Effects of Fluid Resuscitation With Colloids vs Crystalloids on Mortality in Critically Ill Patients Presenting With Hypovolemic Shock: The CRISTAL Randomized Trial
What is the impact on mortality of using colloids versus crystalloids for fluid resuscitation in patients presenting with shock?
The authors performed a multicenter, randomized clinical trial stratified by case mix (sepsis, trauma, or hypovolemic shock without sepsis or trauma) comparing colloids to crystalloids for all fluid interventions other than maintenance fluids. Patients were randomized in an open-label fashion, but outcome assessment was blinded to treatment assignment. The colloids arm received gelatins, dextrans, hydroxyethyl starches, or 4% or 20% of albumin, whereas the fluids used in the crystalloids arm were isotonic or hypertonic saline or Ringer lactate solution. The primary outcome was death within 28 days. Secondary outcomes included 90-day mortality; and days alive and not receiving renal replacement therapy, mechanical ventilation, or vasopressor therapy.
There was no difference in mortality within 28 days (25.4% in the colloid group vs. 27% in the crystalloids group; relative risk [RR], 0.96; 95% confidence interval [CI], 0.88-1.04; p = 0.26). The 90-day mortality was lower in the colloid group (30.7% vs. 34.2%; RR, 0.92; 95% CI, 0.86-0.99; p = 0.03). There was no difference in use of renal replacement therapy (11% vs. 12.5%; RR, 0.93; 95% CI, 0.83-1.03; p = 0.19). Patients randomized to colloids were more likely to be alive without mechanical ventilation by 28 days (mean: 14.6 vs. 13.5 days; mean difference, 1.10; 95% CI, 0.14-2.06 days; p = 0.01) and alive without vasopressor therapy by 28 days (mean: 16.2 vs. 15.2 days; mean difference, 1.04; 95% CI, -0.04 to 2.10 days; p = 0.03).
Among intensive care unit patients with hypovolemia, there was no difference in 28-day mortality with use of colloids versus crystalloids. Use of colloids was associated with a reduction in the secondary endpoint of 90-day mortality.
The optimal fluid choice for resuscitation continues to be debated, and most data suggest that crystalloids are associated with as good, if not better, outcome than colloids. Previously, concern had been raised that use of hydroxyl ethyl starches may be associated with increased kidney injury and mortality (Zarychansk, JAMA 2013). This study did not specifically examine the impact of each type of fluid, but there was no signal that the observed findings differed based on the specific type of resuscitation fluid, and no excess mortality with hydroxyl ethyl starch was noted. Since crysalloids are cheaper, they should remain the preferred agents with colloid use restricted to unique circumstances.
Clinical Topics: Anticoagulation Management
Keywords: Resuscitation, Sepsis, Shock, Gelatin, Hypovolemia, Diagnosis-Related Groups, Dextrans, Hydroxyethyl Starch Derivatives, Fluid Therapy, Cardiovascular Diseases, Colloids, Critical Illness, Confidence Intervals, Lactic Acid, Isotonic Solutions, Respiration, Renal Replacement Therapy
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