MedicalResearch.com: What are the main findings of the study?
Answer: The CRISTAL trial was designed in 2002 to clarify whether correction of acute hypovolemia in critically ill patients with colloids may increase the risk of death as compared to resuscitation with crystalloids. The trial has enrolled 2857 patients in 57 ICUs in France, Belgium, Canada and North Africa. The relative risk of death was at 28 day of 0.96 (95% CI: 0.88 to 1.04; P=0.26), and at 90 day of 0.92 (95%CI: 0.86 to 0.99; P=0.03) in favor of colloids. Colloids-treated patients had more days alive and off mechanical ventilation and off vasopressor both within 7 days and 28 days of randomization. There was no evidence for increased risk of kidney injury with colloids.
MedicalResearch.com: Were any of the findings unexpected?
Answer: The trial was designed to confirm the superiority of crystalloids as suggested by the available evidence in 2002, at the time the trial was designed. Thus, it was very surprising to found fewer deaths at 90 days in colloids treated patients. As hydroxyethyl starches were used in close to 70% in the colloids arm, it was also surprising not to find an increase risk of renal injury. These findings may be explained by a very strict limitation of the dose of starches solution, the exclusion of patients with severe chronic renal diseases, potential kidney protection via reduction in the duration of circulatory shock and respiratory failure. In addition, in the crystalloids group, isotonic saline was used in almost ¾ of patients. It is well known that chloride rich solution such normal saline may alter renal function.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: In under-resuscitated hypovolemic ICU patients, treatment with colloids did not increase the risk of dying as compared with crystalloids. As mortality at 90-day was not the primary outcome, the findings of fewer death with colloids by this time point should be considered as exploratory findings to be confirmed in future trial. Meanwhile, there is no evidence in this group of patients to abandon the use of colloids.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
One of the main remaining issues is the role of buffered solutions. Thus, future trial should be designed to compare buffered versus non-buffered fluid therapies.
Annane D, Siami S, Jaber S, et al. Effects of Fluid Resuscitation With Colloids vs Crystalloids on Mortality in Critically Ill Patients Presenting With Hypovolemic Shock: The CRISTAL Randomized Trial. JAMA. 2013;():-. doi:10.1001/jama.2013.280502.