Oxygen therapy in chronic obstructive pulmonary disease

Correlation of Body Mass Index and Oxygen Saturation in Chronic Obstructive Pulmonary Disease Patients at a Tertiary Care Center in Nepal: A Cross-Sectional Study

Purpose

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity worldwide. COPD is associated with clinically relevant pulmonary and extrapulmonary manifestations, including hypoxemia and weight loss. The correlation of body mass index (BMI) and oxygen saturation (SpO2) with COPD grades may provide a useful additional marker for understanding and managing the disease. The aim of the study was to study the correlation of BMI and oxygen saturation with COPD in patients presenting to a tertiary care center in Nepal.

Patients and Methods

A descriptive cross-sectional study was conducted among 145 COPD patients visiting the Department of Medicine in Shree Birendra Hospital between 1 March 2019 and 28 February 2020. A non-probability purposive sampling method was used and data were analyzed using SPSS version 21. A p-value of <0.05 was considered significant.

Results

Out of 145 COPD patients, 58 (40%) were underweight, 53 (36.55%) were of normal weight, 20 (13.79%) were overweight, and 14 (9.6%) were obese. The number of underweight patients was highest in COPD grade 4 and lowest in COPD grade 1. The proportion of subjects with underweight BMI and hypoxia increased with COPD severity, and both were statistically significant (p-values <0.01).

Conclusion

Our study shows that BMI and oxygen saturation have an inverse association with COPD severity. The correlation of BMI and oxygen saturation with COPD grade could provide a supplementary marker of disease severity, which could be useful in the understanding of the disease process and subsequent management of COPD.

A Real-Life Study of Combined Treatment with Long-Term Non-Invasive Ventilation and High Flow Nasal Cannula in Patients with End-Stage Chronic Obstructive Lung Disease

Patients with end-stage chronic obstructive pulmonary disease (COPD) often develop persistent hypoxic or hypercapnic respiratory failure, or a combination of both. Ventilatory support, in terms of a long-term high-flow nasal cannula (LT-HFNC) and long-term non-invasive ventilation (LT-NIV), may be indicated. Often, clinicians choose either one or the other. This paper explores combined treatment with LT-HFNC and LT-NIV in a real-life setting. In total, 33 patients with COPD and persistent respiratory failure were included in this study. Of those, 17 were initiated on LT-HFNC and used it for 595 (374) days and 16 were initiated on LT-NIV and used it for 558 (479) days. On average, patients used respiratory support continuously for 908 (586) days. Baseline characteristics were comparable, apart from PaCO₂ at first ventilatory support initiation (LT-HFNC/LT-NIV 7.1 (1.1) kPa/8.8 (0.9) kPa respectively (p = 0.002)). Both groups experienced a reduction in hospitalizations in the first twelve months after treatment initiation, compared to the twelve months before (LT-HFNC p = 0.022 and LT-NIV p = 0.014). In total, 25% of LT-NIV patients stopped treatment after HFNC initiation due to intolerance and 59% stopped LT-HFNC treatment 126 (36) days after LT-NIV initiation as monotherapy was sufficient. In 44% of these patients, LT-HFNC was re-initiated at the end of life. At the time of analysis, 70% of patients had died. In the last three months of life, patients stopped using LT-NIV, whereas 91% used LT-HFNC. In conclusion, the combined use of LT-NIV and LT-HFNC reduced hospitalizations in patients with COPD and persistent respiratory failure. The study indicates that LT-HFNC is well tolerated, and better tolerated than LT-NIV at the very end stages of COPD.

Oxygen Desaturation Is Associated With Fibrocyte Activation via Epidermal Growth Factor Receptor/Hypoxia-Inducible Factor-1α Axis in Chronic Obstructive Pulmonary Disease

Fibrocytes are bloodborne mesenchymal progenitors which accumulate and differentiate at the disease site. We investigated whether hypoxemia activates fibrocytes, accelerating airflow limitation and exercise intolerance in chronic obstructive pulmonary disease (COPD) patients. Flow cytometry was used to determine collagen I+/CD45+ fibrocytes and α-smooth muscle actin+ differentiating fibrocytes within peripheral blood and cultured cells, as well as the expression of CXC chemokine receptor 4 (CXCR4), epidermal growth factor receptor (EGFR), connective tissue growth factor (CTGF) and hypoxia-inducible factor (HIF)-1α. Fibrocytes in lung specimens were identified by confocal microscopy. Compared to non-desaturators, COPD desaturators (peripheral blood oxygen saturation ≤88% during exercise) had greater number of fibrocytes in peripheral blood and lung specimens, paralleled with faster yearly lung function decline and a 6-minute walk distance. Fibrocytes from desaturators expressed more EGFR, CXCR4, CTGF, and HIF-1α, with a higher capacity of proliferation and myofibroblastic differentiation. Hypoxia (5% oxygen) increased the expression of EGFR, CXCR4, CTGF, and HIF-1α, the number and differentiation in fibrocytes. These effects were attenuated by EGFR inhibitor gefitinib, HIF-1α gene silencing, and anti-CTGF antibody. These data elucidate that hypoxemia triggers fibrocyte activation through the EGFR/HIF-1α axis, aggravating airflow obstruction in COPD.

Korean physician prescription patterns for home oxygen therapy in chronic obstructive pulmonary disease patients

BACKGROUND/AIMS

Hypoxemia in chronic obstructive pulmonary disease (COPD) leads to reduced ability to exercise, decreased quality of life, and, eventually, increased mortality. Home oxygen therapy in patients with severe COPD reduces distress symptoms and mortality rates. However, there have been few studies on physicians' prescription behavior toward home oxygen therapy. Therefore, we investigated the respiratory specialists' perspective on home oxygen therapy.

METHODS

In this cross-sectional, study, a questionnaire was completed by 30 pulmonary specialists who worked in tertiary hospitals and prescribed home oxygen therapy. The questionnaire consisted of 28 items, including 15 items on oxygen prescription for outpatients, four for inpatients, and nine on service improvement.

RESULTS

All physicians were prescribing less than 2 L/min of oxygen for either 24 (n = 10, 33.3%) or 15 hours (n = 9, 30.3%). All (n = 30) used pulse oximetry, 26 (86.7%) analyzed arterial blood gas. Thirteen physicians had imposed restrictions and recommended oxygen use only during exercise or sleep. Sixteen (53.3%) physicians were educating their patients about home oxygen therapy. Furthermore, physicians prescribed home oxygen to patients that did not fit the typical criteria for long-term oxygen therapy, with 30 prescribing it for acute relief and 17 for patients with borderline hypoxemia.

CONCLUSION

This study identified the prescription pattern of home oxygen therapy in Korea. Respiratory physicians prescribe home oxygen therapy to hypoxemic COPD patients for at least 15 hours/day, and at a rate of less than 2 L/min. More research is needed to provide evidence for establishing policies on oxygen therapy in COPD patients.

