Conservative versus Interventional Treatment for Spontaneous Pneumothorax.

BACKGROUND: Whether conservative management is an acceptable alternative to interventional management for uncomplicated, moderate-to-large primary spontaneous pneumothorax is unknown. METHODS: In this open-label, multicenter, noninferiority trial, we recruited patients 14 to 50 years of age with a first-known, unilateral, moderate-to-large primary spontaneous pneumothorax. Patients were randomly assigned to immediate interventional management of the pneumothorax (intervention group) or a conservative observational approach (conservative-management group) and were followed for 12 months. The primary outcome was lung reexpansion within 8 weeks. RESULTS: A total of 316 patients underwent randomization (154 patients to the intervention group and 162 to the conservative-management group). In the conservative-management group, 25 patients (15.4%) underwent interventions to manage the pneumothorax, for reasons prespecified in the protocol, and 137 (84.6%) did not undergo interventions. In a complete-case analysis in which data were not available for 23 patients in the intervention group and 37 in the conservative-management group, reexpansion within 8 weeks occurred in 129 of 131 patients (98.5%) with interventional management and in 118 of 125 (94.4%) with conservative management (risk difference, -4.1 percentage points; 95% confidence interval [CI], -8.6 to 0.5; P = 0.02 for noninferiority); the lower boundary of the 95% confidence interval was within the prespecified noninferiority margin of -9 percentage points. In a sensitivity analysis in which all missing data after 56 days were imputed as treatment failure (with reexpansion in 129 of 138 patients [93.5%] in the intervention group and in 118 of 143 [82.5%] in the conservative-management group), the risk difference of -11.0 percentage points (95% CI, -18.4 to -3.5) was outside the prespecified noninferiority margin. Conservative management resulted in a lower risk of serious adverse events or pneumothorax recurrence than interventional management. CONCLUSIONS: Although the primary outcome was not statistically robust to conservative assumptions about missing data, the trial provides modest evidence that conservative management of primary spontaneous pneumothorax was noninferior to interventional management, with a lower risk of serious adverse events. (Funded by the Emergency Medicine Foundation and others; PSP Australian New Zealand Clinical Trials Registry number, ACTRN12611000184976.).

Controlled Trial of Budesonide-Formoterol as Needed for Mild Asthma.

BACKGROUND: In double-blind, placebo-controlled trials, budesonide-formoterol used on an as-needed basis resulted in a lower risk of severe exacerbation of asthma than as-needed use of a short-acting ß2-agonist (SABA); the risk was similar to that of budesonide maintenance therapy plus as-needed SABA. The availability of data from clinical trials designed to better reflect clinical practice would be beneficial. METHODS: We conducted a 52-week, randomized, open-label, parallel-group, controlled trial involving adults with mild asthma. Patients were randomly assigned to one of three treatment groups: albuterol (100 µg, two inhalations from a pressurized metered-dose inhaler as needed for asthma symptoms) (albuterol group); budesonide (200 µg, one inhalation through a Turbuhaler twice daily) plus as-needed albuterol (budesonide maintenance group); or budesonide-formoterol (200 µg of budesonide and 6 µg of formoterol, one inhalation through a Turbuhaler as needed) (budesonide-formoterol group). Electronic monitoring of inhalers was used to measure medication use. The primary outcome was the annualized rate of asthma exacerbations. RESULTS: The analysis included 668 of 675 patients who underwent randomization. The annualized exacerbation rate in the budesonide-formoterol group was lower than that in the albuterol group (absolute rate, 0.195 vs. 0.400; relative rate, 0.49; 95% confidence interval [CI], 0.33 to 0.72; P<0.001) and did not differ significantly from the rate in the budesonide maintenance group (absolute rate, 0.195 in the budesonide-formoterol group vs. 0.175 in the budesonide maintenance group; relative rate, 1.12; 95% CI, 0.70 to 1.79; P = 0.65). The number of severe exacerbations was lower in the budesonide-formoterol group than in both the albuterol group (9 vs. 23; relative risk, 0.40; 95% CI, 0.18 to 0.86) and the budesonide maintenance group (9 vs. 21; relative risk, 0.44; 95% CI, 0.20 to 0.96). The mean (±SD) dose of inhaled budesonide was 107±109 µg per day in the budesonide-formoterol group and 222±113 µg per day in the budesonide maintenance group. The incidence and type of adverse events reported were consistent with those in previous trials and with reports in clinical use. CONCLUSIONS: In an open-label trial involving adults with mild asthma, budesonide-formoterol used as needed was superior to albuterol used as needed for the prevention of asthma exacerbations. (Funded by AstraZeneca and the Health Research Council of New Zealand; Novel START Australian New Zealand Clinical Trials Registry number, ACTRN12615000999538.).

