Bronchial Thermoplasty Improves Ventilation Heterogeneity Measured by Functional Respiratory Imaging in Severe Asthma.

Purpose: Bronchial thermoplasty (BT) is a bronchoscopic intervention for the treatment of severe asthma. Despite demonstrated symptomatic benefit, the underlying mechanisms by which this is achieved remain uncertain. We hypothesize that the effects of BT are driven by improvements in ventilation heterogeneity as assessed using functional respiratory imaging (FRI). Patient and Methods: Eighteen consecutive patients with severe asthma who underwent clinically indicated BT were recruited. Patients were assessed at baseline, 4-week after treatment of the left lung, and 12-month after treatment of the right lung. Data collected included short-acting beta-agonist (SABA) and oral prednisolone (OCS) use, asthma control questionnaire (ACQ-5) and exacerbation history. Patients also underwent lung function tests and chest computed tomography. Ventilation parameters including interquartile distance (IQD; measure of ventilation heterogeneity) were derived using FRI. Results: 12 months after BT, significant improvements were seen in SABA and OCS use, ACQ-5, and number of OCS-requiring exacerbations. Apart from pre-bronchodilator FEV1, no other significant changes were observed in lung function. Ventilation heterogeneity significantly improved after treatment of the left lung (0.18 ± 0.04 vs 0.20 ± 0.04, p=0.045), with treatment effect persisting up to 12 months later (0.18 ± 0.05 vs 0.20 ± 0.04, p=0.028). Ventilation heterogeneity also improved after treatment of the right lung, although this did not reach statistical significance (0.18 ± 0.05 vs 0.19 ± 0.04, p=0.06). Conclusion: Clinical benefits after BT are accompanied by improvements in ventilation heterogeneity, advancing our understanding of its mechanism of action. Beyond BT, FRI has the potential to be expanded into other clinical applications.

Epidemiological trends of respiratory tract pathogens detected via mPCR in Australian adult patients before COVID-19.

BACKGROUND: Respiratory tract infections (RTIs) are a major global health burden due to their high morbidity and mortality. This retrospective study described the epidemiology of respiratory pathogens in adults over a 5-year period at an Australian tertiary healthcare network. METHODS: All multiplex reverse transcription polymerase chain reaction respiratory samples taken between the 1st of November 2014 and the 31st of October 2019 were included in this study. Overall prevalence and variations according to seasons, age groups and sex were analysed, as well as factors associated with prolonged hospital and intensive care length of stay. RESULTS: There were 12,453 pathogens detected amongst the 12,185 positive samples, with coinfection rates of 3.7%. Picornavirus (Rhinovirus), Influenza A and respiratory syncytial virus were the most commonly detected pathogens. Mycoplasma pneumoniae was the most commonly detected atypical bacteria. Significant differences in the prevalence of Chlamydia pneumoniae and Human metapneumovirus infections were found between sexes. Longest median length of intensive care and hospital stay was for Legionella species. Seasonal variations were evident for certain pathogens. CONCLUSIONS: The high rates of pathogen detection and hospitalisation in this real-world study highlights the significant burden of RTIs, and the urgent need for an improved understanding of the pathogenicity as well as preventative and treatment options of RTIs.

Functional lung imaging using novel and emerging MRI techniques.

Respiratory diseases are leading causes of death and disability in the world. While early diagnosis is key, this has proven difficult due to the lack of sensitive and non-invasive tools. Computed tomography is regarded as the gold standard for structural lung imaging but lacks functional information and involves significant radiation exposure. Lung magnetic resonance imaging (MRI) has historically been challenging due to its short T2 and low proton density. Hyperpolarised gas MRI is an emerging technique that is able to overcome these difficulties, permitting the functional and microstructural evaluation of the lung. Other novel imaging techniques such as fluorinated gas MRI, oxygen-enhanced MRI, Fourier decomposition MRI and phase-resolved functional lung imaging can also be used to interrogate lung function though they are currently at varying stages of development. This article provides a clinically focused review of these contrast and non-contrast MR imaging techniques and their current applications in lung disease.

