What's New in Shock, May 2017?
The first article by Etchill et al. (1) is an extensive review that deals with the important topic of thrombocytopenia and platelet transfusion practices in surgical and critical care settings. Thrombocytopenia is a common problem in critically ill patients and an independent predictor of mortality. The authors provide a critical appraisal of data reported by 153 manuscripts focusing on transfusion practices in different settings of thrombocytopenia. A highlight of the study is the description of point-of-care laboratory assays, which emphasizes the importance of platelet function testing. The authors also provide a synopsis of recent advances in transfusion medicine and research into synthetic platelet substitutes that may overcome some of the complications and critical contraindications associated with platelet transfusion.
The study by Long et al. (2) of the Paediatric Research in Emergency Departments International Collaborative is a systematic review and meta-analysis of data on respiratory variation in the inferior vena cava (IVC) diameter as a predictor of fluid responsiveness in patients with acute circulatory failure. Assessment for volume responsiveness prior to fluid resuscitation is already recommended by the European Society of Intensive Care Medicine, since prediction of fluid responsiveness would allow for resuscitation with fluids to patients who would benefit, while it would reduce adverse effects of fluid overload. A noninvasive tool, such as the measurement of respiratory variation in IVC diameter, would, therefore, provide additional benefit without added risk. After a critical analysis of 17 studies assessed for the design and reporting quality and the risk of bias, the authors conclude that respiratory variation in IVC diameter is moderately predictive of fluid responsiveness. This noninvasive test is most useful in mechanically ventilated patients where invasive monitoring carries high risk or is impractical.
Another extensive review by Antonucci et al. (3) deals with the challenging management of patients with refractory septic shock and proposes a very debated topic of the need for novel vasopressor therapies. Specifically, the authors focus on the potential therapeutic benefits of angiotensin II (Ang II) in catecholamine-resistant shock. In this review, the authors first address the biological mechanisms of the renin–angiotensin–aldosterone system in septic shock by assembling an extensive number of preclinical studies. The authors then comment on the few available clinical studies, including the phase II ATHOS clinical trial, which shows some promising results in distributive shock in a single-center pilot study. The authors also outline the important drawbacks and potential deleterious effects of Ang II on microcirculation. At this stage of knowledge, we cannot agree more with the authors that it is still premature to state that Ang II is beneficial in refractory shock. Only large-scale randomized trials can provide relevant information on the clinical relevance of this treatment approach.
The article by Fox et al. (4) is an Invited Opinion on behalf of the investigators from the Pragmatic, Randomized Optimal Platelet and Plasm Ratios group and addresses the critical importance of choosing appropriate endpoints in hemorrhagic shock trials. Recent hemorrhagic shock trials have used 24 h and/or 30-day all-cause mortality as the primary endpoint. The study by Fox et al.