Pair instability supernovae across cosmic time

openPair instability (PISNe) and pulsational pair instability supernovae (PPISNe) are a key to understand the final fate of massive stars. Despite the robust theoretical framework they are grounded in, we still do not have any uncontroversial detection of PISNe and PPISNe. The aim of this work is to investigate their event rate as a function of cosmic time, with particular focus on the effects of metallicity and binary evolution, and make a comparison with observational constraints. For this purpose, we use the population-synthesis code SEVN (Stellar EVolution for N-body) to produce catalogues of single and binary stellar populations. We feed these catalogues to the code CosmoRate, to evaluate the event rate density in cosmological epochs. From our simulations it appears that binary evolution is a key ingredient that enhances the rate of PISNe and PPISNe. We further speculate about a possible tension with observational constraints.Pair instability (PISNe) and pulsational pair instability supernovae (PPISNe) are a key to understand the final fate of massive stars. Despite the robust theoretical framework they are grounded in, we still do not have any uncontroversial detection of PISNe and PPISNe. The aim of this work is to investigate their event rate as a function of cosmic time, with particular focus on the effects of metallicity and binary evolution, and make a comparison with observational constraints. For this purpose, we use the population-synthesis code SEVN (Stellar EVolution for N-body) to produce catalogues of single and binary stellar populations. We feed these catalogues to the code CosmoRate, to evaluate the event rate density in cosmological epochs. From our simulations it appears that binary evolution is a key ingredient that enhances the rate of PISNe and PPISNe. We further speculate about a possible tension with observational constraints

Non-invasive positive pressure ventilation in acute hypercapnic respiratory failure: ten-year’s clinical experience of a Respiratory Semi-Intensive Care Unit.

PremessaSebbene numerosi studi prospettici, controllati e randomizzati abbiano dimostrato il successo della ventilazione non-invasiva a pressione positiva (NIV) in casi selezionati di insufficienza respiratoria acuta ipercapnica (IRA) in setting con intensità di cura differenti, i dati di pratica clinica relativi all’uso della NIV nel “mondo reale” sono limitati. Scopo Riportare i risultati della nostra esperienza clinica sulla NIV nell’IRA applicata nell’Unità di Terapia Semi-Intensiva Respiratoria (UTSIR) allocata all’interno dell’Unità Operativa di Pneumologia di Arezzo negli anni 1996-2006 in termini di: tollerabilità, effetti sui gas ematici, tasso di successo e fattori predittivi del fallimento.MetodiTrecentocinquanta dei 1484 pazienti (23.6%) consecutivamente ammessi per IRA nella nostra Unità Operativa di Pneumologia durante il periodo di studio hanno ricevuto la NIV in aggiunta alla terapia standard, in seguito al raggiungimento di criteri predefiniti impiegati di routine.RisultatiOtto pazienti (2.3%) non hanno tollerato la NIV per discomfort alla maschera, mentre i rimanenti 342 (M: 240, F: 102; età: mediana (interquartili) 74.0 (68.0-79.3) anni; BPCO: 69.3%) sono stati ventilati per >1 ora. I gas ematici sono significativamente migliorati dopo 2 ore di NIV (media (deviazione standard) pH: 7.33 (0.07) versus 7.28 (7.25-7.31), p 48 ore di ventilazione) dopo iniziale risposta positiva.ConclusioniSecondo la nostra esperienza clinica di dieci anni realizzata in una UTSIR, la NIV si conferma essere ben tollerata, efficace nel migliorare i gas ematici e utile nell’evitare l’intubazione in molti episodi di IRA non-responsivi alla terapia standard.BackgroundAlthough several prospective controlled randomized trials demonstrated the success of non-invasive positive pressure ventilation (NIV) in selected cases of acute hypercapnic respiratory failure (IRA) in setting with different care levels, clinical practice data about the use of NIV in the “real world” are limited.AimTo report the results of our clinical experience in NIV applied for IRA in the Respiratory Semi-Intensive Care Unit (UTSIR) allocated within the Respiratory Division of Arezzo in the years 1996-2006 in terms of: tolerance, effects upon arterial blood gases, success rate and predictors of failure.MethodsThree hundred filthy of the 1484 patients (23.6%) consecutively admitted for IRA to our Respiratory Division during the study period received NIV in addition to standard therapy, according to the pre-defined routinely used criteria.ResultsEight patients (2.3%) did not tolerated NIV because of mask discomfort, while the remaining 342 (M: 240, F: 102; median (interquartiles) age: 74.0 (68.0-79.3) yrs; COPD: 69.3%) were ventilated for >1 hour. Arterial blood gases significantly improved after two hours of NIV (mean (standard deviation) pH: 7.33 (0.07) versus 7.28 (7.25-7.31), p 48 hrs of ventilation) after an initial positive response.ConclusionsAs results of our ten-year’s clinical experience performed in a UTSIR, NIV is confirmed to be well tolerated, effective in improving arterial blood gases and useful in avoiding intubation in most IRA episodes non-responder to standard therapy

Noninvasive ventilation in acute respiratory failure: which recipe for success?