Single dose of budesonide/formoterol turbuhaler compared to salbutamol pMDI for speed of bronchodilator onset in asthma: a randomised cross-over trial.

OBJECTIVE: To compare bronchodilator response after to salbutamol and budesonide/formoterol in adults with stable asthma. METHODS: A double-blind, cross-over, single-centre, placebo-controlled, non-inferiority trial. Adults with stable asthma were randomised to different orders of two treatment regimens: two actuations of placebo via MDI and one actuation of budesonide/formoterol 200/6 µg via turbuhaler; and one actuation of placebo turbuhaler and two actuations of salbutamol 100 µg via MDI. The primary outcome measure was FEV1 after 2 min. Secondary outcome measures included FEV1, mBorg Dyspnoea Scale score and visual analogue score for breathlessness over 30 min. RESULTS: Forty-nine of 50 potential participants were randomised. One participant withdrew following the first intervention visit and another could not be randomised due to COVID-19 restrictions. The mean (SD) change from baseline FEV1 2 min after treatment administration for budesonide/formoterol and salbutamol was 0.08 (0.14) L, n=49, and 0.17 (0.18) L, n=48, respectively, mean (95% CI) paired difference of -0.097 L (-0.147 to -0.047), p=0.07, against a non-inferiority bound of -0.06 L. In the secondary analysis, FEV1 over 30 min was lower for budesonide/formoterol compared with salbutamol, difference (95% CI): -0.10 (-0.12 to -0.08) L, p<0.001. There were no differences in Visual Analogue Scale score or mBorg Dyspnoea Scale score between treatments. CONCLUSION: The results do not support the primary hypothesis of non-inferiority at the boundary of -0.06 L for the difference between budesonide/formoterol 200/6 µg compared with salbutamol 200 µg for FEV1 at 2 min, and could be consistent with inferiority with a p value of 0.07. For the secondary analysis of FEV1 measurements over time, the FEV1 was higher with salbutamol. TRIAL REGISTRATION NUMBER: Australian and New Zealand Clinical Trials Registry (ACTRN 12619001387112).

Effects of inhaled JAK inhibitor GDC-4379 on exhaled nitric oxide and peripheral biomarkers of inflammation.

