Diagnosis Of Airway Obstruction Research Articles

Correlation of Impulse Oscillometry with Spirometry in Deployed Military Personnel with Airway Obstruction.

Evaluation of chronic respiratory symptoms in deployed military personnel has been conducted at Brooke Army Medical Center as part of the Study of Active Duty Military for Pulmonary Disease Related to Environmental Deployment Exposures III study. Although asthma and airway hyperreactivity have been the most common diagnoses, the clinical findings in these patients may be multifactorial. This study aims to evaluate the utility of impulse oscillometry (IOS) in diagnosing airway obstruction in patients undergoing multiple pulmonary function testing (PFT) studies. Military personnel referred for deployed-related pulmonary symptoms underwent a standardized evaluation at Brooke Army Medical Center and Walter Reed National Military Medical Center over a 5-year span. Initial studies included laboratory tests, high-resolution computed tomography imaging, cardiac evaluation with electrocardiogram, and echocardiography. PFT consisted of full PFTs, forced inspiratory/expiratory pressures, post-spirometry bronchodilator testing, IOS, exhaled nitric oxide, and methacholine challenge testing. A total of 360 patients have completed an evaluation to date. In this cohort, 108 patients (30.0%) have evidence of obstruction by spirometry, whereas 74 (20.6%) had IOS values of both an R5 > 150% and X5 < -1.5. Only 32 (8.9%) had evidence of obstruction by both spirometry and IOS, whereas 210 (57.3%) had neither. A comparison among R5 (resistance at 5 Hz), R20 (resistance at 20 Hz), and X5 (reactance at 5 Hz) was performed in those individuals with and without spirometric obstruction. R5 (% predicted) was 156.2 ± 57.4% (obstruction) vs. 129.1 ± 39.6% (no obstruction) (P < .001); R20 (% predicted) was 138.1 ± 37.7% (obstruction) vs. 125.3 ± 31.2% (no obstruction) (P = .007); and X5 (cmH2O/L/s) was -1.62 ± 1.28 (obstruction) vs. -1.25 ± 0.55 (no obstruction) (P < .001). Impulse oscillometry has been advocated as a supplemental pulmonary function test to aid in the diagnosis of airway obstruction. The use of IOS has been primarily used in pediatrics and elderly populations as a validated tool to establish a diagnosis of airway obstruction but is limited in the adult population because of a well-validated set of reference values. Prior studies in adults have most often demonstrated a correlation with an elevated R5 > 150%, elevated resonant frequency, and a negative X5 < -1.5 or a decrease of 30 to 35% in R5 post-bronchodilator. Impulse oscillometry may serve as an adjunct to diagnosis but likely cannot replace a standard spirometric evaluation. Our study highlights the future utility for diagnosing early obstructive disease in the symptomatic individual.

Intelligent injury prediction for traumatic airway obstruction.

Airway obstruction is one of the crucial causes of death in trauma patients during the first aid. It is extremely challenging to accurately treat a great deal of casualties with airway obstruction in hospitals. The diagnosis of airway obstruction in an emergency mostly relies on the medical experience of physicians. In this paper, we propose the feature selection approach genetic algorithm-mean decrease impurity (GA-MDI) to effectively minimize the number of features as well as ensure the accuracy of prediction. Furthermore, we design a multi-modal neural network, called fully convolutional network with squeeze-and-excitation and multilayer perceptron (FCN-SE + MLP), to help physicians to predict the severity of airway obstruction. We validate the effectiveness of the proposed feature selection approach and multi-modal model on the emergency medical database from the Chinese General Hospital of the PLA. The experimental results show that GA-MDI outperforms the existing feature selection algorithms, while it is also validated that the model FCN-SE + MLP can effectively and accurately achieve the prediction of the severity of airway obstruction, which can assist clinicians in making treatment decisions for airway obstruction casualties.