Lung Disease-Related Pulmonary Hypertension

Patients with advanced lung disease can develop pulmonary hypertension and succumb to right ventricular failure/cor pulmonale. Patients with pulmonary hypertension owing to chronic lung disease, or World Health Organization group 3 pulmonary hypertension, are more limited and carry a high risk of mortality. Adjunctive therapies remain the cornerstones of treatment. Recent evidence suggests that inhaled pulmonary vasodilator therapy can be helpful in patients with pulmonary hypertension owing to interstitial lung disease. Lung transplantation may be the only life-saving option in select patients, whereas palliative care and hospice should be sought for those who are not candidates as the disease progresses.

The relationship between frontal QRS-T angle and the severity of newly diagnosed chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterised by persistent airflow restriction and respiratory symptoms. Studies demonstrated that cardiac arrhythmias and cardiovascular mortality increased in these patients as a result of altered myocardial repolarization. Frontal QRS-T angle is a novel marker of myocardial depolarization and repolarization heterogeneity. In this study, we aimed to investigate the relationship between frontal QRS-T angle and disease severity in patients with newly diagnosed COPD.

METHODS

A total of 104 newly diagnosed COPD patients were included in this study. Patients were divided into two groups according to GOLD (Global Obstructive Lung Disease) stage as follows: patients with mild and moderate COPD (group I), and severe and very severe COPD (group II). Frontal QRS-T angle was calculated from the automatic report of the electrocardiography device.

RESULTS

Frontal QRS-T angle was significantly higher in group II patients compared with in group I patients (43.0 [25.5-60.0] vs. 20.0 [12.0-32.0], P < .001). The best cut-off value of frontal QRS-T angle for predicting severe-very severe COPD was ≥34.5°. Correlation analysis showed that frontal QRS-T angle was negatively correlated with FEV1/FVC (r = -.524, P < .001) and MEF25-75 (r = -.453, P < .001). Multivariate logistic regression analysis was showed that frontal QRS-T angle was the only independent predictor of severe-very severe COPD (OR: 1.051, 95% CI: 1.024-1.079, P < .001).

CONCLUSIONS

Frontal QRS-T angle is an easily obtainable marker form surface electrocardiography. In this study, we have shown for the first time that frontal QRS-T angle was significantly increased in patients with severe and very severe COPD.

Paradoxical role of oxygen in the treatment of patients with COVID-19

Dear Editor, Coronavirus disease-2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) was declared a pandemic by WHO on 11 March 2020 and has adversely affected human society and disrupted global health...

A Feasibility and Efficacy Randomized Controlled Trial of Two Exercise Programs in Severe AECOPD Patients with Resting Hypoxemia

Resting hypoxemia is the most severe stage of Chronic Obstructive Pulmonary Disease (COPD). Due to their impairments during the exacerbation, these patients are limited to traditional exercise rehabilitation and are excluded from the majority of the studies. The aim of this study was to assess the feasibility and the efficacy of two exercise programs in Acute Exacerbation of COPD (AECOPD) patients with resting hypoxemia. In this randomized clinical trial, patients hospitalized due to an acute exacerbation of COPD with hypoxemia at rest were included. Patients were randomly assigned into three groups. A Control Group (pharmacological treatment), a Global Exercise Group (GEG), and a Functional Electrostimulation Group (FEG). Patients were treated during the hospitalization period. The main outcomes were lower limb strength (assessed by a dynamometer), balance (assessed by the one leg standing balance test), health related quality of life (assessed by the EQ-5D), adverse events and adherence. At the end of the intervention, there were significant differences in all the variables in favour of the experimental groups (p < 0.05). We concluded that conducting an exercise program is feasible and improves lower limb strength, balance, and health related quality of life in AECOPD patients with resting hypoxemia.

The Performance of Digital Monitoring Devices for Oxygen Saturation and Respiratory Rate in COPD: A Systematic Review

Healthcare access and delivery for individuals with chronic obstructive pulmonary disease (COPD) who live in remote areas or who are susceptible to contracting communicable diseases, such as COVID-19, may be a challenge. Telehealth and remote monitoring devices can be used to overcome this issue. However, the accuracy of these devices must be ensured before forming healthcare decisions based on their outcomes. Therefore, a systematic review was performed to synthesize the evidence on the reliability, validity and responsiveness of digital devices used for tracking oxygen saturation (SpO₂) and/or respiratory rate (RR) in individuals with COPD, in remote settings. Three electronic databases were searched: MEDLINE (1996 to October 8, 2020), EMBASE (1996 to October 8, 2020) and CINAHL (1998 to October 8, 2020). Studies were included if they aimed to evaluate one or more measurement properties of a digital device measuring SpO₂ or RR in individuals with COPD. Six-hundred and twenty-five articles were identified and after screening, 7 studies matched the inclusion criteria; covering 11 devices measuring SpO₂ and/or RR. Studies reported on the reliability (n = 1), convergent validity (n = 1), concurrent validity (n = 2) and predictive validity (n = 2) of SpO₂ devices and on the convergent validity (n = 1), concurrent validity (n = 1) and predictive validity (n = 1) of RR devices. SpO₂ and RR devices were valid when compared against other respiration monitoring devices but were not precise in predicting exacerbation events. More well-designed measurement studies are needed to make firm conclusions about the accuracy of such devices.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2021.1945021 .

Influence of Hypoxia on the Epithelial-Pathogen Interactions in the Lung: Implications for Respiratory Disease

Under normal physiological conditions, the lung remains an oxygen rich environment. However, prominent regions of hypoxia are a common feature of infected and inflamed tissues and many chronic inflammatory respiratory diseases are associated with mucosal and systemic hypoxia. The airway epithelium represents a key interface with the external environment and is the first line of defense against potentially harmful agents including respiratory pathogens. The protective arsenal of the airway epithelium is provided in the form of physical barriers, and the production of an array of antimicrobial host defense molecules, proinflammatory cytokines and chemokines, in response to activation by receptors. Dysregulation of the airway epithelial innate immune response is associated with a compromised immunity and chronic inflammation of the lung. An increasing body of evidence indicates a distinct role for hypoxia in the dysfunction of the airway epithelium and in the responses of both innate immunity and of respiratory pathogens. Here we review the current evidence around the role of tissue hypoxia in modulating the host-pathogen interaction at the airway epithelium. Furthermore, we highlight the work needed to delineate the role of tissue hypoxia in the pathophysiology of chronic inflammatory lung diseases such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease in addition to novel respiratory diseases such as COVID-19. Elucidating the molecular mechanisms underlying the epithelial-pathogen interactions in the setting of hypoxia will enable better understanding of persistent infections and complex disease processes in chronic inflammatory lung diseases and may aid the identification of novel therapeutic targets and strategies.

