One large mRCT on the impact of colloids on survival in critically ill patients was published after the Consensus Conference [8]. The CRISTAL trial (Colloids versus Crystalloids for the Resuscitation of the Critically Ill) involved 57 ICUs from five different countries and enrolled 2,857 patients. Patients with hypovolemic shock were randomized to receive fluid resuscitation by either colloid or crystalloids. There was no blinding, and clinicians could choose to administer whichever fluid was available in their institution. Most of the patients in the crystalloid group received normal saline; most of the patients in the colloid group received hydroxyethyl starches. Enrolment was stopped early due to futility at an ad interim analysis; therefore, no significant difference was found in 28-day mortality (primary end point). The need of renal replacement therapy did not differ between the two groups. Ninety-day mortality was investigated as a secondary post hoc endpoint, and a statistical significant difference was found: relative risk (RR) 0.92 (95 % confidence interval (CI) 0.86–0.99), p = 0.03. The authors themselves highlighted the weakness of this result that should be considered as explorative. Nevertheless, this trial started a vivacious debate on the impact of colloids on mortality and on renal impairment. Perner noted that the CRISTAL trial had a high risk of bias, as it was open-label and allocation might have been inadequate [11]. The open-label design imposes to demonstrate equal-quality resuscitation and continuous monitoring of renal function, but both of these points were suboptimal in Annane’s work, according to Bellomo and colleagues [12]. Moreover, the use of different fluids in each intervention group makes the interpretation of these results difficult [11]. The implications of Annane’s work are discussed in Chap. 9, dedicated to the detrimental effect of colloids.

Heart diseases still rank as United States first cause of death. Out-of-hospital CCA has an overall incidence of 126 cases per 100,000 inhabitants/year. Survival till hospital discharge is less than 5 % and doubles in case of treatment by the emergency medical services. In case of in-hospital CCA, survival increases up to 24 % [13]. Moreover, among CCA survivors, the prevalence of severe cerebral disability or vegetative state ranges from 25 to 50 %.