Diagnostic Performance of Forced Expiratory Volume in Six Seconds for the Detection of Obstructive and Restrictive Pulmonary Diseases in a Population of Young Adults in South of Iran

Background: Forced expiratory volume in 6 seconds (FEV6) is a reliable substitute for forced vital capacity (FVC) to identify pulmonary diseases. This study aimed to determine the diagnostic performance of FEV6 in the detection of obstructive and restrictive spirometric patterns. Methods: In this cross-sectional study, spirometry was performed on patients referred to the occupational medicine clinic of Shahid Mohammadi Hospital, Bandar Abbas, Iran, 2018. Spirometric parameters, including FEV1, FVC, and FEV6, were recorded for those tests meeting the American Thoracic Society (ATS) standards. Taken as the reference, the FEV1/FVC ratio&lt;70% indicated airway obstruction, and the restrictive pattern was defined as FVC&lt;80%. Results: In general, 1100 spirometries were included after meeting the ATS standards. The optimal cut-off of FEV1/FEV6 for the prediction of airway obstruction was 71.45% with a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of 97.22%, 98.22%, 89.17%, 99.57%, and 98.09%, respectively. The best cut-off of FEV6 for the prediction of the restrictive pattern was 79.23% with the corresponding diagnostic indices of 97.29%, 99.05%, 94.11%, 99.57%, and 98.81%, respectively. Based on the FEV1/FEV6 cut-off, the frequency of obstruction was 14.27% (157/1100) compared to 13.09% based on FEV1/FVC. The frequency of restriction was 13.90% (153/1100) according to the FEV6 cut-off compared to 13.45% with respect to FVC. Conclusion: Overall, our results indicated the applicability of FEV1/FEV6 as an accepted surrogate for FEV1/FVC to diagnose airway obstruction, particularly to screen for chronic obstructive pulmonary disease (COPD) among high-risk patients. In addition, FEV6 is potentially an appropriate substitute for FVC to detect a restrictive pattern.

Linear Cephalometric Analysis of Pharynx at the Level of Epiglottis among Snorers and Nonsnorers: A Cross-Sectional Study.

Aim Snoring, which falls within the spectrum of sleep-related breathing disorders, is considered to be one of the common symptoms of airway obstruction. Lateral cephalometric analysis is an effective way of diagnosing airway obstruction by evaluating skeletal and soft tissue abnormalities in patients with sleep-disordered breathing (SDB). The present study was planned to analyze the pharyngeal space among snorers and nonsnorers in the retroglossal region and in the region of hypopharynx at the level of epiglottis. Materials and Methods The present cross-sectional study included a total of 60 individuals who were grouped into snorers and nonsnorers based on their answers for the study questionnaire related to snoring. Digital lateral cephalograms were taken for all maintaining the exposure parameters while Digora software was used for measurements related to the soft tissue parameters. The two significant soft tissue parameters analyzed were the distance of epiglottis from the tip of the soft palate, the retroglossal length, and the distance of posterior pharynx from the tip of the epiglottis, the pharyngeal space. Statistical Analysis The statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, Illinois, United States) while paired t -test was used for intergroup analysis. A p -value of < 0.05 was considered statistically significant. Results The mean retroglossal length was found to be 25.52 mm among the snorers and 23.70 mm among the nonsnorers. In case of pharyngeal space, a mean of 8.54 mm was recorded among the snorers whereas among the nonsnorers, the respective mean value of 10.16 mm was observed. Conclusion In the present study, pharyngeal space was found to be less at the level of the tip of epiglottis among the snorers compared with nonsnorers which can be attributed to be one of the significant reasons behind snoring and obstructive sleep apnea syndrome.