Shedding Light on the Main Characteristics and Perspectives of Romanian Medicinal Oxygen Market

Medicinal oxygen plays an important role in healthcare, being essential for the existence and maintenance of the health of millions of people, who depend on medicinal oxygen every day, both in hospitals and at home. Medicinal oxygen is the primary treatment administrated to the majority of patients suffering from respiratory problems and low levels of oxygen in the blood, and in the context of the actual health crisis caused by the new COVID-19, the challenge is represented by increasing the supply of medicinal oxygen while reducing cost so that it is accessible where it is needed most, free at the point of use. It will take increased investment and commitment to put oxygen at the center of strategies for universal health coverage. In this context, it becomes essential to investigate the main characteristics of the Romanian market of medicinal oxygen, highlighting top key players, market development, key driving factors, types of products, market perspectives as well as shedding light on the segmentation of this particular market based on considerations regarding regions, hospital competence class and hospital specialization. Also, the research aims to explore the regional disparities in the decision of using O93%medicinal oxygen, revealing the main factors related to the usage of this type of product among Romanian public hospitals. The research relies on the first quantitative survey regarding medicinal oxygen usage among 121 public hospital units from a total of 461 public hospitals in 2018, which meet the specific requirements: includes the entire population according to the list published on the website of the Ministry of Health, is the most recent data and does not show repetition. The sampling was of probabilistic stage-type stratification, with the following sampling layers: hospital county distribution, hospital competence class officially assigned by the Ministry of Health and also area of residence (urban/rural). In order to analyze the main characteristics of the Romanian oxygen market, the following methods have been used: analysis of variance (ANOVA) together with Kruskal-Wallis, Pearson correlation coefficient as well as Goodman and Kruskal gamma, Kendall's tau-b and Cramer's V, as well as multilevel logistic regression analysis using hierarchical data (hospitals grouped in regions). The Romanian market of medicinal oxygen is rather an oligopoly market characterized by the existence of a small number of producers and two types of products currently used for the same medical purpose and having a substitutable character: medicinal oxygen O99.5%, and medicinal oxygen O93%. An overwhelming proportion of public hospitals agree that both types of medicinal oxygen serve the same therapeutic purpose. The Romanian market of medicinal oxygen highlighted a significant segmentation on considerations based on regions, hospital competence class and hospital specialization. Regarding the main perspectives, the Romanian market of medical oxygen keeps the growth trend registered globally, with development perspectives for competitors. Exploring the regional disparities in the decision of using O93 medicinal oxygen, the empirical results acknowledged the important role of unitary price, hospital capacity and the relevance of this product seen as a medicine. Medicinal oxygen is vital in sustaining life, proving its utility mainly in the context of the actual health crisis. In this context, the Romanian local market exhibits prospects for further development, being characterized by an important segmentation depending on regions, hospital competence class and hospital specialization.

K2P2.1 (TREK-1) potassium channel activation protects against hyperoxia-induced lung injury

No targeted therapies exist to counteract Hyperoxia (HO)-induced Acute Lung Injury (HALI). We previously found that HO downregulates alveolar K_2P2.1 (TREK-1) K⁺ channels, which results in worsening lung injury. This decrease in TREK-1 levels leaves a subset of channels amendable to pharmacological intervention. Therefore, we hypothesized that TREK-1 activation protects against HALI. We treated HO-exposed mice and primary alveolar epithelial cells (AECs) with the novel TREK-1 activators ML335 and BL1249, and quantified physiological, histological, and biochemical lung injury markers. We determined the effects of these drugs on epithelial TREK-1 currents, plasma membrane potential (Em), and intracellular Ca²⁺ (iCa) concentrations using fluorometric assays, and blocked voltage-gated Ca²⁺ channels (Ca_V) as a downstream mechanism of cytokine secretion. Once-daily, intra-tracheal injections of HO-exposed mice with ML335 or BL1249 improved lung compliance, histological lung injury scores, broncho-alveolar lavage protein levels and cell counts, and IL-6 and IP-10 concentrations. TREK-1 activation also decreased IL-6, IP-10, and CCL-2 secretion from primary AECs. Mechanistically, ML335 and BL1249 induced TREK-1 currents in AECs, counteracted HO-induced cell depolarization, and lowered iCa²⁺ concentrations. In addition, CCL-2 secretion was decreased after L-type Ca_V inhibition. Therefore, Em stabilization with TREK-1 activators may represent a novel approach to counteract HALI.

Factors Associated with Exercise-Induced Desaturation in Patients with Chronic Obstructive Pulmonary Disease

Purpose

The 6-min walk test (6MWT) is a useful tool to assess the physiologic function in patients with chronic obstructive pulmonary disease (COPD). The recent study showed that patients with COPD with oxygen desaturation during the 6MWT had an increased risk of exacerbation and death compared with those without oxygen desaturation. This study aimed to explore the potential risk factors for exercise-induced desaturation (EID) in patients with COPD.

Patients and Methods

Adult patients with COPD were enrolled from the Chang Gung Research Database between January 2013 and January 2017. Age, sex, body mass index, underlying diseases, medications, and results of the pulmonary function tests and 6MWT were retrospectively collected and analyzed.

Results

Among 1768 patients with COPD, 932 (52.7%) had oxygen desaturation, and the other 836 (47.3%) had no desaturation during the 6MWT. The patients with EID had a shorter 6-min walk distance than those without desaturation (352.08±120.29 vs 426.56±112.56, p<0.0001). In the multivariate logistic regression analysis, older age, female sex, lower forced expiratory volume in 1 s, and comorbidity with atrial fibrillation (AF) were associated with oxygen desaturation during the 6MWT. Patients with EID had higher exacerbation frequency than those without desaturation in the 1-year follow-up period (0.59±1.50 vs 0.34±1.26, p<0.0001). Patients with COPD with AF also had a higher rate of exacerbation requiring emergency department visit or hospitalization in the 1-year follow-up.

Conclusion

This study demonstrates that older age, low FEV1, and female sex are risk factors for EID. Desaturation during 6MWT is related to frequent acute exacerbation of COPD in the 1-year follow-up.

Inhibition of CX3C receptor 1-mediated autophagy in macrophages alleviates pulmonary fibrosis in hyperoxic lung injury

AIMS

To investigate the role of CX3CR1 in hyperoxic lung injury induced pulmonary fibrosis.

MATERIALS AND METHODS

Hyperoxic lung injured mice were used as the disease model. Pulmonary fibrosis was determined by H&E and Masson's staining. Autophagy was investigated by western blot, immunofluorescence staining, and transmission electron microscopy.

