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BackgroundNasal High Flow (NHF) therapy delivers flows of heated humidified gases up to 60 LPM (litres per minute) via a nasal cannula. Particles of oral/nasal fluid released by patients undergoing NHF therapy may pose a cross-infection risk, which is a potential concern for treating COVID-19 patients.MethodsLiquid particles within the exhaled breath of healthy participants were measured with two protocols: (1) high speed camera imaging and counting exhaled particles under high magnification (6 participants) and (2) measuring the deposition of a chemical marker (riboflavin-5-monophosphate) at a distance of 100 and 500 mm on filter papers through which air was drawn (10 participants). The filter papers were assayed with HPLC. Breathing conditions tested included quiet (resting) breathing and vigorous breathing (which here means nasal snorting, voluntary coughing and voluntary sneezing). Unsupported (natural) breathing and NHF at 30 and 60 LPM were compared.ResultsImaging: During quiet breathing, no particles were recorded with unsupported breathing or 30 LPM NHF (detection limit for single particles 33 μm). Particles were detected from 2 of 6 participants at 60 LPM quiet breathing at approximately 10% of the rate caused by unsupported vigorous breathing. Unsupported vigorous breathing released the greatest numbers of particles. Vigorous breathing with NHF at 60 LPM, released half the number of particles compared to vigorous breathing without NHF.Chemical marker tests: No oral/nasal fluid was detected in quiet breathing without NHF (detection limit 0.28 μL/m3). In quiet breathing with NHF at 60 LPM, small quantities were detected in 4 out of 29 quiet breathing tests, not exceeding 17 μL/m3. Vigorous breathing released 200-1000 times more fluid than the quiet breathing with NHF. The quantities detected in vigorous breathing were similar whether using NHF or not.ConclusionDuring quiet breathing, 60 LPM NHF therapy may cause oral/nasal fluid to be released as particles, at levels of tens of μL per cubic metre of air. Vigorous breathing (snort, cough or sneeze) releases 200 to 1000 times more oral/nasal fluid than quiet breathing (p < 0.001 with both imaging and chemical marker methods). During vigorous breathing, 60 LPM NHF therapy caused no statistically significant difference in the quantity of oral/nasal fluid released compared to unsupported breathing. NHF use does not increase the risk of dispersing infectious aerosols above the risk of unsupported vigorous breathing. Standard infection prevention and control measures should apply when dealing with a patient who has an acute respiratory infection, independent of which, if any, respiratory support is being used.Clinical trial registrationACTRN12614000924651.

Background: Nasal High Flow (NHF) therapy delivers flows of heated humidified gases up to 60 LPM (litres per minute) via a nasal cannula. Particles of oral/nasal fluid released by patients undergoing NHF therapy may pose a cross-infection risk, which is a potential concern for treating COVID-19 patients., Methods: Liquid particles within the exhaled breath of healthy participants were measured with two protocols: (1) high speed camera imaging and counting exhaled particles under high magnification (6 participants) and (2) measuring the deposition of a chemical marker (riboflavin-5-monophosphate) at a distance of 100 and 500 mm on filter papers through which air was drawn (10 participants). The filter papers were assayed with HPLC. Breathing conditions tested included quiet (resting) breathing and vigorous breathing (which here means nasal snorting, voluntary coughing and voluntary sneezing). Unsupported (natural) breathing and NHF at 30 and 60 LPM were compared., Results: Imaging: During quiet breathing, no particles were recorded with unsupported breathing or 30 LPM NHF (detection limit for single particles 33 μm). Particles were detected from 2 of 6 participants at 60 LPM quiet breathing at approximately 10% of the rate caused by unsupported vigorous breathing. Unsupported vigorous breathing released the greatest numbers of particles. Vigorous breathing with NHF at 60 LPM, released half the number of particles compared to vigorous breathing without NHF.Chemical marker tests: No oral/nasal fluid was detected in quiet breathing without NHF (detection limit 0.28 μL/m3). In quiet breathing with NHF at 60 LPM, small quantities were detected in 4 out of 29 quiet breathing tests, not exceeding 17 μL/m3. Vigorous breathing released 200-1000 times more fluid than the quiet breathing with NHF. The quantities detected in vigorous breathing were similar whether using NHF or not., Conclusion: During quiet breathing, 60 LPM NHF therapy may cause oral/nasal fluid to be released as particles, at levels of tens of μL per cubic metre of air. Vigorous breathing (snort, cough or sneeze) releases 200 to 1000 times more oral/nasal fluid than quiet breathing (p < 0.001 with both imaging and chemical marker methods). During vigorous breathing, 60 LPM NHF therapy caused no statistically significant difference in the quantity of oral/nasal fluid released compared to unsupported breathing. NHF use does not increase the risk of dispersing infectious aerosols above the risk of unsupported vigorous breathing. Standard infection prevention and control measures should apply when dealing with a patient who has an acute respiratory infection, independent of which, if any, respiratory support is being used., Clinical Trial Registration: ACTRN12614000924651., Competing Interests: Authors CJS, JFO, RK and PR are employees of the funder, Fisher and Paykel Healthcare. The specific roles of these authors are articulated in the ‘author contributions’ section. YJ and HH carried out statistical analyses under consulting service agreements with Fisher & Paykel Healthcare Ltd. This does not alter our adherence to PLOS ONE policies on sharing data and materials.” I am not aware that the work described in the manuscript has had any impact on product development or marketing, and I am not aware of any affiliation between any of the authors and any manufacturers competing with the funder.

