Phenotyping COVID-19 respiratory failure in spontaneously breathing patients with AI on lung CT-scan.

BACKGROUND: Automated analysis of lung computed tomography (CT) scans may help characterize subphenotypes of acute respiratory illness. We integrated lung CT features measured via deep learning with clinical and laboratory data in spontaneously breathing subjects to enhance the identification of COVID-19 subphenotypes. METHODS: This is a multicenter observational cohort study in spontaneously breathing patients with COVID-19 respiratory failure exposed to early lung CT within 7 days of admission. We explored lung CT images using deep learning approaches to quantitative and qualitative analyses; latent class analysis (LCA) by using clinical, laboratory and lung CT variables; regional differences between subphenotypes following 3D spatial trajectories. RESULTS: Complete datasets were available in 559 patients. LCA identified two subphenotypes (subphenotype 1 and 2). As compared with subphenotype 2 (n = 403), subphenotype 1 patients (n = 156) were older, had higher inflammatory biomarkers, and were more hypoxemic. Lungs in subphenotype 1 had a higher density gravitational gradient with a greater proportion of consolidated lungs as compared with subphenotype 2. In contrast, subphenotype 2 had a higher density submantellar-hilar gradient with a greater proportion of ground glass opacities as compared with subphenotype 1. Subphenotype 1 showed higher prevalence of comorbidities associated with endothelial dysfunction and higher 90-day mortality than subphenotype 2, even after adjustment for clinically meaningful variables. CONCLUSIONS: Integrating lung-CT data in a LCA allowed us to identify two subphenotypes of COVID-19, with different clinical trajectories. These exploratory findings suggest a role of automated imaging characterization guided by machine learning in subphenotyping patients with respiratory failure. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04395482. Registration date: 19/05/2020.

Ultrasound evaluation of cardiac and diaphragmatic function at different positions during a spontaneous breathing trial predicting extubation outcomes: a retrospective cohort study.

BACKGROUND: The ratio (E/Ea) of mitral Doppler inflow velocity to annular tissue Doppler wave velocity by transthoracic echocardiography and diaphragmatic excursion (DE) by diaphragm ultrasound have been confirmed to predict extubation outcomes. However, few studies focused on the predicting value of E/Ea and DE at different positions during a spontaneous breathing trial (SBT), as well as the effects of △E/Ea and △DE (changes in E/Ea and DE during a SBT). METHODS: This study was a reanalysis of the data of 60 difficult-to-wean patients in a previous study published in 2017. All eligible participants were organized into respiratory failure (RF) group and extubation success (ES) group within 48 h after extubation, or re-intubation (RI) group and non-intubation (NI) group within 1 week after extubation. The risk factors for respiratory failure and re-intubation including E/Ea and △E/Ea, DE and △DE at different positions were analyzed by multivariate logistic regression, respectively. The receiver operating characteristic (ROC) curves of E/Ea (septal, lateral, average) and DE (right, left, average) were compared with each other, respectively. RESULTS: Of the 60 patients, 29 cases developed respiratory failure within 48 h, and 14 of those cases required re-intubation within 1 week. Multivariate logistic regression showed that E/Ea were all associated with respiratory failure, while only DE (right) and DE (average) after SBT were related to re-intubation. There were no statistic differences among the ROC curves of E/Ea at different positions, nor between the ROC curves of DE. No statistical differences were shown in △E/Ea between RF and ES groups, while △DE (average) was remarkably higher in NI group than that in RI group. However, multivariate logistic regression analysis showed that △DE (average) was not associated with re-intubation. CONCLUSIONS: E/Ea at different positions during a SBT could predict postextubation respiratory failure with no statistical differences among them. Likewise, only DE (right) and DE (average) after SBT might predict re-intubation with no statistical differences between each other.

Lung Ultrasound Score for Prediction of Surfactant Administration in Preterm Infants with Respiratory Failure.

