Microcirculatory perfusion disturbances in septic shock: results from the ProCESS trial

Abstract Background We sought to determine the effects of alternative resuscitation strategies on microcirculatory perfusion and examine any association between microcirculatory perfusion and mortality in sepsis. Methods This was a prospective, formally designed substudy of participants in the Protocolized Care in Early Septic Shock (ProCESS) trial. We recruited from six sites with the equipment and training to perform these study procedures. All subjects were adults with septic shock, and each was assigned to alternative resuscitation strategies. The two main analyses assessed (1) the impact of resuscitation strategies on microcirculatory perfusion parameters and (2) the association of microcirculatory perfusion with 60-day in-hospital mortality. We measured sublingual microcirculatory perfusion using sidestream dark field in vivo video microscopy at the completion of the 6-h ProCESS resuscitation protocol and then again at 24 and 72 h. Results We enrolled 207 subjects (demographics were similar to the overall ProCESS cohort) and observed 40 (19.3%) deaths. There were no differences in average perfusion characteristics between treatment arms. Analyzing the relationship between microcirculatory perfusion and mortality, we found an association between vascular density parameters and mortality. Total vascular density (beta = 0.006, p < 0.003), perfused vascular density (beta = 0.005, p < 0.04), and De Backer score (beta = 0.009, p < 0.01) were higher overall in survivors in a generalized estimating equation model, and this association was significant at the 72-h time point (p < 0.05 for each parameter). Conclusions Microcirculatory perfusion did not differ between three early septic shock treatment arms. We found an association between microcirculatory perfusion parameters of vascular density at 72 h and mortality. Trial registration ClinicalTrials.gov, NCT00510835. Registered on August 2, 2007

Fluid therapy in critical illness

Major surgery and critical illnesses such as sepsis and trauma all disturb normal physiological fluid handling. Intravenous fluid therapy for resuscitation and fluid maintenance is a central part of medical care during these conditions, yet the evidence base supporting practice in this area lacks answers to a number of important questions. Recent research developments include a refinement of our knowledge of the endothelial barrier structure and function and a focus on the potential harm that may be associated with intravenous fluid therapy. Here, we briefly describe the contemporary view of fluid physiology and how this may be disrupted by pathological processes. The important themes in critical illness fluid research are discussed, with a particular focus on two emerging ideas: firstly, that individualising fluid treatment to the patient, their underlying disease state and the phase of that illness may be key to improving clinical outcomes using fluid interventions and, secondly, that fluids should be considered to be drugs, with specific indications and contraindications, dose ranges and potential toxicities