Venous blood gases in the assessment of respiratory failure in patients undergoing sleep studies: a randomized study.

STUDY OBJECTIVES: Venous blood gases (VBGs) are not consistently considered suitable surrogates for arterial blood gases (ABGs) in assessing acute respiratory failure due to variable measurement error. The physiological stability of patients with chronic ventilatory failure may lead to improved agreement in this setting. METHODS: Adults requiring ABGs for sleep or ventilation titration studies had VBGs drawn before or after each ABG, in a randomized order. Veno-arterial correlation and agreement were examined for carbon dioxide tension (PCO2), pH, oxygen tension (PO2) and oxygen saturation (SO2). RESULTS: We analyzed 115 VBG-ABG pairs from 61 patients. Arterial and venous measures were correlated (with p<0.05) for PCO2 (r=0.84) and pH (r=0.72), but not for PO2 or SO2. Adjusted mean veno-arterial differences (95% limits of agreement) were +5.0mmHg (-4.4 to +14.4) for PCO2; -0.02 (-0.09 to +0.04) for pH; -34.3mmHg (-78.5 to +10.0) for PO2; and -23.9% (-61.3 to +13.5) for SO2. VBGs obtained from the dorsal hand demonstrated a lower mean PCO2 veno-arterial difference (p<0.01). A venous PCO2 threshold of ≥45.8mmHg was >95% sensitive for arterial hypercapnia, so measurements below this can exclude the diagnosis without an ABG. A venous PCO2 threshold of ≥53.7mmHg was >95% specific for arterial hypercapnia, so such readings can be assumed diagnostic. The area under the receiver operating characteristic curve of 0.91 indicated high discriminatory capacity. CONCLUSIONS: A venous PCO2 <45.8mmHg or ≥53.7mmHg would exclude or diagnose hypercapnia, respectively, in patients referred for sleep studies, but VBGs are poor surrogates for ABGs where precision is important. CLINICAL TRIAL REGISTRATION: Registry: Australian New Zealand Clinical Trials Register; Name: A comparison of arterial and blood gas analyses in sleep studies; Identifier: ACTRN12617000562370; URL https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372717.

Factors influencing the timeliness of care for patients with lung cancer in Bangladesh.

BACKGROUND: This study explored the factors associated with timeliness of care in the healthcare seeking pathway among patients with lung cancer in Bangladesh. METHODS: A structured questionnaire was used for data collection from 418 patients with lung cancer through face-to-face interviews in three tertiary care hospitals. Log-rank tests were performed to test differences in the length of intervals between points in healthcare by socioeconomic characteristics and care seeking behaviours of the patients. Cox Proportional Hazard (PH) regression analysis was performed to identify the predictors of the intervals after adjustment for variations in other variables. RESULTS: A higher education level was associated significantly (p < 0.05) with a shorter interval between first contact with a healthcare provider (HCP) and diagnosis (median 81 days) and initiation of treatment (median 101 days). Higher monthly household income was associated significantly with a shorter time from first contact and diagnosis (median 91 days), onset of symptom and diagnosis (median 99 days), onset of symptom and treatment (median 122 days), and first contact with any HCP to treatment (median 111 days). Consulting with additional HCPs prior to diagnosis was associated significantly with longer intervals from first contact with any HCP and diagnosis (median 127 days), onset of symptom and diagnosis (median 154 days), onset of symptom and treatment (median 205 days), and first contact with any HCP to treatment (median 174 days). Consulting with informal HCPs was associated significantly with a longer time interval from symptom to treatment (median 171 days). Having more than one triggering symptom was associated significantly with a shorter interval between onset of symptoms and first contact with any HCP. CONCLUSION: The predictors for timeliness of lung cancer care used in this study affected different intervals in the care seeking pathway. Higher education and income predicted shorter intervals whereas consulting informal healthcare providers and multiple providers were associated with longer intervals.

Defining timeliness in care for patients with lung cancer: a scoping review.

OBJECTIVES: Early diagnosis and reducing the time taken to achieve each step of lung cancer care is essential. This scoping review aimed to examine time points and intervals used to measure timeliness and to critically assess how they are defined by existing studies of the care seeking pathway for lung cancer. METHODS: This scoping review was guided by the methodological framework for scoping reviews by Arksey and O'Malley. MEDLINE, EMBASE, CINAHL and PsycINFO electronic databases were searched for articles published between 1999 and 2019. After duplicate removal, all publications went through title and abstract screening followed by full text review and inclusion of articles in the review against the selection criteria. A narrative synthesis describes the time points, intervals and measurement guidelines used by the included articles. RESULTS: A total of 2113 articles were identified from the initial search. Finally, 68 articles were included for data charting process. Eight time points and 14 intervals were identified as the most common events researched by the articles. Eighteen different lung cancer care guidelines were used to benchmark intervals in the included articles; all were developed in Western countries. The British Thoracic Society guideline was the most frequently used guideline (20%). Western guidelines were used by the studies in Asian countries despite differences in the health system structure. CONCLUSION: This review identified substantial variations in definitions of some of the intervals used to describe timeliness of care for lung cancer. The differences in healthcare delivery systems of Asian and Western countries, and between high-income countries and low-income-middle-income countries may suggest different sets of time points and intervals need to be developed.