KEY FINDINGS

We observed that increased CX3CR1 expression corresponded with increased pulmonary fibrosis. Additionally, silencing of CX3CR1 significantly alleviated the fibrosis when compared to the control. We observed that exposure of mouse to hyperoxic environment increased macrophage levels along with an increased CD11b expression in the lung tissues. Subsequently, we also observed an increased expression of LC3-II and decreased p62 expression in hyperoxic mice models, suggesting the potential role of hyperoxia induced autophagy. CD11b and LC3/CX3CR1 were expressed and co-localized in a manner indicating CX3CR1 indeed does regulate macrophage autophagy in the hyperoxic lung injury model. We observed a decrease in hyperoxia-associated fibrosis, along with a decrease in autophagy when we used 3-MA (autophagy inhibitor) in our hyperoxic lung injury model. To elucidate the pathway through which CX3CR1 regulated autophagy, we further analyzed the Akt1 pathway. Our experimental results indicated that the Akt1 inhibitor (A-674563) did significantly decrease macrophage autophagy and fibrosis in hyperoxic mice models.

SIGNIFICANCE

Thus, our data indicates a novel role of CX3CR1 in regulation of macrophage autophagy and promotion of pulmonary fibrosis in hyperoxic lung injured mice.

The predictive value of PaO2/FIO2 and additional parameters for in-hospital mortality in patients with acute pulmonary embolism: an 8-year prospective observational single-center cohort study

BACKGROUND

Rapid stratification and appropriate treatment on admission are critical to saving lives of patients with acute pulmonary embolism (PE). None of the clinical prediction tools perform well when applied to all patients with acute PE. It may be important to integrate respiratory features into the 2014 European Society of Cardiology model. First, we aimed to assess the relationship between the arterial partial pressure of oxygen/fraction of inspired oxygen (PaO₂/FIO₂) ratio and in-hospital mortality, determine the optimal cutoff value of PaO₂/FIO₂, and determine if this value, which is quick and easy to obtain on admission, is a predictor of in-hospital mortality in this population. Second, we aimed to evaluate the potential additional determinants including laboratory parameters that may affect the in-hospital mortality. We hypothesized that the PaO2/FiO2 ratio would be a clinical prediction tool for in-hospital mortality in patients with acute PE.

METHODS

A prospective single-center observational cohort study was conducted in Beijing Hospital from January 2010 to November 2017. Arterial blood gas analysis data captured on admission, clinical characteristics, risk factors, laboratory data, imaging findings, and in-hospital mortality were compared between survivors and non-survivors. The area under the receiver operating characteristic curve (AUC) for in-hospital mortality based on the PaO₂/FiO₂ value was determined, and the association between the parameters and in-hospital mortality was analyzed by using logistic regression analysis.

RESULTS

Body mass index, history of cancer, PaO₂/FiO₂ value, pulse rate, cardiac troponin I level, lactate dehydrogenase level, white blood cell count, D-dimer level, and risk stratification measurements differed between survivors and non-survivors. The optimal cutoff value of PaO₂/FiO₂ for predicting mortality was 265 (AUC = 0.765, P < 0.001). Only a PaO₂/FiO₂ ratio < 265 (95% confidence interval [CI] 1.823-21.483, P = 0.004), history of cancer (95% CI 1.161-15.927, P = 0.029), and risk stratification (95% CI 1.047-16.957, P = 0.043) continued to be associated with an increased risk of in-hospital mortality of acute PE.

CONCLUSION

A simple determination of the PaO₂/FiO₂ ratio at <265 may provide important information on admission about patients' in-hospital prognosis, and PaO₂/FiO₂ ratio < 265, history of cancer, and risk stratification are predictors of in-hospital mortality of acute PE.

Effect of Nebulized Verapamil on Oxygenation in Chronic Obstructive Pulmonary Disease (COPD) Patients Admitted to the Intensive Care Unit

BACKGROUND

Many pharmacological and behavioral therapies have been investigated to improve oxygenation in the intensive care unit (ICU). In patients with chronic obstructive pulmonary disease (COPD), the purpose of therapy is to correct the ventilation perfusion (V/Q) mismatch. Agents, such as calcium blockers, can affect both ventilation and vasculature. The inhalation route allows a more rapid achievement of therapeutic effects with few systemic side effects. Therefore, the present study aimed to investigate the effect of nebulized verapamil on oxygenation in COPD patients.

MATERIALS AND METHODS

In this double-blind, randomized clinical trial, twenty hypoxic COPD patients, admitted to ICU, were treated with 10 mg of verapamil twice daily for three days. Also, twenty patients with COPD, who were matched in terms of age, sex, and severity of the disease, were enrolled in the control group and received nebulized normal saline. The oxygenation parameters were compared using an arterial blood gas (ABG) test before and after the intervention.

RESULTS

The mean oxygen saturation was 91.2%±12.15 before verapamil inhalation, which increased to 95.75%±14.57 after receiving nebulized verapamil (P<0.05). Also, correction of blood pH, blood oxygen pressure, and oxygen ratio (PaO₂/FIO₂) were higher in patients receiving verapamil, compared to the control group. The length of hospital stay was similar in the two groups. During the first three days, 30% of patients in the verapamil group and 20% of patients in the control group were intubated.

CONCLUSION

Our results indicated that verapamil inhalation increased oxygen saturation and accelerated extubation in patients with COPD.

Assessment of knowledge, attitude and practice regarding oxygen therapy at emergency departments in Riyadh in 2017: A cross-sectional study

BACKGROUND

Administering oxygen therapy (OT) has an essential role in preventing/managing hypoxemia in both acute and chronic conditions. It should be adjusted to achieve the normal oxygen saturation of 94%-98% in most cases. This study aims to evaluate knowledge, attitude and practice (KAP) of nurses, paramedics, emergency medical technicians (EMTs) and Emergency Medical Services (EMS) physicians working at emergency departments (ED) in Riyadh, Saudi Arabia.

METHODS

In this cross-sectional study, a structured questionnaire was used to assess KAP related to OT of nurses, paramedics, EMTs and EMS physicians currently working at an ED of a tertiary care hospital. Knowledge and attitude were assessed using a Likert scale from 1-5, whereas practice was assessed as a yes/no categorical variable.

RESULTS

A total of 444 emergency health-care workers (EHCWs) participated, of which 225 (50.7%) were male, with the majority (77%) in the age group of 20-35 years. Over half of the sample were nurses (266; 59.9%). The mean score for knowledge about OT was 5.51±1.45, attitude was 26.31±3.17 and for practices 4.55±1.76. The main factors which were associated with poor KAP were workload and lack of local guidelines. The distribution of overall practice score was significantly better among paramedics - nurses group and EMT - nurses group.

CONCLUSION

This study demonstrates that there is a gap in EHCWs' KAP, particularly regarding when to provide OT to a patient. This gap can affect patients' safety. Extensive educational and training programs about OT are needed to raise awareness among health-care providers.

Complementary regional heterogeneity information from COPD patients obtained using oxygen-enhanced MRI and chest CT

Background

The heterogeneous distribution of emphysema is a key feature of chronic obstructive pulmonary disease (COPD) patients that typically is evaluated using high-resolution chest computed tomography (HRCT). Oxygen-enhanced pulmonary magnetic resonance imaging (OEMRI) is a new method to obtain information regarding regional ventilation, diffusion, and perfusion in the lung without radiation exposure. We aimed to compare OEMRI with HRCT for the assessment of heterogeneity in COPD patients.