Differences between FEV6, FVC and VC at the diagnosis of obstructive ventilatory defect

IntroductionThe diagnosis of airway obstruction can be made through FEV1/FVC ratio <0.7 or FEV1/VC ratio < lower limit of normality (LLN). Several authors advocate that FEV1/FEV6 ratio is an alternative to diagnosing obstructive ventilatory defect, while others have determined that the best cut-off for this ratio (best combined sensitivity and specificity) is 0.73. ObjectiveTo evaluate the non-inferiority of FEV1/FEV6 ratio < 0.73 when compared to FEV1/FVC ratio < 0.7 and FEV1/VC < LLN in diagnosing airway obstruction. MethodsA retrospective analysis of the medical records from patients who underwent spirometry or plethysmography in a university central hospital from June 1st to December 31st, 2018 was carried out. Only medical records which included FEV1/FVC < 0.7 or FEV1/VC < LLN were selected, and these results were compared to FEV1/FEV6 ratio. ResultsA total of 526 patients with obstructive ventilatory defect were identified by one of the two ratios described. Of these, 95.1%, 87.4% and 88.6% were obstructive by FEV1/FVC, FEV1/VC, and FEV1/FEV6 ratio, respectively. The positive predictive value (PPV) of FEV1/FEV6 in relation to FEV1/FVC ratio was 99.6% (p < 0.001) with a diagnostic efficacy of 92.8%, whereas the PPV of FEV1/FEV6 in relation to FEV1/VC was 91.0% (p < 0.001) and diagnostic efficacy was 85.2%. Most false negatives, comparing FEV6 with the other two tests, were found in patients with FEV1 > 70% (mild obstruction) and in individuals aged >50 years. ConclusionsFEV1/FEV6 < 0.73 may be a good alternative ratio, as it is non-inferior to FEV1/VC and FEV1/FVC in diagnosing obstructive ventilatory defect.

Linear Cephalometric Analysis of Pharynx at the Level of Epiglottis among Snorers and Nonsnorers: A Cross-Sectional Study.

Background and Aim:Snoring, which falls within the spectrum of sleep-related breathing disorders, is considered to be one of the common symptoms of airway obstruction. Lateral cephalometric analysis is an effective way of diagnosing airway obstruction by evaluating skeletal and soft-tissue abnormalities in patients with sleep-disordered breathing. The present study was planned to analyze the pharyngeal space among snorers and nonsnorers in retroglossal region and in the region of the hypopharynx at the level of epiglottis.Materials and Methods:The present cross-sectional study included a total of 60 individuals who were grouped into snorers and nonsnorers based on their answers for the study questionnaire related to snoring. Digital lateral cephalograms were taken for all maintaining the exposure parameters, whereas Digora software was used for measurements related to the soft-tissue parameters. The two significant soft-tissue parameters analyzed were the distance of epiglottis from the tip of the soft palate, the retroglossal length and the distance of posterior pharynx from the tip of the epiglottis, the pharyngeal space.Statistical Analysis Used:The statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, IL, USA), whereas paired t-test was used for inter-group analysis. P <0.05 was considered statistically significant.Results:The mean retroglossal length was found to be 25.52 mm among the snorers and 23.70 mm among the nonsnorers. In the case of pharyngeal space, a mean of 8.54 mm was recorded among the snorers, whereas among the nonsnorers, the respective mean value of 10.16 mm was observed.Conclusion:In the present study, pharyngeal space was found to be less at the level of the tip of epiglottis among the snorers compared to nonsnorers which can be attributed to be one of the significant reasons behind snoring and obstructive sleep apnea syndrome.

Comparing Traditional and Augmented Reality Training for Identifying Critical Symptoms for Diagnosing Airway Obstruction Cases: A Pilot Study

Recent developments in the portability, flexibility, and affordability of augmented reality technology allow it to address some limitations of current medical training. This pilot study aims to determine whether augmented reality can enhance the detection and identification of subtle cues used to make accurate medical diagnoses. We randomly assigned five participants to a control group, where they received diagnostic training by reading a standard textbook, and an experimental group, where they received diagnostic training by a combination of reading a standard textbook and augmented reality-based training. All participants were tested with a tension pneumothorax scenario, where they listed symptoms and made a diagnosis. We recorded the time until a final diagnosis was made and categorized the diagnosis and symptoms as accurate or inaccurate. A two-tailed t-test was used to assess differences between groups. The experimental group correctly identified more symptoms than the control group (average 12 vs. 5). These results indicate the potential of AR-based training to enhance detection and identification of cues in medical diagnostics.

