Risk factors for and impact of carbapenem-resistant Acinetobacter baumannii colonization and infection: matched case-control study

The objective of this investigation was to identify risk factors for carbapenem-resistant Acinetobacter baumannii (CRAB) and its association with mortality. A population-based matched case-control study using the computerized database of Clalit Health Services (CHS) in the period between 2007 and 2012 was conducted. Hospitalized patients with CRAB colonization or infection were compared to hospitalized patients without evidence of A. baumannii, matched by age, ward of hospitalization, season, Charlson score, and length of hospitalization. Risk factors for CRAB isolation were searched for using multivariate analysis. Association of CRAB and other risk factors with mortality were assessed in the cohort. A total of 1190 patients with CRAB were matched to 1190 patients without CRAB. Low socioeconomic status was independently associated with CRAB isolation and CRAB bacteremia [odds ratio 2.18, 95% confidence interval (CI) 1.02-5]. Other risk factors were invasive procedures and bacteremia with other pathogens prior to CRAB isolation, and various comorbidities. Among all patients, CRAB isolation was independently associated with increased mortality (hazard ratio 2.33, 95% CI 2.08-2.6). Socioeconomic status is associated with health outcomes. Our population-based study revealed an almost doubled risk for CRAB in patients at lower socioeconomic status and an association with healthcare exposure. CRAB was associated with mortality and might become a risk indicator for complex morbidity and mortality.

Plankton food web and its seasonal dynamics in a large monsoonal estuary (Cochin backwaters, India)-significance of mesohaline region

The paper presents the ecology and dynamics of plankton food web in the Cochin backwaters (CBW), the largest monsoonal estuary along the west coast of India. The data source is a time series measurement carried out in the CBW during the Spring Intermonsoon (March-May) and the Southwest Monsoon (June-September). The plankton food web consisting of autotrophic/heterotrophic picoplankton, autotrophic/heterotrophic nanoplankton, microzooplankton, and mesozooplankton was quantified in relation to the seasonal hydrographical settings in the CBW. The study showed that significant changes in the abundance and dynamics of plankton food web components were governed mostly by the spatial and seasonal changes in hydrography rather than short-term changes induced by tide. During the Spring Intermonsoon, all plankton consumers in the CBW was higher than the Southwest Monsoon, and the trophic interaction was more effective in upstream where there was a close coupling between all prey components and their consumers. During the Southwest Monsoon, on the other hand, the trophic interaction was more effective downstream where the abundance of all plankton consumers was significantly higher than the upstream. Based on statistical analyses NMDS/SIMPROF and RDA, we demarcated the spatial difference/mismatch in the prey and consumer distribution in the CBW and showed that a more efficient plankton food web exists in the mesohaline regions during both seasons. This suggests that a noticeable spatial shift occurs seasonally in the active plankton food web zone in the CBW; it is upstream during the Spring Intermonsoon and downstream during the Southwest Monsoon.

[18F]FDG-PET/CT for the diagnosis of patients with fever of unknown origin

BACKGROUND AND AIMS

The diagnosis of patients with fever of unknown origin (FUO) remains a challenging medical problem. We aimed to assess the diagnostic contribution of 18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET)/computed tomography (CT) for the evaluation of FUO.

METHODS

We performed a 4-year retrospective single-center study of all hospitalized patients that underwent FDG-PET/CT for evaluation of FUO. The final diagnosis of the febrile disease was based on clinical, microbiological, radiological and pathological data available at the final follow-up. Predictors for a contributory exam were sought.

RESULTS

One hundred and twelve patients underwent FDG-PET/CT for the investigation of FUO in the years 2008-2012 and were included in the study. A final diagnosis was determined in 83 patients (74%) and included: infectious disease in 49 patients (43%), non-infectious inflammatory disease in 17 patients (16%), malignancies in 15 patients (14%), other diagnoses in 2 patients (1.7%), FUO resolved with no diagnosis and no evidence of disease during a 6-month follow-up in 23 patients (20%), and death with fever and with no diagnosis in 6 patients (5%). Seventy-four FDG-PET/CT studies (66%) were considered clinically helpful and contributory to diagnosis (46% positive contributory value and 20.5% contributory to exclusion of diagnosis). PET/CT had a sensitivity of 72.2%, a specificity of 57.5%, a positive predictive value (PPV) of 74.2% and a negative predictive value (NPV) of 53.5%. On multivariable analysis, significant predictors of a positive PET/CT contributory to diagnosis were a short duration of fever and male gender.

CONCLUSIONS

PET/CT is an important diagnostic tool for patients with FUO.

Venous thromboembolism prophylaxis with anticoagulation in septic patients: a prospective cohort study

BACKGROUND

Venous thromboembolism (VTE) is a feared complication during hospitalization. The practice of administering pharmacological prophylaxis is highly endorsed despite failure of studies to show reduction in mortality.

AIM

: To determine the benefit of VTE prophylaxis in acutely ill medical patients with sepsis.

METHODS

A prospective cohort, with enrollment between January 2010 and April 2011. Patients were detected in four medicine departments at a university-affiliated hospital and followed for 90 days for pre-specified outcomes. We included all septic patients at high VTE risk defined by Padua score ≥ 4. The primary outcome was 30-day mortality. Incidence of pulmonary embolism, deep vein thrombosis or major bleeding episodes at 30 and 90 days, and 90-day mortality were secondary outcomes.