OBJECTIVE: We investigated the predictive value of a lung ultrasound score (LUS) for surfactant administration in a United States Level 4 Neonatal Intensive Care Unit. STUDY DESIGN: Thirty infants born at <37 weeks gestational age with respiratory distress syndrome associated respiratory failure requiring continuous positive airway pressure were included. A LUS was obtained within six hours of life. Surfactant administration in the first five days of life was recorded. Receiver operating characteristic (ROC) analysis for LUS and surfactant administration was performed. RESULTS: Median completed gestational age was 33 weeks (31-34 weeks interquartile range) and median birth weight was 2.0 kg (1.5-2.3 kg). LUS for predicting an initial surfactant dose had an area under the ROC curve of 0.97. A score > 9 provided 100% sensitivity and 91% specificity for predicting administration of an initial surfactant dose. CONCLUSION: A LUS > 9 provided excellent sensitivity and specificity for predicting which infants will receive surfactant for associated respiratory failure.

Characterizing Lung Parenchymal Aeration via Standardized Signal Intensity from Free-breathing 4D Dynamic MRI in Phantoms, Healthy Children, and Pediatric Patients with Thoracic Insufficiency Syndrome.

Purpose To investigate free-breathing thoracic bright-blood four-dimensional (4D) dynamic MRI (dMRI) to characterize aeration of parenchymal lung tissue in healthy children and patients with thoracic insufficiency syndrome (TIS). Materials and Methods All dMR images in patients with TIS were collected from July 2009 to June 2017. Standardized signal intensity (sSI) was investigated, first using a lung aeration phantom to establish feasibility and sensitivity and then in a retrospective research study of 40 healthy children (16 male, 24 female; mean age, 9.6 years ± 2.1 [SD]), 20 patients with TIS before and after surgery (11 male, nine female; mean age, 6.2 years ± 4.2), and another 10 healthy children who underwent repeated dMRI examinations (seven male, three female; mean age, 9 years ± 3.6). Individual lungs in 4D dMR images were segmented, and sSI was assessed for each lung at end expiration (EE), at end inspiration (EI), preoperatively, postoperatively, in comparison to normal lungs, and in repeated scans. Results Air content changes of approximately 6% were detectable in phantoms via sSI. sSI within phantoms significantly correlated with air occupation (Pearson correlation coefficient = -0.96 [P < .001]). For healthy children, right lung sSI was significantly lower than that of left lung sSI (at EE: 41 ± 6 vs 47 ± 6 and at EI: 39 ± 6 vs 43 ± 7, respectively; P < .001), lung sSI at EI was significantly lower than that at EE (P < .001), and left lung sSI at EE linearly decreased with age (r = -0.82). Lung sSI at EE and EI decreased after surgery for patients (although not statistically significantly, with P values of sSI before surgery vs sSI after surgery, left and right lung separately, in the range of 0.13-0.51). sSI varied within 1.6%-4.7% between repeated scans. Conclusion This study demonstrates the feasibility of detecting change in sSI in phantoms via bright-blood dMRI when air occupancy changes. The observed reduction in average lung sSI after surgery in pediatric patients with TIS may indicate postoperative improvement in parenchymal aeration. Keywords: MR Imaging, Thorax, Lung, Pediatrics, Thoracic Surgery, Lung Parenchymal Aeration, Free-breathing Dynamic MRI, MRI Intensity Standardization, Thoracic Insufficiency Syndrome Supplemental material is available for this article. © RSNA, 2024.

Paradoxical thinning of the diaphragm on ultrasound is a risk factor for requiring non-invasive ventilation in patients with neuromuscular diaphragmatic dysfunction.

INTRODUCTION/AIMS: Point-of-care ultrasound of the diaphragm is highly sensitive and specific in the detection of neuromuscular diaphragmatic dysfunction. In some patients with neuromuscular diaphragmatic dysfunction, paradoxical thinning of the diaphragm during inspiration is observed on ultrasound; however, its frequency, electrodiagnostic associations, and prognostic significance remain uncertain. METHODS: Medical records of patients presenting to two electrodiagnostic laboratories (Mayo Clinic, Rochester, Minnesota and University of Alberta, Edmonton, Alberta) from January 1, 2022 to December 31, 2022, for evaluation of suspected neuromuscular respiratory failure, were reviewed. RESULTS: 214 patients were referred and 19 patients excluded due to incomplete information. Of 195 patients (384 hemidiaphragms), 104 had phrenic neuropathy, 12 had myopathy, and 79 had no evidence of neuromuscular disease affecting the diaphragm. Paradoxical thinning occurred in 31 (27%) patients with neuromuscular diaphragmatic dysfunction and was unilateral in 30, the majority (83%) having normal contralateral ultrasound. Phrenic nerve conduction studies and diaphragm electromyography results did not distinguish patients with paradoxical thinning versus without. Most patients (71%) with paradoxical thinning required non-invasive ventilation (NIV), including 16 with unilateral paradoxical thinning. Paradoxical thinning and BMI ≥30 kg/m2 were risk factors for requiring NIV in multivariable logistic regression analysis, with odds ratios of 2.887 (95% CI:1.166, 7.151) and 2.561 (95% CI: 1.186, 5.532), respectively. DISCUSSION: Paradoxical thinning of the diaphragm occurs in patients with prominent neuromuscular diaphragmatic dysfunction, most commonly from phrenic neuropathy, and is a significant risk factor for requiring NIV. Unilateral paradoxical thinning is sufficient for needing NIV. BMI ≥30 kg/m2 additionally increases risk of requiring NIV in patients with neuromuscular diaphragmatic dysfunction.