Methods

Forty patients with stable COPD underwent quantitative HRCT, OEMRI, and pulmonary function tests, including arterial blood gas analysis. OEMRI was also performed on nine healthy control subjects. We measured the severity of emphysema (percent low attenuation volume; LAV%) in whole lungs and the standard deviations (SDs) of the LAV% values of 10 isovolumetric partitions (SD-LAV) as an index of cranial-caudal heterogeneity. Similarly, relative enhancement ratios of oxygen (RERs) in whole lungs from OEMRI and SD-RER were analyzed.

Results

COPD patients showed a lower mean RER than control subjects (12.6% vs 22.0%, p<0.01). The regional heterogeneity of the RERs was not always consistent with the LAV distribution. Both the HRCT (LAV% and SD-LAV) and the OEMRI (RER and SD-RER) indices were significantly associated with the diffusion capacity (DL_CO) and partial pressure of oxygen in arterial blood (PaO₂). The PaO₂ was associated only with the heterogeneity index of HRCT (SD-LAV) (R² = 0.39); however, the PaO₂ was associated with both the mean RER and heterogeneity (SD-RER) in the multivariate analysis (R² = 0.38).

Conclusions

OEMRI-derived parameters were directly associated with oxygen uptake in COPD patients. Although the OEMRI-derived parameters were not identical to the HRCT-derived parameters, the cranial-caudal heterogeneity in HRCT or OEMRI was complementary to that in evaluations of oxygen uptake in the lungs. Functional imaging seems to provide new insights into COPD pathophysiology without radiation exposure.

Respiratory parameters predict poor outcome in COPD patients, category GOLD 2017 B

Background

Respiratory parameters are important predictors of prognosis in the COPD population. Global Initiative for Obstructive Lung Disease (GOLD) 2017 Update resulted in a vertical shift of patients across COPD categories, with category B being the most populous and clinically heterogeneous. The aim of our study was to investigate whether respiratory parameters might be associated with increased all-cause mortality within GOLD category B patients.

Methods

The data were extracted from the Czech Multicentre Research Database, a prospective, noninterventional multicenter study of COPD patients. Kaplan-Meier survival analyses were performed at different levels of respiratory parameters (partial pressure of oxygen in arterial blood [PaO₂], partial pressure of arterial carbon dioxide [PaCO₂] and greatest decrease of basal peripheral capillary oxygen saturation during 6-minute walking test [6-MWT]). Univariate analyses using the Cox proportional hazard model and multivariate analyses were used to identify risk factors for mortality in hypoxemic and hypercapnic individuals with COPD.

Results

All-cause mortality in the cohort at 3 years of prospective follow-up reached 18.4%. Chronic hypoxemia (PaO₂ <7.3 kPa), hypercapnia (PaCO₂ >7.0 kPa) and oxygen desaturation during the 6-MWT were predictors of long-term mortality in COPD patients with forced expiratory volume in 1 second ≤60% for the overall cohort and for GOLD B category patients. Univariate analyses confirmed the association among decreased oxemia (<7.3 kPa), increased capnemia (>7.0 kPa), oxygen desaturation during 6-MWT and mortality in the studied groups of COPD subjects. Multivariate analysis identified PaO₂ <7.3 kPa as a strong independent risk factor for mortality.

Conclusion

Survival analyses showed significantly increased all-cause mortality in hypoxemic and hypercapnic GOLD B subjects. More important, PaO₂ <7.3 kPa was the strongest risk factor, especially in category B patients. In contrast, the majority of the tested respiratory parameters did not show a difference in mortality in the GOLD category D cohort.

Effectiveness of high-flow nasal cannula oxygen therapy for acute respiratory failure with hypercapnia

Background

Heated and humidified high-flow nasal cannula (HFNC) oxygen therapy has recently been introduced for hypoxic respiratory failure. However, it has not been well-evaluated for acute respiratory failure with hypercapnia.

Methods

This retrospective study included acute respiratory failure patients with hypercapnia in the medical intensive care unit (MICU) from April 2011 to February 2013, who required HFNC oxygen therapy for hypoxemia. Respiratory parameters were recorded and arterial blood gas analyses conducted before, and at 1 and 24 h after initiation of HFNC oxygen therapy.

Results

Thirty-three patients were studied [median age, 72 years; range, 17-85 years; men, 24 (72.7%)]. Pneumonia (36.4%) and acute exacerbation of chronic obstructive pulmonary disease (33.4%) were the most common reasons for oxygen therapy. Most patients (60.6%) received oxygen therapy via nasal prong before HFNC application. The mean fraction of inspired oxygen (FiO₂) and HFNC flow rate were 0.45±0.2 and 41.1±7.1 L/min, respectively; mean duration of application was 3.6±4.1 days. The partial pressure of arterial carbon dioxide (PaCO₂) was 55.0±12.2 mmHg at admission, and increased by approximately 1.0±7.7 mmHg with conventional oxygen therapy. In contrast, with HFNC therapy, PaCO₂ decreased by 4.2±5.5 and 3.7±10.8 mmHg in 1 and 24 h, respectively, resulting in significant improvement in hypercapnia (P=0.006 and 0.062, respectively).

Conclusions

HFNC oxygen therapy with sufficient FiO₂ to maintain a normal partial pressure of arterial oxygen (PaO₂) significantly reduced PaCO₂ in acute respiratory failure with hypercapnia.

Increased Small Intestinal Permeability during Severe Acute Exacerbations of COPD

BACKGROUND

Disturbances of intestinal integrity, manifested by increased gastro-intestinal (GI) permeability, have been found in chronic obstructive pulmonary disease (COPD) patients during physical activity, often associated with intermittent hypoxic periods. Evidence about extrapulmonary organ disturbances, especially of the GI tract, during hospitalised acute exacerbation of COPD (AE-COPD) with hypoxaemic respiratory failure (RF) is lacking.

OBJECTIVE

The aim was to assess changes in GI permeability in patients with AE-COPD and during recovery 4 weeks later.

METHODS

All patients admitted to our hospital with AE-COPD accompanied by hypoxaemia at admission (PaO2 <8.7 kPa or O2 saturation <93%) were screened between October 2013 and February 2014. Patients with a history of GI or renal disease, chronic heart failure, or use of non-steroidal anti-inflammatory drugs in the 48 h before the test were excluded. GI permeability was assessed by evaluating urinary excretion ratios of the orally ingested sugars lactulose/L-rhamnose (L/R ratio), sucrose/L-rhamnose (Su/R ratio) and sucralose/erythritol (S/E ratio).

