Statistical analyses of ordinal outcomes in randomised controlled trials: a scoping review.

BACKGROUND: Randomised controlled trials (RCTs) aim to estimate the causal effect of one or more interventions relative to a control. One type of outcome that can be of interest in an RCT is an ordinal outcome, which is useful to answer clinical questions regarding complex and evolving patient states. The target parameter of interest for an ordinal outcome depends on the research question and the assumptions the analyst is willing to make. This review aimed to provide an overview of how ordinal outcomes have been used and analysed in RCTs. METHODS: The review included RCTs with an ordinal primary or secondary outcome published between 2017 and 2022 in four highly ranked medical journals (the British Medical Journal, New England Journal of Medicine, The Lancet, and the Journal of the American Medical Association) identified through PubMed. Details regarding the study setting, design, the target parameter, and statistical methods used to analyse the ordinal outcome were extracted. RESULTS: The search identified 309 studies, of which 144 were eligible for inclusion. The most used target parameter was an odds ratio, reported in 78 (54%) studies. The ordinal outcome was dichotomised for analysis in 47 ( 33 % ) studies, and the most common statistical model used to analyse the ordinal outcome on the full ordinal scale was the proportional odds model (64 [ 44 % ] studies). Notably, 86 (60%) studies did not explicitly check or describe the robustness of the assumptions for the statistical method(s) used. CONCLUSIONS: The results of this review indicate that in RCTs that use an ordinal outcome, there is variation in the target parameter and the analytical approaches used, with many dichotomising the ordinal outcome. Few studies provided assurance regarding the appropriateness of the assumptions and methods used to analyse the ordinal outcome. More guidance is needed to improve the transparent reporting of the analysis of ordinal outcomes in future trials.

Non-invasive versus invasive respiratory support in preterm infants.

Respiratory insufficiency is almost ubiquitous in infants born preterm, with its incidence increasing with lower gestational age. A wide range of respiratory support management strategies are available for these infants, separable into non-invasive and invasive forms of respiratory support. Here we review the history and evolution of respiratory care for the preterm infant and then examine evidence that has emerged to support a non-invasive approach to respiratory management where able. Continuous positive airway pressure (CPAP) is the non-invasive respiratory support mode currently with the most evidence for benefit. CPAP can be delivered safely and effectively and can commence in the delivery room. Particularly in early life, time spent on non-invasive respiratory support, avoiding intubation and mechanical ventilation, affords benefit for the preterm infant by virtue of a lessening of lung injury and hence a reduction in incidence of bronchopulmonary dysplasia. In recent years, enthusiasm for application of non-invasive support has been further bolstered by new techniques for administration of exogenous surfactant. Methods of less invasive surfactant delivery, in particular with a thin catheter, have allowed neonatologists to administer surfactant without resort to endotracheal intubation. The benefits of this approach appear to be sustained, even in those infants subsequently requiring mechanical ventilation. This cements the notion that any reduction in exposure to mechanical ventilation leads to alleviation of injury to the vulnerable preterm lung, with a long-lasting effect. Despite the clear advantages of non-invasive respiratory support, there will continue to be a role for intubation and mechanical ventilation in some preterm infants, particularly for those born <25 weeks' gestation. It is currently unclear what role early non-invasive support has in this special population, with more studies required.

Surfactant as a drug carrier.

Drug delivery using a surfactant vehicle has the potential to prevent systemic side effects by delivering therapeutic agents directly to the respiratory system. The inherent chemical properties of surfactant allows it to readily distribute throughout the respiratory system. Therapeutic agents delivered by surfactant can primarily confer additional benefits but have potential to improve surfactant function. It is critically important that additional agents do not interefere with the innate surface tension lowering function of surfactant. Systemic evaluation through benchtop, translational and human trials are required to translate this potential technique into clinical practice.

Intratracheal budesonide mixed with surfactant to increase survival free of bronchopulmonary dysplasia in extremely preterm infants: statistical analysis plan for the international, multicenter, randomized PLUSS trial.