Visual lung ultrasound protocol (VLUP) in acute respiratory failure: description and application in clinical cases.

Lung ultrasound (LUS) is widely used as a diagnostic and monitoring tool in critically ill patients. Lung ultrasound score (LUSS) based on the examination of twelve thoracic regions has been extensively validated for pulmonary assessment. However, it has revealed significant limitations: when applied to heterogeneous lung diseases with intermediate LUSS pattern (LUSS 1 and 2), for instance, intra-observer consistency is relatively low. In addition, LUSS is time-consuming and a more rapid overview of the extent of lung pathology and residual lung aeration is often required, especially in emergency setting. We propose a Visual Lung Ultrasound Protocol (VLUP) as a rapid monitoring tool for patients with acute respiratory failure. It consists of a probe sliding along the mid-clavicular, mid-axillary and scapular lines in transversal scan. VLUP allows a visualization of a large portion of the antero-lateral and/or posterior pleural surface. Serial assessments of two clinical cases are recorded and visually compared, enabling rapid understanding of lung damage and its evolution over time. VLUP allows a semi-quantitative and qualitative point-of-care assessment of lung injury. Through this standardized approach it is possible to accurately compare subsequent scans and to monitor the evolution of regional parenchymal damage. VLUP enables a quick estimation of the quantitative-LUSS (qLUSS) as the percentage of pleura occupied by artifacts, more suitable than LUSS in inhomogeneous diseases. VLUP is designed as a standardized, point-of-care lung aeration assessment and monitoring tool. The purpose of the paper is to illustrate this new technique and to describe its applications.

Diagnostic role of thoracic ultrasound in patients with acute respiratory failure at emergency service.

BACKGROUND AND AIM: This study aimed to elucidate the effectiveness of bedside thoracic ultrasound according to BLUE protocol and to investigate its superiority over other imaging methods in the emergency service. METHODS: A total of 120 patients admitted to our institution's emergency care department due to respiratory distress have been enrolled in this prospective research. Thorax USG has been performed in the right and left hemithorax at the points specified in the BLUE protocol for each patient. Pleural sliding motion, A-lines, B-lines, consolidation, effusion, and the presence of barcode signs were evaluated individually. Age, sex, comorbid diseases, other radiological examination findings, laboratory findings, final clinical diagnosis, and hospitalization-discharge status of the patients were recorded. RESULTS: When a correct diagnosis of pneumonia has been analyzed for imaging techniques, the diagnostic rate of chest radiography was 83.3%, CT was 100.0%, and USG was 66.6%. The correct diagnostic rate of chest radiography was 94.5%; CT and USG were 100.0%. The correct diagnosis of pulmonary edema on chest radiography was 94.5%; CT and USG were 100.0%. While the correct diagnosis of pleural effusion on chest radiography and CT was 100.0%, it was 92.3% in USG imaging. Finally, CT and USG imaging performed better than chest radiography in patients with pneumothorax (chest radiography 80.0%, CT and USG 100%). CONCLUSION: USG imaging could be preferred in the diagnosis of pneumonia, pulmonary edema, pleural effusion, pneumothorax, pulmonary embolism, and differential diagnosis at the emergency service.

Inspiratory-expiratory variation of pleural line thickness in neonates with and without acute respiratory failure.

