pathogen transmission to staff and patients. Conversely, ventilation was consistently high in the ICU and operating theatre clinical environments. Carbon dioxide monitoring could be used to measure and guide improvements in hospital ventilation.

Traditional farmers' pig trait preferences and awareness levels toward reproductive biotechnology application in Zambia.

Objective: This study assessed traditional farmers' preferences for indigenous pigs and their awareness levels toward reproductive biotechnology. Materials and Methods: This cross-sectional, descriptive study employed a mixed-methods concurrent triangulation design with a pragmatic approach. For quantitative data collection, a randomly selected sample size of 622 respondents was interviewed using a structured questionnaire. A semi-structured interview guide was used in seven focus group discussions (FGDs) for qualitative data. For quantitative data, descriptive statistics were used to find out how often something happened, and chi-square tests were used to look for relationships. For qualitative data, thematic analysis was used. Results: The majority (66.9%) of respondents were female, and they had largely (64.8%) attended a primary level of education. A slight majority (43.1%) of the respondents were 30-45 years old. Most respondents (65.1%) were low-income earners (below K500). Incidentally, the majority (74.1%) of respondents had low awareness of reproductive biotechnologies. Respondents' awareness levels were associated with gender (p < 0.001), education (p < 0.001), income (p < 0.01), and not age (p > 0.05). With regard to trait preference, a total of seven indigenous pig traits were reportedly preferred, of which disease resistance (25.9%) and litter size (23.8%) were the most preferred. From FGDs, participants valued indigenous pigs, citing many preferred traits, of which disease resistance and litter size were the most emphasized traits. Some participants were aware of many reproductive biotechnologies and their perceived advantages. However, they were more familiar with artificial insemination, heat detection methods, and synchronization. Conclusions: The majority of respondents had low awareness of reproductive biotechnologies. Respondents' awareness was associated with sociodemographic characteristics. The identified indigenous pig traits preferred by traditional farmers included adaptive and productive traits.

Attitudes and preferences of traditional farmers toward reproductive biotechnology application for improved indigenous pig production in Zambia.

Background and Aim: Pig production remains crucial to the livelihood of farmers in Zambia. However, low production continues to undermine efforts to reduce animal protein deficit; hence, the need emerges to improve production through biotechnology. To contribute to the prediction of their acceptance, this study assessed the attitudes and preferences of traditional farmers toward reproductive biotechnologies by exploring the socio-demographic characteristics of farmers. Materials and Methods: The study conducted a cross-sectional descriptive survey that employed a mixed-methods design with a qualitative-quantitative methodological triangulation. Quantitative data were obtained from 622 respondents using a questionnaire, whereas seven focus group discussions (FGDs) were conducted to obtain qualitative data. Descriptive statistics and thematic analysis were used to analyze quantitative and qualitative data, respectively. Results: The majority (65.1%) of the respondents were low-income earners who mainly (64.8%) attained primary education. In addition, pig farming was dominated by middle-aged (43.7%) and elderly (40.7%) individuals. Moreover, most of the respondents owned (51.3% and 78.0%) more than 2 acres and six pigs, respectively. Furthermore, the respondents expressed a positive attitude (3.84±0.42) toward reproductive biotechnology application. However, despite supportive opinions (4.17±0.54) and favorable behavioral intentions (4.09±0.51), their feelings were generally neutral (3.10±0.89). In addition, the study observed various contrasting attitudes across socio-demographic factors. The respondents mainly preferred artificial insemination (AI; 66.2%). The results of the FGDs supported the survey findings. Nevertheless, the lack of information, knowledge and practical exposure, absence of peer influence, perceived beliefs and risks, poverty situations, and gender issues were pinpointed as the identified barriers to the biotechnology acceptance of the participants. Conclusion: The respondents generally supported reproductive biotechnology application and its contribution to improved production. However, further promotion of the favorable attitudes of the farmers will be required. In this case, interventions sensitive to their socio-demographic characteristics, perceived barriers, and identified contributing factors to favorable attitudes will be crucial. In addition, despite the overwhelming preference for AI, efforts to promote AI-supporting reproductive technologies are required because they contribute to AI success rate.

The effect of respiratory activity, non-invasive respiratory support and facemasks on aerosol generation and its relevance to COVID-19.

