Reducing unnecessary testing on sputum specimens from patients with cystic fibrosis: pathology stewardship in microbiology.

Chronic respiratory tract infection by Pseudomonas aeruginosa is the hallmark of established lung disease in patients with cystic fibrosis (CF). Antibiotic therapy can usually only suppress but not eradicate infection. In recent years, pulmonary infection with non-tuberculous Mycobacteria (NTM) species has also been increasing. These patients are often colonised with multiple isolates and determination of clinical significance of each isolate is difficult. The clinical value of frequent routine susceptibility testing of individual isolates is unproven, particularly since a delay in susceptibility testing is inevitable when purification of multiple cultured isolates is required to test each isolate separately. From August 2019 until December 2020 we ceased routine susceptibility testing on P. aeruginosa respiratory tract isolates from patients with CF if a previous isolate from the patient had susceptibility testing performed. We found that the proportion of P. aeruginosa isolates that had susceptibility testing performed dropped from 97% to 11% as a result of this change in laboratory process. During this time, we also ceased routine culture for acid-fast bacilli if this had been performed within the previous 6 months. We present the cost and resource savings for these changes in laboratory process and assess for clinical impact measured as hospital admissions, length of stay in hospital and mortality.

Effect of COVID-19 lockdown on body weight in chronic obstructive pulmonary disease.

A series of studies has reported weight gain in association with COVID-19 lockdowns; typically, this research has had short-term follow-up in populations that tended to gain weight. In this study, the effect of prolonged lockdowns on weight was assessed in a population of patients with chronic obstructive pulmonary disease. Before lockdown subjects gained an average of 0.022 kg per month; after lockdown this trend reversed with subjects losing weight at 0.032 kg per month, a trend that was highly significant (P < 0.001).

Swallow patterns associated with aspiration in COPD: a prospective analysis.

Few studies have examined swallow of large liquid volumes representative of everyday drinking in COPD. Swallow by cup-drinking was evaluated in COPD using videofluoroscopy. Slower swallow was linked to aspiration indicating altered swallow habits in COPD. https://bit.ly/3wpdnO3.

Prevalence of reduced carbon monoxide transfer factor in smokers with normal spirometry.

We report the prevalence of reduced levels of carbon monoxide transfer factor (TLCO) in middle-aged current or ex-smokers with normal spirometry. Spirometry and TLCO measurements were performed and we identified 391 subjects aged 40-60 years, with a significant smoking history and normal spirometry. In this group, 96 subjects (24%) had TLCO measuremements below the lower limit of normal when using the newly established Global Lung Initiative (GLI) reference equations. The measurement of TLCO should be considered as part of the standard assessment of smokers.

Aspiration and severe exacerbations in COPD: a prospective study.

RATIONALE: Swallow may be compromised in COPD leading to aspiration and adverse respiratory consequences. However, prevalence and consequences of detectable aspiration in stable COPD are not known. OBJECTIVES: We tested the hypothesis that a significant number of patients with stable COPD will have detectable aspiration during swallow (prandial aspiration) and that they would experience more frequent severe acute exacerbations of COPD (AECOPD) over the subsequent 12 months. METHODS: Patients (n=151) with verified and stable COPD of all severities were recruited at a tertiary care hospital. Videofluoroscopy was conducted to evaluate aspiration using Rosenbek's scale for penetration-aspiration during 100-mL cup drinking. AECOPD was documented as moderate (antibiotics and/or corticosteroid treatment) or severe (emergency department admission or hospitalisation) over the ensuing 12 months. MEASUREMENTS AND MAIN RESULTS: Aspiration was observed in 30 out of 151 patients (19.9%, 18 males, 12 females; mean age 72.4 years). Patients with aspiration had more overall AECOPD events (3.03 versus 2 per patient; p=0.022) and severe AECOPD episodes (0.87 versus 0.39; p=0.032). Severe AECOPD occurred in more patients with aspiration (50% of patients versus 18.2%; OR 4.5, CI 1.9-10.5; p=0.001) and with silent aspiration (36.7% versus 18.2%; OR 2.6, CI 1.1-6.2; p=0.045). Aspiration was related to a shorter exacerbation-free period during the 12-month follow-up period (p=0.038). CONCLUSIONS: Prandial aspiration is detectable in a subset of patients with COPD and was predictive of subsequent severe AECOPD. Studies to examine if the association is causal are essential to direct strategies aimed at prevention of aspiration and AECOPD.

Arytenoid cartilage movements are hypokinetic in Parkinson's disease: A quantitative dynamic computerised tomographic study.