BACKGROUND: There are relatively few data about the ultrasound evaluation of pleural line in patients with respiratory failure. We measured the pleural line thickness during different phases of the respiratory cycle in neonates with and without acute respiratory failure as we hypothesized that this can significantly change. METHODS: Prospective, observational, cohort study performed in an academic tertiary neonatal intensive care unit recruiting neonates with transient tachypnoea of the neonate (TTN), respiratory distress syndrome (RDS) or neonatal acute respiratory distress syndrome (NARDS). Neonates with no lung disease (NLD) were also recruited as controls. Pleural line thickness was measured with high-frequency ultrasound at end-inspiration and end-expiration by two different raters. RESULTS: Pleural line thickness was slightly but significantly higher at end-expiration (0.53 [0.43-0.63] mm) than at end-inspiration (0.5 [0.4-0.6] mm; p = 0.001) for the whole population. End-inspiratory (NLD: 0.45 [0.38-0.53], TTN: 0.49 [0.43-0.59], RDS: 0.53 [0.41-0.62], NARDS: 0.6 [0.5-0.7] mm) and -expiratory (NLD: 0.47 [0.42-0.56], TTN: 0.48 [0.43-0.61], RDS: 0.53 [0.46-0.65], NARDS: 0.61 [0.54-0.72] mm) thickness were significantly different (overall p = 0.021 for both), between the groups although the absolute differences were small. The inter-rater agreement was optimal (ICC: 0.95 (0.94-0.96)). Coefficient of variation was 2.8% and 2.5% for end-inspiratory and end-expiratory measurements, respectively. These findings provide normative data of pleural line thickness for the most common forms of neonatal acute respiratory failure and are useful to design future studies to investigate possible clinical applications.

Use of point-of-care ultrasound (POCUS) to monitor neonatal and pediatric extracorporeal life support.

Extracorporeal membrane oxygenation (ECMO) is an invasive life support technique that requires a blood pump, an artificial membrane lung, and vascular cannulae to drain de-oxygenated blood, remove carbon dioxide, oxygenate, and return it to the patient. ECMO is generally used to provide advanced and prolonged cardiopulmonary support in patients with refractory acute cardiac and/or respiratory failure. After its first use in 1975 to manage a severe form of meconium aspiration syndrome with resultant pulmonary hypertension, the following years were dominated by the use of ECMO to manage neonatal respiratory failure and limited to a few centers across the world. In the 1990s, evidence for neonatal respiratory ECMO support increased; however, the number of cases began to decline with the use of newer pharmacologic therapies (e.g., inhaled nitric oxide, exogenous surfactant, and high-frequency oscillatory ventilation). On the contrary, pediatric ECMO sustained steady growth. Combined advances in ECMO technology and bedside medical management have improved general outcomes, although ECMO-related complications remain challenging. Point-of-care ultrasound (POCUS) is an essential tool to monitor all phases of neonatal and pediatric ECMO: evaluation of ECMO candidacy, ultrasound-guided ECMO cannulation, daily evaluation of heart and lung function and brain perfusion, detection and management of major complications, and weaning from ECMO support.  Conclusion: Based on these considerations and on the lack of specific guidelines for the use of POCUS in the neonatal and pediatric ECMO setting, the aim of this paper is to provide a systematic overview for the application of POCUS during ECMO support in these populations. What is Known: • Extracorporeal membrane oxygenation (ECMO) provides advanced cardiopulmonary support for patients with refractory acute cardiac and/or respiratory failure and requires appropriate monitoring. • Point-of-care ultrasound (POCUS) is an accessible and adaptable tool to assess neonatal and pediatric cardiac and/or respiratory failure at bedside. What is New: • In this review, we discussed the use of POCUS to monitor and manage at bedside neonatal and pediatric patients supported with ECMO. • We explored the potential use of POCUS during all phases of ECMO support: pre-ECMO assessment, ECMO candidacy evaluation, daily evaluation of heart, lung and brain function, detection and troubleshooting of major complications, and weaning from ECMO support.

Setting positive end-expiratory pressure: lung and diaphragm ultrasound.