The Melbourne epidemic thunderstorm asthma event 2016: a 5-year longitudinal study.

Background: In 2016, Melbourne was struck by the world's largest and most devastating epidemic thunderstorm asthma (ETSA) episode. While affected individuals displayed worsened short-term asthma control, little is known about their longer-term natural history, nor about interventions that restore control. Objective: We assessed the asthma symptomatology and related behaviours of ETSA-affected individuals through a single-centre prospective 5-year longitudinal study. We embedded an open-label observational trial investigating the role of grass pollen sublingual tablet (Oralair) allergen immunotherapy in improving asthma and allergic rhinitis symptoms. Methods: Allergic rhinitis symptom severity, frequency of asthma symptoms and inhaled corticosteroid usage were assessed via questionnaire yearly. In 2018, a subgroup of participants was enrolled in an observational study of Oralair treatment compared to control. The active group received Oralair from 2019 to 2021; both groups were followed-up for 5 years. Subgroup analyses were performed for participants with complete datasets, and who completed the trial per-protocol. Results: Year-on-year data across 5 years was available for 30 participants. The rate of persistent asthma symptoms declined from 37% to 7% in 2016 to 2021. Only 10%-27% of participants reported being completely asymptomatic in any given year. The inhaled preventer prescription rate was 67%, with only 35% being adherent. Twenty-seven participants with available data completed the Oralair trial per-protocol. No significant difference was noted between control and active groups for allergic rhinitis symptoms or asthma control, although the Oralair group saw a significant improvement in asthma control comparing 2019 with 2021. Conclusion: This is the longest documented follow-up of ETSA-affected individuals. Five years following sentinel event, there was progressive reduction but some persistence in asthma symptoms. Oralair allergen immunotherapy did not further improve allergic rhinitis or asthma symptoms compared to control, but there were no further ETSA events to test a protective effect during the study period.

Barriers to sleep in acute hospital settings.

OBJECTIVE: This study aimed to examine the environmental and operational factors that disrupt sleep in the acute, non-ICU hospital setting. DESIGN, SETTING AND PARTICIPANTS: This was a prospective study of adult patients admitted to an acute tertiary hospital ward (shared versus single room) and sleep laboratory (single room conducive to sleep). MAIN OUTCOME MEASURES: This study measured ambient light (lux) and sound (dB), number of operational interruptions, and questionnaires assessing sleep and mental health. RESULTS: Sixty patients were enrolled, 20 in a double bedroom located close to the nursing station ('shared ward'), 20 in a single bedroom located distant to the nursing station ('single ward') and 20 attending the sleep laboratory for overnight polysomnography ('sleep laboratory'). Sleep was disturbed in 45% of patients in the shared and single ward groups (Pittsburgh Sleep Quality Index > 5). Light levels were appropriately low across all 3 locations. Sound levels (significant effect of room F(1.38) = 6.452, p = 0.015) and operational interruptions (shared ward 5.6 ± 2.5, single ward 6.2 ± 2.9, sleep laboratory 2.7 ± 2.1 per night, p < 0.05 wards compared to sleep laboratory) were higher in the shared and single ward group compared to the sleep laboratory but not compared to each other. Noise was rated as the greatest environmental disturbance by 70% of ward patients compared to 10% in the sleep laboratory. CONCLUSION: Higher noise levels and frequent operational interruptions are potential barriers to sleep and recovery on an acute medical ward which are not ameliorated by being in a single bedroom located distant to the nursing station.

Intrapleural Hyaluronidase in Viscous Malignant Mesothelioma Pleural Effusion.

Malignant pleural effusion is common in mesothelioma. We report a case of viscous recurrent malignant mesothelioma pleural effusion. The viscosity was due to the presence of hyaluronic acid and resulted in prolonged drainage time. The use of intrapleural hyaluronidase significantly reduced fluid viscosity and drainage duration. No adverse reactions were noted. This novel case highlights the feasibility and safety of the use of intrapleural hyaluronidase in the management of hyaluronic acid-rich viscous malignant pleural effusion.

