Sepsis guidelines recommend obtaining blood cultures before starting anti-infective therapy in patients with sepsis. However, little is known of how antibiotic treatment before sampling affects ...bacterial growth. The aim of this study was to compare the results of blood cultures drawn before and during antibiotic therapy.
Prospective clinical cohort study of septic patients. Adult intensive care unit patients with two or three blood culture sets at the beginning of sepsis between 2010 and 2017 were included. Patients with blood culture samples obtained before antibiotic therapy were compared with patients with samples taken during antibiotic therapy. Blood culture positivity, defined as presence of a microbiological pathogen, was compared between the groups. Logistic regression was performed to adjust the impact of different factors with respect to blood culture positivity.
In total, 559 patients with 1364 blood culture sets at the beginning of sepsis were analysed. Blood culture positivity was 50.6% (78/154) among patients with sepsis who did not receive antibiotics and only 27.7% (112/405) in those who were already receiving antibiotics (p <0.001). Logistic regression revealed antibiotic therapy as an independent factor for less pathogen identification (odds ratio 0.4; 95% CI 0.3–0.6). Gram-positive pathogens (28.3% (111/392) versus 11.9% (116/972); p <0.001) and also Gram-negative pathogens (16.3% (64/392) versus 9.3% (90/972); p <0.001) were more frequent in blood culture sets drawn before antibiotic therapy compared with sets obtained during antibiotic therapy.
Obtaining blood cultures during antibiotic therapy is associated with a significant loss of pathogen detection. This strongly emphasizes the current recommendation to obtain blood cultures before antibiotic administration in patients with sepsis.
Abstract
Gamma-ray bursts (GRBs) are classified into long and short events. Long GRBs (LGRBs) are associated with the end states of very massive stars, while short GRBs (SGRBs) are linked to the ...merger of compact objects. GRB 200826A was a peculiar event, because by definition it was an SGRB, with a rest-frame duration of ∼0.5 s. However, this event was energetic and soft, which is consistent with LGRBs. The relatively low redshift (
z
= 0.7486) motivated a comprehensive, multiwavelength follow-up campaign to characterize its host, search for a possible associated supernova (SN), and thus understand the origin of this burst. To this aim we obtained a combination of deep near-infrared (NIR) and optical imaging together with spectroscopy. Our analysis reveals an optical and NIR bump in the light curve whose luminosity and evolution are in agreement with several SNe associated to LGRBs. Analysis of the prompt GRB shows that this event follows the
E
p,i
–
E
iso
relation found for LGRBs. The host galaxy is a low-mass star-forming galaxy, typical of LGRBs, but with one of the highest star formation rates, especially with respect to its mass (
log
M
*
/
M
⊙
=
8.6
, SFR ∼ 4.0
M
⊙
yr
−1
). We conclude that GRB 200826A is a typical collapsar event in the low tail of the duration distribution of LGRBs. These findings support theoretical predictions that events produced by collapsars can be as short as 0.5 s in the host frame and further confirm that duration alone is not an efficient discriminator for the progenitor class of a GRB.
There is growing evidence that beta-blockade may reduce mortality in selected patients with sepsis. However, it is unclear if a pre-existing, chronic oral beta-blocker therapy should be continued or ...discontinued during the acute phase of severe sepsis and septic shock.
The present secondary analysis of a prospective observational single centre trial compared patient and treatment characteristics, length of stay and mortality rates between adult patients with severe sepsis or septic shock, in whom chronic beta-blocker therapy was continued or discontinued, respectively. The acute phase was defined as the period ranging from two days before to three days after disease onset. Multivariable Cox regression analysis was performed to compare survival outcomes in patients with pre-existing chronic beta-blockade.
A total of 296 patients with severe sepsis or septic shock and pre-existing, chronic oral beta-blocker therapy were included. Chronic beta-blocker medication was discontinued during the acute phase of sepsis in 129 patients and continued in 167 patients. Continuation of beta-blocker therapy was significantly associated with decreased hospital (P=0.03), 28-day (P=0.04) and 90-day mortality rates (40.7% vs 52.7%; P=0.046) in contrast to beta-blocker cessation. The differences in survival functions were validated by a Log-rank test (P=0.01). Multivariable analysis identified the continuation of chronic beta-blocker therapy as an independent predictor of improved survival rates (HR = 0.67, 95%-CI (0.48, 0.95), P=0.03).
Continuing pre-existing chronic beta-blockade might be associated with decreased mortality rates up to 90 days in septic patients.