RESULTS

Seventeen patients with severe to very severe COPD completed the study. L/R ratio (×103) at admission of AE-COPD was significantly higher than in the recovery condition (40.9 [29.4-49.6] vs. 27.3 [19.5-47.7], p = 0.039), indicating increased small intestinal permeability. There were no significant differences in the individual sugar levels in urine nor in the 0- to 5-h urinary S/E and Su/R ratios between the 2 visits.

CONCLUSION

This is the first study showing increased GI permeability during hospitalised AE-COPD accompanied by hypoxaemic RF. Therefore, GI integrity in COPD patients is an attractive target for future research and for the development of interventions to alleviate the consequences of AE-COPD.

Parental preference and perspectives on continuous pulse oximetry in infants and children with bronchiolitis

OBJECTIVE

The purpose of the study was to investigate parental preference of continuous pulse oximetry in infants and children with bronchiolitis.

MATERIALS AND METHODS

A cross-sectional prospective study was conducted at Hamad Medical Corporation in Qatar. Parents of infants and children <24 months old and hospitalized with bronchiolitis were offered an interview survey.

RESULTS

A total of 132 questionnaires were completed (response rate 100%). Approximately 90% of participants were 20-40 years of age, and 85% were females. The mean age of children was 7.2±5.8 months. Approximately eight in ten parents supported the idea of continuous pulse oximetry in children with bronchiolitis. Almost 43% of parents believed that continuous pulse-oximetry monitoring would delay their children's hospital discharge. Interestingly, approximately 85% of caregivers agreed that continuous pulse oximetry had a good impact on their children's health. In addition, around one in two of the participants stated that good bedside examinations can obviate the need for continuous pulse oximetry. Furthermore, 80% of parents believed that continuous pulse-oximetry monitoring would give the health-care provider a good sense of security regarding the child's health. Finally, being a male parent was associated with significantly increased risk of reporting unnecessary fatigue, attributed to the sound of continuous pulse oximetry (P=0.031).

CONCLUSION

Continuous pulse-oximetry monitoring in children with bronchiolitis was perceived as reassuring for parents. Involving parents in decision-making is considered essential in the better management of children with bronchiolitis or any other disease. The first step to decrease continuous pulse oximetry will require provider education and change as well. Furthermore, we recommend proper counseling for parents, emphasizing that medical technology is not always essential, but is a complementary mode of managing a disease.

Rapid decline in lung function in healthy adults predicts incident excess urinary albumin excretion later in life

Introduction

Chronic lung disease, often characterised by rapid decline in lung function, is associated with vascular endothelial dysfunction (characterised by moderate to severe excess urinary albumin excretion (eUAE) but their longitudinal relationship is inadequately studied. In a bidirectional longitudinal examination of healthy adults, we analysed the following two hypotheses: (1) rapid decline (ie, highest tertile of lung function decline) predicts eUAE and (2) eUAE predicts rapid decline.

Methods

We performed a secondary data analysis from 3052 eligible participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study. For analysis 1, the predictor was rapid decline in lung function between the peak value (attained at or before CARDIA visit year 10 or Y10 at a mean age of 35 years) and Y20; and the outcome was incident eUAE at Y20 and/or Y25. For analysis 2, the predictor was eUAE at Y10 and the outcome was rapid decline between Y10 and Y20.

Results

After adjustment for covariates in analysis 1, rapid decline in FEV₁ or FVC between peak and Y20 predicted incident eUAE at Y20 and/or Y25 (OR 1.51 and 1.44, respectively; p≤0.05 for both analyses). In analysis 2, eUAE at Y10 did not predict subsequent rapid decline.

Conclusions

Healthy adults with rapid decline in lung function are at risk for developing vascular endothelial dysfunction, as assessed by incident eUAE, later in life.

Long-Term Oxygen Therapy in COPD Patients Who Do Not Meet the Actual Recommendations

Chronic respiratory failure due to chronic obstructive pulmonary disease (COPD) is an increasing problem worldwide. Many patients with severe COPD develop hypoxemic respiratory failure during the natural progression of disease. Long-term oxygen therapy (LTOT) is a well-established supportive treatment for COPD and has been shown to improve survival in patients who develop chronic hypoxemic respiratory failure. The degree of hypoxemia is severe when partial pressure of oxygen in arterial blood (PaO₂) is ≤55 mmHg and moderate if PaO₂ is between 56 and 69 mmHg. Although current guidelines consider LTOT only in patients with severe resting hypoxemia, many COPD patients with moderate to severe disease experience moderate hypoxemia at rest or during special circumstances, such as while sleeping or exercising. The efficacy of LTOT in these patients who do not meet the actual recommendations is still a matter of debate, and extensive research is still ongoing to understand the possible benefits of LTOT for survival and/or functional outcomes such as the sensation of dyspnea, exacerbation frequency, hospitalizations, exercise capacity, and quality of life. Despite its frequent use, the administration of "palliative" oxygen does not seem to improve dyspnea except for delivery with high-flow humidified oxygen. This narrative review will focus on current evidence for the effects of LTOT in the presence of moderate hypoxemia at rest, during sleep, or during exercise in COPD.

Spanish Guidelines for Management of Chronic Obstructive Pulmonary Disease (GesEPOC) 2017. Pharmacological Treatment of Stable Phase

The clinical presentation of chronic obstructive pulmonary disease (COPD) varies widely, so treatment must be tailored according to the level of risk and phenotype. In 2012, the Spanish COPD Guidelines (GesEPOC) first established pharmacological treatment regimens based on clinical phenotypes. These regimens were subsequently adopted by other national guidelines, and since then, have been backed up by new evidence. In this 2017 update, the original severity classification has been replaced by a much simpler risk classification (low or high risk), on the basis of lung function, dyspnea grade, and history of exacerbations, while determination of clinical phenotype is recommended only in high-risk patients. The same clinical phenotypes have been maintained: non-exacerbator, asthma-COPD overlap (ACO), exacerbator with emphysema, and exacerbator with bronchitis. Pharmacological treatment of COPD is based on bronchodilators, the only treatment recommended in low-risk patients. High-risk patients will receive different drugs in addition to bronchodilators, depending on their clinical phenotype. GesEPOC reflects a more individualized approach to COPD treatment, according to patient clinical characteristics and level of risk or complexity.

Reactive Oxygen Species in COPD-Related Vascular Remodeling

The pathogenesis of chronic obstructive pulmonary disease (COPD) is a multifaceted process involving the alteration of pulmonary vasculature. Such vascular remodeling can be associated with inflammation, shear stress, and hypoxia-conditions commonly seen in patients with lung diseases. Particularly, the overproduction of reactive oxygen species (ROS) in the diseased lungs contributes greatly to pulmonary vascular remodeling. ROS play an important role in vascular homeostasis, yet excessive ROS can alter pulmonary vasculature and impair lung function, as implicated in COPD at all stages. Increased inflammatory cell infiltration and endothelial dysfunction both correspond to the severity of COPD. As a byproduct of vascular remodeling, pulmonary hypertension negatively affects the long-term survival rate of COPD patients. While there is currently no cure for COPD, several treatment options have focused on alleviating COPD symptoms. Interventions such as long-term oxygen therapy, endothelium-targeted treatment, and pharmacological therapies show promising results in improving the life span of COPD patients and attenuating the progression of pulmonary hypertension. In this chapter, we aim to discuss the contributing factors of pulmonary vascular remodeling in COPD with an emphasis on the ROS, as well as potential redox treatments for COPD-related vascular remodeling.

