Mucus clears from the trachea in a helix: a new twist to understanding airway diseases.

BACKGROUND: Mucociliary clearance (MCC) is critical to lung health and is impaired in many diseases. The path of MCC may have an important impact on clearance but has never been rigorously studied. The objective of this study is to assess the three-dimensional path of human tracheal MCC in disease and health. METHODS: Tracheal MCC was imaged in 12 ex-smokers, 3 non-smokers (1 opportunistically imaged during acute influenza and repeated after recovery) and 5 individuals with primary ciliary dyskinesia (PCD). Radiolabelled macroaggregated albumin droplets were injected into the trachea via the cricothyroid membrane. Droplet movement was tracked via scintigraphy, the path of movement mapped and helical and axial models of tracheal MCC were compared. MEASUREMENTS AND MAIN RESULTS: In 5/5 participants with PCD and 1 healthy participant with acute influenza, radiolabelled albumin coated the trachea and did not move. In all others (15/15), mucus coalesced into globules. Globule movement was negligible in 3 ex-smokers, but in all others (12/15) ascended the trachea in a helical path. Median cephalad tracheal MCC was 2.7 mm/min ex-smokers vs 8.4 mm/min non-smokers (p=0.02) and correlated strongly to helical angle (r=0.92 (p=0.00002); median 18o ex-smokers, 47o non-smokers (p=0.036)), but not to actual speed on helical path (r=0.26 (p=0.46); median 13.6 mm/min ex-smokers vs 13.9 mm/min non-smokers (p=1.0)). CONCLUSION: For the first time, we show that human tracheal MCC is helical, and impairment in ex-smokers is often caused by flattened helical transit, not slower movement. Our methodology provides a simple method to map tracheal MCC and speed in vivo.

Restless legs syndrome.

BACKGROUND: Restless legs syndrome (RLS) is a common sensorimotor disorder causing significant distress and is commonly seen in the primary care setting. OBJECTIVE: This article outlines the epidemiology, pathophysiology, diagnosis and management of RLS, with a focus on the primary care setting. DISCUSSION: RLS is a clinical diagnosis, although mimics exist. Brain iron deficiency, dopaminergic dysfunction and genetics underpin the poorly understood pathophysiology of this common condition. After repleting iron stores, reviewing any exacerbating medications and attending to non-pharmacological management options, there are pharmacological options that prove to be effective, although with class-specific effects that need to be considered.

Mechanisms of gas transfer impairment utilizing nitric oxide following severe COVID-19 pneumonitis.

Reduced carbon monoxide diffusing capacity (DLCO ) is common after recovery from severe COVID-19 pneumonitis. The extent to which this relates to alveolar membrane dysfunction as opposed to vascular injury is uncertain. Simultaneous measurement of nitric oxide diffusing capacity (DLNO ) and DLCO can partition gas diffusion into its two components: alveolar-capillary membrane conductance (DmCO ) and capillary blood volume (VC ). We sought to evaluate DmCO and VC in the early and later recovery periods after severe COVID-19. Patients attended for post-COVID-19 clinical review and lung function testing including DLNO /DLCO . Repeat testing occurred when indicated and comparisons made using t-tests. Forty-nine (eight female) subjects (mean ± SD age: 58 ± 13, BMI: 34 ± 8) who had severe COVID-19 pneumonitis, WHO severity classification of 6 ± 1, and prolonged (21 ± 22 days) hospital stay, were assessed 2 months (61 ± 35 days) post discharge. DLCO adj (z-score -1.70 ± 1.49, 25/49 < lower limit of normal [LLN]) and total lung capacity (z-score -1.71 ± 1.30) were both reduced. DmCO and VC and were reduced to a similar extent (z-score -1.19 ± 1.05 and -1.41 ± 1.20, p = 0.4). Seventeen (one female) patients returned for repeat testing 4 months (122 ± 61 days) post discharge. In this subgroup with more impaired lung function, DLCO adj improved but remained below LLN (z-score -3.15 ± 0.83 vs. -2.39 ± 0.86, p = 0.01), 5/17 improved to >LNN. DmCO improved (z-score -2.05 ± 0.89 vs. -1.41 ± 0.78, p = 0.01) but VC was unchanged (z-score -2.51 ± 0.55 vs. -2.29 ± 0.59, p = 0.16). Alveolar membrane conductance is abnormal in the earlier recovery phase following severe COVID-19 but significantly improves. In contrast, reduced VC persists. These data raise the possibility that persisting effects of acute vascular injury may contribute to gas diffusion impairment long after severe COVID-19 pneumonitis.

Lung Health in the Solomon Islands: A Mixed Methods Study.

BACKGROUND AND OBJECTIVES: Despite a population of 600,000 people from 900 islands, there is little published data on the prevalence of lung disease in the Solomon Islands. We sought to 1) estimate the prevalence of obstructive lung disease (OLD) in Gizo, Solomon Islands, 2) identify risk factors for respiratory disease in this population and 3) review current management practices for respiratory disease through an audit of local emergency department (ED) presentations. METHODS: A two-part mixed methods study was performed between March and May 2019; the first was a population-based, cross-sectional study conducted in Gizo, Solomon Islands, with a random sample undergoing questionnaires and spirometry. The second was an audit of Gizo Hospital ED records to assess presentation numbers, diagnoses and outcomes. RESULTS: A total of 104 patients were randomly selected for spirometry. The mean age was 46.9 years. Current smoking rates were high (24.0% overall, 43.3% age < 40, 16.2% age ≥ 40) as was regular (>10h/week) exposure to indoor/enclosed wood fire ovens (51.5%). The prevalence of COPD was 3.2% overall. A further 9.7% of participants demonstrated significant bronchodilator responsiveness suggestive of possible asthma. Most patients seen in ED presented with a respiratory condition or fever/viral illness, but spirometry was not available. Only four outpatients were prescribed salbutamol and two patients inhaled corticosteroid. CONCLUSION: There appears to be a high burden of obstructive lung disease in the Solomon Islands with high smoking rates, indoor smoke exposure and bronchodilator responsiveness. Respiratory symptoms are common amongst hospital ED presentations; however, inhaled asthma treatments are infrequently prescribed to outpatients.

Management of recurrent haemoptysis in malignancy with combined TISSEEL and intrabronchial valves.

Management of recurrent haemoptysis poses a difficult clinical scenario. TISSEEL (Baxter Healthcare Corporation Deerfield, IL, USA) is a fibrin sealant often used in surgery to aid control of bleeding. However, when endoscopic TISSEEL is used independently, migration, dislodgement, or even expectoration of the fibrin clot is a common complication that may lead to recurrence of haemoptysis. Here we describe two patients with recurrent haemoptysis in the context of malignancy who underwent bronchoscopy, during which they were managed with application of topical TISSEEL to the bleeding area, followed by deployment of an intrabronchial valve, followed by a further application of TISSEEL over the valve. The combination of TISSEEL and intrabronchial valve appeared to control haemoptysis and was resistant to expectoration or migration in these two cases. Thus, this combination may provide a safe and effective therapeutic option for the control of bronchial bleeding secondary to malignancy.