PURPOSE OF REVIEW: The purpose of this review is to summarize the role of lung ultrasound and diaphragm ultrasound in guiding ventilator settings with an emphasis on positive end-expiratory pressure (PEEP). Recent advances for using ultrasound to assess the effects of PEEP on the lungs and diaphragm are discussed. RECENT FINDINGS: Lung ultrasound can accurately diagnose the cause of acute respiratory failure, including acute respiratory distress syndrome and can identify focal and nonfocal lung morphology in these patients. This is essential in determining optimal ventilator strategy and PEEP level. Assessment of the effect of PEEP on lung recruitment using lung ultrasound is promising, especially in the perioperative setting. Diaphragm ultrasound can monitor the effects of PEEP on the diaphragm, but this needs further validation. In patients with an acute exacerbation of chronic obstructive pulmonary disease, diaphragm ultrasound can be used to predict noninvasive ventilation failure. Lung and diaphragm ultrasound can be used to predict weaning outcome and accurately diagnose the cause of weaning failure. SUMMARY: Lung and diaphragm ultrasound are useful for diagnosing the cause of respiratory failure and subsequently setting the ventilator including PEEP. Effects of PEEP on lung and diaphragm can be monitored using ultrasound.

Electrical Impedance Tomography to Monitor Hypoxemic Respiratory Failure.

Hypoxemic respiratory failure is one of the leading causes of mortality in intensive care. Frequent assessment of individual physiological characteristics and delivery of personalized mechanical ventilation (MV) settings is a constant challenge for clinicians caring for these patients. Electrical impedance tomography (EIT) is a radiation-free bedside monitoring device that is able to assess regional lung ventilation and changes in aeration. With real-time tomographic functional images of the lungs obtained through a thoracic belt, clinicians can visualize and estimate the distribution of ventilation at different ventilation settings or following procedures such as prone positioning. Several studies have evaluated the performance of EIT to monitor the effects of different MV settings in patients with acute respiratory distress syndrome, allowing more personalized MV. For instance, EIT could help clinicians find the positive end-expiratory pressure that represents a compromise between recruitment and overdistension and assess the effect of prone positioning on ventilation distribution. The clinical impact of the personalization of MV remains to be explored. Despite inherent limitations such as limited spatial resolution, EIT also offers a unique noninvasive bedside assessment of regional ventilation changes in the ICU. This technology offers the possibility of a continuous, operator-free diagnosis and real-time detection of common problems during MV. This review provides an overview of the functioning of EIT, its main indices, and its performance in monitoring patients with acute respiratory failure. Future perspectives for use in intensive care are also addressed.

The utility of diaphragm ultrasound thickening indices for assessing respiratory decompensation in amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: Amyotrophic lateral sclerosis (ALS) leads to diaphragmatic weakness at some point during its course, which is a major cause of respiratory insufficiency. The aim of this study was to evaluate ultrasound-based measures for assessing the diaphragmatic competency and the need for ventilatory support. METHODS: Twenty-six subjects with ALS and 12 healthy controls were enrolled. All participants underwent B-mode diaphragm ultrasound (DUS). Diaphragm thickness and thickening indices were recorded. In the subjects with ALS, further assessments included functional scales and spirometry. We investigated the diagnostic accuracy of DUS thickening indices in predicting diaphragmatic dysfunction and the correlation between clinical, spirometric, and DUS data. RESULTS: Significant relationships were found between forced vital capacity and all diaphragmatic thickening indices. Similarly, all diaphragmatic thickening indices correlated with both Milano Torino staging and disease progression rate. Only thickening fraction (TFdi) correlated with score on the revised ALS Functional Rating Scale (r = 0.459, P = .024). TFdi had better accuracy in predicting diaphragmatic dysfunction (area under the curve [AUC] = 0.839, 95% confidence interval [CI] 0.643 to 0.953) and the need for initiation of noninvasive ventilation (NIV) (AUC = 0.989, 95% CI 0.847 to 1.000) compared with the other indices. A TFdi cut-off point of 0.50 was a sensitive threshold to consider NIV. DISCUSSION: DUS successfully identifies diaphragmatic dysfunction in ALS, being a valuable accessory modality for investigating respiratory symptoms. TFdi was found to be the most useful DUS index, which encourages further investigation.

Comparison of chest radiograph and lung ultrasound in children with acute respiratory failure.