BACKGROUND: Janus Kinases (JAKs) mediate activity of many asthma-relevant cytokines. GDC-0214, an inhaled small molecule JAK1 inhibitor, has previously been shown to reduce fractional exhaled nitric oxide (FeNO) in patients with mild asthma, but required an excessive number of inhalations. AIM: To assess whether GDC-4379, a new inhaled JAK inhibitor, reduces FeNO and peripheral biomarkers of inflammation. METHODS: This study assessed the activity of GDC-4379 in a double-blind, randomized, placebo-controlled, Phase 1 study in patients with mild asthma. Participants included adults (18-65y) with a diagnosis of asthma for ≥6 months, forced expiratory volume in 1 s (FEV1)> 70% predicted, FeNO >40 ppb, using as-needed short-acting beta-agonist medication only. Four sequential, 14-day, ascending-dose cohorts (10 mg QD, 30 mg QD, 40 mg BID, and 80 mg QD) of 12 participants each were randomized 2:1 to GDC-4379 or placebo. The primary activity outcome was percent change from baseline (CFB) in FeNO to Day 14 compared to the pooled placebo group. Safety, tolerability, pharmacokinetics, and pharmacodynamic biomarkers, including blood eosinophils, serum CCL17, and serum CCL18, were also assessed. RESULTS: Of 48 enrolled participants, the mean age was 25 years and 54% were female. Median (range) FeNO at baseline was 79 (41-222) ppb. GDC-4379 treatment led to dose-dependent reductions in FeNO. Compared to placebo, mean (95% CI) percent CFB in FeNO to Day 14 was: -6 (-43, 32) at 10 mg QD, -26 (-53, 2) at 30 mg QD, -55 (-78, -32) at 40 mg BID and -52 (-72, -32) at 80 mg QD. Dose-dependent reductions in blood eosinophils and serum CCL17 were also observed. Higher plasma drug concentrations corresponded with greater FeNO reductions. No serious AEs occurred. The majority of AEs were mild to moderate. The most common AEs were headache and oropharyngeal pain. Minor changes in neutrophils were noted at 80 mg QD, but were not considered clinically meaningful. CONCLUSIONS: In patients with mild asthma, 14-day treatment with GDC-4379 reduced FeNO levels and peripheral biomarkers of inflammation. Treatment was well tolerated without any major safety concerns. AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY: ACTRN12619000227190.

Panic or peace - prioritising infant welfare when medicating feverish infants: a grounded theory study of adherence in a paediatric clinical trial.

BACKGROUND: Literature on factors influencing medication adherence within paediatric clinical trials is sparse. The Paracetamol and Ibuprofen in the Primary Prevention of Asthma in Tamariki (PIPPA Tamariki) trial is an open-label, randomised controlled trial aiming to determine whether paracetamol treatment, compared with ibuprofen treatment, as required for fever and pain in the first year of life, increases the risk of asthma at age six years. To inform strategies for reducing trial medication crossovers, understanding factors influencing the observed ibuprofen-to-paracetamol crossovers (non-protocol adherence) is vital. The aim of this study was to investigate the factors influencing the decision-making process when administering or prescribing ibuprofen to infants that may contribute to the crossover events in the PIPPA Tamariki trial. METHODS: Constructivist grounded theory methods were employed. We conducted semi-structured interviews of caregivers of enrolled PIPPA Tamariki infants and healthcare professionals in various healthcare settings. Increasing theoretical sensitivity of the interviewers led to theoretical sampling of participants who could expand on the teams' early constructed codes. Transcribed interviews were coded and analysed using the constant comparative method of concurrent data collection and analysis. RESULTS: Between September and December 2020, 20 participants (12 caregivers; 8 healthcare professionals) were interviewed. We constructed a grounded theory of prioritising infant welfare that represents a basic social process when caregivers and healthcare professionals medicate feverish infants. This process comprises three categories: historical, trusting relationships and being discerning; and is modified by one condition: being conflicted. Participants bring with them historical ideas. Trusting relationships with researchers, treating clinicians and family play a central role in enabling participants to challenge historical ideas and be discerning. Trial medication crossovers occur when participants become conflicted, and they revert to historical practices that feel familiar and safer. CONCLUSIONS: We identified factors and a basic social process influencing ibuprofen use in infants and trial medication crossover events, which can inform strategies for promoting adherence in the PIPPA Tamariki trial. Future studies should explore the role of trusting relationships between researchers and treating clinicians when conducting research.

Experiences, patient interactions and knowledge regarding the use of cannabis as a medicine in a cohort of New Zealand doctors in an oncology setting.