BACKGROUND: Bronchopulmonary dysplasia (BPD), an inflammatory-mediated chronic lung disease, is common in extremely preterm infants born before 28 weeks' gestation and is associated with an increased risk of adverse neurodevelopmental and respiratory outcomes in childhood. Effective and safe prophylactic therapies for BPD are urgently required. Systemic corticosteroids reduce rates of BPD in the short term but are associated with poorer neurodevelopmental outcomes if given to ventilated infants in the first week after birth. Intratracheal administration of corticosteroid admixed with exogenous surfactant could overcome these concerns by minimizing systemic sequelae. Several small, randomized trials have found intratracheal budesonide in a surfactant vehicle to be a promising therapy to increase survival free of BPD. The primary objective of the PLUSS trial is to determine whether intratracheal budesonide mixed with surfactant increases survival free of bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age (PMA) in extremely preterm infants born before 28 weeks' gestation. METHODS: An international, multicenter, double-blinded, randomized trial of intratracheal budesonide (a corticosteroid) mixed with surfactant for extremely preterm infants to increase survival free of BPD at 36 weeks' postmenstrual age (PMA; primary outcome). Extremely preterm infants aged < 48 h after birth are eligible if (1) they are mechanically ventilated, or (2) they are receiving non-invasive respiratory support and there is a clinical decision to treat with surfactant. The intervention is budesonide (0.25 mg/kg) mixed with poractant alfa (200 mg/kg first intervention, 100 mg/kg if second intervention), administered intratracheally via an endotracheal tube or thin catheter. The comparator is poractant alfa alone (at the same doses). Secondary outcomes include the components of the primary outcome (death, BPD prior to or at 36 weeks' PMA), and potential systemic side effects of corticosteroids. Longer-term outcomes will be published separately, and include cost-effectiveness, early childhood health until 2 years of age, and neurodevelopmental outcomes at 2 years of age (corrected for prematurity). STATISTICAL ANALYSIS PLAN: A sample size of 1038 infants (519 in each group) is required to provide 90% power to detect a relative increase in survival free of BPD of 20% (an absolute increase of 10%), from the anticipated event rate of 50% in the control arm to 60% in the intervention (budesonide) arm, alpha error 0.05. To allow for up to 2% of study withdrawals or losses to follow-up, PLUSS aimed to enroll a total of 1060 infants (530 in each arm). The binary primary outcome will be reported as the number and percentage of infants who were alive without BPD at 36 weeks' PMA for each randomization group. To estimate the difference in risk (with 95% CI), between the treatment and control arms, binary regression (a generalized linear multivariable model with an identity link function and binomial distribution) will be used. Along with the primary outcome, the individual components of the primary outcome (death, and physiological BPD at 36 weeks' PMA), will be reported by randomization group and, again, binary regression will be used to estimate the risk difference between the two treatment groups for survival and physiological BPD at 36 weeks' PMA.

Heterogeneity and Gaps in Reporting Primary Outcomes From Neonatal Trials.

OBJECTIVES: Clear outcome reporting in clinical trials facilitates accurate interpretation and application of findings and improves evidence-informed decision-making. Standardized core outcomes for reporting neonatal trials have been developed, but little is known about how primary outcomes are reported in neonatal trials. Our aim was to identify strengths and weaknesses of primary outcome reporting in recent neonatal trials. METHODS: Neonatal trials including ≥100 participants/arm published between 2015 and 2020 with at least 1 primary outcome from a neonatal core outcome set were eligible. Raters recruited from Cochrane Neonatal were trained to evaluate the trials' primary outcome reporting completeness using relevant items from Consolidated Standards of Reporting Trials 2010 and Consolidated Standards of Reporting Trials-Outcomes 2022 pertaining to the reporting of the definition, selection, measurement, analysis, and interpretation of primary trial outcomes. All trial reports were assessed by 3 raters. Assessments and discrepancies between raters were analyzed. RESULTS: Outcome-reporting evaluations were completed for 36 included neonatal trials by 39 raters. Levels of outcome reporting completeness were highly variable. All trials fully reported the primary outcome measurement domain, statistical methods used to compare treatment groups, and participant flow. Yet, only 28% of trials fully reported on minimal important difference, 24% on outcome data missingness, 66% on blinding of the outcome assessor, and 42% on handling of outcome multiplicity. CONCLUSIONS: Primary outcome reporting in neonatal trials often lacks key information needed for interpretability of results, knowledge synthesis, and evidence-informed decision-making in neonatology. Use of existing outcome-reporting guidelines by trialists, journals, and peer reviewers will enhance transparent reporting of neonatal trials.

Strengthening Reporting of Neonatal Trials.

