LAUSR

The February issue of SHOCK continues to build on our understanding of shock’s physiologic underpinnings as well as the translation of basic science to clinical practice, led by two reviews. First, Nolt et al. review a problem that has long vexed intensivists treating septic patients: the interpretation and import of serum lactate (1). The authors summarize what is known about lactate as an immunosuppressive metabolite and its potential role in the regulation of the immune cellular response. Such data would support lactate not only as more than as marker of disease severity, resuscitation efficacy, and clinical prognosis, but also as a contributing factor to the evolution of sepsis physiology in and of itself. In a second review, Zhang et al. summarize a body of work investigating potential mechanisms by which an infusion of exogenous atrial natriuretic peptide (ANP) may be protective in shock (2). Already in clinical use for the management of cardiac failure in Asia, ANP seems to impact reactive oxygen species (ROS) production as well as natriuretic peptic receptor-mediated signaling pathways, particularly in intestinal epithelium. The authors speculate that a positive ROS feedback loop, stimulated by exogenous ANP, sustains another wise transient expression of endogenous ANP to effect the organ protection observed in animal models and clinical trials. Four clinical studies are included in the current issue. Distinguishing between causes of shock in the emergency room can be challenging, yet crucial to initiation of timely and effective treatment. Henning et al. performed a secondary analysis of a prospectively collected, observational cohort of persistently hypotensive adults presenting to their institution (3). Using logistic regression analysis, a predictive score utilizing serum troponin, evidence of ECG ischemia, shortness of breath, absence of fever, and a history of heart failure was developed and validated against outcome. Although it may seem obvious that this constellation of clinical history and physical findings would be indicative of a cardiogenic etiology for hypotension, it is not uncommon for such data to initially be dismissed or attributed to something else. Simple screening tools utilizing readily available data put the pieces together early in the patient’s presentation and may help prevent delay of timely interventions. Norepinephrine is recommended as the vasopressor of choice for hemodynamic support in sepsis. Given that the gut barrier is