Respirable aerosols (< 5 µm in diameter) present a high risk of SARS-CoV-2 transmission. Guidelines recommend using aerosol precautions during aerosol-generating procedures, and droplet (> 5 µm) precautions at other times. However, emerging evidence indicates respiratory activities may be a more important source of aerosols than clinical procedures such as tracheal intubation. We aimed to measure the size, total number and volume of all human aerosols exhaled during respiratory activities and therapies. We used a novel chamber with an optical particle counter sampling at 100 l.min-1 to count and size-fractionate close to all exhaled particles (0.5-25 µm). We compared emissions from ten healthy subjects during six respiratory activities (quiet breathing; talking; shouting; forced expiratory manoeuvres; exercise; and coughing) with three respiratory therapies (high-flow nasal oxygen and single or dual circuit non-invasive positive pressure ventilation). Activities were repeated while wearing facemasks. When compared with quiet breathing, exertional respiratory activities increased particle counts 34.6-fold during talking and 370.8-fold during coughing (p < 0.001). High-flow nasal oxygen 60 at l.min-1 increased particle counts 2.3-fold (p = 0.031) during quiet breathing. Single and dual circuit non-invasive respiratory therapy at 25/10 cm.H2 O with quiet breathing increased counts by 2.6-fold and 7.8-fold, respectively (both p < 0.001). During exertional activities, respiratory therapies and facemasks reduced emissions compared with activities alone. Respiratory activities (including exertional breathing and coughing) which mimic respiratory patterns during illness generate substantially more aerosols than non-invasive respiratory therapies, which conversely can reduce total emissions. We argue the risk of aerosol exposure is underappreciated and warrants widespread, targeted interventions.

Airborne transmission of severe acute respiratory syndrome coronavirus-2 to healthcare workers: a narrative review.

Healthcare workers are at risk of infection during the severe acute respiratory syndrome coronavirus-2 pandemic. International guidance suggests direct droplet transmission is likely and airborne transmission occurs only with aerosol-generating procedures. Recommendations determining infection control measures to ensure healthcare worker safety follow these presumptions. Three mechanisms have been described for the production of smaller sized respiratory particles ('aerosols') that, if inhaled, can deposit in the distal airways. These include: laryngeal activity such as talking and coughing; high velocity gas flow; and cyclical opening and closure of terminal airways. Sneezing and coughing are effective aerosol generators, but all forms of expiration produce particles across a range of sizes. The 5-µm diameter threshold used to differentiate droplet from airborne is an over-simplification of multiple complex, poorly understood biological and physical variables. The evidence defining aerosol-generating procedures comes largely from low-quality case and cohort studies where the exact mode of transmission is unknown as aerosol production was never quantified. We propose that transmission is associated with time in proximity to severe acute respiratory syndrome coronavirus-1 patients with respiratory symptoms, rather than the procedures per se. There is no proven relation between any aerosol-generating procedure with airborne viral content with the exception of bronchoscopy and suctioning. The mechanism for severe acute respiratory syndrome coronavirus-2 transmission is unknown but the evidence suggestive of airborne spread is growing. We speculate that infected patients who cough, have high work of breathing, increased closing capacity and altered respiratory tract lining fluid will be significant producers of pathogenic aerosols. We suggest several aerosol-generating procedures may in fact result in less pathogen aerosolisation than a dyspnoeic and coughing patient. Healthcare workers should appraise the current evidence regarding transmission and apply this to the local infection prevalence. Measures to mitigate airborne transmission should be employed at times of risk. However, the mechanisms and risk factors for transmission are largely unconfirmed. Whilst awaiting robust evidence, a precautionary approach should be considered to assure healthcare worker safety.

Axium MicroFX coil for the completing endovascular aneurysm surgery study (ACCESS). A prospective evaluation of the safety and durability of Axium MicroFX PGLA coils.

