Daily Ards Research Analysis

UNLABELLED: The purpose of this study is to evaluate if non-invasive high-frequency oscillation ventilation (NHFOV) is non-inferior to nasal continuous positive airway pressure (CPAP) as primary non-invasive respiratory support (NRS) in preterm neonates of ≥ 30 weeks' gestation with respiratory distress syndrome (RDS). In this open-label randomized controlled trial (RCT) with a non-inferiority design conducted in a lower middle-income country, 142 preterm neonates were randomized to receive NHFOV (n = 71) or CPAP (n = 71) at equivalent pressures after lung recruitment with nasal mask (NM) interface. A non-inferiority margin of 20% was pre-specified and a two-sided 90% confidence interval (CI) standardly used in non-inferiority trials was chosen. For the outcome treatment failure (requirement of an alternate NRS as rescue), the event rate was 4.2% in both groups, risk difference (RD) with 90% CI being 0.00 (- 0.06 to + 0.06), and that for IMV requirement was - 0.01 (- 0.04 to 0.01). Since upper limits of CIs for both primary outcomes were well below the non-inferiority margin, NHFOV was proven to be non-inferior compared to CPAP. Duration of primary NRS was significantly lesser (median difference (MD) (95% CI), 7 h lesser (- 14 to 0); p = 0.03) and ventilator-free days for primary NRS were significantly higher (MD (95% CI), 0.30 days (0.00 to 0.60); p = 0.02) in the NHFOV group. CONCLUSION: In preterm neonates of ≥ 30 weeks' gestation with RDS, NHFOV delivered through NM at equivalent pressures is non-inferior to CPAP when used as primary NRS. The finding of shorter NRS duration with NHFOV needs to be proven in adequately powered trials. Use of NM interface with equivalent pressures addresses the lacunae in the current literature on NHFOV and provides a rigorous comparison between the two NRS modes. TRIAL REGISTRATION: www.ctri.nic.in , id CTRI/2024/10/074939, registered on 8 October 2024. WHAT IS KNOWN: • CPAP as initial respiratory support for preterm neonates with RDS is the standard of care in LMICs. • NHFOV is more efficacious than CPAP when used as a post-extubation respiratory support modality, evidence for the same being uncertain when used as primary support. WHAT IS NEW: • NHFOV is non-inferior to CPAP as primary support in preterm neonates ≥ 30 weeks with RDS for the outcomes of treatment failure and IMV requirement with equivalent pressures after lung recruitment and nasal mask interface. • A superiority design RCT comparing these two non-invasive respiratory support modalities in this subgroup of preterm neonates may not be feasible. The low baseline event rate of IMV necessitates an impractically large sample size to achieve adequate power.

OBJECTIVE: To identify the risk factors for the progression of severe pneumonia to acute respiratory distress syndrome (ARDS) and to construct a prediction model based on the random forest algorithm, providing a basis for disease assessment, early intervention, and prognosis improvement in severe pneumonia. METHODS: A retrospective observational study was conducted. Patients with severe pneumonia admitted to the intensive care unit (ICU) of the Second Affiliated Hospital of Zunyi Medical University from January 2020 to May 2024 were enrolled. Data including general patient information, vital signs, blood test results, disease assessment indicators within 24 hours of ICU admission, and outcome measures were collected. Patients were divided into ARDS group and non-ARDS group according to whether they progressed to ARDS. Univariate Logistic regression analysis was used to screen the risk factors for the progression of severe pneumonia to ARDS, and a random forest based prediction model was constructed. Model performance and stability were validated using 1 000 resampling iterations. RESULTS: A total of 181 severe pneumonia patients were included, of whom 73 progressed to ARDS, with an incidence rate of 40.3%. Compared to the non-ARDS group, the ARDS group had significantly lower lowest systolic blood pressure, lowest diastolic blood pressure, lowest oxygenation index, pH value, and albumin level, while showing significantly higher maximum activated partial thromboplastin time (APTT), Acute Physiology and Chronic Health Evaluation (APACHE), and Lung Injury Prediction Score (LIPS; all P<0.05). There were no statistically significant differences in other baseline data comparisons (all P>0.05). Univariate Logistic regression analysis showed that pH, lowest systolic blood pressure, albumin, APACHE score, and LIPS score were risk factors for the progression to ARDS in severe pneumonia patients [pH: odds ratio (OR)=0.04, 95% confidence interval (95%CI) was 0.00-0.96, P=0.047, cut-off was 7.34; lowest systolic blood pressure: OR=0.98, 95%CI was 0.97-1.00, P=0.044, cut-off was 90 mmHg (1 mmHg=0.133 kPa); albumin: OR=0.94, 95%CI was 0.89-0.99, P=0.032, cut-off was 28.05 g/L; APACHE score: OR=1.08, 95%CI was 1.02-1.14, P=0.008, cut-off was 23; LIPS: OR=1.37, 95%CI was 1.09-1.72, P=0.007, cut-off was 5]. A random forest model constructed with these risk factors ranked the importance of the indicators from high to low as follows: pH, lowest systolic blood pressure, albumin, APACHE score, and LIPS (with Gini Index of 31.08, 30.74, 29.35, 28.01, and 24.92, respectively). Validation with 1 000 bootstrap resamplings showed that the model had an area under the receiver operator characteristic curve (AUC) of 0.909 (95%CI was 0.870-0.943), a sensitivity of 0.823 (95%CI was 0.699-0.932), and a specificity of 0.869 (95%CI was 0.741-0.963). CONCLUSIONS: pH<7.34, lowest systolic blood pressure<90 mmHg, albumin<28.05 g/L, APACHE>23, and LIPS>5 are risk factors for the progression of severe pneumonia to ARDS. The model constructed based on these factors using the random forest algorithm can effectively predict whether severe pneumonia patients will progress to ARDS.

BackgroundProgressive respiratory failure is the leading cause of death in patients with severe COVID-19. Histopathological findings in acute severe COVID-19 are foremost based on post-mortem findings. On computed tomography (CT), acute COVID-19 pneumonia is characterized by ground-glass opacities (GGOs) and, later, by a crazy-paving pattern (CPP) and consolidations.PurposeTo investigate if CT patterns corresponded to histopathological post-mortem findings.Material and MethodsEight patients were identified with a chest CT performed between testing positive for COVID-19 and death. CT images, histological slides, and medical records were retrospectively reviewed. The lungs were photographed during the gross investigation to ascertain the exact position of the tissue blocks in relation to the relevant anatomical structures. Each slide was compared side by side with the in vivo chest CT pattern on the corresponding site.ResultsAt CT, the most predominant finding was GGOs, present in all eight cases. CPP was observed in 6/8 (75%) patients, and consolidation in 7/8 (87.5%) patients, both predominantly located in the lower lung zones. In 5 (62.5%) patients, so-called fibrotic-like changes were present. In four patients with CT angiogram, no findings of pulmonary thromboembolism were present. At autopsy, all patients demonstrated macroscopic consolidation, while pleural effusion was seen in 2 (25%) cases. Microscopically, edema was present in all cases, hyaline membranes in 7/8 (87.5%) cases, but no signs of acute interstitial inflammation were observed. Thromboembolic findings were evident in 4 (50%) patients, of whom two were negative on CT and 3 (37.5%) cases had fibrosis.ConclusionThe results demonstrate a clear association between radiological signs of GGO, consolidation and features of organizing pneumonia to microscopical signs of edema and diffuse alveolar damage. However, fibrotic-like changes and thromboembolism in the small vessels had a poorer compliance.