Imaging of Airway Obstruction in Children.

Various imaging techniques may be used to diagnose airway obstruction in children. Digital radiography, computed tomography and magnetic resonance imaging are the most important modalities, but the choice of technique will depend on the level and nature of suspected obstruction, as well as patient-specific factors such as age and ability to cooperate. This review examines the forms of airway obstruction that are commonly encountered in childhood.

Correlation of FEV1/FEV6 with BODE Index, CAT Score and DLCO in COPD Patients

Chronic Obstructive Pulmonary Disease is associated with progressive airflow limitation. Spirometry is one of the most important non-invasive tests that help in diagnosing airway obstruction. A Post bronchodilator FEV1/FVC ratio &lt; 0.7 according to GOLD guidelines is considered to be diagnostic of COPD, wherein FEV1 is the forced expiratory volume in the first second, and FVC is the forced vital capacity which requires complete emptying of lungs that may require longer expiratory time and a more significant expiratory effort. The value of FEV1/FEV6 ratio is similar to the FEV1/FVC rate in diagnosing obstruction. FEV1/FEV6 is one such spirometric measurement which reduces the effort of expiration and helps in detecting the airway obstruction at the end of the sixth second during forceful exhalation thus serving as a natural, cost-effective bedside investigation that can be used in every health care facility for prompt diagnosis and management of the disease. FEV1/FEV6 can also be used to assess the prognosis of patients with COPD. It can even independently predict the reduction of lung function, rate of death and risk of carcinoma. The vitalograph is a smooth handheld device which helps in early detection of COPD in a quick, simple and reproducible manner. It not only displays the FEV1, FEV6 ratio and FEV1 per cent predicted but also provided information regarding the severity of COPD classification and lung age estimation. It can be used as a tool to avoid over diagnosis of COPD, especially in elderly patients. It has the advantage of requiring minimal instruction for use by non-respiratory specialists as well. This work concludes that FEV1/FEV6 can be used as a simple, cost-effective bedside investigation to diagnose COPD as an alternative to the conventional spirometry to detect undiagnosed airway obstruction in individuals with a low expiratory effort, especially in poor resource settings.

Fixed Ratio versus Lower Limit of Normality for Diagnosing COPD in Primary Care: Long-Term Follow-Up of EGARPOC Study.

PurposeThe best criterion for diagnosing airway obstruction in COPD, fixed ratio (FR: FEV1/FVC<0.7) or lower limit of normality (LLN), remains controversial. We compared the long-term evolution of COPD patients according to the initial obstruction criteria.Patients and MethodsBetween 2005 and 2008, we evaluated 1728 subjects over 45 years of age with smoking history, pertaining to a primary care center. A total of 424 patients were obstructive by FR, after a bronchodilator test. Of those, 289 patients met obstruction criteria for both FR and LLN and were considered concordant patients (FR+LLN+), while 135 patients were obstructive by FR but non-obstructive by LLN and were defined as discordant patients (FR+LLN-).ResultsForty-eight patients (11.3%) were lost in follow-up, and 158 died (37.3%). After a median time of 120.4 months (IQR 25–75%: 110.2–128.8), 215 patients were spirometrically reevaluated. The annualized loss of FEV1/FVC was greater in discordant (FR+LLN-) patients [0.54 (0.8) vs 0.82 (0.7); p = 0.008], while 81% became concordant (FR+LLN+) during the follow-up. Hospitalization for COPD exacerbations was more frequent in concordant (FR+LLN+) patients (1.57±3.51 vs 0.77±2.29; p = 0.002). Adjusting for age, concordant (FR+LLN+) patients had greater COPD mortality (HR: 2.97; CI 95%: 1.27–7.3; p = 0.02).ConclusionLLN seems to be less useful for COPD diagnosis in primary care. Discordant (FR+LLN-) patients lost more FEV1/FVC during their evolution and tended to become concordant. LLN predicted COPD hospitalizations and mortality more poorly.

