Vocal cord dysfunction/inducible laryngeal obstruction cannot be diagnosed from symptoms.

Vocal cord dysfunction/inducible laryngeal obstruction is highly variable. Standard clinical symptoms and questionnaires cannot predict laryngoscopic diagnosis in a "lung disease" population. https://bit.ly/3QUtsbB.

Computed Tomography Imaging of the Larynx for Diagnosis of Vocal Cord Dysfunction.

BACKGROUND: Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathlessness and often mimics or accompanies severe asthma. The disorder occurs intermittently, and the diagnosis is established by using laryngoscopy. Dynamic computed tomography (CT) imaging of the larynx at low-radiation doses has the potential to provide an alternative method to make the diagnosis of VCD/ILO. METHODS: We report two case series: in series A, laryngoscopy (diagnostic standard) and CT imaging of the larynx were each performed within 1 hour of each other (n=31), and in series B, the procedures were performed on separate days 4 to 6 weeks apart (n=72). Diagnosis of VCD/ILO by laryngoscopy used conventional criteria, and diagnosis by CT imaging was based on vocal cord narrowing in excess of a validated normal threshold. In each series, we evaluated the accuracy of CT imaging of the larynx to establish a diagnosis of VCD/ILO compared with laryngoscopy. RESULTS: In series A, the sensitivity of CT imaging of the larynx was 53.8%, and specificity was 88.9%; in series B, the sensitivity of CT imaging of the larynx was 76.2%, and specificity was 93.3%. At a disease prevalence of 30% (which was known to be the case in our clinic), the positive predictive value was 67.5% in series A and 83% in series B. Negative predictive values were 81.8% and 90.1% in series A and B, respectively, and false-positive rates were 11.1% and 6.7%. CONCLUSIONS: When the population prevalence was assumed to be 30%, low-dose CT imaging of the larynx detected VCD/ILO with negative predictive values greater than 80% in both series settings and agreed with each other within 9 percentage points. Positive predictive values for laryngeal CT imaging varied substantially between the settings of the two case series. (Supported by Monash Lung and Sleep Institute and Grant APP ID 1198362 and others.)

Thunderstorm asthma in seasonal allergic rhinitis: The TAISAR study.

BACKGROUND: Asthma epidemics associated with thunderstorms have had catastrophic effects on individuals and emergency services. Seasonal allergic rhinitis (SAR) is present in the vast majority of people who develop thunderstorm asthma (TA), but there is little evidence regarding risk factors for TA among the SAR population. OBJECTIVE: We sought to identify risk factors for a history of TA and hospital presentation in a cohort of individuals with SAR. METHODS: This multicenter study recruited adults from Melbourne, Australia, with a past diagnosis of TA and/or self-reported SAR. Clinical information, spirometry results, white blood cell count, ryegrass pollen-specific (RGP-sp) IgE concentration, and fractional exhaled nitric oxide were measured to identify risk factors for a history of TA in individuals with SAR. RESULTS: From a total of 228 individuals with SAR, 35% (80 of 228) reported SAR only (the I-SAR group), 37% (84 of 228) reported TA symptoms but had not attended hospital for treatment (the O-TA group), and 28% (64 of 228) had presented to the hospital for TA (the H-TA group). All patients in the H-TA group reported a previous asthma diagnosis. Logistic regression analysis of factors associated with O-TA and H-TA indicated that lower FEV1 value and an Asthma Control Questionnaire score higher than 1.5 were associated with H-TA. Higher blood RGP-sp IgE concentration, eosinophil counts, and fractional exhaled nitric oxide level were significantly associated with both O-TA and H-TA. Receiver operating curve analysis showed an RGP-sp IgE concentration higher than 10.1 kU/L and a prebronchodilator FEV1 value of 90% or lower to be biomarkers of increased H-TA risk. CONCLUSION: Clinical tests can identify risk of a history of TA in individuals with SAR and thereby inform patient-specific treatment recommendations.

Oral corticosteroids stewardship for asthma in adults and adolescents: A position paper from the Thoracic Society of Australia and New Zealand.

Oral corticosteroids (OCS) are frequently used for asthma treatment. This medication is highly effective for both acute and chronic diseases, but evidence indicates that indiscriminate OCS use is common, posing a risk of serious side effects and irreversible harm. There is now an urgent need to introduce OCS stewardship approaches, akin to successful initiatives that optimized appropriate antibiotic usage. The aim of this TSANZ (Thoracic Society of Australia and New Zealand) position paper is to review current knowledge pertaining to OCS use in asthma and then delineate principles of OCS stewardship. Recent evidence indicates overuse and over-reliance on OCS for asthma and that doses >1000 mg prednisolone-equivalent cumulatively are likely to have serious side effects and adverse outcomes. Patient perspectives emphasize the detrimental impacts of OCS-related side effects such as weight gain, insomnia, mood disturbances and skin changes. Improvements in asthma control and prevention of exacerbations can be achieved by improved inhaler technique, adherence to therapy, asthma education, smoking cessation, multidisciplinary review, optimized medications and other strategies. Recently, add-on therapies including novel biological agents and macrolide antibiotics have demonstrated reductions in OCS requirements. Harm reduction may also be achieved through identification and mitigation of predictable adverse effects. OCS stewardship should entail greater awareness of appropriate indications for OCS prescription, risk-benefits of OCS medications, side effects, effective add-on therapies and multidisciplinary review. If implemented, OCS stewardship can ensure that clinicians and patients with asthma are aware that OCS should not be used lightly, while providing reassurance that asthma can be controlled in most people without frequent use of OCS.