Excess iron promotes emergence of foamy macrophages that overexpress ferritin in the lungs of silicosis patients.

BACKGROUND AND OBJECTIVE: Inhalation of high concentrations of respirable crystalline silica (RCS) can lead to silicosis. RCS contains varying levels of iron, which can cause oxidative stress and stimulate ferritin production. This study evaluated iron-related and inflammatory markers in control and silicosis patients. METHODS: A cohort of stone benchtop industry workers (n = 18) were radiologically classified by disease severity into simple or complicated silicosis. Peripheral blood and bronchoalveolar lavage (BAL) were collected to measure iron, ferritin, C-reactive protein, serum amyloid A and serum silicon levels. Ferritin subunit expression in BAL and transbronchial biopsies was analysed by reverse transcription quantitative PCR. Lipid accumulation in BAL macrophages was assessed by Oil Red O staining. RESULTS: Serum iron levels were significantly elevated in patients with silicosis, with a strong positive association with serum ferritin levels. In contrast, markers of systemic inflammation were not increased in silicosis patients. Serum silicon levels were significantly elevated in complicated disease. BAL macrophages from silicosis patients were morphologically consistent with lipid-laden foamy macrophages. Ferritin light chain (FTL) mRNA expression in BAL macrophages was also significantly elevated in simple silicosis patients and correlated with systemic ferritin. CONCLUSION: Our findings suggest that elevated iron levels during the early phases of silicosis increase FTL expression in BAL macrophages, which drives elevated BAL and serum ferritin levels. Excess iron and ferritin were also associated with the emergence of a foamy BAL macrophage phenotype. Ferritin may represent an early disease marker for silicosis, where increased levels are independent of inflammation and may contribute to fibrotic lung remodelling.

Duration of intervals in the care seeking pathway for lung cancer in Bangladesh: A journey from symptoms triggering consultation to receipt of treatment.

Timeliness in seeking care is critical for lung cancer patients' survival and better prognosis. The care seeking trajectory of patients with lung cancer in Bangladesh has not been explored, despite the differences in health systems and structures compared to high income countries. This study investigated the symptoms triggering healthcare seeking, preferred healthcare providers (including informal healthcare providers such as pharmacy retailers, village doctors, and "traditional healers"), and the duration of intervals in the lung cancer care pathway of patients in Bangladesh. A cross-sectional study was conducted in three tertiary care hospitals in Bangladesh among diagnosed lung cancer patients through face-to-face interview and medical record review. Time intervals from onset of symptom and care seeking events were calculated and compared between those who sought initial care from different providers using Wilcoxon rank sum tests. Among 418 study participants, the majority (90%) of whom were males, with a mean age of 57 ±9.86 years, cough and chest pain were the most common (23%) combination of symptoms triggering healthcare seeking. About two-thirds of the total respondents (60%) went to informal healthcare providers as their first point of contact. Living in rural areas, lower levels of education and lower income were associated with seeking care from such providers. The median duration between onset of symptom to confirmation of diagnosis was 121 days, between confirmation of diagnosis and initiation of treatment was 22 days, and between onset of symptom and initiation of treatment was 151 days. Pre-diagnosis durations were longer for those who had sought initial care from an informal provider (p<0.05). Time to first contact with a health provider was shorter in this study compared to other developed and developing countries but utilizing informal healthcare providers caused delays in diagnosis and initiation of treatment. Encouraging people to seek care from a formal healthcare provider may reduce the overall duration of the care seeking pathway.

Defining timeliness in care for patients with lung cancer: protocol for a scoping review.

INTRODUCTION: Cancer is the second leading cause of death worldwide, and lung cancer is the single leading cause of cancer mortality worldwide. Early diagnosis of lung cancer is the key to better prognosis and longer survival. While there are substantial literature reporting delays in cancer diagnosis, there is a lack of consensus in the definitions and terms used to describe 'delay' in the treatment pathway. The aim of this scoping review is to identify and critically synthesise the operational definitions and terminologies used to describe the timely initiation of care and consequent treatments over the care pathway for patients with lung cancer. This scoping review will also compare how timeliness was operationalised in Western and Asian countries. METHODS AND ANALYSIS: The scoping review will use the methodology described by Arksey and O'Malley and endorsed by the Joanna Briggs Institute. MEDLINE, EMBASE, CINAHL and PsycINFO electronic databases will be searched. Grey literature sources and the reference lists of key studies will be used to identify additional relevant studies. The scoping review will include all studies, irrespective of study methodology and quality. Two reviewers will independently screen all titles and abstracts to identify eligible studies for inclusion. The full texts of identified studies will be further examined and charted using a data extraction form. A narrative synthesis will be performed to assess and categorise available definitions of timeliness. ETHICS AND DISSEMINATION: Ethical approval is not needed as this scoping review will be reviewing already published articles. The results produced from this review will be submitted to a scientific peer-reviewed journal for publication and will be presented at scientific meetings.