0901 Role of Nasopharynx Radiography in Diagnosis of Sleep Disordered Breathing in Children

Abstract Introduction Sleep disordered breathing (SDB) in children comprises a wide spectrum of presentation ranging from primary snoring (prevalence 6-12%) to obstructive sleep apnea (OSA; prevalence 1-3%). In younger children, SDB is often secondary to adenotonsillar hypertrophy. Polysomnography is the gold standard test for evaluation of sleep disordered breathing. Yet, many providers order ancillary tests such as Radiography of Nasopharynx (NPX-ray) to assess for adenoidal hypertrophy. Previous studies evaluating efficacy of NPX-rays to diagnose airway obstruction have shown mixed results. Methods Retrospective chart review of 65 consecutive normally developed children who have had diagnostic polysomnography and NPX-rays over the past 3 years was performed. Data on age, sex, Obstructive Apnea Hypopnea Index (OAHI) and NPX-ray findings were collected. Our cohort mostly had the following diagnosis such as GERD, Asthma, Allergic rhinitis, ADHD and Obesity. Our cohort did not have neurological disorders or medications that could affect tone of upper airway. Standard pediatric AHI criteria was applied to categorize mild, moderate and severe OSA. Results Our cohort’s age ranged from 3-18 years (median age 10 years); 43 were males. Of the 24 children with normal sized adenoids with no obstruction; 6 had severe OSA and 4 had moderate OSA. 3 had hypertrophied adenoids on X-ray with occlusion of nasopharynx but only had mild OSA. Of the 15 children with prominent adenoids with some narrowing but no occlusion; 9 had severe OSA. Of the 9 children that had hypertrophied adenoids with no occlusion; 3 had moderate OSA and 3 had severe OSA. Of the 12 with mild enlargement, 4 had severe OSA. None of the 19 children with severe OSA showed airway occlusion by adenoids. Conclusion In our study, the size of the adenoids on X-ray of the Nasopharynx did not correlate with severity of SDB in children. Airway obstruction in OSA is dynamic and can occur at multiple sites affected by anatomical factors and upper airway collapsibility. As use of Nasopharyngeal radiography involves exposure to radiation, it should be used judiciously in diagnosis of SDB in children. Polysomnography is the gold standard test for evaluation of SBD in children. Support None.

FEV1 (Force Expiratory Volume)/FEV6 and FEV6 as an alternative for FEV1/FVC (Forced vital capacity) and FVC in the detection of airway obstruction.

Objectives: To evaluate the use of FEV6 and FEV1/FEV6 as an alternative of FVC and FEV1/FVC in determining airways restriction and obstruction. Study Design: Cross sectional Study. Setting: Department of pulmonology, DHQ Hospital Faisalabad. Period: 6 months (January-June, 2017). Material &amp; Methods: Sample size of 250 patients, with 45-80 years of age who can exhale for 6 seconds were included in the study. Reference equations were used to detect lower normal limits (LNL) of FEV6, FVC, FEV1/FEV6 and FEV1/FVC. A person was said to have obstruction if FEV1/FVC was below LNL. We considered a person to have restriction if FVC was below LNL without any obstructive pattern. FEV1/FEV6 and FEV6 sensitivity and specificity were determined from this data. Results: Sensitivity of FEV1/FEV6 was 97.4% while specificity was 85.2%, in case of airway obstruction positive predictive value was 96.5% and negative predictive value was 88.5%. In case of restrictive pattern detected by spirometry a sensitivity of FEV6 was 96.5 % and 85.71 % was specificity 97.6% was PPVs and 80% was NPVs .Values were close to LNL in case when difference was noted between two indexes. Conclusion: Instead of FEV1/FVC, FEV1/FEV6 can be used for diagnosing airway obstruction, particularly for screening population having high risk for COPD. For determining restrictive pattern by spirometry FEV6 can also be used instead of FVC by providing less confusing and easier results.