Recanalization of previously coiled aneurysms remains a major drawback of endovascular aneurysm therapy. We performed a prospective single arm trial to provide early initial data regarding the safety and angiographic durability of a new coil technology, the Axium MicroFX Polyglycolic/polylactic acid (PGLA) coil, which was designed to lower recanalization rates. Fifteen patients (16 aneurysms) were prospectively enrolled. Demographic and peri-procedural data were collected. Angiographic images of the initial coil embolization and three to six month follow-up angiographic images underwent blinded evaluation. Seven (47%) SAH and eight (53%) elective patients were enrolled. Blinded evaluation of the initial embolization demonstrated that 5/16 (31%) aneurysms achieved Raymond grade 1, 5/16 (31%) grade 2 and 6/16 (38%) grade 3. Three to six month angiography was obtained in 12/15 patients (80%); two patients expired (1 SAH, 1 elective) and one was lost to follow-up (SAH). All patients who underwent follow-up angiography had a mRS ≤1. Blinded evaluation of embolization demonstrated 7/13 aneurysms (54%) improved in Raymond grading, five (38%) were stable and one aneurysm (8%) worsened. One patient developed an asymptomatic peri-aneurysmal parent vessel stenosis. Axium MicroFX coils appear to be safe, though the small number of patients in this series obviates comparative analysis with other series. Further studies are needed with more patients to compare the angiographic durability of Axium MicroFX coils to other coils.

Heavy marijuana users show increased serum apolipoprotein C-III levels: evidence from proteomic analyses.

Marijuana (MJ) is the most commonly used illicit drug in the United States. Its abuse is associated with cognitive dysfunctions and increased resistance to blood flow in the cerebral vasculature. In addition, MJ abuse is associated with increased risks of potentially serious cardiovascular disorders. In the present study, we used the protein chip platform based on surface-enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI-TOF-MS) to test the possibility that MJ abuse might be associated with changes in serum protein levels. Indeed, MJ users showed significant increases in three protein peaks, which were identified as three isoforms of apolipoprotein (apo) C-III. Immunoprecipitation using an apoC-III antibody also validated the identification of the proteins. Marijuana-induced increases in apoC-III levels might occur through chronic stimulation of hepatic cannabinoid receptors (CB1 and/or CB2) by its active ingredient, Delta(9)tetrahydrocannibol (THC). Thus, chronic MJ abuse might cause increased transcription and/or translation of apoC-III in the liver with corresponding changes reflected in the plasma of these patients. In any case, because apoC-III is a cardiovascular risk factor, the increased levels observed in MJ users might explain, in part, the cardiac and cerebral abnormalities reported in these patients.

The importance of nurse-led home visits in the assessment of children with problematic asthma.

OBJECTIVE: To evaluate and identify potentially modifiable factors in children with problematic asthma by a nurse-led assessment and home visit. DESIGN: Observational cohort study. SETTING: A tertiary paediatric respiratory centre. PATIENTS: 71 children, aged 4.5-17.5 years, with problematic asthma currently under follow-up at a tertiary respiratory centre. INTERVENTIONS: A nurse-led hospital visit followed by a home visit. MAIN OUTCOME MEASURES: Identification and attempted change of exacerbating factors so that further investigations and consideration of off-label, potentially toxic, asthma therapies were not necessary. RESULTS: Potentially modifiable factors were identified in 56 (79%) children. Many children had multiple causes for poor control. The most important were ongoing allergen exposure, 22 children (31%); passive or active smoking, 18 children (25%); medication issues including adherence, 34 children (48%); psychosocial factors, 42 families (59%). The home visit contributed valuable information to this assessment. At the home visit house dust mite avoidance measures were found to be inadequate in 84% of those sensitised; medications were not easily available for inspection or were out of date in 23%; 74% of psychology referrals were made after the home visit. In 39 children (55%) the factors identified and the interventions recommended meant that further escalation of treatment was avoided. CONCLUSIONS: Nurse-led assessments including a home visit can help identify potentially modifiable factors for poorly controlled symptoms in children with problematic asthma.

Implications of screening for abdominal aortic aneurysms on surgical workload.

BACKGROUND: The Multicentre Aneurysm Screening Study (MASS) provided strong evidence for both the clinical benefit and the cost-effectiveness of a screening programme for abdominal aortic aneurysms (AAAs) in men. If a national screening programme for AAA were adopted in the UK, it would be expected to increase the elective and decrease the emergency surgical workload. METHODS: The MASS trial randomized 67,800 men aged 65-74 years to be invited to attend for ultrasonographic screening for AAA or to a control group that received no invitation. Predictions of elective and emergency surgical workload were made for a 20-year interval after the introduction of a screening programme for 65-year-old men, based on surgical rates observed in the MASS trial and national mortality statistics. RESULTS: For a district general hospital serving a population of 400,000, there was an estimated reduction from nine emergency operations per year before introduction of the screening programme to three emergency operations annually in men aged 65 years and over by the end of the 20-year interval, and an increase from 24 to 43 AAA operations overall. The corresponding estimated annual costs for all AAA surgery increased by 47 per cent, from pound 209,000 to pound 308,000. These results were not affected by changes in the underlying assumptions. CONCLUSION: The results support the expectation of very few emergency operations, and principally elective operations, being performed following the introduction of a screening programme. For a typical district general hospital, a screening programme would be expected to lead to two additional elective AAA operations per month, and to save 11 AAA-related deaths per year.