BACKGROUND: Voice change is one of the earliest features of Parkinson's disease. However, quantitative studies of vocal fold dynamics which are needed to provide insight into disease biology, aid diagnosis, or track progression, are few. METHODS: We therefore quantified arytenoid cartilage movements and glottic area during repeated phonation in 15 patients with Parkinson's disease (symptom duration < 6 years) and 19 controls, with 320-slice computerised tomography (CT). We related these measures to perceptual voice evaluations and spirometry. We hypothesised that Parkinson's disease patients have a smaller inter-arytenoid distance, a preserved or larger glottic area because vocal cord bowing has previously been reported, less variability in loudness, more voice dysdiadochokinesis and breathiness and a shortened phonation time because of arytenoid hypokinesis relative to glottic area. RESULTS: Inter-arytenoid distance in Parkinson's disease patients was moderately smaller (Mdn = 0.106, IQR = 0.091-0.116) than in controls (Mdn = 0.132, IQR = 0.116-0.166) (W = 212, P = 0.015, r = -0.42), normalised for anatomical and other inter-subject variance, analysed with two-tailed Wilcoxon's rank sum test. This finding was confirmed in a linear mixed model analysis-Parkinson's disease significantly predicted a reduction in the dependent variable, inter-arytenoid distance (b = -0.87, SEb = 0.39, 95% CI [-1.66, -0.08], t(31) = -2.24, P = 0.032). There was no difference in glottic area. On perceptual voice evaluation, patients had more breathiness and dysdiadochokinesis, a shorter maximum phonation time, and less variability in loudness than controls. There was no difference in spirometry after adjustment for smoking history. CONCLUSIONS: As predicted, vocal fold adduction movements are reduced in Parkinson's disease on repeated phonation but glottic area is maintained. Some perceptual characteristics of Parkinsonian speech reflect these changes. We are the first to use 320-slice CT to study laryngeal motion. Our findings indicate how Parkinson's disease affects intrinsic laryngeal muscle position and excursion.

A double blind randomized placebo control crossover trial on the effect of dietary nitrate supplementation on exercise tolerance in stable moderate chronic obstructive pulmonary disease.

BACKGROUND: Dietary nitrate supplementation has been shown to decrease the oxygen cost of exercise and prolong exercise tolerance, as measured by sub-maximal exercise endurance distance and time at 85% V̇O2max, in both elite athletes and normal healthy subjects. Patients with chronic obstructive pulmonary disease (COPD) have reduced quality of life and ability to perform activities of daily living attributable to diminished exercise tolerance, and dietary nitrate may be able to ameliorate this. METHODS: We performed a double-blind, computer-randomized placebo control crossover trial at a tertiary Australian hospital to investigate whether dietary nitrate supplementation as beetroot juice (BR) would augment submaximal exercise endurance in individuals with spirometrically confirmed stable moderate COPD. Volunteers underwent an incremental shuttle walk test to determine V̇O2max followed by a test dose of BR to establish safety in the study population. Participants performed an endurance shuttle walk test (ESWT) at 85% V̇O2max after randomization to either a 3 day wash-in of BR (4.8 mmol twice a day) or placebo (nitrate deplete BR), with a final dose on the morning of testing. They then crossed over after 4 day washout. Repeated measures two sided paired t-tests were employed. RESULTS: 35 participants were recruited with 19 completing the trial. In the initial safety phase, we measured systolic blood pressure over four hours post first dose of BR, and found a mean 10 mmHg decrement maximal at 1 hour. One individual developed symptomatic postural hypotension and was excluded. The primary outcomes of ESWT distance and time to fatigue improved by 11% and 6% respectively; however these differences did not achieve statistical significance (p = 0.494 and 0.693 respectively). CONCLUSIONS: Our study does not support a role for routine dietary nitrate supplementation for enhancement of exercise endurance in COPD. TRIAL REGISTRATION: Australia and New Zealand Clinical Trial Register: ACTRN12611001088932.

Laughter and humor therapy in dialysis.

Laughter and humor therapy have been used in health care to achieve physiological and psychological health-related benefits. The application of these therapies to the dialysis context remains unclear. This paper reviews the evidence related to laughter and humor therapy as a medical therapy relevant to the dialysis patient population. Studies from other groups such as children, the elderly, and persons with mental health, cancer, and other chronic conditions are included to inform potential applications of laughter therapy to the dialysis population. Therapeutic interventions could range from humorous videos, stories, laughter clowns through to raucous simulated laughter and Laughter Yoga. The effect of laughter and humor on depression, anxiety, pain, immunity, fatigue, sleep quality, respiratory function and blood glucose may have applications to the dialysis context and require further research.

Lung-volume controlled computerised tomography in real-life acute severe asthma.