Utility of FEV1/FEV6 index in patients with multimorbidity hospitalized for decompensation of chronic diseases.

Spirometry remains essential for the diagnosis of airway obstruction. Nevertheless, its performance in elderly hospitalized patients with multimorbidity can be difficult. The aim of this study is to assess the utility of the COPD-6 portable device in this population. We included all patients hospitalized for exacerbation of chronic diseases in a medical ward specialized in the care of multimorbidity patients, between September 2017 and May 2018. A questionnaire including sociodemographic, cognitive and functional impairment, among other variables, was completed the last day of admission. Subsequently, patients attempted to perform three valid respiratory manoeuvres with the COPD-6 device and then conventional spirometry. A total of 184 patients were included (mean age of 79.61 years, 55% men). Forty-seven (25.54%) patients were able to perform complete spirometric manoeuvres and 99 (53.8%) could perform a valid FEV1/FEV6 determination. The inability to perform a valid spirometry was related with the patient’s age, functional physical disability, cognitive impairment or the presence of delirium or dysphagia during admission. Only 9% of patients with a Mini Mental Cognitive Examination (MMEC) lower than 24 points could perform a valid spirometry. Of the patients with an MMEC < 24 points and unable to perform spirometry, 34% were able to complete the FEV1/FEV6 manoeuvres. No differences were found in the Charlson index, multimorbidity scale, number of domiciliary drugs, or length of stay between those patients able and those not able to perform respiratory manoeuvres. The agreement between the values for FEV1 measured with COPD-6 and those observed in the spirometry was good (r: 0.71; p<0.0001). Inability to perform a valid spirometry during hospitalization in elderly patients with multimorbidity is frequent and related with functional and cognitive impairment. FEV1/FEV6 determination using the COPD-6 portable device allows an important percentage of the patients with limitations to complete spirometric measurement.

Stick with the Guideline-Recommended Threshold of 0.70 to Diagnose Airway Obstruction

Demonstration of airway obstruction (by spirometry) is required for diagnosing chronic obstructive pulmonary disease (COPD). Current Global Initiative

Cervical lymphatic malformations: Prenatal characteristics and ex utero intrapartum treatment

The ex utero intrapartum treatment (EXIT) is utilized to transition fetuses with prenatally diagnosed airway obstruction to postnatal life. We describe the unique clinical course, diagnosis, treatment, and outcomes of patients with cervical lymphatic malformation (CLM) managed with EXIT. Review of fetuses with diagnosed CLM was delivered by EXIT (2001-2018) in a tertiary referral fetal center. Outcomes included survival, tracheostomy at discharge, neonatal course after delivery, and pulmonary hypoplasia. Data are reported as median [range] and rate (%). Out of 45 patients delivered by EXIT, 10 were delivered for CLM: seven had polyhydramnios, one had nonimmune hydrops, five delivered preterm, and three were emergency EXITs. The EXIT time and estimated blood loss were 125minutes (95, 158) and 900mL (500, 1500), respectively. Airway was secured in all. There was one neonatal death (day 8) with prematurity, sepsis, and pulmonary hypoplasia. Three out of nine were discharged with a tracheostomy. In CLM, close monitoring for structural neck involvement and development of polyhydramnios are important and may be an indication for EXIT as the optimal delivery mode. An experienced multidisciplinary team is a key factor for an effective approach to the obstructed airway in CLM.

