Tracheal Diverticulum in SARS-CoV-2 Patients on Non-Invasive Ventilation A not so “Spontaneous” Cause of Pneumomediastinum? An imaging Pictorial Presentation of Two Cases with Review of Literature

Spontaneous pneumomediastinum is a rare but potentially life-threatening condition, the incidence of which has showed an increase in patients with SARS-CoV-2 pneumonia, especially when they are on positive pressure ventilation. None of the reported cases of covid related pneumomediastinum had an associated tracheal diverticulum. Also, to the best of our knowledge, tracheal diverticulum has not been reported in patients on NIV. We report 2 cases of COVID-19 pneumonia on NIV with pneumomediastinum, which also had associated tracheal diverticulum, one of which developed after NIV. Though the establishment of causality needs further research, early detection of a tracheal diverticulum, which might be a harbinger of pneumomediastinum, can be a timely alarm to prompt titration of the pressure settings and judicious use of NIV. The role of inverted grey scale CT images in mediastinal window is a simple, yet hardly utilised radiological tool to increase detection of ‘mediastinal air’, let it be free air or air within a diverticulum. Through this case report, we would like to highlight the role of conventional and inverted CT imaging of pneumomediastinum and tracheal diverticulum in general and in SARS-CoV-2 pneumonia in particular, and to call for more objective research to throw light on the plausible relationship between pneumomediastinum and tracheal diverticulum.

Improving Newborn Resuscitation by Making Every Birth a Learning Event

One third of all neonatal deaths are caused by intrapartum-related events, resulting in neonatal respiratory depression (i.e., failure to breathe at birth). Evidence-based resuscitation with stimulation, airway clearance, and positive pressure ventilation reduces mortality from respiratory depression. Improving adherence to evidence-based resuscitation is vital to preventing neonatal deaths caused by respiratory depression. Standard resuscitation training programs, combined with frequent simulation practice, have not reached their life-saving potential due to ongoing gaps in bedside performance. Complex neonatal resuscitations, such as those involving positive pressure ventilation, are relatively uncommon for any given resuscitation provider, making consistent clinical practice an unrealistic solution for improving performance. This review discusses strategies to allow every birth to act as a learning event within the context of both high- and low-resource settings. We review strategies that involve clinical-decision support during newborn resuscitation, including the visual display of a resuscitation algorithm, peer-to-peer support, expert coaching, and automated guidance. We also review strategies that involve post-event reflection after newborn resuscitation, including delivery room checklists, audits, and debriefing. Strategies that make every birth a learning event have the potential to close performance gaps in newborn resuscitation that remain after training and frequent simulation practice, and they should be prioritized for further development and evaluation.

High-Frequency Positive Pressure Ventilation as Primary Rescue Strategy for Patients with Congenital Diaphragmatic Hernia: A Comparison to High-Frequency Oscillatory Ventilation

Objective The aim of this article was to evaluate high-frequency positive pressure ventilation (HFPPV) compared with high-frequency oscillatory ventilation (HFOV) as a rescue ventilation strategy for patients with congenital diaphragmatic hernia (CDH). HFPPV is a pressure-controlled conventional ventilation method utilizing high respiratory rate and low positive end-expiratory pressure. Study Design Seventy-seven patients diagnosed with CDH from January 2005 to September 2019 who were treated with stepwise progression from HFPPV to HFOV versus only HFOV were included. Fisher's exact test and the Kruskal–Wallis test were used to compare outcomes. Results Patients treated with HFPPV + HFOV had higher survival to discharge (80 vs. 50%, p = 0.007) and to surgical intervention (95.6 vs. 68.8%, p = 0.003), with average age at repair 2 days earlier (p = 0.004). Need for extracorporeal membrane oxygenation (p = 0.490), inhaled nitric oxide (p = 0.585), supplemental oxygen (p = 0.341), and pulmonary hypertension medications (p = 0.381) were similar. Conclusion In CDH patients who fail respiratory support with conventional ventilation, HFPPV may be used as an intermediary mode of rescue ventilation prior to HFOV without adverse effects. Key Points

Development of a Novel Anesthesia Airway Management Robot

Non-invasive positive pressure ventilation has attracted increasing attention for air management in general anesthesia. This work proposes a novel robot equipped with two snake arms and a mask-fastening mechanism to facilitate trachea airway management for anesthesia as well as deep sedation and to improve surgical outcomes. The two snake arms with supporting terminals have been designed to lift a patient’s jaw with design optimization, and the mask-fastening mechanism has been utilized to fasten the mask onto a patient’s face. The control unit has been developed to implement lifting and fastening force control with safety and robustness. Loading experiments on the snake arm and tension experiments on the mask-fastening mechanism have been performed to investigate and validate the performances of the proposed anesthesia airway management robot. Experiments on a mock person have also been employed to further verify the effectiveness and reliability of the developed robot system. As an early study of an anesthesia airway management robot, it was verified as a valid attempt to perform mask non-invasive positive pressure ventilation technology by taking advantage of a robotic system.

Lung histopathologic clusters in severe COVID-19: a link between clinical picture and tissue damage

Background Autoptic pulmonary findings have been described in severe COVID-19 patients, but evidence regarding the correlation between clinical picture and lung histopathologic patterns is still weak. Methods This was a retrospective cohort observational study conducted at the referral center for infectious diseases in northern Italy. Full lung autoptic findings and clinical data of patients who died from COVID-19 were analyzed. Lung histopathologic patterns were scored according to the extent of tissue damage. To consider coexisting histopathologic patterns, hierarchical clustering of histopathologic findings was applied. Results Whole pulmonary examination was available in 75 out of 92 full autopsies. Forty-eight hospitalized patients (64%), 44 from ICU and four from the medical ward, had complete clinical data. The histopathologic patterns had a time-dependent distribution with considerable overlap among patterns. Duration of positive-pressure ventilation (p < 0.0001), mean positive end-expiratory pressure (PEEP) (p = 0.007), worst serum albumin (p = 0.017), interleukin 6 (p = 0.047), and kidney SOFA (p = 0.001) differed among histopathologic clusters. The amount of PEEP for long-lasting ventilatory treatment was associated with the cluster showing the largest areas of early and late proliferative diffuse alveolar damage. No pharmacologic interventions or comorbidities affected the lung histopathology. Conclusions Our study draws a comprehensive link between the clinical and pulmonary histopathologic findings in a large cohort of COVID-19 patients. These results highlight that the positive end-expiratory pressures and the duration of the ventilatory treatment correlate with lung histopathologic patterns, providing new clues to the knowledge of the pathophysiology of severe SARS-CoV-2 pneumonia.