PURPOSE OF STUDY: To explore the experiences, patient interactions and knowledge regarding the use of cannabis as a medicine in New Zealand doctors in an oncology setting. STUDY DESIGN: An observational cross-sectional survey undertaken between November 2019 and January 2020 across four secondary-care hospital oncology departments within New Zealand (Auckland, Wellington, Christchurch and Dunedin). Participants were a convenience sample of doctors; consultants, registrars, medical officers of special status and house surgeons working in oncology departments. Of 53 individuals approached, 45 participated (85% Response Rate). The primary outcome was reporteddoctor-patient interactions. Secondary outcomes included knowledge of cannabis-based products, their efficacy, prescribing regulations and educational access. RESULTS: Of 44 doctors, 37 (84%, 95% CI: 70 to 93) reported patient requests to prescribe cannabis-based products and 43 (98%, 95% CI: 88 to 100) reported patients using illicit cannabis for medical symptoms. Primary request reasons were pain, nausea/vomiting and cancer treatment. 33/45 (73%, 95% CI: 58 to 85) cited knowledge of at least one cannabis-based product and 27/45 (60%, 95% CI: 44 to 74) indicated at least one condition that had evidence of efficacy. 36/44 (82%, 95% CI: 67 to 92) expressed future prescribing concerns but all were willing to use a cannabis-based product developed with traditional medical provenance. CONCLUSION: In the oncology setting, patients are asking doctors about symptomatic and curative treatment with cannabis-based products. Doctors are not biased against the use of products showing medical provenance; however, NZ-specific clinical and regulatory guidelines are essential to support patient discussions and appropriate prescribing.

Inhaled JAK inhibitor GDC-0214 reduces exhaled nitric oxide in patients with mild asthma: A randomized, controlled, proof-of-activity trial.

BACKGROUND: The Janus kinase (JAK) pathway mediates the activity of many asthma-relevant cytokines, including IL-4 and IL-13. GDC-0214 is a potent, inhaled, small-molecule JAK inhibitor being developed for the treatment of asthma. OBJECTIVE: We sought to determine whether GDC-0214 reduces fractional exhaled nitric oxide (Feno), a JAK1-dependent biomarker of airway inflammation, in patients with mild asthma. METHODS: We conducted a double-blind, randomized, placebo-controlled, phase 1 proof-of-activity study in adults with mild asthma and Feno higher than 40 parts per billion (ppb). Subjects were randomized 2:1 (GDC-0214:placebo) into 4 sequential ascending-dose cohorts (1 mg once daily [QD], 4 mg QD, 15 mg QD, or 15 mg twice daily). All subjects received 4 days of blinded placebo, then 10 days of either active drug or placebo. The primary outcome was placebo-corrected percent reduction in Feno from baseline to day 14. Baseline was defined as the average Feno during the blinded placebo period. Pharmacokinetics, safety, and tolerability were also assessed. RESULTS: Thirty-six subjects (mean age, 28 years; 54% females) were enrolled. Mean Feno at baseline across all subjects was 93 ± 43 ppb. At day 14, placebo-corrected difference in Feno was -23% (95% CI, -37.3 to -9) for 15 mg QD and -42% (95% CI, -57 to -27.4) for 15 mg twice daily. Higher plasma exposure was associated with greater Feno reduction. No dose-limiting adverse events, serious adverse events, or treatment discontinuations occurred. There were no major imbalances in adverse events or laboratory findings, or evidence of systemic JAK inhibition. CONCLUSIONS: GDC-0214, an inhaled JAK inhibitor, caused dose-dependent reductions in Feno in mild asthma and was well tolerated without evidence of systemic toxicity.

Optimal Asthma Control: Time for a New Target.

The stepwise approach to pharmacological treatment in adult asthma mandates that asthma treatment is progressively stepped up to achieve symptom control and reduce the risk of exacerbations and stepped down after a period of prolonged control. This review proposes that in adults without good asthma control, well-controlled asthma can only be achieved in approximately 70% of patients across the strata of severity, and only if there is a progressive increase in inhaled corticosteroid/long-acting ß2 agonist therapy to a maintenance inhaled corticosteroid dose that causes the same magnitude of systemic side effects as oral prednisone at a 5-mg daily dose. Another consideration is that in a person with asthma, there are numerous overlapping disorders that can present with symptoms indistinguishable from asthma, comorbidities that contribute to poor control and lifestyle/environmental factors that require treatment in their own right and that if specifically managed might lead to better outcomes. The disparity between patients' perceptions and guideline assessment of control may be due to partially controlled asthma being associated with near-maximal levels of quality of life, with minimal impairment. Finally, it is widely assumed that asthma symptom control equates to elimination of risk of asthma attacks, an assumption that may not apply to many patients, particularly those with more severe asthma. We propose that further research be undertaken to determine the optimal levels of asthma control and the potential value of different treatment targets, such as control of type-2 airway inflammation, that can be achieved with currently available treatment, based on efficacy, side effects, and cost.

