What's new in Shock, February 2009?

Something new is being tried for writing What’s New in Shock. Writing this edition occurs while flying over the Persian Gulf and just to the west of Baghdad, Iraq. Publication in February will verify that the flight was uneventful. This edition of Shock has 16 articles, including 1 review, 6 clinical articles, and 9 basic science contributions. There are also 3 commentaries, which will not be further commented on. The excellent review article by the group of Novotny et al. (1) out of Indiana University re-examines the evidence for using "-blockers to treat sepsis. This review spans a range of topics including the impact of "-blockade on metabolism, glucose regulation, the inflammatory response (including cytokine production), cardiac function, and, perhaps the most important of all, mortality. The review also spans a range of time stretching from 1969 to 2008, with 39 references from the last 3 years. The conclusion from this well-written and timely review: it is time to launch clinical trials to fully test the clinical benefits of "-blockers. There are three articles discussing the topic of predicting outcome in critically ill patients: two discussing septic patients and one looking at burn patients. Chen et al. (2) used the RIFLE system to predict in-hospital mortality in 121 septic patients. The RIFLE system was originally designed to predict outcome in acute kidney injury (the acronym is rather long and will not be repeated here). Extending these parameters to predict outcome in septic patients is innovative. The RIFLE findings correlated with the more traditional Acute Physiology and Chronic Health Evaluation (APACHE) or Sequential Organ Failure Assessment (SOFA) scoring systems, and the RIFLE score on admission independently predicted mortality. In the second sepsis study, Rhee et al. (3) examined the Pitt bacteremia and APACHE II scoring systems to predict outcome in 134 patients. The data were analyzed by the area under the curve calculated with receiver operator characteristic curves. Investigators not familiar with receiver operator characteristic curve should learn the fundamentals because the methodology provides an integration of sensitivity and specificity into a single parameter. In this study, the Pitt bacteremia score predicted mortality better than APACHE II. The final study by Lorente et al. (4) used the SOFA score in 439 patients. Sequential Organ Failure Assessment score was calculated on admission and daily up to day 4. Sequential Organ Failure Assessment scores on day 1, day 4, or the difference in SOFA between days 4 and 0 all independently predicted outcome in burn patients. Biomarkers that accurately predict outcome would be a tremendous advance in any field of medicine, whether it is shock, cancer, or cardiovascular disease. Jochberger et al. (5) looked at arginine vasopressin levels in different groups of patients and found that those who failed to generate an appropriate arginine vasopressin response, that is, increased plasma levels, in response to the systemic inflammatory response syndrome had a worse outcome. In the study by Ramakers et al. (6), glutathione S-transferase A1-1 (GSTA1-1) was evaluated as an early biomarker to predict hepatic injury in septic patients. Repeated injections of endotoxin in human volunteers did not increase GSTA1-1, although the endotoxin injections did elevate plasma cytokine levels. However, in the 21 septic patients who were examined, GSTA1-1 levels measured within 12 hours of admission predicted hepatic damage on day as assessed by elevated transaminase levels. An in vivoYex vivo study was used by Tsen et al. (7) to examine the ability of plasma from septic patients to alter neutrophil endothelial interactions in the presence of different anticoagulants. The ex vivo study allowed the investigators to look at these multiple interactions in a controlled manner. Several different anticoagulants decreased sepsis-induced neutrophil endothelial cell interactions induced by plasma from septic patients, and thrombin reversed the effects of these agents. Shock investigators understand that significant differences exist between the different diseases and models that we study. Two articles in this edition directly examined these differences. In the first by Tschop et al. (8), the immunological phenotypes induced by scald and flame burns were studied. Both burn methods caused a full-thickness burn, but the scald injury resulted in greater morbidity and mortality compared with the burn injury. Thus, even within the spectrum of burn models, there are significant differences. The Gomez et al. (9) laboratory also looked at burn injury induced by scalding and compared the hepatic inflammatory response with that caused by LPS injection. This study also looked at the effects of aging and IL-6 in both these models. The authors conclude that the nature of the insult helps determine the remote tissue response (in this case, the liver), whereas the contribution of IL-6 may be specific to the insult. The inflammatory response may remain localized, become systemic, or be a continuum between local and systemic. To determine whether the response has become systemic, it is frequently necessary to measure more than one aspect. LPS was also used to induce inflammation in the article by Gamble et al. (10), but the LPS was given intratracheally. After the intratracheal injection of LPS, the TNF response stayed localized, but IL-6 and LPS binding protein increased both within the lung and the plasma.