RESULTS

A total of 1540 patients were identified, of which 720 (55%) were at high risk for VTE and included. A total of 213 (29.6%) patients received prophylaxis. VTE occurred in 6 control patients and 2 treated (0.9 and 1.2%, respectively, RR 0.79, CI: 0.16-3.95). Major bleeding events occurred in 4 (0.8%) control and 7 (3.3%) treated patients (RR 4.1, CI: 1.24-14.08, P = 0.01). After adjusting for covariates, VTE prophylaxis conferred no 30- or 90-day mortality benefit (OR 1.24, CI: 0.79-1.93 and OR 1.47, CI: 0.99-2.17, respectively). Lack of significant benefit with prophylaxis persisted after propensity-score matching (OR for 30-day mortality 1.01, CI: 0.66-1.55).

CONCLUSIONS

In acutely ill inpatients with sepsis, no significant benefit was demonstrated for VTE prophylaxis, with higher rates of bleeding. The risk-benefit ratio of this intervention should be carefully examined.

Abundance of live ²⁴⁴Pu in deep-sea reservoirs on Earth points to rarity of actinide nucleosynthesis

Half of the heavy elements including all actinides are produced in r-process nucleosynthesis, whose sites and history remain a mystery. If continuously produced, the Interstellar Medium is expected to build-up a quasi-steady state of abundances of short-lived nuclides (with half-lives ≤100 My), including actinides produced in r-process nucleosynthesis. Their existence in today’s interstellar medium would serve as a radioactive clock and would establish that their production was recent. In particular ²⁴⁴Pu, a radioactive actinide nuclide (half-life=81 My), can place strong constraints on recent r-process frequency and production yield. Here we report the detection of live interstellar ²⁴⁴Pu, archived in Earth’s deep-sea floor during the last 25 My, at abundances lower than expected from continuous production in the Galaxy by about 2 orders of magnitude. This large discrepancy may signal a rarity of actinide r-process nucleosynthesis sites, compatible with neutron-star mergers or with a small subset of actinide-producing supernovae.

The build-up of short-lived nuclides in the interstellar medium tells us about production frequency and yield of heavy elements by nucleosynthesis. Wallner et al. find a low abundance of live interstellar 244Pu detected from the deep-sea floor, suggesting a rarity for r-process nucleosynthesis sites.

Detection and analysis of temperature-sensitive dermal blood perfusion dynamics and distribution by a hybrid camera system

In this paper we present an application of two optical imaging modalities for non-invasive assessment of dermal perfusion. This hybrid setup consists of a photo-plethysmographic camera sensing in the visible spectrum and a thermal camera sensing in the infrared-C-band. This allows to combine the information of both sources complementarily: The extracted perfusion index as well as the skin surface temperature. The feasibility of the presented system is tested in two studies with local temperature stress on the forehead of a subject. In the first, a local cooling on the subject's forehead is monitored and further analyzed. In the second, skin perfusion reactions to heat are considered. For both experiments the results are compared to baseline measurements and non-affected areas in the field of view of the cameras. As results, the dependencies between temperature and perfusion change are presented. Further, influences of the stressor can be visualized in functional mappings of calculated perfusion indices. For the performed test, a linear correlation between temperature and perfusion change is obtained.

The significance of persistent fever in the treatment of suspected bacterial infections among inpatients: a prospective cohort study

Antibiotic escalations are frequently guided by fever persistence. Unnecessary antibiotic escalation is associated with resistance induction. We examined whether fever persistence is associated with adverse outcomes among medical inpatients with sepsis. In a single-center prospective cohort study, we included consecutive medical inpatients with suspected or documented bacterial infections. Data were collected on days 0, 2, 4, and 30 days from episode onset. We examined the association between fever persistence at 4 days and 30-day mortality on univariate and multivariate analysis. Inappropriate empirical antibiotic treatment (IAET) was defined for patients with microbiologically documented infections (MDIs). Odds ratios (ORs) are presented with 95% confidence intervals (CIs). A total of 1,621 patients were included. Among patients with MDIs, 38/206 (18.4%) given appropriate empiric therapy had continued fever on day 4, compared to 64/231 (27.7%) of patients receiving IAET, OR 0.59, 95% CI 0.37-0.93. Fever persistence was not associated with mortality after adjustment for other risk factors. Among patients with presumed sepsis who did not have MDIs, persistent fever was significantly associated with 30-day mortality on a multivariate analysis, adjusted OR 2.77 (95% CI 1.78-4.31). Other risk factors for mortality included older age, nosocomial infections, malignancy, dyspnea, shock, decreased albumin, and elevated creatinine. For patients with MDIs, fever persistence for up to 4 days is a marker of IAET, but is not associated with mortality, and should not, in itself, trigger antibiotic escalation. For patients without MDIs, fever persistence should trigger careful re-evaluation, as it is associated with mortality.

Ethical dilemmas in antibiotic treatment: focus on the elderly

Maximal antibiotic treatment for all patients suspected of harbouring a bacterial infection is non-viable, because it will rapidly induce resistance and exhaust this finite resource. This raises two ethical dilemmas: the question of whether we are justified in increasing the danger to a present, named, patient so as to benefit future, unknown, patients; and whether we are allowed to do so without asking the present patient for consent. Although the considerations for healthy elderly patients are similar to younger adults, the answers are complex when addressing patients with dementia, severely reduced quality of life and at end of life. We argue that a public debate on the balance between benefit to a present patient versus harm to future patients should be conducted. Such a debate should include examinations of scenarios in which antibiotic treatment does not gain any benefit in a patient with infection: at the end of life; in situations in which resistance is such that empirical antibiotic treatment seldom matches the susceptibilities of the pathogen; and in patients with no quality of life. An explicit cost-benefit model, incorporating quality of life and risk of resistance, in computerized decision support might obviate a clinician's need to deal with these difficult issues at bedside.