Determination of oxygen saturation compared to a prescribed target range using continuous pulse oximetry in acutely unwell medical patients.

BACKGROUND: Both inadequate and excessive administration of oxygen to acutely unwell patients results in risk of harm. Guidelines recommend titration of oxygen to achieve a target oxygen saturation (SpO2) range. Information regarding whether this is being achieved is limited. METHODS: In this two-centre non-interventional study we used continuous pulse oximetry in acutely unwell medical patients over a 24-h period to determine the proportion of time spent with SpO2 within the prescribed target range and whether this is influenced by the target range, age, care in a high-dependency area and the number of oxygen adjustments. RESULTS: Eighty participants were included in the analysis. The mean (SD) proportion of time spent in target range was 55.6% (23.6), this was lower in those with a reduced hypercapnic target range (88-92% or below) compared to those with a range of 92-96%; difference - 13.1% (95% CI - 3.0 to - 23.2), P = 0.012. The proportion of time spent above range was 16.2% (22.9); this was higher in those with a reduced hypercapnic range; difference 21.6% (31.4 to 12), P < 0.001. The proportion of time below range was 28.4% (25.2); there was no difference between target ranges. The proportion of time spent in range was higher for those in a high dependency area in the multivariate model; difference 15.5% (95% CI 2.3 to 28.7), P = 0.02. CONCLUSIONS: Medical patients receiving oxygen in a ward setting spend significant periods of time with SpO2 both above and below the prescribed target range while receiving oxygen therapy.

A systematic review of the label accuracy of cannabinoid-based products in regulated markets: is what's on the label what's in the product?

OBJECTIVES: To review the literature regarding label accuracy and contamination of medical cannabinoid-based products. METHODS: A systematic review with meta-analysis following PRISMA guidelines. This study is registered with PROSPERO (CRD42019131565). RESULTS: Five studies reported label accuracy data ranging between 17% and 86%. Four studies reported contaminants, including pesticides, solvents and AB-FUBINACA. Meta-analysis was limited to the proportion of pesticide-contaminated samples found in two studies (0.25 (95% CI [0.10, 0.40])) and displayed significant heterogeneity. CONCLUSIONS: Label inaccuracies and contaminants are found across a spectrum of cannabinoid-based products. The review highlights the paucity and heterogeneity of research relating to cannabinoid-based products in light of changing global legislation. Further robust research is required to support ongoing pharmacovigilance and patient safety.

Public engagement with clinical research on social media; which visual medium works best? A 5-year retrospective analysis.

'Public engagement' describes a collaborative relationship between scientists and the public we serve. This has the potential to improve clinical research and is encouraged by key research funding bodies, however the objective evidence base for effective approaches remains limited. Social media algorithms determine what content users see and are known to weight post media differently. While visual content is understood to improve reach and engagement broadly, less is known about which kinds of visuals are most effective for engaging people with clinical research. We present a five year retrospective analysis of public engagement with Facebook posts made by an independent medical research institute, classified by their visual media content. Inclusion of visual post media was associated with positive effects on both reach and engagement. We present medium and strong evidence that this effect was most pronounced for comics compared to other visual media types. This data evidences objective value of using comics and other visual media for public engagement with clinical research. The metrics evaluated are easily accessible on many social media platforms meaning this approach could readily be applied by other researchers to measure the impact of their public engagement efforts, and inform science communication strategies and resource allocation.

Using comics and curiosity to drive pandemic research on a national scale.