The effectiveness of lower limit of normal criteria and cutoff rate of forced expiratory volume in 1 s/forced expiratory volume in 6 s using in the diagnosis of airway obstruction in chronic obstructive pulmonary disease patients diagnosed with fixed ratio

AIMS: The definition of limited airflow as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio for chronic obstructive pulmonary disease (COPD) is still controversial. The objective of this study was to compare the prevalence of COPD using fixed ratio and lower limit of normal (LLN) of FEV1/FVC for the presence of airflow limitation and evaluate the performance of FEV1/forced expiratory volume in 6 s (FEV6) in patients diagnosed with COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) fixed ratio. SUBJECTS AND METHODS: Patients who presented to the pulmonary disease clinic between May 2008 and December 2017 and who were diagnosed with COPD were evaluated retrospectively. The distribution of FEV1/FVC-LLN according to the GOLD fixed ratio was evaluated after the patients were divided based on age groups. A receiver operating characteristics curve was used to determine the best FEV1/FEV6 cutoff value which fit into the FEV1/FVC RESULTS: Of the patients, 165 (85.9%) were male and 27 were female, with a mean age of 64.40 ± 10.66 years (range, 40–85). Among the patients, 11.5% of 61 patients aged 40–60 years, 28.4% of 67 patients aged 61–70 years, and 26.6% of 64 patients aged over 70 years were out of the diagnosis of obstruction according to the fixed ratio of FEV1/FVC >LLN. The cutoff value of FEV1/FEV6 for airway obstruction according to FEV1/FVC CONCLUSIONS: In this study, older patients, particularly, were diagnosed less often with an FEV1/FVC

Prevalence and features of asthma–chronic obstructive pulmonary disease overlap in Northern Italy general population

ABSTRACTObjective: There is controversy about the diagnostic criteria, prevalence, symptoms, and spirometry characteristics of asthma–chronic obstructive pulmonary disease (COPD) overlap (ACO). Recent data indicate that the fixed method for diagnosing airway obstruction (AO) may overestimate ACO prevalence in the elderly, and a variable method may be more accurate. We aimed at estimating ACO prevalence in a general population sample and comparing patient and clinical features in subjects with ACO, COPD, and asthma. Methods: We analyzed data from a cross-sectional study estimating COPD prevalence in randomly selected adults aged 20–79 years in Verona, Italy, and estimated prevalence and analyzed characteristics of asthma, COPD, and ACO. ACO was defined as AO (Forced Expiratory Volume in one second–FEV1/ Forced Vital Capacity–FVC < Lower Limit of Normal–LLN), highly positive bronchodilator test (≥15% increase in FEV1 and FVC ≥400 mL), and personal self-reported history of physician diagnosed asthma and atopy. Results: One thousand two hundred and thirty-six patients were included; 207 (16.7%) had asthma, COPD, or ACO (mean ages: 61.2, 59.7, and 57.2 years, respectively). The 3 groups had similar clinical and demographic variables; however, spirometry revealed differences between ACO and COPD patients, particularly post-bronchodilator FEV1 reversibility, which was detected in ACO and asthma patients but not in those with COPD. Conclusion: ACO prevalence in Northern Italy was estimated at 2.1%, in the range of values reported by previous studies. Marked differences between ACO and COPD revealed by spirometry may have important clinical implications in terms of treatment for patients with ACO.

The impact of different spirometric definitions on the prevalence of airway obstruction and their association with respiratory symptoms.

