Effects of Fluid Resuscitation With Colloids vs Crystalloids on Mortality in Critically Ill Patients Presenting With Hypovolemic Shock: The CRISTAL Randomized Trial
Annane D, Siami S, Jaber S, et al; CRISTAL Investigators
Fluid administration is one of the most common items managed every day in hospitalized and intensive care unit (ICU) patients, and it is the core principle for managing patients with hypovolemic shock.
However, the optimal fluid for resuscitation remains unknown, and concerns about both crystalloids and colloids have been raised.[1,2] The investigators of this study sought to determine whether colloids or crystalloids may be superior for resuscitation of critically ill patients with shock.
This study was a multicenter, randomized clinical trial conducted between 2003 and 2012, in which open-label fluids were used in 57 French, Belgian, and Canadian ICUs. There were 2857 ICU patients treated with colloids (n = 1414; gelatins, dextrans, hydroxyethyl starches, or 4% or 20% albumin) or crystalloids (n = 1443; isotonic or hypertonic saline, or Ringer lactate solution) for all fluid interventions, other than maintenance, throughout the ICU stay.
Within 28 days, there were 359 deaths (25.4%) in the colloids group and 390 deaths (27.0%) in the crystalloids group, yielding a relative risk of 0.96 (P = .26). At 90 days, there were 434 deaths (30.7%) in the colloids group vs 493 deaths (34.2%) in the crystalloids group (relative risk, 0.92; P = .03).
Renal replacement therapy did not statistically differ between the groups, and there were more days alive without mechanical ventilation and alive without vasopressor therapy in the colloids group. The investigators concluded that for ICU patients with hypovolemia, colloids are at least as efficacious as crystalloids.
This study measured a broad population of ICU patients needing fluid resuscitation, potentially making it more generalizable than more narrowly defined clinical trials. It also suffers from being conducted over a very long period (10 years), no blinding to the administration of various fluids, and permitting the use of heterogeneous fluids and combining them for the overall study analysis.
For example, a growing body of literature suggests that hydroxyethyl starch solutions may cause renal damage, particularly in patients with sepsis.[3,4,5,6] These findings recently resulted in regulatory warnings against their use in many critically ill patients. Conversely, albumin has been suggested to confer benefit in sepsis resuscitation.[7,8]
Combining these different fluids together in this study is likely to obscure very different risks and benefits to the patients. Although this study included many patients, it should not change practice because of its severe flaws and limited ability to draw conclusions about specific patients and specific fluids.
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Cite this: Greg Martin. Hypovolemic Shock: Effect of Fluid Choice on Mortality - Medscape - Jan 02, 2015.