Association of frailty with short-term outcomes,organ support and resource use in critically ill patients

Purpose

Frail patients are known to experience poor outcomes. Nevertheless, we know less about how frailty manifests itself in patients’ physiology during critical illness and how it affects resource use in intensive care units (ICU). We aimed to assess the association of frailty with short-term outcomes and organ support used by critically ill patients.

Methods

Retrospective analysis of prospective collected data from 93 ICUs in Brazil from 2014 to 2015. We assessed frailty using the modified frailty index (MFI). The primary outcome was in-hospital mortality. Secondary outcomes were discharge home without need for nursing care, ICU and hospital length of stay (LOS), and utilization of ICU organ support and transfusion. We used mixed logistic regression and competing risk models accounting for relevant confounders in outcome analyses.

Results

The analysis consisted of 129,680 eligible patients. There were 40,779 (31.4%) non-frail (MFI?=?0), 64,407 (49.7%) pre-frail (MFI?=?1–2) and 24,494 (18.9%) frail (MFI?≥?3) patients. After adjusted analysis, frailty was associated with higher in-hospital mortality (OR 2.42, 95% CI 1.89–3.08), particularly in patients admitted with lower SOFA scores. Frail patients were less likely to be discharged home (OR 0.36, 95% CI 0.54–0.79) and had higher hospital and ICU LOS than non-frail patients. Use of all forms of organ support (mechanical ventilation, non-invasive ventilation, vasopressors, dialysis and transfusions) were more common in frail patients and increased as MFI increased.

Conclusions

Frailty, as assessed by MFI, was associated with several patient-centered endpoints including not only survival, but also ICU LOS and organ support.

     

A review of potential pharmacogenetic effects on catecholamine responses

Considerably, variability in the clinical response to inotropic agents is observed and could be explained partially by the genetic variants, such as single-nucleotide polymorphism (SNP) in genes encoding for enzymes implicated in catecholamines synthesis, metabolism, storage and release or in the signaling pathway. This review highlights the potential effect of pharmacogenetics studies in hemodynamic response and identified 11 SNPs that could be relevant to explain the high variability drug response for a same dose. Cardiovascular instability, such as hypotension, is one of the premature birth complications. The pharmacogenetics studies evaluating these SNP may be useful to better understand the clinical outcome, particularly in this population.     

Enzymatic characterization of Vibrio alginolyticus strains isolated from bivalves harvested at Venice Lagoon (Italy) and Guanabara Bay (Brazil)

The aquatic ecosystem is the natural habitat of microorganisms including Vibrio and Aeromonas genus which are pathogenic to human and animals. In the present investigation the frequency of these bacteria and the enzymatic characteristics of 34 Vibrio alginolyticus strains isolated from bivalves harvested in Venice Lagoon (Italy) and Guanabara Bay (Brazil) were carried out from November 2003 to February 2004. The mussels' samples were submitted to enrichment in Alkaline Peptone Water (APW) added with 1% of sodium chloride (NaCl) and APW plus 3% NaCl incubated at 37 degrees C for 18-24 h. Following the samples were streaked onto TCBS Agar (Thiossulfate Citrate Bile Sucrose Agar) and the suspected colonies were submitted to biochemical characterization. Also, the Vibrio alginolyticus strains were evaluated to collagenase, elastase and chondroitinase production. The results showed the isolation of 127 microorganisms distributed as follows: 105 Vibrio strains such as V. alginolyticus (32.4%), V. harveyi (19%) and V. parahaemolyticus (7.6%), 20 Aeromonas strains and two Plesiomonas shigelloides were the main pathogens isolated. We observed the production of the three enzymes from V. alginolyticus strains considered as the main virulence factors of the bacteria, especially in cases of human dermatological infection.     

Long-term fluvastatin reduces the hazardous effect of renal impairment on four-year atherosclerotic outcomes (a LIPS substudy)

Mild renal impairment is an important risk factor for late cardiovascular complications. This substudy of the Lescol Intervention Prevention Study (LIPS) assessed the effect of fluvastatin on outcome of patients who had renal dysfunction and those who did not. Complete data for creatinine clearance calculation (Cockcroft-Gault formula) were available for 1,558 patients (92.9% of the LIPS population). Patients were randomized to fluvastatin or placebo after successful completion of a first percutaneous coronary intervention. Follow-up time was 3 to 4 years. The effect of baseline creatinine clearance on coronary atherosclerotic events (cardiac death, nonfatal myocardial infarction, and coronary reinterventions not related to restenosis) was evaluated. Baseline creatinine clearance (logarithmic transformation) was inversely associated with an incidence of adverse events among patients who received placebo (hazard ratio 0.99, 95% confidence interval 0.982 to 0.998, p = 0.01). However, no association was noted between creatinine clearance and the incidence of adverse events among patients who received fluvastatin (hazard ratio 1.0, 95% confidence interval 0.99 to 1.0, p = 0.63). No further deterioration in creatinine clearance was observed during follow-up, regardless of baseline renal function or allocated treatment. Occurrence of adverse events was not related to changes in renal function during follow-up. Fluvastatin therapy markedly decreased the risk of coronary atherosclerotic events after percutaneous intervention in patients who had lower values of creatinine clearance at baseline. The benefit of fluvastatin was unrelated to any effect on renal function.     

