From SARS and MERS to COVID-19: a brief summary and comparison of severe acute respiratory infections caused by three highly pathogenic human coronaviruses.

Within two decades, there have emerged three highly pathogenic and deadly human coronaviruses, namely SARS-CoV, MERS-CoV and SARS-CoV-2. The economic burden and health threats caused by these coronaviruses are extremely dreadful and getting more serious as the increasing number of global infections and attributed deaths of SARS-CoV-2 and MERS-CoV. Unfortunately, specific medical countermeasures for these hCoVs remain absent. Moreover, the fast spread of misinformation about the ongoing SARS-CoV-2 pandemic uniquely places the virus alongside an annoying infodemic and causes unnecessary worldwide panic. SARS-CoV-2 shares many similarities with SARS-CoV and MERS-CoV, certainly, obvious differences exist as well. Lessons learnt from SARS-CoV and MERS-CoV, timely updated information of SARS-CoV-2 and MERS-CoV, and summarized specific knowledge of these hCoVs are extremely invaluable for effectively and efficiently contain the outbreak of SARS-CoV-2 and MERS-CoV. By gaining a deeper understanding of hCoVs and the illnesses caused by them, we can bridge knowledge gaps, provide cultural weapons for fighting and controling the spread of MERS-CoV and SARS-CoV-2, and prepare effective and robust defense lines against hCoVs that may emerge or reemerge in the future. To this end, the state-of-the-art knowledge and comparing the biological features of these lethal hCoVs and the clinical characteristics of illnesses caused by them are systematically summarized in the review.

Selective bronchial intubation for one-lung ventilation and independent-lung ventilation in pediatric age: state of the art.

Selective bronchial intubation (SBI) to ventilate a single lung (one-lung ventilation, OLV) or to apply separate lung ventilation (independent-lung ventilation, ILV) can be frequently required under general anesthesia in pediatrics, mainly in video assisted thoracoscopy surgery, in the postoperative care of cardio-thoracic surgery, and for the treatment of lung pathologies with unilateral prevalence in intensive care. In children over 6-8 years of age SBI, OLV and ILV can be performed using marketed double-lumen tubes (DLTs). In neonates, infants and younger children the application of ILV is limited due to the lack of DLTs. For children of this age, a specific DLT for ILV was developed (Marraro Paediatric Endobronchial Bilumen Tube®) but is currently available only as a special product. The DLT represents the device of choice for OLV and ILV while the use of bronchial blocker is suggested as an alternative to achieve the SBI and the OLV when suitable DLTs are not available. Different catheters types can be used as bronchial blocker. If SBI is not possible using DLT or bronchial blocker, a conventional single-lumen tube of adequate length can allow SBI in all pediatric ages. Using the bronchial blocker and single lumen tube it is possible to perform OLV but it is impossible to apply ILV. The main complications of SBI and DLT are largely due to limited operator experience. Airway trauma, dislodgment and obstruction of the devices are quite frequent and can lead to severe hypoxia if not recognized and treated early.

Consideration of the respiratory support strategy of severe acute respiratory failure caused by SARS-CoV-2 infection in children.

The recent ongoing outbreak of severe pneumonia associated with a novel coronavirus (SARS-CoV-2), currently of unknown origin, creates a world emergency that has put global public health institutions on high alert. At present there is limited clinical information of the SARS-CoV-2 and there is no specific treatment recommended, although technical guidances and suggestions have been developed and will continue to be updated as additional information becomes available. Preventive treatment has an important role to control and avoid the spread of severe respiratory disease, but often is difficult to obtain and sometimes cannot be effective to reduce the risk of deterioration of the underlining lung pathology. In order to define an effective and safe treatment for SARS-CoV-2-associated disease, we provide considerations on the actual treatments, on how to avoid complications and the undesirable side effects related to them and to select and apply earlier the most appropriate treatment. Approaching to treat severe respiratory disease in infants and children, the risks related to the development of atelectasis starting invasive or non-invasive ventilation support and the risk of oxygen toxicity must be taken into serious consideration. For an appropriate and effective approach to treat severe pediatric respiratory diseases, two main different strategies can be proposed according to the stage and severity of the patient conditions: patient in the initial phase and with non-severe lung pathology and patient with severe initial respiratory impairment and/or with delay in arrival to observation. The final outcome is strictly connected with the ability to apply an appropriate treatment early and to reduce all the complications that can arise during the intensive care admission.

Acute respiratory distress syndrome in the pediatric age: an update on advanced treatment.

Acute respiratory distress syndrome (ARDS) is a heterogeneous syndrome that lacks definitive treatment. The cornerstone of management is sound intensive care treatment and early anticipatory ventilation support. A mechanical ventilation strategy aiming at optimal alveolar recruitment, judicious use of positive end-respiratory pressure (PEEP) and low tidal volumes (VT) remains the mainstay for managing this lung disease. Several treatments have been proposed in rescue settings, but confirmation is needed from large controlled clinical trials before they be recommended for routine care. Non-invasive ventilation (NIV) is suggested with a cautious approach and a strict selection of candidates for treatment. Mild and moderate cases can be efficiently treated by NIV, but this is contra-indicated with severe ARDS. The extra-corporeal carbon dioxide removal (ECCO2 R), used as an integrated tool with conventional ventilation, is playing a new role in adjusting respiratory acidosis and CO2. The proposed benefits of ECCO2 R over extra-corporeal membrane oxygenation (ECMO) consist in a reduction of artificial surface contact, avoidance of pump-related side effects and technical complications, as well as lower costs. The advantages and disadvantages of inhaled nitric oxide (iNO) are better recognized today and iNO is not recommended for ARDS and acute lung injury (ALI) in children and adults because iNO results in a transient improvement in oxygenation but does not reduce mortality, and may be harmful. Several trials have found no clinical benefit from various surfactant supplementation methods in adult patients with ARDS. However, studies which are still controversial have shown that surfactant supplementation can improve oxygenation and decrease mortality in pediatric and adolescent patients in specific conditions and, when applied in different modes and doses, also in neonatal respiratory distress syndrome (RDS) of preemies. Management of ARDS remains supportive, aimed at improving gas exchange and preventing complications. Progress in the treatment of ARDS must be addressed toward the new paradigm of the disease pathobiology to be applied to the disease definition and to predict the treatment outcome, also with the perspective to develop predictive and personalized medicine that highlights new and challenging opportunities in terms of benefit for patient's safety and doctor's responsibility, with further medico-legal implication.