PURPOSE: Chest x-ray (CXR) is the standard imaging used to evaluate children in acute respiratory distress and failure. Our objective was to compare the lung-imaging techniques of CXR and lung ultrasound (LUS) in the evaluation of children with acute respiratory failure (ARF) to quantify agreement and to determine which technique identified a higher frequency of pulmonary abnormalities. METHODS: This was a secondary analysis of a prospective observational study evaluating the sensitivity and specificity of LUS in children with ARF from 12/2018 to 02/2020 completed at the University of Wisconsin-Madison (USA). Children > 37.0 weeks corrected gestational age and ≤ 18 years of age admitted to the PICU with ARF were evaluated with LUS. We compared CXR and LUS completed within 6 h of each other. Kappa statistics (k) adjusted for maximum attainable agreement (k/kmax) were used to quantify agreement between imaging techniques and descriptive statistics were used to describe the frequency of abnormalities. RESULTS: Eighty-eight children had LUS completed, 32 with concomitant imaging completed within 6 h are included. There was fair agreement between LUS and CXR derived diagnoses with 58% agreement (k/kmax = 0.36). Evaluation of imaging patterns included: normal, 57% agreement (k = 0.032); interstitial pattern, 47% agreement (k = 0.003); and consolidation, 65% agreement (k = 0.29). CXR identified more imaging abnormalities than LUS. CONCLUSIONS: There is fair agreement between CXR and LUS-derived diagnoses in children with ARF. Given this, clinicians should consider the benefits and limitations of specific imaging modalities when evaluating children with ARF. Additional studies are necessary to further define the role of LUS in pediatric ARF given the small sample size of our study.

Role of ultrasound in acute respiratory failure and in the weaning of mechanical ventilation.

Comprehensive ultrasound assessment has become an essential tool to facilitate the diagnosis and therapeutic management of critically ill patients with acute respiratory failure (ARF). There is evidence supporting the use of ultrasound for the diagnosis of pneumothorax, acute respiratory distress syndrome, cardiogenic pulmonary edema, pneumonia and acute pulmonary thromboembolism, and in patients with COVID-19. In addition, in recent years, the use of ultrasound to evaluate responses to treatment in critically ill patients with ARF has been developed, providing a noninvasive tool for titrating positive end-expiratory pressure, monitoring recruitment maneuvers and response to prone position, as well as for facilitating weaning from mechanical ventilation. The objective of this review is to summarize the basic concepts on the utility of ultrasound in the diagnosis and monitoring of critically ill patients with ARF.

Cardiopulmonary Ultrasound-Guided Treatment of Premature Infants with Respiratory Failure and Patent Ductus Arteriosus: A Randomized, Controlled Trial.

OBJECTIVES: To evaluate the role of cardiopulmonary ultrasonography in the treatment of preterm infants with respiratory failure combined with patent ductus arteriosus (PDA). METHODS: A single-center, prospective, randomized, controlled trial of premature infants born in the authors' hospital with a birth weight ≤ 1500 g and respiratory failure combined with PDA was conducted from January 2020 to December 2021. The included infants were randomly assigned to the cardiopulmonary ultrasound-guided therapy group or the traditional therapy group. The primary outcome of this study was data on respiratory support and PDA. RESULTS: A total of 76 premature infants were included in the study. There were 39 patients in the cardiopulmonary ultrasound-guided therapy group and 37 patients in the traditional therapy group. There was no difference in the baseline data, and the cardiopulmonary ultrasound-guided therapy group had a higher initial positive end-expiratory pressure [difference in median = -1.5 cm H2O, 95% confidence interval (CI): -2.0 to -1.0, p < 0.0001], earlier use of ibuprofen to close the PDA (difference in median = 2.5 d, 95% CI: 1.0-4.0, p = 0.004), fewer patients requiring invasive respiratory support [risk ratio (RR) = 0.63, 95% CI: 0.41-0.99, p = 0.04], and a lower incidence of moderate to severe bronchopulmonary dysplasia (RR = 0.44, 95% CI: 0.44-0.96, p = 0.04). There was no difference in the incidence of adverse events. CONCLUSIONS: For premature infants with respiratory failure combined with PDA, cardiopulmonary ultrasonography can better guide respiratory support. The timely administration of drugs helps treat PDA, thereby decreasing the risk of intubation and BPD. TRIAL REGISTRATION: https://www.trialos.com/index/ , TRN: 20220420024607012, date of registration: 2022/03/28, retrospectively registered.