An independent online Public Health survey regarding the COVID-19 pandemic was conducted during an Alert Level 4 lockdown, the highest possible, in New Zealand. An illustrated and curiosity-driven public engagement campaign was designed to advertise survey participation, and performance compared with a standard approach using randomised controlled A/B Split tests. The 'Caretoon' approach featured comic illustrations, appealed to goodwill and was intended to pique curiosity. This linked to an illustrated version of the survey which, upon completion, gave a personalised comic summary showing how respondent's answers compared with national averages. The standard ad and survey were not illustrated with comics, and did not provide a personalised comic summary on completion. Both approaches were cost- and time-effective, together resulting in 18,788 responses over six days. The Caretoon approach outperformed the standard approach in terms of the number of people reached, engaged, survey link clicks, gender and ethnic diversity amongst respondents, and cost-effectiveness of advertising. This came at the expense of a small reduction in the proportion of completed surveys and male respondents. The research evidences objective value of public engagement activity, comics and curiosity as tools which can support Public Health research on a national scale.

Change in biomarkers of type-2 inflammation following severe exacerbations of asthma.

We investigated the time course of change of type-2 asthma biomarkers after a severe asthma exacerbation. Blood eosinophils were lowest immediately after treatment was initiated (0.07 vs 0.33×109/L, p<0.001) while serum IgE levels were at their highest (339 vs 249 U/L, p<0.001). Fractional exhaled Nitric Oxide levels were lowest 2 weeks after treatment (23 vs 33 ppb, p=0.06) and serum periostin levels were lowest 1 week after treatment (45·9 vs 50·9 ng/mL, p<0.001). A delay of 4-8 weeks following a severe exacerbation is required if these biomarkers are used to guide the ongoing management of patients with asthma. TRIAL REGISTRATION NUMBER: Post-results; The Australia New Zealand Trial Registry, >ACTRN12614000443695.

Trends in international asthma mortality: analysis of data from the WHO Mortality Database from 46 countries (1993-2012).

BACKGROUND: International time trends in asthma mortality have been strongly affected by changes in management and in particular drug treatments. However, little is known about how asthma mortality has changed over the past decade. In this study, we assessed these international trends. METHODS: We collated age-standardised country-specific asthma mortality rates in the 5-34 year age group from the online WHO Mortality Database for 46 countries. To be included in the analysis, we specified that a country must have 10 years of complete data in the WHO Mortality Database between 1993 and 2012. In the absence of consistent and accurate asthma prevalence and prescribing data, we chose to use a locally weighted scatter plot smoother (LOESS) curve, weighted by the individual country population in the 5-34-year age group to show the global trends in asthma mortality rates with time. FINDINGS: Of the 46 countries included in the analysis of asthma mortality, 36 were high-income countries, and 10 were middle-income countries. The LOESS estimate of the global asthma mortality rate was 0·44 deaths per 100 000 people (90% CI 0·39-0·48) in 1993 and 0·19 deaths per 100 000 people (0·18-0·21) in 2006. Despite apparent further reductions in some countries and regions of the world, there was no appreciable change in global asthma mortality rates from 2006 through to 2012, when the LOESS estimate was also 0·19 deaths per 100 000 people (0·16-0·21). INTERPRETATION: The trend for reduction in global asthma mortality observed since the late 1980s might have stalled, with no appreciable difference in a smoothed LOESS curve of asthma mortality from 2006 to 2012. Although better implementation of established management strategies that have been shown to reduce mortality risk is needed, to achieve a further substantive reduction in global asthma mortality novel strategies will also be required. FUNDING: The Medical Research Institute of New Zealand, which is supported by Health Research Council of New Zealand Independent Research Organisation.

Anti-inflammatory duration of action of fluticasone furoate/vilanterol trifenatate in asthma: a cross-over randomised controlled trial.