Correlation of power Doppler with microvessel density in assessing prostate needle biopsy.

AIM: To correlate hypervascular power Doppler ultrasonography with the histological evaluation of microvasculature in the prostate using trans-rectal ultrasound (TRUS)-guided needle biopsy. MATERIALS AND METHODS: Ninety-six patients with a lower urinary tract symptoms (LUTS) and prostate specific antigen (PSA) value more than 4 ng/ml were evaluated using power Doppler ultrasonography before biopsy. The vascularity of the peripheral zone was graded on a scale of PZ0 to PZ2. Core needle biopsies were immunostained with CD31(DAKO) and counting was performed manually on separate high power fields (HPF; x 400) in areas containing the highest number of vessels. RESULTS: There was a significant correlation between the grading system used for power Doppler and the microvessel density (MVD; PZ0 28.61 +/- 8.97,PZ1 36.00 +/- 12.11 & PZ2 64.008 +/- 15.86; p < 0.001). There was also a significant difference in MVD between benign, malignant and tissue cores with atypia and prostatic intra-epithelial neoplasia (PIN; p < 0.001 and p < 0.018 respectively). There was a significant correlation between malignant tissue having a higher Gleason score and increased MVD (p < 0.001) Furthermore, cancer biopsies having a high flow PZ2 are nearly twice as likely (63.2%) to have a Gleason score of 7 or more when compared those having a Gleason score of less than 7 (36.8%). CONCLUSION: The grading system of assessing the power Doppler flow signals appears to be of value as an indicator of MVD. It also correlates with a higher Gleason score and this may reflect the clinical outcome in prostate cancer. It deserves further study and evaluation as a prognostic indicator.

Cough frequency in children with stable asthma: correlation with lung function, exhaled nitric oxide, and sputum eosinophil count.

BACKGROUND: A study was undertaken to assess the correlation between cough frequency in asthmatic children with lung function and two non-invasive markers of airway inflammation. METHODS: Thirty two children of median age 12.0 years (interquartile range (IQR) 9.5-13.4) with stable asthma were recruited. They underwent spirometric testing, exhaled nitric oxide (eNO) measurement, sputum induction for differential cell count, and ambulatory cough monitoring over 17 hours and 40 minutes. Coughing episodes were counted both as individual spikes and as clusters. RESULTS: Complete cough frequency data were available in 29 children (90%) and their median forced expiratory volume in 1 second (FEV1) and eNO were 88.5% (IQR 79.5-98) and 23.9 ppb (IQR 11.4-41.5), respectively. The median number of cough episodes was 14 (IQR 7.0-24.0) which was significantly higher than that of normal children (6.7 (IQR 4.1-10.5), p<0.001). Sputum induction was successful in 61% of the subjects; the median induced sputum eosinophil count was 0.05% (IQR 0-9.0). Cough frequency was found to have a significant positive correlation with eNO (Spearman's r =0.781, p<0.001) but not with FEV1 or sputum eosinophil count (r =-0.270, p=0.157; r =0.173, p=0.508, respectively). CONCLUSIONS: Children with stable asthma have increased cough frequency compared with normal controls and cough frequency was greater during the day than at night. Cough may be a more sensitive marker of airway inflammation than simple spirometry.

Nitric oxide in chronic airway inflammation in children: diagnostic use and pathophysiological significance.