Noninvasive positive-pressure ventilation (NPPV) to treat acute respiratory failure has expanded tremendously over the world in terms of the spectrum of diseases that can be successfully managed, the locations of its application and achievable goals.The turning point for the successful expansion of NPPV is its ability to achieve the same physiological effects as invasive mechanical ventilation with the avoidance of the life-threatening risks correlated with the use of an artificial airway.Cardiorespiratory arrest, extreme psychomotor agitation, severe haemodynamic instability, nonhypercapnic coma and multiple organ failure are absolute contraindications for NPPV. Moreover, pitfalls of NPPV reduce its rate of success; consistently, a clear plan of what to do in case of NPPV failure should be considered, especially for patients managed in unprotected setting. NPPV failure is likely to be reduced by the application of integrated therapeutic tools in selected patients handled by expert teams.In conclusion, NPPV has to be considered as a rational art and not just as an application of science, which requires the ability of clinicians to both choose case-by-case the best "ingredients" for a "successful recipe" (i.e. patient selection, interface, ventilator, interface, etc.) and to avoid a delayed intubation if the ventilation attempt fails

High-flow nasal oxygen therapy in acute respiratory failure

High-flow nasal cannula (HFNC) is a new effective device, which is able to deliver oxygen-therapy at a reliable FiO2 but also a certain amount of respiratory assistance; however HFNC could not be defined as a mechanical ventilator. The main physiologic advantage as compared to conventional oxygen therapy (COT) is the capability of HFNC to meet the increased ventilator demand in patients with respiratory distress and therefore reduce the amount of respiratory muscle’s workload. The main clinical advantage over both COT and noninvasive ventilation (NIV) is the greater comfort and acceptability reported by patients. So far there are several indications for HFNC use both in and outside ICU especially for milder hypoxemic spontaneously breathing patients and prevention of extubation failure in intubated patients, as well as palliative care in end stage neoplastic and nonneoplastic respiratory diseases. A large proportion of potential HFNC candidates belongs to advanced age people. Caution should be taken in the selection of the patients, monitoring, escalating treatment and setting of aplication

Gastro-intestinal parasites of pigs in Sardinia: a copromicroscopical investigation

This paper illustrates a copromicroscopical investigation carried out in Sardinia to update epidemiological data on diffusion of gastro-intestinal parasites in swine. Results obtained lead to suggest the employment of copromicroscopic exam to monitorate parasites diffusion in swine breedings in order to set up correct prophylactic and therapeutically intervents

Obesity can influence children’s and adolescents’ airway hyperresponsiveness differently

BACKGROUND: Literature is still arguing about a possible relationship between airway hyperresponsiveness (AHR) and body mass index (BMI). This study aimed at evaluating the influence of BMI on AHR and pulmonary function in children and adolescents that performed a methacholine test for suggestive asthma symptoms. METHODS: 799 consecutive children/adolescents (535 M; mean age: 15 ± 3 yrs; median FEV(1)% predicted: 101.94% [93.46-111.95] and FEV(1)/FVC predicted: 91.07 [86.17-95.38]), were considered and divided into underweight, normal, overweight and obese. Different AHR levels were considered as moderate/severe (PD(20) ≤ 400 μg) and borderline (PD(20) > 400 μg). RESULTS: 536 children/adolescents resulted hyperreactive with a median PD(20) of 366 μg [IQR:168–1010.5]; 317 patients were affected by moderate/severe AHR, whereas 219 showed borderline hyperresponsiveness. Obese subjects aged > 13 years showed a lower (p = 0.026) median PD(20) (187μg [IQR:110–519]) compared to overweight (377 μg [IQR:204–774]) and normal-weight individuals’ values (370.5 μg [IQR:189–877]). On the contrary, median PD(20) observed in obese children aged ≤ 13 years (761 μg [IQR:731–1212]) was higher (p = 0.052) compared to normal-weight children’s PD20 (193 μg [IQR:81–542]) and to obese adolescents’ values (aged > 13 years) (p = 0.019). Obesity was a significant AHR risk factor (OR:2.853[1.037-7.855]; p = 0.042) in moderate/severe AHR adolescents. Females showed a higher AHR risk (OR:1.696[1.046-2.751] p = 0.032) compared to males. A significant relationship was found between BMI and functional parameters (FEV(1), FVC, FEV(1)/FVC) only in hyperreactive females. CONCLUSIONS: Obesity seems to influence AHR negatively in female but not in male adolescents and children. In fact, AHR is higher in obese teenagers, in particular in those with moderate/severe hyperresponsiveness, and may be mediated by obesity-associated changes in baseline lung function