BACKGROUND: Fluticasone furoate/Vilanterol trifenatate (FF/VI) is an inhaled corticosteroid/long-acting beta-agonist combination with a prolonged bronchodilator duration of action. We characterised the time-course of onset and offset of airway anti-inflammatory action of FF/VI, as assessed by fraction of exhaled nitric oxide (FeNO), and compared this to the bronchodilator duration of action. METHODS: A single-centre, randomised, double-blind, placebo-controlled, two-period, crossover study was undertaken in 28 steroid-naïve adults with asthma. Participants with an FEV1 ≥ 60% predicted, reversible airway disease, and FeNO > 40 ppb received FF/VI 100/25 mcg or placebo once daily for 14 days. FeNO and peak expiratory flow were measured twice-daily during treatment and during a 21-day washout period. FEV1 was measured for five days from treatment cessation. The primary outcome measure was FeNO change from baseline ratio for 21 days following treatment cessation. RESULTS: In the 27 subjects who completed the study, median (range) baseline FeNO was 87 ppb (42-212). FF/VI 100/25 mcg reduced FeNO by day 3, ratio FF/VI versus placebo 0.72 (95% confidence interval 0.61-0.86) with the maximum reduction occurring at day 14, 0.32 (0.27-0.37). Following cessation of treatment FeNO remained suppressed for 18 days, ratio on day 18 0.77 (0.59-1.00), whereas improvements in FEV1 and peak flow were maintained for 3 to 4 days post-treatment. CONCLUSIONS: The anti-inflammatory duration of action of FF/VI is consistent with the high glucocorticoid receptor affinity and long lung retention of fluticasone furoate. The anti-inflammatory effect of FF/VI was of greater duration than its bronchodilator effect in adults with mild asthma. Funding GlaxoSmithKline (201499). TRIAL REGISTRATION: Prospectively registered on ClinicalTrials.gov registry number NCT02712047 .

Nasal high flow therapy and PtCO2 in stable COPD: A randomized controlled cross-over trial.

BACKGROUND AND OBJECTIVE: Hypercapnia is associated with worse clinical outcomes in exacerbations of COPD. The present study aimed to determine the effects of nasal high flow (NHF) therapy on transcutaneous partial pressure of carbon dioxide (PtCO2 ) in stable COPD patients. METHODS: In a single-blind randomized controlled cross-over trial, 48 participants with COPD were allocated in random order to all of four 20 min interventions: NHF at 15 L/min, 30 L/min and 45 L/min or breathing room air with each intervention followed by a washout period of 15 min. The primary outcome measure was PtCO2 at 20 min, adjusted for baseline PtCO2 . Secondary outcomes included respiratory rate at 20 min, adjusted for baseline. RESULTS: The mean (95% CI) change in PtCO2 at 20 min was -0.6 mm Hg (-1.1 to 0.0), P = 0.06; -1.3 mm Hg (-1.9 to 0.8), P < 0.001; and -2.4 mm Hg (-2.9 to -1.8), P < 0.001; for NHF at 15 L/min, 30 L/min and 45 L/min compared with room air, respectively. The mean (95% CI) change in respiratory rate at 20 min was -1.5 (-2.7 to -0.3), P = 0.02; -4.1 (-5.3 to -2.9), P < 0.001; and -4.3 (-5.5 to -3.1), P < 0.001; breaths per minute compared with room air, respectively. CONCLUSION: NHF results in a small flow-dependent reduction in PtCO2 and respiratory rate in patients with stable COPD.

High flow or titrated oxygen for obese medical inpatients: a randomised crossover trial.