Objective: To establish the cost-effectiveness of long-term humidification therapy (LTHT) added to usual care for patients with moderate or severe chronic obstructive pulmonary disease or bronchiectasis., Methods: Resource usage in a 12-month clinical trial of LTHT was estimated from hospital records, patient diaries, and the equipment supplier. Health state utility values were derived from the St. Georges Respiratory Questionnaire (SGRQ) total score. All patients who remained in the trial for 12 months and who had at least 90 days of diary records were included (87 of 108)., Results: Clinical costs were NZ $3973 (95% confidence interval [CI] $1614-$6332) for the control group and NZ $3331 (95% CI $948-$6920) for the intervention group. The mean health benefit per patient was -6.9 SGRQ units (95% CI -13.0 to -7.2; P < 0.05) or +0.0678 quality-adjusted life-years (95% CI 0.001-0.135). With the intervention costing NZ $2059 annually, the mean cost per quality-adjusted life-year was NZ $20,902 (US $18,907) and the bootstrap median was NZ $19,749 (2.5th percentile -$40,923, 97.5th percentile $221,275). At a willingness-to-pay (WTP) threshold of NZ $30,000, the probability of cost-effectiveness was 61%, ranging from 49% to 72% as the cost of LTHT was varied by ±30%. At a WTP of NZ $20,000, the probability was 49% (range 34%-61%)., Conclusions: LTHT is moderately cost-effective for patients with moderate to severe chronic obstructive pulmonary disease or bronchiectasis at a WTP threshold that is acceptable for public funding of medicines in New Zealand. These findings must be interpreted with caution because of the modest size of the clinical study, necessary lack of blinding in the clinical trial, and uncertainty in estimating health state utility from the SQRQ., (Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.)

A common but not necessarily logical requirement in drug development is that a 'limit of quantitation' be set for chemical assays and that observations that fall below the limit should not be treated as real data but should be labelled as below the limit and set aside for special treatment. We examine five of seven approaches to analysing such data considered by Beal in 2001, concentrating in particular on two: one that treats the data as a truncated sample and another that treats them as a censored sample. In fact, using a pattern-mixture framework, one can show that the former consists of using the conditional distribution of the 'acceptable values' and the latter adds the information from the marginal mixing distribution. We illustrate these approaches with a real example, concentrating in particular on the two likelihood-based methods, provide various formulae that may be used to compare these and other approaches, check these formulae using simulations and make some recommendations as to which approach one should use., (Copyright © 2012 John Wiley & Sons, Ltd.)