BACKGROUND AND OBJECTIVES: There is variability in the selection and reporting of outcomes in neonatal trials with key information frequently omitted. This can impact applicability of trial findings to clinicians, families, and caregivers, and impair evidence synthesis. The Neonatal Core Outcomes Set describes outcomes agreed as clinically important that should be assessed in all neonatal trials, and Consolidated Standards of Reporting Trials (CONSORT)-Outcomes 2022 is a new, harmonized, evidence-based reporting guideline for trial outcomes. We reviewed published trials using CONSORT-Outcomes 2022 guidance to identify exemplars of neonatal core outcome reporting to strengthen description of outcomes in future trial publications. METHODS: Neonatal trials including >100 participants per arm published between 2015 to 2020 with a primary outcome included in the Neonatal Core Outcome Set were identified. Primary outcome reporting was reviewed using CONSORT 2010 and CONSORT-Outcomes 2022 guidelines by assessors recruited from Cochrane Neonatal. Examples of clear and complete outcome reporting were identified with verbatim text extracted from trial reports. RESULTS: Thirty-six trials were reviewed by 39 assessors. Examples of good reporting for CONSORT 2010 and CONSORT-Outcomes 2022 criteria were identified and subdivided into 3 outcome categories: "survival," "short-term neonatal complications," and "long-term developmental outcomes" depending on the core outcomes to which they relate. These examples are presented to strengthen future research reporting. CONCLUSIONS: We have identified examples of good trial outcome reporting. These illustrate how important neonatal outcomes should be reported to meet the CONSORT 2010 and CONSORT-Outcomes 2022 guidelines. Emulating these examples will improve the transmission of information relating to outcomes and reduce associated research waste.

Intratracheal budesonide mixed with surfactant to increase survival free of bronchopulmonary dysplasia in extremely preterm infants: study protocol for the international, multicenter, randomized PLUSS trial.

BACKGROUND: Bronchopulmonary dysplasia (BPD), an inflammatory-mediated chronic lung disease, is common in extremely preterm infants born before 28 weeks' gestation and is associated with an increased risk of adverse neurodevelopmental and respiratory outcomes in childhood. Effective and safe prophylactic therapies for BPD are urgently required. Systemic corticosteroids reduce rates of BPD in the short-term but are associated with poorer neurodevelopmental outcomes if given to ventilated infants in the first week after birth. Intratracheal administration of corticosteroid admixed with exogenous surfactant could overcome these concerns by minimizing systemic sequelae. Several small, randomized trials have found intratracheal budesonide in a surfactant vehicle to be a promising therapy to increase survival free of BPD. METHODS: An international, multicenter, double-blinded, randomized trial of intratracheal budesonide (a corticosteroid) mixed with surfactant for extremely preterm infants to increase survival free of BPD at 36 weeks' postmenstrual age (PMA; primary outcome). Extremely preterm infants aged < 48 h after birth are eligible if: (1) they are mechanically ventilated, or (2) they are receiving non-invasive respiratory support and there is a clinical decision to treat with surfactant. The intervention is budesonide (0.25 mg/kg) mixed with poractant alfa (200 mg/kg first intervention, 100 mg/kg if second intervention), administered intratracheally via an endotracheal tube or thin catheter. The comparator is poractant alfa alone (at the same doses). Secondary outcomes include the components of the primary outcome (death, BPD prior to or at 36 weeks' PMA), potential systemic side effects of corticosteroids, cost-effectiveness, early childhood health until 2 years of age, and neurodevelopmental outcomes at 2 years of age (corrected for prematurity). DISCUSSION: Combining budesonide with surfactant for intratracheal administration is a simple intervention that may reduce BPD in extremely preterm infants and translate into health benefits in later childhood. The PLUSS trial is powered for the primary outcome and will address gaps in the evidence due to its pragmatic and inclusive design, targeting all extremely preterm infants regardless of their initial mode of respiratory support. Should intratracheal budesonide mixed with surfactant increase survival free of BPD, without severe adverse effects, this readily available intervention could be introduced immediately into clinical practice. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( https://www.anzctr.org.au ), ACTRN12617000322336. First registered on 28th February 2017.

Nasal high flow therapy for primary respiratory support in preterm infants.