Point-of-care lung ultrasound score for predicting escalated care in children with respiratory distress.

PURPOSE: Respiratory distress due to lower respiratory illnesses is a leading cause of death in children. Early recognition of high-risk populations is critical for the allocation of adequate resources. Our goal was to assess whether the lung ultrasound (US) score obtained at admission in children with respiratory distress predicts the need for escalated care. METHODS: This prospective study included 0-18-year-old patients with respiratory distress admitted to three emergency departments in the state of Sao Paulo, Brazil, between July 2019 and September 2021. The enrolled patients underwent lung US performed by a pediatric emergency physician within two hours of arrival. Lung ultrasound scores ranging from 0 to 36 were computed. The primary outcome was the need for high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), or mechanical ventilation within 24 h. RESULTS: A total of 103 patients were included. The diagnoses included wheezing (33%), bronchiolitis (27%), pneumonia (16%), asthma (9%), and miscellaneous (16%). Thirty-five patients (34%) required escalated care and had a higher lung ultrasound score: median 13 (0-34) vs 2 (0-21), p < 0.0001; area under the curve (AUC): 0.81 (95% confidence interval [CI]: 0.71-0.90). The best cut-off score derived from Youden's index was seven (sensitivity: 71.4%; specificity: 79.4%; odds ratio (OR): 9.6 [95% CI: 3.8-24.7]). A lung US score above 12 was highly specific and had a positive likelihood ratio of 8.74 (95% CI:3.21-23.86). CONCLUSION: An elevated lung US score measured in the first assessment of children with any type of respiratory distress was predictive of severity as defined by the need for escalated care with HFNC, NIV, or mechanical ventilation.

Association of subpleural ground-glass opacities with respiratory failure and RNAemia in COVID-19.

OBJECTIVES: To examine the radiological patterns specifically associated with hypoxemic respiratory failure in patients with coronavirus disease (COVID-19). METHODS: We enrolled patients with COVID-19 confirmed by qPCR in this prospective observational cohort study. We explored the association of clinical, radiological, and microbiological data with the development of hypoxemic respiratory failure after COVID-19 onset. Semi-quantitative CT scores and dominant CT patterns were retrospectively determined for each patient. The microbiological evaluation included checking the SARS-CoV-2 viral load by qPCR using nasal swab and serum specimens. RESULTS: Of the 214 eligible patients, 75 developed hypoxemic respiratory failure and 139 did not. The CT score was significantly higher in patients who developed hypoxemic respiratory failure than in those did not (median [interquartile range]: 9 [6-14] vs 0 [0-3]; p < 0.001). The dominant CT patterns were subpleural ground-glass opacities (GGOs) extending beyond the segmental area (n = 44); defined as "extended GGOs." Multivariable analysis showed that hypoxemic respiratory failure was significantly associated with extended GGOs (odds ratio [OR] 29.6; 95% confidence interval [CI], 9.3-120; p < 0.001), and a CT score > 4 (OR 12.7; 95% CI, 5.3-33; p < 0.001). The incidence of RNAemia was significantly higher in patients with extended GGOs (58.3%) than in those without any pulmonary lesion (14.7%; p < 0.001). CONCLUSIONS: Extended GGOs along the subpleural area were strongly associated with hypoxemia and viremia in patients with COVID-19. KEY POINTS: • Extended ground-glass opacities (GGOs) along the subpleural area and a CT score > 4, in the early phase of COVID-19, were independently associated with the development of hypoxemic respiratory failure. • The absence of pulmonary lesions on CT in the early phase of COVID-19 was associated with a lower risk of developing hypoxemic respiratory failure. • Compared to patients with other CT findings, the extended GGOs and a higher CT score were also associated with a higher incidence of RNAemia.

Diaphragmatic Ultrasound Predictors of High-Flow Nasal Cannula Therapeutic Failure in Critically Ill Patients With SARS-CoV-2 Pneumonia.

