Oxygen saturation or respiratory rate to improve risk stratification in hemodynamically stable patients with acute pulmonary embolism.

Essentials In acute pulmonary embolism (PE), risk stratification is essential to drive clinical management. Improving the 2014-ESC risk stratification strategy is crucial in hemodynamically stable patients. Oxygen saturation and respiratory rate improve risk stratification in hemodynamically stable PE. Simple and routine tests improve risk stratification of hemodynamically stable PE. SUMMARY: Background In patients with acute pulmonary embolism (PE), risk stratification for short-term death is recommended to drive clinical management. A risk stratification strategy combining the simplified Pulmonary Embolism Severity Index (PESI), echocardiography and troponin was proposed by the European Society of Cardiology (ESC) in 2014. The identification of hemodynamically stable patients at increased risk of death by this strategy needs improvement. Objective To assess whether further stratification by serial cut-off values of oxygen saturation or respiratory rate improves the accuracy of the ESC risk stratification strategy in hemodynamically stable PE patients. Methods Prospective cohorts of hemodynamically stable patients with PE were merged in a collaborative database. The accuracy of risk stratification for 30-day mortality by the original and a modified 2014 ESC strategy was assessed. Results Overall, 255 patients (27%) were categorized as low, 510 (54%) as intermediate-low and 181 (19%) as intermediate-high risk according to the original 2014 ESC strategy. Thirty-day mortality was 1.2% in low, 10% in intermediate-low and 11% in intermediate-high-risk patients. By adding oxygen saturation in air of < 88%, the discriminatory power of the 2014 ESC model improved for 30-day mortality (c-statistics, 0.71; 95% confidence interval [CI], 0.65-0.77 vs. 0.63, 95% CI, 0.56-0.69) and for PE-related death (c-statistics, 0.75; 95% CI, 0.69-0.81 vs. 0.63, 95% CI 0.56-0.69). Conclusions Simple and routine tests, such as oxygen saturation or respiratory rate, could be added to the 2014 ESC strategy for risk stratification to identify hemodynamically stable PE patients at increased risk of death who are potentially candidates for more aggressive treatment.

Star formation inside a galactic outflow.

Recent observations have revealed massive galactic molecular outflows that may have the physical conditions (high gas densities) required to form stars. Indeed, several recent models predict that such massive outflows may ignite star formation within the outflow itself. This star-formation mode, in which stars form with high radial velocities, could contribute to the morphological evolution of galaxies, to the evolution in size and velocity dispersion of the spheroidal component of galaxies, and would contribute to the population of high-velocity stars, which could even escape the galaxy. Such star formation could provide in situ chemical enrichment of the circumgalactic and intergalactic medium (through supernova explosions of young stars on large orbits), and some models also predict it to contribute substantially to the star-formation rate observed in distant galaxies. Although there exists observational evidence for star formation triggered by outflows or jets into their host galaxy, as a consequence of gas compression, evidence for star formation occurring within galactic outflows is still missing. Here we report spectroscopic observations that unambiguously reveal star formation occurring in a galactic outflow at a redshift of 0.0448. The inferred star-formation rate in the outflow is larger than 15 solar masses per year. Star formation may also be occurring in other galactic outflows, but may have been missed by previous observations owing to the lack of adequate diagnostics.

Gas accretion as the origin of chemical abundance gradients in distant galaxies.

It has recently been suggested that galaxies in the early Universe could have grown through the accretion of cold gas, and that this may have been the main driver of star formation and stellar mass growth. Because the cold gas is essentially primordial, it has a very low abundance of elements heavier than helium (referred to as metallicity). If funnelled to the centre of a galaxy, it will result in the central gas having an overall lower metallicity than gas further from the centre, because the gas further out has been enriched by supernovae and stellar winds, and not diluted by the primordial gas. Here we report chemical abundances across three rotationally supported star-forming galaxies at redshift z ≈ 3, only 2 Gyr after the Big Bang. We find 'inverse' gradients, with the central, star-forming regions having lower metallicities than less active ones, which is opposite to what is seen in local galaxies. We conclude that the central gas has been diluted by the accretion of primordial gas, as predicted by 'cold flow' models.

GRB 090423 at a redshift of z approximately 8.1.

