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Paolo Scarpazza1, Cristoforo Incorvaia2, Paolo Amboni3, Giuseppe di Franco1, Stefania Raschi1, Pierfranco Usai1, Monica Bernareggi1, Cristiano Bonacina1, Chiara Melacini1, Roberta Cattaneo1, Serena Bencini1, Chiara Pravettoni2, Gian Galeazzo Riario-Sforza2, Gianni Passalacqua4, Walter Casali11Divisione di Broncopneumotisiologia, Ospedale Civile, Vimercate, Italy; 2Pulmonary Rehabilitation, Istituti Clinici di Perfezionamento, Milan, Italy; 3Clinical Chemistry Laboratory, Ospedali Riuniti, Bergamo, Italy; 4Allergy and Respiratory Diseases, University Of Genoa, Genoa, ItalyBackground: Noninvasive mechanical ventilation (NIMV) is an effective tool in treating patients with acute respiratory failure (ARF), since it reduces both the need for endotracheal intubation and the mortality in comparison with nonventilated patients. A particular issue is represented by the outcome of NIMV in patients referred to the emergency department for ARF and with a do-not-intubate (DNI) status because of advanced age or excessively critical conditions. This study evaluated long-term survival in a group of elderly patients with acute hypercapnic ARF who had a DNI order and who were successfully treated by NIMV.Methods: The population consisted of 54 patients with a favorable outcome after NIMV for ARF. They were followed up for 3 years by regular control visits, with at least one visit every 4 months, or as needed according to the patient’s condition. Of these, 31 continued NIMV at home and 23 were on long-term oxygen therapy (LTOT) alone.Results: A total of 16 of the 52 patients had not survived at the 1-year follow-up, and another eight patients died during the 3-year observation, with an overall mortality rate of 30.8% after 1 year and 46.2% after 3 years. Comparing patients who continued NIMV at home with those who were on LTOT alone, 9 of the 29 patients on home NIMV died (6 after 1 year and 3 after 3 years) and 15 of the 23 patients on LTOT alone died (10 after 1 year and 5 after 3 years).Conclusion: These results show that elderly patients with ARF successfully treated by NIMV following a DNI order have a satisfactory long-term survival.Keywords: COPD, acute respiratory failure, mortality rate, respiratory failure

Paolo Scarpazza,1 Cristoforo Incorvaia,2 Chiara Melacini,1 Roberta Cattaneo,1 Cristiano Bonacina,1 Gian Galeazzo Riario-Sforza,2 Walter Casali1 1Pneumology Unit, Ospedale Civile, Vimercate, 2Pulmonary Rehabilitation, Istituti Clinici di Perfezionamento, Milan, Italy Abstract: Noninvasive ventilation (NIV) was introduced as an alternative to invasive mechanical ventilation for acute respiratory failure caused from exacerbations of chronic obstructive pulmonary disease in the 1980s, and its use gradually rose worldwide. Seventy-eight patients (57 males, mean age 78.3 ± 9.2 years) undergoing NIV were evaluated. Of them, 48 (62.3%) had acute hypercapnic respiratory failure because of a chronic obstructive pulmonary disease exacerbation, and the remaining 30 had acute hypercapnic respiratory failure from other causes, mainly cardiac failure. All patients were treated by NIV using the bi-level positive airway pressure set up at high pressure/high backup rate. NIV was successful in 67 subjects (85.9%) and the patients were discharged, 57 of whom continued NIV at home and ten had spontaneous breathing. NIV was unsuccessful in eleven patients, ten of whom died and one was successfully treated by invasive mechanical ventilation. Significant differences were detected for a higher basal Glasgow Coma Scale score in successfully treated patients (P = 0.007), a higher basal Acute Physiology and Chronic Health Evaluation score in unsuccessfully treated patients (P = 0.004), and a lower pH after 1 hour in unsuccessfully treated patients (P = 0.015). These findings show a very high rate of success of NIV in patients with acute hypercapnic respiratory failure not only from chronic obstructive pulmonary disease but also from cardiac failure. This suggests that the use of invasive mechanical ventilation may be further reduced, with a decrease in its known complications as well. Keywords: invasive ventilation, noninvasive ventilation, acute respiratory failure

Natural convection in rectangular cavities has been the subject of numerous studies carried out using numerical methods, and also of some experimental studies. In general, however, the majority of numerical studies lack comparisons with experimental data. In experimental studies, it is generally the total heat flow exchanged across the cavity that is measured; rarely are local measurement of velocities reported. In this study the authors have analysed free convection in a rectangular cavity with an aspect ratio of ∼5, in which a preset temperature difference is maintained between two vertical walls, and the other walls are insulated. Numerical analysis was carried out using a penalty finite element method, for different values of the Rayleigh number and different meshes. The numerically predicted velocities are compared with the first experimental data obtained for a rectangular cavity filled with silicone oil. [ABSTRACT FROM AUTHOR]