OBJECTIVES: High flow nasal cannula (HFNC) is frequently used in patients with acute respiratory failure, but there is limited evidence regarding predictors of therapeutic failure. The objective of this study was to assess diaphragmatic ultrasound criteria as predictors of failure to HFNC, defined as the need for orotracheal intubation or death. METHODS: Prospective cohort study including adult patients consecutively admitted to the critical care unit, from July 24 to October 20, 2020, with respiratory failure secondary to SARS-CoV-2 pneumonia who required HFNC. After 12 hours of HFNC initiation we measured ROX index (ratio of SpO2 /FiO2 to respiratory rate), excursion and diaphragmatic contraction speed (diaphragmatic excursion/inspiratory time) by ultrasound, both in supine and prone position. RESULTS: In total, 41 patients were analyzed, 25 succeeded and 16 failed HFNC therapy. At 12 hours, patients who succeeded HFNC therapy presented higher ROX index in supine position (9.8 [9.1-15.6] versus 5.4 [3.9-6.8], P < .01), and higher PaO2 /FiO2 ratio (186 [135-236] versus 117 [103-162] mmHg, P = .03). To predict therapeutic failure, the supine diaphragmatic contraction speed presented sensitivity of 89% and a specificity of 57%, while the ROX index presented a sensitivity of 92.8% and a specificity of 75%. CONCLUSIONS: Diaphragmatic contraction speed by ultrasound emerges as a diagnostic complement to clinical tools to predict HFNC success. Future studies should confirm these results.

The Role of Echocardiography in Extracorporeal Membrane Oxygenation.

PURPOSE OF REVIEW: Extracorporeal membrane oxygenation (ECMO) is increasingly used to temporarily support patients in severe circulatory and/or respiratory failure. Echocardiography is a core component of successful ECMO deployment. Herein, we review the role of echocardiography at different phases on extracorporeal support including candidate identification, cannulation, maintenance, complication vigilance, and decannulation. RECENT FINDINGS: During cannulation, ultrasound is used to confirm intended vascular access and appropriate inflow cannula positioning. While on ECMO, echocardiographic evaluation of ventricular loading conditions and hemodynamics, cannula positioning, and surveillance for intracardiac or aortic thrombi is needed for complication mitigation. Echocardiography is crucial during all phases of ECMO use. Specific echocardiographic queries depend on the ECMO type, V-V, or V-A, and the specific cannula configuration strategy employed.

Ultrasound-assessed lung aeration correlates with respiratory system compliance in adults and neonates with acute hypoxemic restrictive respiratory failure: an observational prospective study.

BACKGROUND: Lung ultrasound allows lung aeration to be assessed through dedicated lung ultrasound scores (LUS). Despite LUS have been validated using several techniques, scanty data exist about the relationships between LUS and compliance of the respiratory system (Crs) in restrictive respiratory failure. Aim of this study was to investigate the relationship between LUS and Crs in neonates and adults affected by acute hypoxemic restrictive respiratory failure, as well as the effect of patients' age on this relationship. METHODS: Observational, cross-sectional, international, patho-physiology, bi-center study recruiting invasively ventilated, adults and neonates with acute respiratory distress syndrome (ARDS), neonatal ARDS (NARDS) or respiratory distress syndrome (RDS) due to primary surfactant deficiency. Subjects without lung disease (NLD) and ventilated for extra-pulmonary conditions were recruited as controls. LUS, Crs and resistances (Rrs) of the respiratory system were measured within 1 h from each other. RESULTS: Forty adults and fifty-six neonates were recruited. LUS was higher in ARDS, NARDS and RDS and lower in control subjects (overall p < 0.001), while Crs was lower in ARDS, NARDS and RDS and higher in control subjects (overall p < 0.001), without differences between adults and neonates. LUS and Crs were correlated in adults [r = - 0.86 (95% CI - 0.93; - 0.76), p < 0.001] and neonates [r = - 0.76 (95% CI - 0.85; - 0.62), p < 0.001]. Correlations remained significant among subgroups with different causes of respiratory failure; LUS and Rrs were not correlated. Multivariate analyses confirmed the association between LUS and Crs both in adults [B = - 2.8 (95% CI - 4.9; - 0.6), p = 0.012] and neonates [B = - 0.045 (95% CI - 0.07; - 0.02), p = 0.001]. CONCLUSIONS: Lung aeration and compliance of the respiratory system are significantly and inversely correlated irrespective of patients' age. A restrictive respiratory failure has the same ultrasound appearance and mechanical characteristics in adults and neonates.