Multidisciplinary team clinic for vocal cord dysfunction directs therapy and significantly reduces healthcare utilization.

BACKGROUND AND OBJECTIVE: Multidisciplinary team (MDT) clinics use an integrated approach to individualize care of complex medical conditions. Vocal cord dysfunction (VCD) is a challenging condition that is likely to benefit from MDT clinics but this has not been researched. METHODS: A prospective observational cohort study of a novel VCD MDT clinic was conducted in patients with suspected VCD. Relevant questionnaires, medical history, physical examination, spirometry, dynamic computerized tomography (CT) larynx and laryngoscopy were utilized and patients were allocated to treatment pathways depending on putative diagnosis. Speech pathology intervention with laryngeal retraining (LR) was offered and if LR therapy failed botulinum toxin injection was offered. Primary outcome was reductions in healthcare utilization. RESULTS: Overall, 80 consecutive patients were included in analyses. A definitive diagnosis of VCD was made in 56 of 80 (70%) patients. After LR (n = 35), emergency department (ED)/hospital admissions declined significantly in the subsequent 12 months (P = 0.001). General practice visits also reduced (P < 0.001). Botulinum toxin injections were administered in 21 patients unresponsive to LR therapy and both general practice and ED/hospital visits declined (P < 0.001 and P = 0.01, respectively) after injection. CONCLUSION: A multidisciplinary approach to VCD confers benefit and can be used to allocate appropriate management leading to a reduction in healthcare utilization.

The 2016 Melbourne thunderstorm asthma epidemic: Risk factors for severe attacks requiring hospital admission.

BACKGROUND: The world's most catastrophic and deadly thunderstorm asthma epidemic struck Melbourne, Australia, on November 21, 2016. OBJECTIVE: Among thunderstorm-affected patients presenting to emergency rooms (ERs), we investigated risk factors predicting severe attacks requiring admission to hospital. METHODS: Thunderstorm-affected patients were identified from ER records at the eight major Melbourne health services and interviewed by telephone. Risk factors for hospital admission were analyzed. RESULTS: We interviewed 1435/2248 (64%) of thunderstorm-affected patients, of whom 164 (11.4%) required hospital admission. Overall, rhinitis was present in 87%, and current asthma was present in 28%. Odds for hospital admission were higher with increasing age (odds ratio 1.010, 95% CI 1.002, 1.019) and among individuals with current asthma (adjusted odds ratio [aOR] 1.87, 95% CI 1.26, 2.78). Prior hospitalization for asthma in the previous 12 months further increased the odds for hospital admission (aOR 3.16, 95% CI 1.63, 6.12). Among patients of Asian ethnicity, the odds for hospital admission were lower than for non-Asian patients (aOR 0.59, 95% CI 0.38, 0.94), but higher if born in Australia (OR = 5.42, 95% CI 1.56, 18.83). CONCLUSIONS: In epidemic thunderstorm asthma patients who presented to the ER, higher odds for hospital admission among patients with known asthma were further amplified by recent asthma admission, highlighting the vulnerability conferred by suboptimal disease control. Odds for hospital admission were lower in Asian patients born overseas, but higher in Asian patients born locally, than in non-Asian patients; these observations suggest susceptibility to severe thunderstorm asthma may be enhanced by gene-environment interactions.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors.