OBJECTIVE: To compare the effects on transcutaneous carbon dioxide tension (Ptco2) of high concentration and titrated oxygen therapy in medical inpatients with morbid obesity who were not selected for a pre-existing diagnosis of obesity hypoventilation syndrome. DESIGN: A randomised, crossover trial undertaken between February and September 2015. SETTING: Internal medicine service, Wellington Regional Hospital, New Zealand. PARTICIPANTS: 22 adult inpatients, aged 16 years or more, with a body mass index exceeding 40 kg/m2. INTERVENTIONS: Participants received in random order two 60-minute interventions, with a minimum 30-minute washout period between treatments: titrated oxygen therapy (oxygen delivered, if required, via nasal prongs to achieve peripheral oxygen saturation [Spo2] of 88-92%), and high concentration oxygen therapy (delivered via Hudson mask at 8 L/min, without regard to Spo2). Ptco2 and Spo2 were recorded at 10-minute intervals. MAIN OUTCOME MEASURE: Ptco2 at 60 minutes, adjusted for baseline. RESULTS: Baseline Ptco2 was 45 mmHg or lower for 16 participants with full data (73%). The mean difference in Ptco2 between high concentration and titrated oxygen therapy at 60 minutes was 3.2 mmHg (95% CI, 1.3-5.2 mmHg; P = 0.002). CONCLUSION: High concentration oxygen therapy increases Ptco2 in morbidly obese patients. Our findings support guidelines that advocate oxygen therapy, if required in patients with morbid obesity, be titrated to achieve a target Spo2 of 88-92%. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12610000522011.

Physiological effects of titrated oxygen via nasal high-flow cannulae in COPD exacerbations: A randomized controlled cross-over trial.

BACKGROUND AND OBJECTIVE: Increased arterial carbon dioxide tension (PaCO2 ) is an important complication of acute exacerbations of COPD. The effects of nasal high-flow cannulae (NHF) on PaCO2 in patients with COPD exacerbations, and whether this therapy should be used in this clinical situation, are less certain. We aimed to investigate the effect of NHF on PaCO2 in patients admitted to hospital with a COPD exacerbation. METHODS: We performed a single-centre randomized controlled cross-over trial in 24 hospital inpatients with acute exacerbations of COPD receiving oxygen via standard nasal prongs (SNPs). Patients received both supplemental oxygen via NHF (35 L/min) and SNP for 30 min each, with oxygen titrated to maintain the patient's baseline oxygen saturation, measured by pulse oximetry (SpO2 ). Interventions were administered in random order with a minimum 15-min washout between interventions. The primary outcome was difference in transcutaneous carbon dioxide tension (PtCO2 ) at 30 min adjusted for time zero. RESULTS: The difference in PtCO2 adjusted for time zero was lower after 30 min for NHF compared with SNP (-1.4 mm Hg (95% CI: -2.2 to -0.6), P = 0.001). There was no difference in SpO2 at 30 min (-0.02% (95% CI: -0.8 to 0.7), P = 0.96). The reduction in respiratory rate for NHF at 30 min was not statistically significant (-2.0 breaths/min (95% CI: -4.5 to 0.4), P = 0.099). CONCLUSION: Short-term use of NHF results in a small reduction in PtCO2 compared with SNP in patients with acute exacerbations of COPD, but whether this is clinically significant is uncertain.

Body mass index and vigorous physical activity in children and adolescents: an international cross-sectional study.

AIM: To examine the relationship between reported vigorous physical activity (VPA) and body mass index (BMI) in children (6-7 years) and adolescents (13-14 years). METHODS: In the International Study of Asthma and Allergies in Childhood Phase Three, 75 895 children's parents and 199 502 adolescents answered questions relating to VPA, height and weight. The association between VPA and BMI was analysed using general linear models, adjusting for country gross national index. RESULTS: Compared to children who undertook no VPA, those in the infrequent group (once or twice per week) and those in the frequent group (three or more times per week) had mean (95% CI) BMI values 0.07 kg/m2 (0.03-0.11) and 0.09 kg/m2 (0.03-0.15) greater, respectively (p = 0.001). Compared to adolescents reporting no VPA, those in the infrequent group had a BMI 0.19 kg/m2 (0.15-0.23) greater while those in the frequent group had a BMI 0.01 kg/m2 (-0.03-0.05) greater (p < 0.0001). CONCLUSION: Reported VPA is not associated with lower BMI among children and adolescents. Investigation of VPA and BMI may be best undertaken in conjunction with other variables in the energy expenditure equation. A focus on VPA alone may be an inefficient way to manage BMI.