OBJECTIVE: It is not known how airway structure is altered during real-life acute asthma exacerbations. The aim of this study was to examine changes in airway structure during acute asthma exacerbations and at convalescence by using lung-volume controlled high resolution computerised tomography (HRCT). METHODS: Eight subjects with acute asthma exacerbation admitted to hospital were recruited. HRCT was performed within 72 h of admission (n = 8) and repeated after 8 weeks of convalescence (n = 7). Individual airways were carefully matched on acute and convalescent CT data sets for comparisons of airway parameters. A novel methodology was employed for standardisation of lung volumes to permit valid comparisons of lung imaging. Measurements of bronchial cross sectional airway area (Aa) and bronchial luminal area (Ai) for each matched airway were obtained using a validated program. RESULTS: The airway wall thickness was analysed as wall area (WA) calculated as a percentage: WA% = WA/Aa × 100. Wilcoxon signed-rank testing was used to compare acute and convalescent asthma and Spearman's correlation to examine associations. Airway lumen (Ai) areas were similar in both acute and stable asthma phases (6.6 ± 3.1 mm(2) versus 7.2 ± 3.8 mm(2) p = 0.8). However, the airway wall was significantly thickened during acute asthma exacerbations compared to convalescence (62 ± 4% versus 55 ± 7%; p = 0.01). There was no correlation between airway structure dimensions and lung function measurements. CONCLUSIONS: This is the first study to demonstrate an increase in airway wall thickness during real-life acute asthma exacerbation. However, narrowing of the airway lumen area was variable and will require larger studies able to detect small differences. These results suggest that airway wall thickening linked to mucosal inflammation is likely to characterise acute asthma in vivo but that changes in the airway lumen accompanying bronchoconstriction may be more heterogeneous.

Laryngeal penetration and aspiration in individuals with stable COPD.

BACKGROUND AND OBJECTIVE: Swallowing is closely coordinated with breathing but in COPD altered synchronization may predispose patients to a breach of the upper airway protective mechanisms. However, aspiration during swallow has never been shown in COPD. We examined penetration of liquid material into the airway of patients with COPD and correlated it with breathing-swallow patterns. METHODS: A case-control study was performed. Patients with COPD (n = 16) were matched with normal control subjects (n = 15). Sub-mandibular videofluoroscopy was carried out during swallow of graduated volumes of barium to detect penetration (contrast enters the airway and may contact vocal folds) and aspiration (contrast passes glottis). Respiration was monitored simultaneously to gauge synchronization. Hospitalization and mortality were assessed after 36 months. RESULTS: Penetration/aspiration scores were higher in patients with COPD (3.3 ± 0.7 vs 1.6 ± 0.4 in healthy controls, P = 0.03; mean ± SE). Penetration with aspiration was observed in 4/16 patients with COPD versus 1/15 controls (P = 0.07). Penetration with or without aspiration was found in 6/16 patients (P = 0.04). Inspiration-swallow-expiration patterns were favoured in individuals with COPD (P = 0.02). Penetration/aspiration was associated with higher respiratory rates (P = 0.01), reduced hyoid elevation (P = 0.04), post-swallow larynx penetration (P = 0.05) and oxygen desaturation (P = 0.01). There was a trend for the penetration/aspiration group to have an adverse outcome. CONCLUSIONS: Upper airway protective mechanisms may be flawed in COPD, possibly through reduced coordination of breathing with swallowing. This abnormality may contribute to COPD morbidity in a subgroup of patients.

Dual-energy X-ray absorptiometry is the method of choice to assess body composition in COPD.

BACKGROUND AND OBJECTIVE: Mortality and morbidity in COPD have been related to reduced FEV1 as well as indices of body composition. Different techniques used to evaluate body composition may vary in accuracy, particularly in conditions with altered fluid balance such as COPD. We hypothesized that direct measurement of fat-free mass index (FFMI) by dual-energy X-ray absorptiometry (DEXA) would provide superior assessment of body composition in COPD. METHODS: We measured body composition in 31 patients with COPD randomly selected from a teaching hospital clinic. To estimate total body water (TBW) and FFMI, skin-fold anthropometry, bioelectrical impedance analysis (BIA) with Schols and Lukaski equations as well as DEXA, total body potassium by whole-body gamma-counting (TBK) and in vivo neutron activation analysis were used. Combined body composition methods providing precise estimations of TBW were used for comparisons. Bland-Altman analyses, ANOVA and chi2-testing were used to examine data. RESULTS: Mean BMI was 27.6 +/- 5.34 kg/m2 (mean +/- SD). Estimations of TBW were similar using Schols BIA or by using combined body composition methods. FFMI did not vary significantly between grades of COPD severity but was significantly different when assessed using DEXA and other methods. Calculated FFM hydration was significantly different from the fixed hydration factor used to calculate FFMI from BIA TBW (P < 0.05). CONCLUSION: The Schols BIA method incorporates a fixed hydration factor that may lead to an erroneous estimation of FFMI with ensuing clinical implications. DEXA can be used to obtain accurate and comprehensive assessments of body composition and should be the preferred investigation in COPD.