Gamma-ray bursts (GRBs) are produced by rare types of massive stellar explosion. Their rapidly fading afterglows are often bright enough at optical wavelengths that they are detectable at cosmological distances. Hitherto, the highest known redshift for a GRB was z = 6.7 (ref. 1), for GRB 080913, and for a galaxy was z = 6.96 (ref. 2). Here we report observations of GRB 090423 and the near-infrared spectroscopic measurement of its redshift, z = 8.1(-0.3)(+0.1). This burst happened when the Universe was only about 4 per cent of its current age. Its properties are similar to those of GRBs observed at low/intermediate redshifts, suggesting that the mechanisms and progenitors that gave rise to this burst about 600,000,000 years after the Big Bang are not markedly different from those producing GRBs about 10,000,000,000 years later.

A supernova origin for dust in a high-redshift quasar.

Interstellar dust plays a crucial role in the evolution of the Universe by assisting the formation of molecules, by triggering the formation of the first low-mass stars, and by absorbing stellar ultraviolet-optical light and subsequently re-emitting it at infrared/millimetre wavelengths. Dust is thought to be produced predominantly in the envelopes of evolved (age >1 Gyr), low-mass stars. This picture has, however, recently been brought into question by the discovery of large masses of dust in the host galaxies of quasars at redshift z > 6, when the age of the Universe was less than 1 Gyr. Theoretical studies, corroborated by observations of nearby supernova remnants, have suggested that supernovae provide a fast and efficient dust formation environment in the early Universe. Here we report infrared observations of a quasar at redshift 6.2, which are used to obtain directly its dust extinction curve. We then show that such a curve is in excellent agreement with supernova dust models. This result demonstrates a supernova origin for dust in this high-redshift quasar, from which we infer that most of the dust at high redshifts probably has the same origin.

Selective decontamination of the digestive tract: a life saver.

Selective decontamination of the digestive tract (SDD), a strategy designed to prevent or minimize the impact of infection by potentially pathogenic micro-organisms in critically ill patients requiring long-term mechanical ventilation, comprises four component protocols, aiming to control the three types of infection occurring in such cases: (i) a parenteral antibiotic, cefotaxime, administered for a few days to prevent primary endogenous infections typically occurring 'early'; (ii) the topical antimicrobials polymyxin E, tobramycin and amphotericin B employed throughout the stay in the intensive care unit to prevent secondary endogenous infections tending to develop 'late'; (iii) a high standard of hygiene to prevent exogenous infections that may occur throughout the stay in the intensive care unit; (iv) surveillance samples of throat and rectum to distinguish between these three types of infection, to monitor the compliance and the efficacy of the treatment, and to detect the emergence of resistance at an early stage. A recent, rigorous, meta-analysis examining 33 randomized SDD trials involving 5727 patients demonstrated a significant reduction in overall mortality (20%) and in the incidence of respiratory tract infections (65%); conclusive evidence that SDD saves the lives of critically ill patients and confirmation that SDD is now an evidence based medicine manoeuvre. This same meta-analysis found no instance of the emergence of resistance or of associated superinfections and/or outbreaks in any of the 33 studies during a period extending upwards of 10 years. By the criterion of cost-per-survivor, four recent randomized trials showed that patient survival is improved more cheaply by employing SDD than by the traditional approaches.

Outcome evaluation in a home palliative care service.

The complexity of assessing the impact of palliative care is much greater than in other fields of medicine, due to the shortcomings of traditional outcome indicators. We conducted a prospective study to describe the patient's quality of life at the outset and during palliative care at home and to define some potential indicators of palliative care outcomes with the aim of assessing the quality of home care as provided by a palliative care unit. Seventy-three patients who received care at home were assessed. The median survival in palliative home care was 29 days. To evaluate the degree of symptom distress, we used an Italian version of the Symptom Distress Scale. Assessing the quality-of-life pattern over time, we observed that palliative care was effective in mitigating pain and, at least in part, in stimulating appetite, curbing nausea, and controlling psychological aspects. The subscales referring to social and functional aspects steadily worsened. The difficulties encountered (the high percentage of missing data, the considerable number of patients treated for less than 10 days, etc.) should be a warning against using only one assessment instrument. It is worthwhile defining the various potential outcomes of palliative care even though all results will not always be measurable in every patients. Only a global assessment, a "multiple outcomes approach," based on different indicators, would allow for evaluation of the outcome of the care process.