Background: Azithromycin is a macrolide antibiotic with anti-inflammatory and immunomodulatory properties. We tested the hypothesis that azithromycin would decrease the frequency of exacerbations, increase lung function, and improve health-related quality of life in patients with non-cystic fibrosis bronchiectasis., Methods: We undertook a randomised, double-blind, placebo-controlled trial at three centres in New Zealand. Between Feb 12, 2008, and Oct 15, 2009, we enrolled patients who were 18 years or older, had had at least one pulmonary exacerbation requiring antibiotic treatment in the past year, and had a diagnosis of bronchiectasis defined by high-resolution CT scan. We randomly assigned patients to receive 500 mg azithromycin or placebo three times a week for 6 months in a 1:1 ratio, with a permuted block size of six and sequential assignment stratified by centre. Participants, research assistants, and investigators were masked to treatment allocation. The coprimary endpoints were rate of event-based exacerbations in the 6-month treatment period, change in forced expiratory volume in 1 s (FEV(1)) before bronchodilation, and change in total score on St George's respiratory questionnaire (SGRQ). Analyses were by intention to treat. This study is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12607000641493., Findings: 71 patients were in the azithromycin group and 70 in the placebo group. The rate of event-based exacerbations was 0·59 per patient in the azithromycin group and 1·57 per patient in the placebo group in the 6-month treatment period (rate ratio 0·38, 95% CI 0·26-0·54; p<0·0001). Prebronchodilator FEV(1) did not change from baseline in the azithromycin group and decreased by 0·04 L in the placebo group, but the difference was not significant (0·04 L, 95% CI -0·03 to 0·12; p=0·251). Additionally, change in SGRQ total score did not differ between the azithromycin (-5·17 units) and placebo groups (-1·92 units; difference -3·25, 95% CI -7·21 to 0·72; p=0·108)., Interpretation: Azithromycin is a new option for prevention of exacerbations in patients with non-cystic fibrosis bronchiectasis with a history of at least one exacerbation in the past year., Funding: Health Research Council of New Zealand and Auckland District Health Board Charitable Trust., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

In this study, we evaluated the performance of a humidified nasal high-flow system (Optiflow, Fisher and Paykel Healthcare) by measuring delivered FiO, and airway pressures. Oxygraphy, capnography and measurement of airway pressures were performed through a hypopharyngeal catheter in healthy volunteers receiving Optiflow humidified nasal high flow therapy at rest and with exercise. The study was conducted in a non-clinical experimental setting. Ten healthy volunteers completed the study after giving informed written consent. Participants received a delivered oxygen fraction of 0.60 with gas flow rates of 10, 20, 30, 40 and 50 l/minute in random order FiO2, F(E)O2, F(E)CO2 and airway pressures were measured. Calculation of FiO2 from F(E)O2 and F(E)CO2 was later performed. Calculated FiO2 approached 0.60 as gas flow rates increased above 30 l/minute during nose breathing at rest. High peak inspiratory flow rates with exercise were associated with increased air entrainment. Hypopharyngeal pressure increased with increasing delivered gas flow rate. At 50 l/minute the system delivered a mean airway pressure of up to 7.1 cm H20. We believe that the high gas flow rates delivered by this system enable an accurate inspired oxygen fraction to be delivered. The positive mean airway pressure created by the high flow increases the efficacy of this system and may serve as a bridge to formal positive pressure systems.

Aim: Persistent airway inflammation with mucus retention in patients with chronic airway disorders such as COPD and bronchiectasis may lead to frequent exacerbations, reduced lung function and poor quality of life. This study investigates if long-term humidification therapy with high flow fully humidified air at 37 degrees C through nasal cannulae can improve these clinical outcomes in this group of patients., Method: 108 patients diagnosed with COPD or bronchiectasis were randomised to daily humidification therapy or usual care for 12 months over which exacerbations were recorded. Lung function, quality of life, exercise capacity, and measures of airway inflammation were also recorded at baseline, 3 and 12 months., Results: Patients on long-term humidification therapy had significantly fewer exacerbation days (18.2 versus 33.5 days; p = 0.045), increased time to first exacerbation (median 52 versus 27 days; p = 0.0495) and reduced exacerbation frequency (2.97/patient/year versus 3.63/patient/year; p = 0.067) compared with usual care. Quality of life scores and lung function improved significantly with humidification therapy compared with usual care at 3 and 12 months., Conclusion: Long-term humidification therapy significantly reduced exacerbation days, increased time to first exacerbation, improved lung function and quality of life in patients with COPD and bronchiectasis. Clinical trial registered with www.actr.org.au; Number ACTRN2605000623695., (Copyright 2010 Elsevier Ltd. All rights reserved.)