JHK photometry in the Mauna Kea Observatories (MKO) near-infrared system is presented for 115 stars. Of these stars, 79 are United Kingdom Infrared Telescope (UKIRT) standards from Hawarden et al., ...and 42 are Las Campanas Observatory (LCO, or NICMOS) standards from Persson et al. The average brightness of the sample in all three bandpasses is 11.5 mag, with a range between 10 and 15. The average number of nights each star was observed is 4, and the average of the internal error of the final results is 0.011 mag. These JHK data agree with those reported by other groups to 0.02 mag, for stars in common, which is consistent with the uncertainties. The measurements are used to derive colour transformations between the MKO JHK photometric system and the UKIRT, LCO and Two Micron All-Sky Survey (2MASS) systems. The 2MASS–MKO data scatter by 0.05 mag for redder stars, which is consistent with a dependence on stellar luminosity: the 2MASS J bandpass includes H2O features in dwarfs and the MKO K bandpass includes CO features in giants. We stress that colour transformations derived for stars whose spectra contain only weak features cannot give accurate transformations for objects with strong absorption features within one, but not both, of the filter bandpasses. We find evidence of systematic effects at the 0.02 mag level in the photometry of stars with J < 11 and H, K < 10.5 presented here and in Hawarden et al. This is due to an underestimate of the linearity correction for stars observed with the shortest exposure times; very accurate photometry of stars approaching the saturation limits of infrared detectors which are operated in double-read mode is difficult to obtain. There are indications that four stars in the sample, GSPC S705-D, FS 116 (B216-b7), FS 144 (Ser-EC84) and FS 32 (Feige 108), may be variable. There are 84 stars in the sample presented here that have 11 < J < 15 and 10.5 < H, K < 15, are not suspected to be variable, and have magnitudes with an estimated error ≤0.027 mag; 79 of these have an error of ≤0.020 mag. These represent the first published high-accuracy JHK stellar photometry in the MKO near-infrared photometric system; we recommend these objects be employed as primary standards for that system.
Aims. We present the characteristics and some early scientific results of the first instrument at the Large Binocular Telescope (LBT), the Large Binocular Camera (LBC). Each LBT telescope unit will ...be equipped with similar prime focus cameras. The blue channel is optimized for imaging in the $UV-B$ bands and the red channel for imaging in the VRIz bands. The corrected field-of-view of each camera is approximately 30 arcmin in diameter, and the chip area is equivalent to a 23$\times$23 arcmin2 field. In this paper we also present the commissioning results of the blue channel. Methods. The scientific and technical performance of the blue channel was assessed by measurement of the astrometric distortion, flat fielding, ghosts, and photometric calibrations. These measurements were then used as input to a data reduction pipeline applied to science commissioning data. Results. The measurements completed during commissioning show that the technical performance of the blue channel is in agreement with original expectations. Since the red camera is very similar to the blue one we expect similar performance from the commissioning that will be performed in the following months in binocular configuration. Using deep UV image, acquired during the commissioning of the blue camera, we derived faint UV galaxy-counts in a ~ 500 sq. arcmin sky area to U(Vega) = 26.5. These galaxy counts imply that the blue camera is the most powerful UV imager presently available and in the near future in terms of depth and extent of the field-of-view. We emphasize the potential of the blue camera to increase the robustness of the UGR multicolour selection of Lyman break galaxies at redshift z ~ 3.
Infections are often caused by pathobionts, endogenous bacteria that belong to the microbiota. Trauma and surgical intervention can allow bacteria to overcome host defences, ultimately leading to ...sepsis if left untreated. One of the main defence strategies of the immune system is the production of highly specific antibodies. In the present proof-of-concept study, plasma antibodies against 9 major pathogens were measured in sepsis patients, as an example of severe systemic infections. The binding of plasma antibodies to bacterial extracellular proteins was quantified using a semi-automated immunoblot assay. Comparison of the pathogen-specific antibody levels before and after infection showed an increase in plasma IgG in 20 out of 37 tested patients. This host-directed approach extended the results of pathogen-oriented microbiological and PCR diagnostics: a specific antibody response to additional bacteria was frequently observed, indicating unrecognised poly-microbial invasion. This might explain some cases of failed, seemingly targeted antibiotic treatment.
We report the discovery of the first new ultra-cool brown dwarf (BDs) found with the Wide-field Infrared Survey Explorer (WISE). The object's preliminary designation is WISEPC J045853.90+643451.9. ...Follow-up spectroscopy with the LUCIFER instrument on the Large Binocular Telescope indicates that it is a very late-type T dwarf with a spectral type approximately equal to T9. Fits to an IRTF/SpeX 0.8-2.5 Delta *mm spectrum to the model atmospheres of Marley and Saumon indicate an effective temperature of approximately 600 K as well as the presence of vertical mixing in its atmosphere. The new BD is easily detected by WISE, with a signal-to-noise ratio of ~36 at 4.6 Delta *mm. Current estimates place it at a distance of 6-10 pc. This object represents the first in what will likely be hundreds of nearby BDs found by WISE that will be suitable for follow-up observations, including those with the James Webb Space Telescope. One of the two primary scientific goals of the WISE mission is to find the coolest, closest stars to our Sun; the discovery of this new BD proves that WISE is capable of fulfilling this objective.