The fixed ratio criterion of forced expiratory volume in 1 s/forced vital capacity <0.70 for diagnosing airway obstruction may overdiagnose the condition, particularly in the elderly, so the lower limit of normal (LLN) is recommended as the most appropriate criterion. Our aim was to compare LLN versus fixed ratio on the prevalence of chronic obstructive pulmonary disease (COPD) and examine the association between respiratory symptoms and airway obstruction defined by LLN and fixed ratio.12 449 twins aged 40–80 years participated in a nationwide survey using the Danish Twin Registry. They completed a questionnaire, underwent clinical examination and recorded prebronchodilator spirometry. Individuals with self-reported asthma were excluded. Clinical COPD was defined by respiratory symptoms together with airway obstruction.10 329 individuals were included, with a mean±sd age of 58.4±9.6 years and mean body mass index of 26.6±4.4 kg·m−2; 20% were current smokers, 37% former smokers and 43% never-smokers; and 48% were male. The prevalence of LLN airway obstruction (LLN-AO) and fixed ratio airway obstruction (FR-AO) was 5.6% and 18.0%, respectively (p<0.001). Overall, 26% reported current respiratory symptoms, but 50% of those with LLN-AO had respiratory symptoms compared to 39% with FR-AO, p<0.001. The prevalence of clinical LLN-COPD and fixed ratio COPD was 2.6% and 6.3%, respectively (p<0.001). Individuals with LLN-AO had a significantly higher probability of reporting respiratory symptoms compared with both healthy individuals and FR-AO when adjusted for sex, age and ever-smoking.The use of fixed ratio more than doubled the prevalence of clinical COPD compared with LLN, this being more pronounced with increased age, and identified subjects with a lower prevalence of respiratory symptoms than LLN-AO.

Public spirometry campaign in chronic obstructive pulmonary disease screening - hope or hype?

Underdiagnosis of COPD seems to be a relevant clinical and social problem. We hypothesized that active public spirometry campaign may help identify subjects with airflow limitation consistent with COPD. The aim of the study was (1) to evaluate the willingness of random smokers to undergo public spirometry, (2) to assess the ability to obtain an acceptable quality spirometry during a public campaign, and (3) to assess the relationships between the presence and severity of respiratory symptoms and readiness to undergo spirometry. Pedestrians aged > 40 years and a smoking history >10 pack-years were recruited by medical students to fill a questionnaire and perform spirometry. Those with obstructive or borderline ventilatory insuffciency were invited and encouraged to undergo stationary spirometry in a pulmonary outpatient department. Nine hundred and five subjects meeting the inclusion criteria were invited to the study. Only 178 subjects agreed to complete the questionnaire and undergo spirometry. Airway obstruction and borderline spirometry result (classified as possible airway obstruction) were found in 22 and 37 subjects, respectively. Of these, only 15 patients attended follow-up visit to verify public spirometry results. Extrapolation of the limited data showed the incidence of newly diagnosed airway obstruction as 10.7%. Public spirometry campaign does not seem to be an effective way of COPD screening. Smokers are reluctant to undergo complimentary spirometry even in the presence of pronounced respiratory symptoms. Our observations may be helpful in elaborating future screening programs for COPD.

Supraglottic devices — future or everyday life?

The most common cause of upper respiratory tract obstruction in an unconscious or unresponsive patient is the loss of muscle tone in the upper airway. Consequently, this leads to a reduction in the tone of the epiglottis, collapse of the tongue and closure of the airway at the level of the pharynx, preventing respiration. Diagnosing airway obstruction is associated with the implementation of urgent procedures aimed at restor­ing and maintaining patency. Among the techniques of restoring airway patency anatomically, we prefer extending the head and pushing the posterior mandible forward. Airway ventilation is not always possible through the use of non-surgical methods. Ventilating patients with obstructed airways using a self-inflating bag can prove to be very difficult. In such situations, it is necessary to use airway adjuncts. The purpose, regardless of the circumstances, is to remove anatomical barriers, prevent gastric aspiration and to facilitate proper lung ventilation. Endotracheal intubation is the gold standard for instrumentally maintaining a secure airway. The procedure, however, is reserved for experienced personnel because of how difficult it is to perform and the many complications that arise with it. In situations where difficulty is encountered, an alternative device to secure airway patency is needed.