Is oxygen saturation variable of simplified pulmonary embolism severity index reliable for identification of patients, suitable for outpatient treatment

INTRODUCTION

The pulmonary embolism severity index (PESI) or simplified version (sPESI) are widely validated risk scores for the identification of eligible patients for outpatient treatment. Saturation is one of these criteria. For this metric, saturation of 90% or greater is assigned zero points. However, 90% saturation does not always exclude hypoxemic respiratory failure.

OBJECTIVE

The aims of this study were first was to define corresponding partial arterial oxygen pressure (PaO₂ ) values according to saturation in pulmonary embolism (PE) patients, and the second was to define a target saturation that can exclude hypoxemic respiratory failure and enable secure discharge of PE patients from emergency departments.

METHODS

This is a retrospective study. To determine the optimal saturation value by which to detect hypoxemic respiratory failure, we generated receiver operating characteristic (ROC) curves and calculated the negative predictive value.

RESULTS

Total of 65 patients were included in this study. Mean PaO₂ levels from SaO₂ 89% to SaO₂ 93% were 52.8, 57.1, 57.3, 61, and 63.8 mmHg, respectively. ROC curve analysis revealed SaO₂ level of 91.5% to be optimal target saturation for excluding respiratory failure with 84.6% specificity and 89.7% sensitivity; area under the curve was 0.885 (95% CI 0.796-0.975). The negative predictive value was 80% for SaO₂ level of 92%.

CONCLUSION

Patients with PE may be in respiratory failure despite an oxyhemoglobin saturation of ≥90%. Although saturation is likely more important than precise PaO₂ in tissue oxygenation, clinicians should be aware of the physiological effects of hypoxemia and take this into account before making outpatient treatment decisions.

DNA damage and repair capacity in lymphocyte of chronic obstructive pulmonary diseases patients during physical exercise with oxygen supplementation

BACKGROUND

We hypothesized that the use of oxygen supplementation during aerobic exercise induces less DNA damage than exercise alone. The aim of this study is to assess the level of DNA damage induced by physical exercise with and without oxygen supplementation in chronic obstructive pulmonary diseases (COPD) patients.

METHODS

Peripheral blood was collected before and after aerobic exercise in two conditions: (I) aerobic exercise without oxygen supplementation (AE group) and (II) with oxygen supplementation (AE-O2 group). Lymphocytes were collected to perform the alkaline version of the Comet Assay. To assess the susceptibility to exogenous DNA damage, the lymphocytes were treated with methyl methanesulphonate (MMS) for 1-h or 3-h. After 3-h treatment, the percentage of residual damage was calculated assuming the value of 1-h MMS treatment as 100%.

RESULTS

AE group showed lower induced damage (1 h of MMS treatment) and consequently less DNA repair compared to AE-O2 group. AE-O2 group showed an increase in the induced DNA damage (1 h of MMS treatment) and an increased DNA repair capacity. Within the AE-O2 group, in the post-exercise situation the induced DNA damage after 1 h of MMS treatment was higher (p = 0.01) than in the pre-exercise.

CONCLUSION

COPD patients who performed physical exercise associated with oxygen supplementation had a better response to DNA damage induced by MMS and a better DNA repair when compared to the condition of physical exercise without oxygen supplementation.

TRIAL REGISTRATION

UNISC N374.298. Registered 04 JUN 2013 (retrospectively registered).

Brain adaptation to hypoxia and hyperoxia in mice

Aims

Hyperoxic breathing might lead to redox imbalance and signaling changes that affect cerebral function. Paradoxically, hypoxic breathing is also believed to cause oxidative stress. Our aim is to dissect the cerebral tissue responses to altered O₂ fractions in breathed air by assessing the redox imbalance and the recruitment of the hypoxia signaling pathways.

Results

Mice were exposed to mild hypoxia (10%O₂), normoxia (21%O₂) or mild hyperoxia (30%O₂) for 28 days, sacrificed and brain tissue excised and analyzed. Although one might expect linear responses to %O₂, only few of the examined variables exhibited this pattern, including neuroprotective phospho- protein kinase B and the erythropoietin receptor. The major reactive oxygen species (ROS) source in brain, NADPH oxidase subunit 4 increased in hypoxia but not in hyperoxia, whereas neither affected nuclear factor (erythroid-derived 2)-like 2, a transcription factor that regulates the expression of antioxidant proteins. As a result of the delicate equilibrium between ROS generation and antioxidant defense, neuron apoptosis and cerebral tissue hydroperoxides increased in both 10%O₂ and 30%O₂, as compared with 21%O₂. Remarkably, the expression level of hypoxia-inducible factor (HIF)−2α (but not HIF-1α) was higher in both 10%O₂ and 30%O₂ with respect to 21%O₂

Innovation

Comparing the in vivo effects driven by mild hypoxia with those driven by mild hyperoxia helps addressing whether clinically relevant situations of O₂ excess and scarcity are toxic for the organism.

Conclusion

Prolonged mild hyperoxia leads to persistent cerebral damage, comparable to that inferred by prolonged mild hypoxia. The underlying mechanism appears related to a model whereby the imbalance between ROS generation and anti-ROS defense is similar, but occurs at higher levels in hypoxia than in hyperoxia.

•

Both oxygen scarcity and oxygen excess are harmful for the brain.

•

Hypoxia increases ROS more than hyperoxia.

•

Hypoxia increases the antioxidant defenses to an extent larger than hyperoxia.

•

Both hypoxia and hyperoxia imbalance the ROS generation/ antiROS defense equilibrium.

•

These findings have implications for those who need supplemental oxygen therapy.

High flow nasal cannula versus conventional oxygen therapy and non-invasive ventilation in adults with acute hypoxemic respiratory failure: A systematic review

INTRODUCTION

Humidified oxygen via a high flow nasal cannula (HFNC) is a form of supplemental oxygen therapy that has significant theoretical advantages over conventional oxygen therapy (COT). However, the clinical role of HFNC in acute hypoxemic respiratory failure (AHRF) has not been well established. This review compares the efficacy of HFNC with COT and non-invasive ventilation (NIV) in patients with AHRF.

METHODS

Studies reviewed were selected based on relevance from a systematic literature search conducted in Medline and EMBASE to include all published original research through May 2016. Twelve studies matched the inclusion criteria.