Background: The aim of the present study was to compare 16 routine clinical and laboratory parameters, acute physiologic and chronic health evaluation (APACHE) and sequential organ failure ...assessment (SOFA) score for their value in predicting mortality during hospital stay in patients admitted to a general intensive care unit (ICU).
Methods: A retrospective observational clinical study was carried out in a 15‐bed ICU in a university hospital. Nine hundred and thirty‐three consecutive patients with ICU stay > 24 h (36.2% surgical, 29.1% medical and 34.7% trauma) were observed. Blood sampling, patient surveillance and data collection were performed. The primary outcome was mortality in the hospital. We used receiver operating characteristic (ROC) analyses and logistic regression to compare the 16 relevant parameters, APACHE II and SOFA scores.
Results: Two hundred and thirty‐three out of the 933 patients died (mortality 25.0%). One laboratory parameter, serum osmolality area under the curve (AUC) 0.732 had a predictive value for mortality which lay between that of APACHE II (AUC 0.784) and SOFA (AUC 0.720) scores. When outcome prediction was restricted to long‐term patients (ICU stay > 5 days), serum osmolality (AUC 0.711) performed better than either of the standard scores (APACHE AUC 0.655, SOFA AUC 0.636). Using logistic regression analysis, the association of clinical parameters, age and diagnosis group with mortality was determined.
Conclusion: Elevated serum osmolality at ICU admission is associated with an increased mortality risk in critically ill patients. Serum osmolality is cheaper and more rapid to determine than the scoring systems. However, further studies are needed to evaluate the predictive value of serum osmolality in different patient populations.
The Early Cretaceous carbonate carbon isotope record is marked by three positive high-amplitude (> 1.5‰) excursions each covering time spans of more than 10
6 years. They are of late ...Valanginian-Hauterivian and early and late Aptian age. In a case study along a transect across the western Tethys Ocean we identified a coincidence between
δ
13C excursions, black shale formation, and widespread carbonate platform drowning events. We conclude that the
δ
13C excursions reflect a change in partitioning of carbon between the organic and carbonate carbon sinks which was triggered by climate induced ecological changes in Cretaceous pelagic and neritic environments. Episodes of intensified greenhouse climate conditions led to an increase in weathering, erosion and runoff rates and to elevated nutrient transfer rates from continents into oceans. The resulting increase in oceanic nutrient levels favoured marine phytoplankton production and black shale deposition while conditions for carbonate producing biotas became unfavourable. Partial choking of carbonate production along river influenced coasts resulted in widespread carbonate platform drowning during times of sea-level rise in the Valanginian and Aptian. Widespread contemporaneous black shale deposits and drowned carbonate platforms therefore reflect the contrasting response of the marine organic and carbonate carbon pumps to nutrient-enhanced phytoplankton productivity. The change in marine carbon partitioning is mirrored in a shift of the
δ
13C record towards more positive values. The transition to the
δ
13C peak values lasted up to several hundred thousand years. The peaks of the excursions, also covering a time span of up to several hundred thousand years, reflect a new stabilisation of the carbon partitioning between carbonate and organic carbon sinks. A renewed intensification of carbonate sedimentation under mesotrophic conditions was facilitated by stabilisation of the sea-level rise at a high level. Decreasing
δ
13C values record increasing carbonate carbon burial rates at constant or decreasing organic carbon accumulation rates. These changes contributed to the stabilisation of the marine carbon budget and the global carbon cycle up to millions of years after its initial perturbation.
The coupled exciton-vibrational dynamics of a three-site model of the Fenna–Matthews–Olson complex is investigated using the numerically exact multilayer multiconfiguration time-dependent Hartree ...approach. Thereby the specific coupling of the vibrational modes to local electronic transitions is adapted from a discretized experimental spectral density. The solution of the resulting time-dependent Schrödinger equation including three electronic and 450 vibrational degrees of freedom is analyzed in terms of excitonic populations and coherences. Emphasis is put onto the role of specific ranges of vibrational frequencies. It is observed that modes between 160 and 300 cm–1 are responsible for the sub-picosecond population and coherence decay. Further, it is found that a mean-field approach with respect to the vibrational degrees of freedom is not applicable.
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