Ambulatory Thoracoscopic Pleurodesis Combined With Indwelling Pleural Catheter in Malignant Pleural Effusion.

Background and Objective: Malignant pleural effusion (MPE) often results in debilitating symptoms. Relief of dyspnoea and improvement in quality of life can be achieved with either talc pleurodesis or insertion of an indwelling tunneled pleural catheter (IPC). The former requires a lengthy hospital stay and the latter is associated with lower pleurodesis rates. In response to limited hospital bed capacity, we developed a pragmatic approach in managing MPE by combining thoracoscopic talc poudrage and insertion of IPC into a single day case procedure. We present data on the safety and efficacy of this approach. Methods: Patients who had undergone the abovementioned procedure between 2017 and 2020 were analyzed. Demographic data, hospital length of stay (LOS), histological diagnosis, rates of pleurodesis success and procedural related complications were collated. Patients were followed-up for 6 months. Results: Forty-five patients underwent the procedure. Mean age was 68.5 ± 10.4 years and 56% were male. Histological diagnosis was achieved in all cases. 86.7% of patients were discharged on the day of the procedure. Median LOS was 0 (IQR 0-0) days. Successful pleurodesis was attained in 77.8% at 6-month follow-up. No procedure related deaths or IPC related infections were recorded. Conclusion: Ambulatory thoracoscopic poudrage and IPC insertion is a safe and effective option in the management of MPE. All patients received a definitive pleural intervention with 77.8% pleurodesis success at 6-months and majority of them discharged on the same day. Future randomized trials are required to confirm these findings.

Use of Intrapleural Fibrinolytic Therapy in a Trapped Lung following Acute Traumatic Haemothorax.

Retained haemothorax is a common sequela of traumatic haemothorax and refers to blood that cannot be drained from the pleural cavity. We report a case of trapped lung secondary to retained haemothorax in a patient who sustained a penetrating chest injury. Initial chest computed tomography (CT) showed a large haemothorax that was managed with an intercostal drain insertion (ICD). Repeat chest CT and thoracic ultrasonography performed after ICD removal showed an organized pleural space resembling haematoma. ICD was reinserted with administration of intrapleural fibrinolytic therapy (IPFT). Subsequent chest CT showed the development of a pleural rind and trapped lung. A second ICD was inserted, and further IPFT were administered together with aggressive negative pressure suction. Haemoglobin remained stable. The patient made a full recovery and imaging performed two weeks later showed minor blunting of the costophrenic angle. This case highlights the feasibility and safety of IPFT in the management of trapped lung associated with traumatic retained haemothorax as an alternative to surgery.

Intrapleural fibrinolysis in acute non-traumatic retained haemothorax.

Haemothorax is an accumulation of blood in the pleural space. Retained haemothorax refers to blood that cannot be drained from the pleural cavity and is associated with an increased risk of empyema and fibrothorax often necessitating surgical evacuation. We describe our experience of using intrapleural fibrinolytic therapy in three patients with different bleeding risk and acute non-traumatic retained haemothorax. The first was a 41-year-old female with disseminated Candida guilliermondii sepsis and an iatrogenic haemothorax, second was a 48-year-old female with transfusion-dependent acute myeloid leukaemia and spontaneous haemothorax, and the third was a 72-year-old female with spontaneous haemothorax from newly diagnosed lung cancer. All patients received one to two doses of intrapleural alteplase without any bleeding complications and resolution of retained haemothorax. This case series demonstrates the successful application and safety of this approach as an alternative to surgery in a well-resourced environment with close monitoring and ready access to blood transfusion.

Natural history of asthma symptoms after epidemic thunderstorm asthma: a 3-year longitudinal study.