RESULTS

In the majority of the studies, HFNC was associated with superior comfort and patient tolerance as compared to NIV or COT. HFNC was associated with reduced work of breathing in comparison with COT in some, but not all, studies in the review. COT and NIV were associated with a higher 90-day mortality rate compared to HFNC in only one multicenter randomized trial versus no mortality difference reported by others. Three out of four studies demonstrated a decreased need for escalation of oxygen therapy with HFNC. Six out of eight studies demonstrated improved oxygenation with HFNC as compared to COT. Two of three studies revealed worse oxygenation with HFNC as compared to NIV.

CONCLUSION

This review suggests that HFNC may be superior to COT in AHRF patients in terms of oxygenation, patient comfort, and work of breathing. It may be reasonable to consider HFNC as an intermediate level of oxygen therapy between COT and NIV.

Myocardial performance index correlates with the BODE index and affects quality of life in COPD patients

Background and objective

COPD, a systemic illness associated with the impairment of different organs, affects patient prognosis and quality of life. The aim of this study was to evaluate the association between right ventricle (RV) function, the BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) index (a multifunctional scale for the assessment of mortality risk), and quality of life in patients with COPD.

Methods

A cross-sectional study was carried out in 107 outpatients presenting with stable COPD who underwent clinical assessment, spirometry, arterial blood gas analyses, a 6-minute walk test, electrocardiography, and echocardiogram and who responded to the Saint George’s Respiratory Questionnaire (SGRQ).

Results

Among the study subjects, 53% (57/107) were males, and the mean age was 65.26±8.81 years. A positive correlation was observed between RV dysfunction measured by the myocardial performance index using tissue Doppler (MPIt) and the BODE index, even after adjustment for age and partial pressure of oxygen (r²=0.47; P<0.01). Patients with alterations in the MPIt had worse quality of life, and a statistically significant difference was found for different domains of the SGRQ. Patients with a normal MPIt had a mean total score of 46.2±18.6, whereas for those with MPIt alterations, the mean total score was 61.6±14.2 (P=0.005). These patients had a 1.49-fold increased risk of exhibiting SGRQ total score above the upper limit of the 95% CI (P=0.01).

Conclusion

The findings of this study suggest that RV dysfunction as measured by the MPIt was associated with impairment in quality of life and a worse BODE index in COPD patients, irrespective of age and hypoxemia status.

Chemotherapy in Non-Small Cell Lung Cancer Patients Receiving Oxygen Therapy

BACKGROUND

Information regarding chemotherapy in non-small cell lung cancer (NSCLC) patients with chronic respiratory failure is limited.

PATIENTS AND METHODS

We retrospectively analyzed patients who received oxygen therapy and underwent chemotherapy for NSCLC at our hospital.

RESULTS

6 patients with NSCLC receiving oxygen therapy (4 with unresectable lung cancer and 2 with postoperative recurrent lung cancer) underwent chemotherapy. 1 patient achieved a partial response and 1 achieved stable disease after first-line chemotherapy. The median overall survival (OS) was 247 days in all patients. Patients with unresectable NSCLC and recurrent NSCLC had median OS times of 282 and 239 days, respectively. Grade 3 lung infection occurred in 4 patients during chemotherapy treatment; however, there were no chemotherapy-related deaths.

CONCLUSION

There is a possibility that chemotherapy could improve the survival of NSCLC patients who receive oxygen therapy.

A Randomized, Placebo-controlled Trial of Roflumilast. Effect on Proline-Glycine-Proline and Neutrophilic Inflammation in Chronic Obstructive Pulmonary Disease

RATIONALE

Roflumilast is a therapeutic agent in the treatment of chronic obstructive pulmonary disease (COPD). It has antiinflammatory effects; however, it is not known whether it can affect a biologic pathway implicated in COPD pathogenesis and progression. The self-propagating acetyl-proline-glycine-proline (AcPGP) pathway is a novel means of neutrophilic inflammation that is pathologic in the development of COPD. AcPGP is produced by extracellular matrix collagen breakdown with prolyl endopeptidase and leukotriene A4 hydrolase serving as the enzymes responsible for its production and degradation, respectively.

OBJECTIVES

We hypothesized that roflumilast would decrease AcPGP, halting the feed-forward cycle of inflammation.

METHODS

We conducted a single-center, placebo-controlled, randomized study investigating 12 weeks of roflumilast treatment added to current therapy in moderate-to-severe COPD with chronic bronchitis. Subjects underwent sputum and blood analyses, pulmonary function testing, exercise tolerance, and quality-of-life assessment at 0, 4, and 12 weeks.

MEASUREMENTS AND MAIN RESULTS

Twenty-seven patients were enrolled in the intention-to-treat analysis. Roflumilast treatment decreased sputum AcPGP by more than 50% (P < 0.01) and prolyl endopeptidase by 46% (P = 0.02), without significant improvement in leukotriene A4 hydrolase activity compared with placebo. Roflumilast also reduces other inflammatory markers. There were no significant changes in lung function, quality of life, or exercise tolerance between roflumilast- and placebo-treated groups.

CONCLUSIONS

Roflumilast reduces pulmonary inflammation through decreasing prolyl endopeptidase activity and AcPGP. As expected for lower AcPGP levels, markers of neutrophilic inflammation are blunted. Inhibiting this self-propagating pathway lessens the overall inflammatory burden, which may alter the natural history of COPD, including the risk of exacerbation. Clinical trial registered with www.clinicaltrials.gov (NCT 01572948).

Pulse oximetry in bronchiolitis: is it needed?

Infants admitted to health-care centers with acute bronchiolitis are frequently monitored with a pulse oximeter, a noninvasive method commonly used for measuring oxygen saturation. The decision to hospitalize children with bronchiolitis has been largely influenced by pulse oximetry, despite its questionable diagnostic value in delineating the severity of the illness. Many health-care providers lack the appropriate clinical fundamentals and limitations of pulse oximetry. This deficiency in knowledge might have been linked to changes in the management of bronchiolitis. The aim of this paper is to provide the current evidence on the role of pulse oximetry in bronchiolitis. We discuss the history, fundamentals of operation, and limitations of the apparatus. A search of the Google Scholar, Embase, Medline, and PubMed databases was carried out for published articles covering the use of pulse oximetry in bronchiolitis.

Primary Care of the Patient with Asthma

Obstructive lung disease includes asthma and chronic obstructive pulmonary disease (COPD). Because a previous issue of Medical Clinics of North America (2012;96[4]) was devoted to COPD, this article focuses on asthma in adults, and addresses some topics about COPD not addressed previously. Asthma is a heterogeneous disease marked by variable airflow obstruction and bronchial hyperreactivity. Onset is most common in early childhood, although many people develop asthma later in life. Adult-onset asthma presents a particular challenge in the primary care clinic because of incomplete understanding of the disorder, underreporting of symptoms, underdiagnosis, inadequate treatment, and high rate of comorbidity.