BACKGROUND: Nasal high flow (nHF) therapy provides heated, humidified air and oxygen via two small nasal prongs, at gas flows of more than 1 litre/minute (L/min), typically 2 L/min to 8 L/min. nHF is commonly used for non-invasive respiratory support in preterm neonates. It may be used in this population for primary respiratory support (avoiding, or prior to the use of mechanical ventilation via an endotracheal tube) for prophylaxis or treatment of respiratory distress syndrome (RDS). This is an update of a review first published in 2011 and updated in 2016. OBJECTIVES: To evaluate the benefits and harms of nHF for primary respiratory support in preterm infants compared to other forms of non-invasive respiratory support. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date March 2022. SELECTION CRITERIA: We included randomised or quasi-randomised trials comparing nHF with other forms of non-invasive respiratory support for preterm infants born less than 37 weeks' gestation with respiratory distress soon after birth. DATA COLLECTION AND ANALYSIS: We used standard Cochrane Neonatal methods. Our primary outcomes were 1. death (before hospital discharge) or bronchopulmonary dysplasia (BPD), 2. death (before hospital discharge), 3. BPD, 4. treatment failure within 72 hours of trial entry and 5. mechanical ventilation via an endotracheal tube within 72 hours of trial entry. Our secondary outcomes were 6. respiratory support, 7. complications and 8. neurosensory outcomes. We used GRADE to assess the certainty of evidence. MAIN RESULTS: We included 13 studies (2540 infants) in this updated review. There are nine studies awaiting classification and 13 ongoing studies. The included studies differed in the comparator treatment (continuous positive airway pressure (CPAP) or nasal intermittent positive pressure ventilation (NIPPV)), the devices for delivering nHF and the gas flows used. Some studies allowed the use of 'rescue' CPAP in the event of nHF treatment failure, prior to any mechanical ventilation, and some allowed surfactant administration via the INSURE (INtubation, SURfactant, Extubation) technique without this being deemed treatment failure. The studies included very few extremely preterm infants less than 28 weeks' gestation. Several studies had unclear or high risk of bias in one or more domains. Nasal high flow compared with continuous positive airway pressure for primary respiratory support in preterm infants Eleven studies compared nHF with CPAP for primary respiratory support in preterm infants. When compared with CPAP, nHF may result in little to no difference in the combined outcome of death or BPD (risk ratio (RR) 1.09, 95% confidence interval (CI) 0.74 to 1.60; risk difference (RD) 0, 95% CI -0.02 to 0.02; 7 studies, 1830 infants; low-certainty evidence). Compared with CPAP, nHF may result in little to no difference in the risk of death (RR 0.78, 95% CI 0.44 to 1.39; 9 studies, 2009 infants; low-certainty evidence), or BPD (RR 1.14, 95% CI 0.74 to 1.76; 8 studies, 1917 infants; low-certainty evidence). nHF likely results in an increase in treatment failure within 72 hours of trial entry (RR 1.70, 95% CI 1.41 to 2.06; RD 0.09, 95% CI 0.06 to 0.12; number needed to treat for an additional harmful outcome (NNTH) 11, 95% CI 8 to 17; 9 studies, 2042 infants; moderate-certainty evidence). However, nHF likely does not increase the rate of mechanical ventilation (RR 1.04, 95% CI 0.82 to 1.31; 9 studies, 2042 infants; moderate-certainty evidence). nHF likely results in a reduction in pneumothorax (RR 0.66, 95% CI 0.40 to 1.08; 10 studies, 2094 infants; moderate-certainty evidence) and nasal trauma (RR 0.49, 95% CI 0.36 to 0.68; RD -0.06, 95% CI -0.09 to -0.04; 7 studies, 1595 infants; moderate-certainty evidence). Nasal high flow compared with nasal intermittent positive pressure ventilation for primary respiratory support in preterm infants Four studies compared nHF with NIPPV for primary respiratory support in preterm infants. When compared with NIPPV, nHF may result in little to no difference in the combined outcome of death or BPD, but the evidence is very uncertain (RR 0.64, 95% CI 0.30 to 1.37; RD -0.05, 95% CI -0.14 to 0.04; 2 studies, 182 infants; very low-certainty evidence). nHF may result in little to no difference in the risk of death (RR 0.78, 95% CI 0.36 to 1.69; RD -0.02, 95% CI -0.10 to 0.05; 3 studies, 254 infants; low-certainty evidence). nHF likely results in little to no difference in the incidence of treatment failure within 72 hours of trial entry compared with NIPPV (RR 1.27, 95% CI 0.90 to 1.79; 4 studies, 343 infants; moderate-certainty evidence), or mechanical ventilation within 72 hours of trial entry (RR 0.91, 95% CI 0.62 to 1.33; 4 studies, 343 infants; moderate-certainty evidence). nHF likely results in a reduction in nasal trauma, compared with NIPPV (RR 0.21, 95% CI 0.09 to 0.47; RD -0.17, 95% CI -0.24 to -0.10; 3 studies, 272 infants; moderate-certainty evidence). nHF likely results in little to no difference in the rate of pneumothorax (RR 0.78, 95% CI 0.40 to 1.53; 4 studies, 344 infants; moderate-certainty evidence). Nasal high flow compared with ambient oxygen We found no studies examining this comparison. Nasal high flow compared with low flow nasal cannulae We found no studies examining this comparison. AUTHORS' CONCLUSIONS: The use of nHF for primary respiratory support in preterm infants of 28 weeks' gestation or greater may result in little to no difference in death or BPD, compared with CPAP or NIPPV. nHF likely results in an increase in treatment failure within 72 hours of trial entry compared with CPAP; however, it likely does not increase the rate of mechanical ventilation. Compared with CPAP, nHF use likely results in less nasal trauma and likely a reduction in pneumothorax. As few extremely preterm infants less than 28 weeks' gestation were enrolled in the included trials, evidence is lacking for the use of nHF for primary respiratory support in this population.