BACKGROUND: The world's most catastrophic epidemic thunderstorm asthma event (ETSA) affected Melbourne in 2016. Little is known about the natural history of individuals affected by such extreme events. OBJECTIVE: In this single center prospective 3-year longitudinal study, symptomatology and behaviors of individuals affected by ETSA were assessed. METHODS: Standardized telephone questionnaire was used to evaluate frequency of asthma symptoms, inhaled corticosteroid preventer use, asthma action plan ownership, and healthcare utilization. Questionnaires were administered at 12, 24, and 36 months after 2016 ETSA. Subgroup analyses of the 'current', 'past', 'possible,' and 'no asthma' subgroups were also conducted. RESULTS: Two hundred and eight, 164, and 112 completed questionnaires were analyzed in 2017, 2018, and 2019, respectively. Seventy to eighty five percent of respondents reported ongoing asthma symptoms in any given year, of which 20%-28% experienced weekly symptoms. Nearly 50% of respondents were prescribed preventers, with approximately 45% adherent at least 5 days a week. Less than 40% had an asthma action plan and 15%-20% sought urgent medical attention for asthma over the follow-up period. Among 106 individuals with 3 consecutive years of completed questionnaires, those with no prior doctor diagnosis of asthma were significantly more likely to be asymptomatic on follow-up than those with a prior doctor diagnosis of asthma (p = 0.02). Subgroup analyses suggest that large proportions of respondents with 'past' and 'no asthma' continue to remain symptomatic throughout the 36-month period. CONCLUSION: In individuals affected by ETSA, we found evidence of ongoing loss of asthma control in those with previously well controlled asthma, and the persistence of symptoms suggestive of asthma in those with no history or symptoms suggestive of prior asthma, even after 36 months from initial ETSA. Low rates of inhaler adherence and asthma action plan ownership may contribute to increased morbidity and mortality from future ETSA events. Further research is required to confirm these findings.

Continued loss of asthma control following epidemic thunderstorm asthma.

BACKGROUND: Epidemic thunderstorm asthma (ETSA) severely affected Melbourne, Australia in November 2016. There is scant literature on the natural history of individuals affected by ETSA. OBJECTIVE: A multicentre 12-month prospective observational study was conducted assessing symptomatology and behaviors of ETSA-affected individuals. METHODS: We used a structured phone questionnaire to assess asthma symptom frequency, inhaled preventer use, asthma action plan ownership and healthcare utilization over 12 months since the ETSA. Analysis of results included subgroup analyses of the "current," "past," "probable," and "no asthma" subgroups defined according to their original 2016 survey responses. RESULTS: Four hundred forty-two questionnaires were analyzed. Eighty percent of individuals reported ongoing asthma symptoms at follow-up, of which 28% were affected by asthma symptoms at least once a week. Risk of persistent asthma symptoms was significantly higher in those with prior asthma diagnosis, current asthma, and probable undiagnosed asthma (all p < 0.01). Of 442 respondents, 53% were prescribed inhaled preventers, of which 51% were adherent at least 5 days a week. Forty-two percent had a written asthma action plan and 16% had sought urgent medical attention for asthma in the preceding year. CONCLUSIONS: Following an episode of ETSA, patients experience a pivotal change in asthma trajectory with both loss of asthma control and persistence of de novo asthma. Suboptimal rates of inhaled preventer adherence and asthma action plan ownership may contribute to asthma exacerbation risk and susceptibility to future ETSA episodes. Longer-term follow-up is needed to determine the extent and severity of this apparent change.

An unusual presentation of carcinomatous meningitis.

A 67-year old previously well male presented with a 1 week history of confusion on a background of 3 weeks of headache. Past history included two superficial melanomas excised 5 years ago. Treatment for meningoencephalitis was commenced based on lumbar puncture (LP) and non-contrast brain magnetic resonance imaging (MRI) results. Lack of a clinical response to antibiotics resulted in a second LP and contrast brain MRI which demonstrated hydrocephalus and leptomeningeal disease. Ongoing deterioration led to a whole-body computed tomographic and spinal MRI that showed widespread metastatic disease and extensive leptomeningeal involvement of the spinal cord. The diagnosis of metastatic melanoma with carcinomatous meningitis was made based on cytological analysis of cerebrospinal fluid. He died 2 weeks later in a palliative care facility. This case illustrates that the diagnosis of carcinomatous meningitis can be difficult to make as the heterogeneous nature of its presentation often delays the diagnosis.