BACKGROUND: A multidisciplinary collaboration investigated the world's largest, most catastrophic epidemic thunderstorm asthma event that took place in Melbourne, Australia, on Nov 21, 2016, to inform mechanisms and preventive strategies. METHODS: Meteorological and airborne pollen data, satellite-derived vegetation index, ambulance callouts, emergency department presentations, and data on hospital admissions for Nov 21, 2016, as well as leading up to and following the event were collected between Nov 21, 2016, and March 31, 2017, and analysed. We contacted patients who presented during the epidemic thunderstorm asthma event at eight metropolitan health services (each including up to three hospitals) via telephone questionnaire to determine patient characteristics, and investigated outcomes of intensive care unit (ICU) admissions. FINDINGS: Grass pollen concentrations on Nov 21, 2016, were extremely high (>100 grains/m3). At 1800 AEDT, a gust front crossed Melbourne, plunging temperatures 10°C, raising humidity above 70%, and concentrating particulate matter. Within 30 h, there were 3365 (672%) excess respiratory-related presentations to emergency departments, and 476 (992%) excess asthma-related admissions to hospital, especially individuals of Indian or Sri Lankan birth (10% vs 1%, p<0·0001) and south-east Asian birth (8% vs 1%, p<0·0001) compared with previous 3 years. Questionnaire data from 1435 (64%) of 2248 emergency department presentations showed a mean age of 32·0 years (SD 18·6), 56% of whom were male. Only 28% had current doctor-diagnosed asthma. 39% of the presentations were of Asian or Indian ethnicity (25% of the Melbourne population were of this ethnicity according to the 2016 census, relative risk [RR] 1·93, 95% CI 1·74-2·15, p <0·0001). Of ten individuals who died, six were Asian or Indian (RR 4·54, 95% CI 1·28-16·09; p=0·01). 35 individuals were admitted to an intensive care unit, all had asthma, 12 took inhaled preventers, and five died. INTERPRETATION: Convergent environmental factors triggered a thunderstorm asthma epidemic of unprecedented magnitude, tempo, and geographical range and severity on Nov 21, 2016, creating a new benchmark for emergency and health service escalation. Asian or Indian ethnicity and current doctor-diagnosed asthma portended life-threatening exacerbations such as those requiring admission to an ICU. Overall, the findings provide important public health lessons applicable to future event forecasting, health care response coordination, protection of at-risk populations, and medical management of epidemic thunderstorm asthma. FUNDING: None.

Dysfunctional breathing is more frequent in chronic obstructive pulmonary disease than in asthma and in health.

Involuntary adaptations of breathing patterns to counter breathlessness may lead to dysfunctional breathing in obstructive lung diseases. However, no studies examining dysfunctional breathing in Chronic Obstructive Pulmonary Disease (COPD) have been reported. Patients with verified COPD (n=34), asthma (n=37) and a healthy control group (n=41) were recruited. All participants completed the Nijmegen questionnaire for dysfunctional breathing as well as measures of disease activity. Comparisons between groups employed analysis of variance with post-hoc Bonferroni analyses and Pearson correlation for associations. Patients with COPD had significantly higher Nijmegen questionnaire scores than asthmatics (COPD: 23.4±10.6 versus 17.3±10.6, p=0.016) and healthy individuals (14.3±9.6, p=0.002). Significantly more patients with COPD had severe dysfunctional breathing with Nijmegen scores >23 (47%; 16/34) compared to asthma (27%; 10/37) and healthy controls (17%; 7/41) respectively (p=0.019). Dysfunctional breathing was detected in ∼50% of patients with COPD, more so than in asthma or health. Strategies to reduce abnormal breathing behaviours may have important benefits for treatment of breathlessness in COPD.

Expiratory central airway collapse in stable COPD and during exacerbations.

BACKGROUND: Tracheal obstruction resulting from expiratory tracheal deformation has been associated with respiratory symptoms and severe airway exacerbations. In chronic obstructive pulmonary disease (COPD), acute exacerbations (AECOPD) create large intrathoracic pressure swings which may increase tracheal deformation. Excessive central airway collapse (ECAC) may be diagnosed when the tracheal area on expiration is less than 50% of that on inspiration. The prevalence of ECAC in AECOPD and its temporal course have not been systematically studied. METHODS: We prospectively recruited healthy volunteers (n = 53), stable outpatients with COPD (n = 40) and patients with hospitalised acute exacerbations of COPD (AECOPD, n = 64). 17 of the AECOPD group returned for repeat evaluation when clinically well at 6-12 weeks. All subjects underwent dynamic 320-slice computed tomography of the larynx and trachea during tidal breathing, enabling quantitation of tracheal area and dimensions (mean ± SD). RESULTS: No healthy individuals had ECAC. The prevalence of ECAC in stable COPD and AECOPD was 35% and 39% respectively. Mean tracheal collapse did not differ between stable COPD (57.5 ± 19.8%), AECOPD (53.8 ± 19.3%) and in the subset who returned when convalescent (54.9 ± 17.2%). AECOPD patients with and without ECAC had similar clinical characteristics. CONCLUSIONS: Tracheal collapse in both stable and AECOPD is considerably more prevalent than in healthy individuals. ECAC warrants assessment as part of comprehensive COPD evaluation and management. Further studies should evaluate the aetiology of ECAC and whether it predisposes to exacerbations.

Dynamic 320-slice CT larynx for detection and management of idiopathic bilateral vocal cord paralysis.

Idiopathic bilateral vocal cord paralysis (VCP) is a rare and difficult condition often undiagnosed and frequently confused with asthma and other respiratory conditions. Accurate diagnosis is crucial since 80% of cases patients require surgical intervention, such as tracheostomy or laser surgery, to relieve symptoms. The "gold standard" for diagnosing VCP has been laryngoscopy. In this case study, we demonstrate for the first time that idiopathic bilateral VCP can be accurately diagnosed by means of a novel noninvasive methodology: dynamic volume 320-slice computed tomography larynx. Three-dimensional reconstruction of laryngeal motion during the breathing cycle permitted functional assessment of the larynx showing absence of vocal cord movements. The new methodology may be valuable for noninvasive diagnosis of vocal cord movement disorders before and for follow-up after surgery.