Estimating Preterm Lung Volume: A Comparison of Lung Ultrasound, Chest Radiography, and Oxygenation.

OBJECTIVE: To determine the relationship between lung ultrasound (LUS) examination, chest radiograph (CXR), and radiographic and clinical evaluations in the assessment of lung volume in preterm infants. STUDY DESIGN: In this prospective cohort study LUS was performed before CXR on 70 preterm infants and graded using (1) a LUS score, (2) an atelectasis score, and (3) measurement of atelectasis depth. Radiographic diaphragm position and radio-opacification were used to determine global and regional radiographic atelectasis. The relationship between LUS, CXR, and oxygenation was assessed using receiver operator characteristic and correlation analysis. RESULTS: LUS scores, atelectasis scores, and atelectasis depth did not correspond with radiographic global atelectasis (area under receiver operator characteristics curves, 0.54 [95% CI, 0.36-0.71], 0.49 [95% CI, 0.34-0.64], and 0.47 [95% CI, 0.31-0.64], respectively). Radiographic atelectasis of the right upper, right lower, left upper, and left lower quadrants was predicted by LUS scores (0.75 [95% CI, 0.59-0.92], 0.75 [95% CI, 0.62-0.89], 0.69 [95% CI, 0.56-0.82], and 0.63 [95% CI, 0.508-0.751]) and atelectasis depth (0.66 [95% CI, 0.54-0.78], 0.65 [95% CI, 0.53-0.77], 0.63 [95% CI, 0.50-0.76], and 0.56 [95% CI, 0.44-0.70]). LUS findings were moderately correlated with oxygen saturation index (ρ = 0.52 [95% CI, 0.30-0.70]) and saturation to fraction of inspired oxygen ratio (ρ = -0.63 [95% CI, -0.76 to -0.46]). The correlation between radiographic diaphragm position, the oxygenation saturation index, and peripheral oxygen saturation to fraction of inspired oxygen ratio was very weak (ρ = 0.36 [95% CI, 0.11-0.59] and ρ = -0.32 [95% CI, -0.53 to -0.07], respectively). CONCLUSIONS: LUS assessment of lung volume does not correspond with radiographic diaphragm position preterm infants. However, LUS predicted radiographic regional atelectasis and correlated with oxygenation. The relationship between radiographic diaphragm position and oxygenation was very weak. Although LUS may not replace all radiographic measures of lung volume, LUS more accurately reflects respiratory status in preterm infants. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12621001119886.

Statistical analyses of ordinal outcomes in randomised controlled trials: protocol for a scoping review.

INTRODUCTION: Randomised controlled trials (RCTs) aim to assess the effect of one (or more) unproven health interventions relative to other reference interventions. RCTs sometimes use an ordinal outcome, which is an endpoint that comprises of multiple, monotonically ordered categories that are not necessarily separated by a quantifiable distance. Ordinal outcomes are appealing in clinical settings as specific disease states can represent meaningful categories that may be of clinical importance to researchers. Ordinal outcomes can also retain information and increase statistical power compared to dichotomised outcomes and can allow multiple clinical outcomes to be comprised in a single endpoint. Target parameters for ordinal outcomes in RCTs may vary depending on the nature of the research question, the modelling assumptions and the expertise of the data analyst. The aim of this scoping review is to systematically describe the use of ordinal outcomes in contemporary RCTs. Specifically, we aim to: [Formula: see text] Identify which target parameters are of interest in trials that use an ordinal outcome, and whether these parameters are explicitly defined. [Formula: see text] Describe how ordinal outcomes are analysed in RCTs to estimate a treatment effect. [Formula: see text] Describe whether RCTs that use an ordinal outcome adequately report key methodological aspects specific to the analysis of the ordinal outcome. Results from this review will outline the current state of practice of the use of ordinal outcomes in RCTs. Ways to improve the analysis and reporting of ordinal outcomes in RCTs will be discussed. METHODS AND ANALYSIS: We will review RCTs that are published in the top four medical journals (British Medical Journal, New England Journal of Medicine, The Lancet and the Journal of the American Medical Association) between 1 January 2012 and 31 July 2022 that use an ordinal outcome as either a primary or a secondary outcome. The review will identify articles through a PubMed-specific search strategy. Our review will adhere to guidelines for scoping reviews as described in the PRISMA-ScR checklist. The study characteristics and details of the study design and analysis, including the target parameter(s) and statistical methods used to analyse the ordinal outcome, will be extracted from eligible studies. The screening, review and data extraction will be conducted using Covidence, a web-based tool for managing systematic reviews. The data will be summarised using descriptive statistics.

