Finding the cause of acute kidney injury: which index of fractional excretion is better?

The fractional excretion of urea (FEU) is a useful index for differentiating the main categories of causes of acute kidney injury, ie, prerenal causes and intrinsic causes. It may be used in preference to the more widely used fractional excretion of sodium (FENa) in situations in which the validity of the latter is limited, such as in patients taking a diuretic.     

How payment systems affect physicians' provision behaviour--an experimental investigation

Understanding how physicians respond to incentives from payment schemes is a central concern in health economics research. We introduce a controlled laboratory experiment to analyse the influence of incentives from fee-for-service and capitation payments on physicians' supply of medical services. In our experiment, physicians choose quantities of medical services for patients with different states of health. We find that physicians provide significantly more services under fee-for-service than under capitation. Patients are overserved under fee-for-service and underserved under capitation. However, payment incentives are not the only motivation for physicians' quantity choices, as patients' health benefits are of considerable importance as well. We find that patients in need of a high (low) level of medical services receive larger health benefits under fee-for-service (capitation).     

The anthrax vaccine adsorbed vaccine generates protective antigen (PA)-Specific CD4+ T cells with a phenotype distinct from that of naive PA T cells

Cellular immune responses against protective antigen (PA) of Bacillus anthracis in subjects that received the anthrax vaccine adsorbed (AVA) vaccine were examined. Multiple CD4(+) T-cell epitopes within PA were identified by using tetramer-guided epitope mapping. PA-reactive CD4(+) T cells with a CD45RA(-) phenotype were also detected by direct ex vivo staining of peripheral blood mononuclear cells (PBMC) with PA-specific tetramers. Surprisingly, PA-specific T cells were also detected in PBMC of nonvaccinees after a single cycle of in vitro PA stimulation. However, PA-reactive CD4(+) T cells in nonvaccinees occurred at lower frequencies than those in vaccinees. The majority of PA-reactive T cells from nonvaccinees were CD45RA(+) and exhibited a Th0/Th1 cytokine profile. In contrast, phenotyping and cytokine profile analyses of PA-reactive CD4(+) T cells from vaccinees indicated that vaccination leads to commitment of PA-reactive T cells to a Th2 lineage, including generation of PA-specific, pre-Th2 central memory T cells. These results demonstrate that the current AVA vaccine is effective in skewing the development of PA CD4(+) T cells to the Th2 lineage. The data also demonstrated the feasibility of using class II tetramers to analyze CD4(+) cell responses and lineage development after vaccination.     

Critical illness associated with 2013-2014 influenza A (H1N1): Postpandemic characteristics,presentation and outcomes

Introduction:

The United States experienced a postpandemic outbreak of H1N1 influenza in 2013–2014. Unlike the pandemic in 2009 clinical course and outcomes associated with critical illness in this postpandemic outbreak has been only sparsely described.

Methods:

We conducted a retrospective analysis of all patients admitted to the Medical Intensive Care Unit with H1N1 influenza infection in 2009–2010 (pandemic) and 2013–2014 (postpandemic).

Results:

Patients admitted in the postpandemic period were older (55 ± 13 vs. 45 ± 12, P = 0.002), and had a higher incidence of underlying pulmonary (17 vs. 7, P = 0.0007) and cardiac (16 vs. 8, P = 0.005) disease. Mechanical ventilation was initiated in most patients in both groups (27 vs. 21, P = 1.00). The PaO₂/FiO₂ ratio was significantly higher in the pandemic group on days 1 (216 vs. 81, P = 0.0009), 3 (202 ± 99 vs. 100 ± 46, P = 0.002) and 7 (199 ± 103 vs. 113 ± 44, P = 0.019) but by day 14 no difference was seen between the groups. Rescue therapies were used in more patients in the postpandemic period (48% vs. 20%, P = 0.028), including more frequent use of prone ventilation (10 vs. 3, P = 0.015), inhaled vasodilator therapy (11 vs. 4, P = 0.015) and extracorporeal membrane oxygenation (ECMO) (4 vs. 2, P = NS). No significant differences in mortality were seen between the two cohorts.

Conclusions:

Compared to the 2009–2010 pandemic, the 2013–2014 H1N1 strain affected older patients with more underlying co-morbid cardio-pulmonary diseases. The patients had worse oxygenation indices and rescue modalities such as prone ventilation, inhaled epoprostenol and ECMO, were used more consistently as compared to the 2009 pandemic.