Ventilation strategies for acute lung injury and acute respiratory distress syndrome

Limiting plateau pressures in the respiratory system of patients with acute lung injury and acute respiratory distress syndrome (ALI/ARDS) to 28 to 30 cm H2O may help guarantee lung protection. In the large multicenter Express trial, Dr Mercat and colleagues set positive end-expiratory pressure (PEEP) as high as possible to avoid plateau pressure above 28 to 30 cm H2O (mean, 27.5 cm H2O). In the lower PEEP (minimal distention) group in the Express trial, plateau pressure was kept as low as possible to maintain oxygenation targets (mean, 21 cm H2O). There was no difference in mortality between the 2 groups, but the higher PEEP/plateau pressure (increased recruitment) group showed a greater number of ventilator-free and organ failure\u2013free days. Plateau pressure in the increased recruitment group dropped to 24 cm H2O within the first week

An integrated approach to prevent and treat respiratory failure in brain-injured patients

PURPOSE OF REVIEW: Brain-injured patients are at increased risk of extracerebral organ dysfunction, in particular ventilator-associated pneumonia. The purpose of this review is to discuss functional abnormalities, clinical treatment, and possible prevention of respiratory function abnormalities in brain-injured patients. RECENT FINDINGS: Ventilator-associated pneumonia worsens the neurologic outcome and increases the intensive care unit and hospital stay, costs, and risk of death. The respiratory dysfunction can be due to several causes, but atelectasis and/or consolidation of the lower lobes predominates in the most severe cases. Strategies should be implemented to prevent lung infections and accelerate weaning from mechanical ventilation to reduce the incidence of respiratory dysfunction and ventilator-associated pneumonia. SUMMARY: An integrated approach including appropriate ventilatory, antibiotic, and fluid management could be extremely useful, not only to prevent and more rapidly treat respiratory failure but also to improve neurologic outcome and reduce hospital stay. Further studies are warranted to better elucidate the pathophysiology and clinical treatment of respiratory dysfunction in brain-injured patients

Application of micro-Raman spectroscopy for conservation projects in art and archaeology with a case study on Cappadocia rock-hewn wall paintings

This paper aims at reporting an overview of the principles and applications of micro-Raman spectroscopy in cultural heritage. Micro-Raman was used for characterizing painting pigments, inorganic binders, degradation materials in artworks with different goals: to know the materials and so the execution technique, to investigate the state of preservation, to establish the authenticity of the artefacts. The micro-Raman analyses were often performed on the occasion of conservative projects and they were able to supply valid and useful information to the conservators during their work. As case study, the project on the investigation of rock-hewn wall paintings in Cappadocia (Turkey) will be shortly presented as exemplificative of application of Raman techniques for the knowledge of the constituent materials, for supporting the conservation work and for detecting degradation products. Analysis were performed in the Interdepartmental instrument Center of Modena and Reggio Emilia University by a bench top system equipped with a microscope allowing for studying in non-destructive way different kinds of samples: powders, cross and thin sections, pre-treated samples

Respiratory and haemodynamic changes during decremental open lung positive end-expiratory pressure titration in patients with acute respiratory distress syndrome

INTRODUCTION: To investigate haemodynamic and respiratory changes during lung recruitment and decremental positive end-expiratory pressure (PEEP) titration for open lung ventilation in patients with acute respiratory distress syndrome (ARDS) a prospective, clinical trial was performed involving 12 adult patients with ARDS treated in the surgical intensive care unit in a university hospital. METHODS: A software programme (Open Lung Tool) incorporated into a standard ventilator controlled the recruitment (pressure-controlled ventilation with fixed PEEP at 20 cmH2O and increased driving pressures at 20, 25 and 30 cmH2O for two minutes each) and PEEP titration (PEEP lowered by 2 cmH2O every two minutes, with tidal volume set at 6 ml/kg). The open lung PEEP (OL-PEEP) was defined as the PEEP level yielding maximum dynamic respiratory compliance plus 2 cmH2O. Gas exchange, respiratory mechanics and central haemodynamics using the Pulse Contour Cardiac Output Monitor (PiCCO), as well as transoesophageal echocardiography were measured at the following steps: at baseline (T0); during the final recruitment step with PEEP at 20 cmH2O and driving pressure at 30 cmH2O, (T20/30); at OL-PEEP, following another recruitment manoeuvre (TOLP). RESULTS: The ratio of partial pressure of arterial oxygen (PaO2) to fraction of inspired oxygen (FiO2) increased from T0 to TOLP (120 +/- 59 versus 146 +/- 64 mmHg, P < 0.005), as did dynamic respiratory compliance (23 +/- 5 versus 27 +/- 6 ml/cmH2O, P < 0.005). At constant PEEP (14 +/- 3 cmH2O) and tidal volumes, peak inspiratory pressure decreased (32 +/- 3 versus 29 +/- 3 cmH2O, P < 0.005), although partial pressure of arterial carbon dioxide (PaCO2) was unchanged (58 +/- 22 versus 53 +/- 18 mmHg). No significant decrease in mean arterial pressure, stroke volume or cardiac output occurred during the recruitment (T20/30). However, left ventricular end-diastolic area decreased at T20/30 due to a decrease in the left ventricular end-diastolic septal-lateral diameter, while right ventricular end-diastolic area increased. Right ventricular function, estimated by the right ventricular Tei-index, deteriorated during the recruitment manoeuvre, but improved at TOLP. CONCLUSIONS: A standardised open lung strategy increased oxygenation and improved respiratory system compliance. No major haemodynamic compromise was observed, although the increase in right ventricular Tei-index and right ventricular end-diastolic area and the decrease in left ventricular end-diastolic septal-lateral diameter during the recruitment suggested an increased right ventricular stress and strain. Right ventricular function was significantly improved at TOLP compared with T0, although left ventricular function was unchanged, indicating effective lung volume optimisation

Choosing a ventilator for home mechanical ventilation

n/

Recruitment maneuvers in acute respiratory distress syndrome and during general anesthesia

The use of low tidal volume ventilation and low to moderate positive end-expiratory pressure (PEEP) levels is a widespread strategy to ventilate patients with non-injured lungs during general anesthesia and in intensive care as well with mild to moderate acute respiratory distress syndrome (ARDS). Higher PEEP levels have been recommended in severe ARDS. Due to the presence of alveolar collapse, recruitment maneuvers (RMs) by causing a transient elevation in airway pressure (i.e. transpulmonary pressure) have been suggested to improve lung inflation in non-inflated and poorly-inflated lung regions. Various types of RMs such as sustained inflation at high pressure, intermittent sighs and stepwise increases of PEEP and/or airway plateau inspiratory pressure have been proposed. The use of RMs has been associated with mixed results in terms of physiological and clinical outcomes. The optimal method for RMs has not yet been identified. The use of RMs is not standardized and left to the individual physician based on his/her experience. Based on the same grounds, RMs have been proposed to improve lung aeration during general anesthesia. The aim of this review was to present the clinical evidence supporting the use of RMs in patients with ARDS and during general anesthesia and as well their potential biological effects in experimental models of acute lung injury