The susceptibility of 1763 yeast isolates (from 22 species and seven genera) was tested using Clinical and Laboratory Standards Institute M27-A2 microdilution methodology. Candida spp. predominated (97.1%), mainly C. albicans (51.4%), C. glabrata (16.4%) and C. tropicalis (13.7%), followed by Trichosporon spp. (1.1%) and Cryptococcus neoformans (1.0%). Most isolates came from blood/catheters (72.0%) or the oesophagus/oropharynx (11.3%). The voriconazole, itraconazole, fluconazole and amphotericin B MIC90 values (minimum inhibitory concentration for 90% of the isolates) for all isolates were 1.0, 2.0, 64 and 1.0 microg/mL, respectively. Voriconazole MICs correlated with those for fluconazole (r = 0.91) and itraconazole (r = 0.90). Only 109 isolates (6.2%) had voriconazole MICs > or = 4.0 microg/mL; all were C. albicans, C. glabrata or C. tropicalis resistant to itraconazole (and most to fluconazole). Isolates from 22 patients with amphotericin MICs > or = 2.0 microg/mL (range 2.0-16.0 microg/mL) were also cross-resistant to one or more of the triazoles. Patients (n = 34) with voriconazole-resistant isolates showed a 56% response to voriconazole therapy, and those patients (n = 261) with susceptible isolates showed a 71% response. Twenty-three voriconazole-treated patients had baseline resistant isolates, in eight patients voriconazole resistance developed during therapy and in three patients a different resistant species arose during therapy. Thus, voriconazole MICs correlate with those of fluconazole and itraconazole and may predict clinical outcome.

Introduction: Fungal pathogens from the voriconazole trials were identified and tested for susceptibility at two reference laboratories., Methods: MICs were measured using CLSI M38-A 48 h microdilution methodology., Results: Moulds from 29 genera and 38 species were isolated from 18 countries. Aspergillus spp. predominated (69%), followed by Scedosporium spp. (11.5%). Aspergillus fumigatus (292/590, 49.5%) was the most common species, followed by Scediosporium apiospermum (9.7%) and Aspergillus terreus (7.3%). The bronchi, lungs and sinuses yielded 45% of the isolates (57% of aspergilli), with 24% from the oropharynx/oesophagus. Other sites included blood/catheter (7.3%) and CNS (5.2%). MIC90s of itraconazole and voriconazole for Aspergillus spp. were the same (0.5 mg/L), but 17 Aspergillus isolates were itraconazole-resistant (MICs > or = 1-16 mg/L). Additionally, in 31 A. fumigatus and 23 A. terreus isolates, amphotericin MICs were > or = 2.0 mg/L. Voriconazole MICs exceeded 4 mg/L in only 5.8% (34/590) of the isolates, including one A. fumigatus (8.0 mg/L), 9/11 Scedosporium prolificans, 10/13 Fusarium solani and all 9 Zygomycetes. Most were also not susceptible to itraconazole or amphotericin B. A notable increase in MIC (more than two doubling dilutions) during voriconazole therapy was seen for one A. fumigatus isolate. The response rate of voriconazole-treated patients with isolate MICs > or = 4.0 mg/L was 38% when compared with 52% for those with MICs < 4.0 mg/L., Conclusions: Voriconazole shows activity, in vitro, similar to that of itraconazole against a wide range of moulds. It is also active against some isolates not susceptible to itraconazole or amphotericin B, but not the Zygomycetes. The relationship between voriconazole MIC and clinical outcome requires further study.