Postnatal corticosteroids and developmental outcomes in extremely preterm or extremely low birth weight infants: The Victorian Infant Collaborative Study 2016-17 cohort.

AIM: Systemic postnatal corticosteroids are used to treat or prevent bronchopulmonary dysplasia (BPD) in extremely preterm (EP) or extremely low birth weight (ELBW) infants but are associated with long-term harm. We aimed to assess the relationship between cumulative postnatal corticosteroid dose and neurodevelopmental outcomes. METHODS: Longitudinal cohort study of all EP/ELBW livebirths in Victoria, Australia 2016-2017. Perinatal data were collected prospectively. Neurodevelopmental assessment was performed at 2 years' corrected age. Linear and logistic regression were used to determine relationships between cumulative corticosteroid dose and neurodevelopment, adjusted for gestational age, birth weight, sex and major intraventricular haemorrhage. RESULTS: Seventy-six EP/ELBW infants received postnatal corticosteroids to treat or prevent BPD, 62/65 survivors were seen at 2 years. Median (IQR) cumulative postnatal corticosteroid dose was 1.36 (0.92-3.45) mg/kg dexamethasone equivalent. Higher cumulative corticosteroid dose was associated with increased odds of cerebral palsy, adjusted OR (95% CI) 1.47 (1.04, 2.07). Higher cumulative corticosteroid dose was also associated with lower cognitive and motor developmental scores, however, this weakened after adjustment for confounding variables: cognitive composite score adjusted coefficient (95% CI) -1.3 (-2.7, 0.1) and motor composite score adjusted coefficient (95% CI) -1.3 (-2.8, 0.2). CONCLUSION: Higher cumulative postnatal corticosteroid dose in EP/ELBW infants is associated with increased odds of cerebral palsy at 2 years' corrected age. Adequately powered studies are needed to assess the independent effects of cumulative steroid dose on neurodevelopmental outcomes.

Lung ultrasound of the dependent lung detects real-time changes in lung volume in the preterm lamb.

BACKGROUND: Effective lung protective ventilation requires reliable, real-time estimation of lung volume at the bedside. Neonatal clinicians lack a readily available imaging tool for this purpose. OBJECTIVE: To determine the ability of lung ultrasound (LUS) of the dependent region to detect real-time changes in lung volume, identify opening and closing pressures of the lung, and detect pulmonary hysteresis. METHODS: LUS was performed on preterm lambs (n=20) during in vivo mapping of the pressure-volume relationship of the respiratory system using the super-syringe method. Electrical impedance tomography was used to derive regional lung volumes. Images were blindly graded using an expanded scoring system. The scores were compared with total and regional lung volumes, and differences in LUS scores between pressure increments were calculated. RESULTS: Changes in LUS scores correlated moderately with changes in total lung volume (r=0.56, 95% CI 0.47-0.64, p<0.0001) and fairly with right whole (r=0.41, CI 0.30-0.51, p<0.0001), ventral (r=0.39, CI 0.28-0.49, p<0.0001), central (r=0.41, CI 0.31-0.52, p<0.0001) and dorsal (r=0.38, CI 0.27-0.49, p<0.0001) regional lung volumes. The pressure-volume relationship of the lung exhibited hysteresis in all lambs. LUS was able to detect hysteresis in 17 (85%) lambs. The greatest changes in LUS scores occurred at the opening and closing pressures. CONCLUSION: LUS was able to detect large changes in total and regional lung volume in real time and correctly identified opening and closing pressures but lacked the precision to detect small changes in lung volume. Further work is needed to improve precision prior to translation to clinical practice.

Quantitative lung ultrasound detects dynamic changes in lung recruitment in the preterm lamb.