BACKGROUND: The levels of exhaled and nasal nitric oxide (eNO and nNO) in groups of patients with inflammatory lung diseases are well documented but the diagnostic use of these measurements in an individual is unknown. METHODS: The levels of nNO and eNO were compared in 31 children with primary ciliary dyskinesia (PCD), 21 with non-CF bronchiectasis (Bx), 17 with cystic fibrosis (CF), 35 with asthma (A), and 53 healthy controls (C) using a chemiluminescence NO analyser. A diagnostic receiver-operator characteristic (ROC) curve for PCD using NO was constructed. RESULTS: The median (range) levels of nNO in parts per billion (ppb) in PCD, Bx, CF, and C were 60.3 (3.3-920), 533.6 (80-2053), 491.3 (31-1140), and 716 (398-1437), respectively; nNO levels were significantly lower in PCD than in all other groups (p<0.05). The median (range) levels of eNO in ppb in PCD, Bx, CF, A, and C were 2.0 (0.2-5.2), 5.4 (1.0-22.1), 2.6 (0.8-12.9), 10.7 (1.6-46.7), and 4.85 (2.5-18.3), respectively. The difference in eNO levels in PCD reached significance (p<0.05) when compared with those in Bx, A and C but not when compared with CF. Using the ROC curve, nNO of 250 ppb showed a sensitivity of 97% and a specificity of 90% for the diagnosis of PCD. CONCLUSIONS: eNO and nNO cannot be used diagnostically to distinguish between most respiratory diseases. However, nNO in particular is a quick and useful diagnostic marker which may be used to screen patients with a clinical suspicion of PCD.

A survey of emergency vascular service provision.

Recommendations exist for the optimal management of vascular surgical emergency patients. A telephone survey of on-call surgical registrars was performed to assess the current state of emergency vascular service provision across the Wessex and South West regions in the UK. Of the 24 hospitals surveyed, 10 had formal on-call arrangements for vascular surgical cover, 14 had informal arrangements where the general surgical consultant on-call provided cover and could contact a vascular surgeon if they were available and 3 hospitals had no such arrangements. No difficulties had been experienced by the on-call staff surveyed with any of the existing arrangements. Only 5 of the hospitals had formal on-call arrangements for interventional radiologists. We conclude that current emergency vascular service provision is suboptimal compared to national guidelines and patients may be subject to unequitable access to services. This may not be tenable in the new era of clinical governance.

Relationship between exhaled nitric oxide and mucosal eosinophilic inflammation in children with difficult asthma, after treatment with oral prednisolone.

Exhaled nitric oxide (FE(NO)) has been proposed as a noninvasive marker of airway inflammation in asthma, and may reflect airway eosinophilia. We examined the relationship between FE(NO) and eosinophilic inflammation in endobronchial biopsies from 31 children with difficult asthma (mean age [range] 11.9 [6-17] yr), following 2 wk of prednisolone (40 mg/d). Endobronchial biopsy was also performed in seven children without asthma. Biopsy eosinophils were detected using antibody to major basic protein, and point-counting used to derive an "eosinophil score." FE(NO) readings and suitable biopsies for analysis were both obtained in 21 of 31 children with asthma. Adherence to prednisolone was demonstrated in 17 of these 21. Within this group, there was a correlation between FE(NO) and eosinophil score (r = 0.54, p = 0.03). The relationship was strongest in patients with persistent symptoms after prednisolone, in whom FE(NO) > 7 ppb was associated with a raised eosinophil score. For all patients, FE(NO) < 7 ppb was associated with an eosinophil score within the nonasthmatic range, regardless of symptoms. We propose that FE(NO) is associated with eosinophilic inflammation in children with difficult asthma, following prednisolone, and may help in identifying patients in whom persistent symptoms are associated with airway eosinophilia.

Asthma severity and inflammation markers in children.

UNLABELLED: The relationship of airway inflammation with asthma severity remains unclear. Our aim was to correlate the results of recommended methods of assessment of inflammation with measures of asthma control, in children with a wide range of asthma severity. The study was a cross-sectional investigation of 58 children receiving a wide range of treatment, including 10 treated without regular maintenance therapy and 29 treated with high-dose inhaled corticosteroids (CS). Exhaled nitric oxide (NO), serum eosinophil cationic protein (ECP), and induced sputum (processed for eosinophil count and ECP level) were related to recent symptoms, lung function, and bronchial responsiveness. There was no significant correlation between the results of any METHOD: Neither did any marker of airway inflammation relate to recent symptoms, unlike PC20, which did. There was a significant, inverse correlation between the forced expiratory volume in 1 s (FEV1) and both NO and sputum ECP (r=-0.46, p=<0.001; r=-0.48, p=0.004, respectively). Sputum eosinophils were inversely related to the dose of methacholine that corresponded to a 20% fall in FEV1 (PC20) (r=-0.57, p=0.02). Serum ECP did not relate to any measure of asthma control. There was no association of any recommended inflammation markers with current symptoms and only a weak relationship between them and physiological measures. The place of these markers remains unclear and their use in clinical practice needs further investigation by long-term longitudinal studies.