Current Opinion in Critical Care:
RESPIRATORY SYSTEM: Edited by Peolo Pelosi
aDepartment of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
bLaboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
Correspondence to Professor Paolo Pelosi, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy. E-mail: firstname.lastname@example.org
Patients with acute respiratory distress syndrome (ARDS) are characterized by high morbidity and mortality . More recently, large clinical observational studies reported that ARDS  and critically ill  patients admitted in medical and surgical ICUs are at high risk for long-term cognitive impairment. Thus, the optimal diagnostic, therapeutic, and clinical management of these patients might affect not only early but also long-term outcome, with major social and economic burden.
A new definition of ARDS, from mild to severe forms, has been proposed to better individualize diagnostic, therapeutic, and clinical management . It has also been demonstrated that protective mechanical ventilation may improve survival in patients with ARDS: lower tidal volume in all patients with ARDS from mild to severe; higher positive end-expiratory pressure and prolonged prone position in severe ARDS; muscle paralysis restricted to the early phases of severe ARDS; as well as extracorporeal membrane oxygenation in very severe ARDS, performed only in specialized centers. Furthermore, experimental and clinical evidence support the use of assisted mechanical ventilation in the early phases from mild to moderate ARDS. More recently, large clinical randomized controlled trials [5,6] showed the importance of protective mechanical ventilation not only in ARDS patients but also in patients at risk of ARDS, from operating room to the ICUs.
In the present issue of Current Opinion in Critical Care, several topics related to updated experimental and clinical knowledge on how to interpret physiological information at the bedside, as well as monitoring and optimization of ventilatory clinical setting in mechanically ventilated patients at risk and with ARDS, are discussed. Kacmarek et al. showed that the incidence and overall mortality of ARDS has not changed substantially since the original ARDSnet study, still higher than 40%. Barbas et al. discussed the clinical applicability and the usefulness of the new Berlin ARDS definition, as well as its potential drawbacks and possibilities for further improvement. Suki et al. reviewed the experimental data regarding the injurious effects of mechanical ventilation on the pulmonary ultrastructure, namely the endothelium, epithelium, and extracellular matrix, whereas Dos Santos et al. evaluated the role of biomarkers to better individualize mechanical ventilation strategies and clinical management in ARDS. Canet et al. discussed the impact of postoperative pulmonary complications on outcome and Schultz et al. emphasized the role of protective mechanical ventilation to minimize ventilator-induced lung injury in patients at risk of ARDS. Gattinoni et al. and Brochard et al. discussed potential monitoring techniques that can improve ventilatory setting at bedside in individual patients with ARDS, like stress and strain, as well as transpulmonary pressure measured by means of esophageal pressure measurement. Corradi et al. described the usefulness of lung ultrasound in the diagnostics and optimization of ventilatory setting in critically ill patients under mechanical ventilation. A further section is dedicated to the impact of different ventilatory strategies on the respiratory function and their specific settings on outcome according to their severity. In this line, Marini et al. discussed the effects of recruitment maneuver, Guerin et al. evaluated the role of the prone position, Ranieri et al. discussed extracorporeal membrane oxygenation, Ferguson et al. assessed the effects of high frequency oscillation, whereas Gama de Abreu et al. discussed the role of assisted mechanical ventilation. The management of fluids is discussed by Leme et al. focusing on the importance of hemodynamics monitoring, whereas Zhang et al. and Laffey et al. discussed new pharmacological approaches and the role of stem cells as possible future treatment of ARDS, respectively.
In conclusion, the clinical early and long-term outcome of ARDS patients, especially at its more severe form, is still poor. An individualized mechanical ventilation setting based on physiologic background might further advance the diagnostic and clinical management. Recent evidence suggests that prevention plays a key role to improve outcome of patients at risk of ARDS.
Conflicts of interest
Professor P. Pelosi and P.R.M. Rocco have no conflicts of interest related to the present manuscript.
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