A heart-specific CD4+ T-cell line obtained from a chronic chagasic mouse induces carditis in heart-immunized mice and rejection of normal heart transplants in the absence of Trypanosoma cruzi

To study the role of autoreactive T cells in the pathogenesis of cardiomyopathy in Chagas' disease, we generated a cell line by repeated in vitro antigenic stimulation of purified splenic CD4+ T lymphocytes from a chronically Trypanosoma cruzi-infected mouse. Cells from this line were confirmed to be CD4+ CD8- and proliferated upon stimulation with soluble heart antigens from different animal species, as well as with T. cruzi antigen, in the presence of syngeneic feeder cells. In vitro antigen stimulation of the cell line produced a Th1 cytokine profile, with high levels of IFNgamma and IL-2 and absence of IL-4, IL-5 and IL-10. The cell line also terminated the beating of fetal heart clusters in vitro when cocultured with irradiated syngeneic normal spleen cells. In situ injection of the cell line into well established heart transplants also induced the cessation of heart beating. Finally, adoptive transfer of the cell line to heart-immunized or T. cruzi-infected BALB/c nude mice caused intense heart inflammation.     

Time course and distribution of tungsten-laden macrophages in the hilar lymph nodes of the dog lung after experimental instillation of calcium tungstate into the left apical bronchus

We sprayed a tungsten powder (CaWO4) into the airway of a single lobe (left apical) of the dog lung in order to study: (a) the kinetics of particle translocation from the bronchoalveolar lining to hilar lymph nodes, and (b) the sorting in lung lymph nodes of inhaled microcrystals. We found that the transport of the tungsten particles to the regional lymph node takes at least 24 hours and reaches its peak at day 7. In situ detection of tungsten by elemental particle analysis of lymph node sections by scanning electron microscopy allowed precise mapping of the marker in the node; the method was complemented by light microscopy and thin-section electron microscopy of the same nodes. Virtually all of the lymph node tungsten was located inside macrophages. The first tungsten-positive macrophages seen in the regional lymph nodes (day 1 to day 3) were restricted to the subcapsular space. This was followed by massive filling of the same sinus and of the narrow interfollicular areas by the particle-laden macrophages (day 3 to day 7). The even distribution of the tungsten-bearing phagocytes found in these anatomical regions of the node indicated that the subcapsular area in the dog was a continuous domain rather than the segmented region observed in nodes of common laboratory animals such as the rat. By day 7 after tungsten instillation, a moderate number of tungsten-positive macrophages was also detected in the paracortical region of the node. Finally, the presence of tungsten-bearing macrophages was extended to the outer lymph node medulla (day 7 to day 14); here, the macrophages were located in association with cords of plasmacytes and showed interdigitations with these lymphocytes. Only minimal amounts of tungsten were detected inside lymphoid follicles in association with dendritic cells. Some of the tungsten initially deposited in the airway of the apical left lung lobe was detected in contralateral hilar lymph nodes. We conclude that: (i) particle translocation from the alveolus to regional lymph nodes is a slow process that is mediated by pulmonary macrophages, in agreement with the findings of Harmsen et al Science 230:1277, 1985); (ii) in the lymph node, particle-bearing macrophages are sorted through narrow interfollicular sinuses into the outer medulla where they interact extensively with plasma cells; (iii) the migrating macrophages cannot penetrate the follicular domains of the node; minute quantities of exogenous particles may, nevertheless, be transferred from macrophages to follicular dendritic cells; and (iv) contralateral drainage may be a feature of the lymphatic system in the lung.     

Time-dependent modulation of AMPA receptor phosphorylation and mRNA expression of NMDA receptors and glial glutamate transporters in the rat hippocampus and cerebral cortex in a pilocarpine model of epilepsy

The pilocarpine model in rodents reproduces the main features of mesial temporal lobe epilepsy related to hippocampus sclerosis (MTLE-HS) in humans. It has been demonstrated in this model that the phosphorylation of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluR1 subunit is increased 1 h after pilocarpine treatment. Moreover, alterations in the levels of glutamate transporters have been associated with chronic epilepsy in humans. Despite these studies, the profile of these changes has not yet been addressed. We analyzed the protein content and phosphorylation profile of the AMPA receptor GluR1 subunit by western blotting. We also used quantitative real-time polymerase chain reaction to analyze the expression of glial glutamate transporters and the N-methyl-d-aspartate receptor NR1 subunit in the hippocampus (Hip) and cerebral cortex (Ctx) at different time points after pilocarpine-induced status epilepticus (Pilo-SE) in male adult Wistar rats. Biochemical analysis was performed in the Hip and Ctx at 1, 3, 12 h (acute period), 5 days (latent period), and 50 days (chronic period) after Pilo-SE. Key findings include an increase in the phosphorylation of GluR1-Ser⁸⁴⁵ in the Ctx and GluR1-Ser⁸³¹ in the Hip at different times during the acute period, and a decrease in the total content of the GluR1 subunit in the Ctx in the latent period. There was a down-regulation of the mRNA expression and protein levels of EAAT1 and EAAT2, and a decrease of the NR1 mRNA expression, in the Ctx during the latent period. Notably, during the chronic period, the EAAT2 mRNA expression and protein levels decreased while the NR1 mRNA levels increased in the Hip. Taken together, our findings suggest a time- and structure-dependent imbalance of glutamatergic transmission in response to Pilo-SE, which might be associated with either epileptogenesis or the seizure threshold in MTLE-HS.