BACKGROUND: Lung ultrasound (LUS) may not detect small, dynamic changes in lung volume. Mean greyscale measurement using computer-assisted image analysis (Q-LUSMGV) may improve the precision of these measurements. METHODS: Preterm lambs (n = 40) underwent LUS of the dependent or non-dependent lung during static pressure-volume curve mapping. Total and regional lung volumes were determined using the super-syringe technique and electrical impedance tomography. Q-LUSMGV and gold standard measurements of lung volume were compared in 520 images. RESULTS: Dependent Q-LUSMGV moderately correlated with total lung volume (rho = 0.60, 95% CI 0.51-0.67) and fairly with right whole (rho = 0.39, 0.27-0.49), central (rho = 0.38, 0.27-0.48), ventral (rho = 0.41, 0.31-0.51) and dorsal regional lung volumes (rho = 0.32, 0.21-0.43). Non-dependent Q-LUSMGV moderately correlated with total lung volume (rho = 0.57, 0.48-0.65) and fairly with right whole (rho = 0.43, 0.32-0.52), central (rho = 0.46, 0.35-0.55), ventral (rho = 0.36, 0.25-0.47) and dorsal lung volumes (rho = 0.36, 0.25-0.47). All correlation coefficients were statistically significant. Distinct inflation and deflation limbs, and sonographic pulmonary hysteresis occurred in 95% of lambs. The greatest changes in Q-LUSMGV occurred at the opening and closing pressures. CONCLUSION: Q-LUSMGV detected changes in total and regional lung volume and offers objective quantification of LUS images, and may improve bedside discrimination of real-time changes in lung volume. IMPACT: Lung ultrasound (LUS) offers continuous, radiation-free imaging that may play a role in assessing lung recruitment but may not detect small changes in lung volume. Mean greyscale image analysis using computer-assisted quantitative LUS (Q-LUSMGV) moderately correlated with changes in total and regional lung volume. Q-LUSMGV identified opening and closing pressure and pulmonary hysteresis in 95% of lambs. Computer-assisted image analysis may enhance LUS estimation of lung recruitment at the bedside. Future research should focus on improving precision prior to clinical translation.

Higher versus lower nasal continuous positive airway pressure for extubation of extremely preterm infants in Australia (ÉCLAT): a multicentre, randomised, superiority trial.

BACKGROUND: Extremely preterm infants often require invasive mechanical ventilation, and clinicians aim to extubate these infants as soon as possible. However, extubation failure occurs in up to 60% of extremely preterm infants and is associated with increased mortality and morbidity. Nasal continuous positive airway pressure (nCPAP) is the most common post-extubation respiratory support, but there is no consensus on the optimal nCPAP level to safely avoid extubation failure in extremely preterm infants. We aimed to determine if higher nCPAP levels compared with standard nCPAP levels would decrease rates of extubation failure in extremely preterm infants within 7 days of their first extubation. METHODS: In this multicentre, randomised, open-label controlled trial done at three tertiary perinatal centres in Australia, we assigned extremely preterm infants to extubation to either higher nCPAP (10 cmH2O) or standard nCPAP (7 cmH2O). Infants were eligible if they were born at less than 28 weeks' gestation, were receiving mechanical ventilation via an endotracheal tube, and were being extubated for the first time to nCPAP. Eligible infants must have received previous treatment with exogenous surfactant and caffeine. Infants were ineligible if they were planned to be extubated to a mode of respiratory support other than nCPAP, if they had a known major congenital anomaly that might affect breathing, or if ongoing intensive care was not being provided. Parents or guardians provided prospective, written, informed consent. Infants were maintained within an assigned nCPAP range for a minimum of 24 h after extubation (higher nCPAP group 9-11 cmH2O and standard nCPAP group 6-8 cmH2O). Randomisation was stratified by both gestation (22-25 completed weeks or 26-27 completed weeks) and recruiting centre. The primary outcome was extubation failure within 7 days and analysis was by intention to treat. This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12618001638224. FINDINGS: Between March 3, 2019, and July 31, 2022, 483 infants were born at less than 28 weeks and admitted to the recruiting centres. 92 infants were not eligible, 172 were not approached, 65 families declined to participate, and 15 consented but were not randomly assigned. 139 infants were enrolled and randomly assigned, 70 to the higher nCPAP group and 69 to the standard nCPAP group. One infant in the higher nCPAP group was excluded from the analysis because consent was withdrawn after randomisation. 104 (75%) of 138 mothers were White. The mean gestation was 25·7 weeks (SD 1·3) and the mean birthweight was 777 grams (201). 70 (51%) of 138 infants were female. Extubation failure occurred in 24 (35%) of 69 infants in the higher nCPAP group and in 39 (57%) of 69 infants in the standard nCPAP group (risk difference -21·7%, 95% CI -38·5% to -3·7%). There were no significant differences in rates of adverse events between groups during the primary outcome period. Three patients died (two in the higher nCPAP group and one in the standard nCPAP group), pneumothorax occurred in one patient from each group, spontaneous intestinal perforation in three patients (two in the higher nCPAP group and one in the standard nCPAP group) and there were no events of pulmonary interstitial emphysema. INTERPRETATION: Extubation of extremely preterm infants to higher nCPAP significantly reduced extubation failure compared with extubation to standard nCPAP, without increasing rates of adverse effects. Future larger trials are essential to confirm these findings in terms of both efficacy and safety. FUNDING: National Health and Medical Research Council Centre for Research Excellence in Newborn Medicine, number 1153176.