Long-term home noninvasive ventilation (LTHNIV) in restrictive thoracic diseases: The Italian snapshot

Long-term home noninvasive ventilation (LTHNIV) in restrictive thoracic diseases was explored via the recently published international REINVENT ERS survey. The Italian subset of respondents (ITA-r), the highest above all participating nations, was analyzed and compared to non-Italian respondents (NO-ITA-r). The ITA-r represented 20% of the total answers examined. Ninety-four percent were physicians, whose half worked in a respiratory ICU (RICU). ITA-r mainly worked in community hospitals vs NO-ITA-r who are largely affiliated with university hospitals (p<0.0001). Amyotrophic lateral sclerosis (ALS) was considered the most common medical condition leading to NIV indication by both ITA-r and NO-ITA-r (93% vs 78%, p>0.5). A greater proportion of ITA-r considered MIP/MEP the most important test for NIV initiation as compared to NO-IRA-r (p<0.05). There was no significant difference for both ITA-r and NO-ITA-r as regards the other questions. This study illustrates Italian LTHNIV practices in patients with NMD and it shows some important differences with the other countries' practices but agreement in terms of goals to achieve, reasons to initiate NIV, and practices among the two communities

Noninvasive mechanical ventilation in high-risk pulmonary infections: a clinical review

The aim of this article was to review the role of noninvasive ventilation (NIV) in acute pulmonary infectious diseases, such as severe acute respiratory syndrome (SARS), H1N1 and tuberculosis, and to assess the risk of disease transmission with the use of NIV from patients to healthcare workers. We performed a clinical review by searching Medline and EMBASE. These databases were searched for articles on "clinical trials" and "randomised controlled trials". The keywords selected were non-invasive ventilation pulmonary infections, influenza-A (H1N1), SARS and tuberculosis. These terms were cross-referenced with the following keywords: health care workers, airborne infections, complications, intensive care unit and pandemic. The members of the International NIV Network examined the major results regarding NIV applications and SARS, H1N1 and tuberculosis. Cross-referencing mechanical ventilation with SARS yielded 76 studies, of which 10 studies involved the use of NIV and five were ultimately selected for inclusion in this review. Cross-referencing with H1N1 yielded 275 studies, of which 27 involved NIV. Of these, 22 were selected for review. Cross-referencing with tuberculosis yielded 285 studies, of which 15 involved NIV and from these seven were selected. In total 34 studies were selected for this review. NIV, when applied early in selected patients with SARS, H1N1 and acute pulmonary tuberculosis infections, can reverse respiratory failure. There are only a few reports of infectious disease transmission among healthcare workers

Associations of awake prone positioning-induced changes in physiology with intubation: An international prospective observational study in patients with acute hypoxemic respiratory failure related to COVID-19

INTRODUCTION: Awake prone positioning has the potential to improve oxygenation and decrease respiratory rate, potentially reducing the need for intubation in patients with acute hypoxemic respiratory failure. We investigated awake prone positioning-induced changes in oxygenation and respiratory rate, and the prognostic capacity for intubation in patients with COVID-19 pneumonia. METHODS: International multicenter prospective observation study in critically ill adult patients with COVID-19 receiving supplemental oxygen. We collected data on oxygenation and respiratory rate at baseline, and at 1 h after being placed in prone positioning. The combined primary outcome was oxygenation and respiratory rate at 1 h. The secondary endpoint was treatment failure, defined as need for intubation within 24 h of start of awake prone positioning. RESULTS: Between March 27th and November 2020, 101 patients were enrolled of which 99 were fully analyzable. Awake prone positioning lasted mean of 3 [2-4] h. In 77 patients (77.7%), awake prone positioning improved oxygenation, and in 37 patients (54.4%) it decreased respiratory rate. Twenty-nine patients (29.3%) were intubated within 24 h. An increase in SpO CONCLUSIONS: Awake prone positioning improves oxygenation in the majority of patients, and decreases respiratory rate in more than half of patients with acute hypoxemic respiratory failure caused by COVID-19. One in three patients need intubation within 24 h. Awake prone position-induced changes in oxygenation and respiratory rate have prognostic capacity for intubation within 24 h