"Harry Potter and the Multitudinous Maladies": a retrospective population-based observational study of morbidity and mortality among witches and wizards.

OBJECTIVES: To describe the prevalence of maladies and deaths among witches and wizards in the Harry Potter world, their causes, and associated therapies. DESIGN: Retrospective population-based observational study (report analysis) undertaken 10 February - 19 March 2022. SETTING: All locations described in the Harry Potter books, predominantly Hogwarts School of Witchcraft and Wizardry, but also selected locations, including Privet Drive No 4, Diagon Alley, the Ministry of Magic, and The Burrow. PARTICIPANTS: All witches and wizards mentioned at least once in any of the seven Harry Potter books. MAIN OUTCOME MEASURES: Overall numbers of maladies and deaths. Secondary outcomes were changes in morbidity and mortality over time, causes of morbidity and mortality, and treatments. RESULTS: A total of 603 wizards or witches named in the Potter books experienced 1541 maladies and injuries (1410 non-fatal) and 131 deaths. Overall morbidity incidence was 471 events per 1000 individuals, and mortality, after adjustment for Lord Voldemort's multi-mortality, was 20.6%. The most frequent causes of morbidity were traumatic injuries during duels or fights (553 cases, 39.2%), magical objects, potions, plants, or creatures (345, 24.5%), and non-combative trauma (221, 15.7%). Most deaths were related to wizarding duels (101 of 131, 77.1%). Treatments were rarely described; the most frequent were jinxes (274, 19.4%) and potions (136, 9.6%). Hospital stays were shorter than a week for almost all non-fatal maladies (1397 of 1410, 99.1%). CONCLUSIONS: Morbidity and, in particular, mortality were very high and predominantly caused by magical means. Further investigation into the safety at Hogwarts School of Witchcraft and Wizardry is warranted. The few treatments used had high success rates; rapid recovery was the rule, and hospital stays generally brief. Efforts should be undertaken to identify the magical therapies and interventions used and to introduce these novel remedies into Muggle medicine.

Rapid centralised randomisation in emergency setting trials using a smartphone.

Randomised trials in emergency settings must quickly confirm eligibility and allocate participants to an intervention group without delaying treatment. We report rapid randomisation during two neonatal resuscitation trials using the non-commercial REDCap platform accessed via smartphone. This simple, reliable method has wide applicability for trials in emergency settings. What is Known: • Randomised trials in emergency settings need to rapidly allocate participants to an intervention group. • This process should not delay treatment. What is New: • This non-commercial, smartphone-accessible application enabled rapid, accurate randomisation at the bedside. • This has broad applicability for emergency setting trials.

Trends in the use of non-invasive respiratory support for term infants in tertiary neonatal units in Australia and New Zealand.

OBJECTIVE: To determine whether the use of non-invasive respiratory support, such as continuous positive airway pressure and nasal high flow, to treat term infants in Australian and New Zealand tertiary neonatal intensive care units (NICUs) has changed over time, and if so, whether there are parallel changes in short-term respiratory morbidities. DESIGN: Retrospective database review of patient-level data from the Australian and New Zealand Neonatal Network (ANZNN) from 2010 to 2018. Denominator data on the number of term inborn livebirths in each facility was only available as annual totals. PATIENTS AND SETTING: Term, inborn infants cared for in NICUs within the ANZNN. MAIN OUTCOME MEASURES: The primary outcome was the annual change in hospital-specific rates of non-invasive respiratory support per 1000 inborn livebirths, expressed as a percentage change. Secondary outcomes were the change in rates of mechanical ventilation, pneumothorax requiring drainage, exogenous surfactant treatment and death before hospital discharge. RESULTS: A total of 14 656 term infants from 21 NICUs were included from 2010 to 2018, of whom 12 719 received non-invasive respiratory support. Non-invasive respiratory support use increased on average by 8.7% per year (95% CI: 7.9% to 9.4% per year); the number of term infants receiving non-invasive respiratory support almost doubled from 980 in 2010 (10.8/1000 livebirths) to 1913 in 2018 (20.8/1000). There was no change over time in rate of mechanical ventilation or death. The rate of pneumothorax requiring drainage increased over time, as did surfactant treatment. CONCLUSIONS: Non-invasive respiratory support use to treat term infants cared for in NICUs within the ANZNN is increasing over time. Clinicians should be diligent in selecting infants most likely to benefit from treatment with non-invasive respiratory support in this relatively low-risk population of term newborn infants. Analysis of patient-level data by individual NICUs is recommended to control for potential confounding due to changes in population over time.