Question special

A few questions in this one again! In PRISM, patients randomized to EGDT had an average baseline ScVO2 >70%, suggesting they were already resuscitated at enrollment. Since the EGDT and usual care groups were similar, they likely also had a similar ScVO2 level. You stratified on many different severities of illness, but since EGDT targets end-points of resuscitation, did you stratify patients on ScVO2 at randomization? In the Rivers trial, ICU physicians were blinded to any care provided in the ED and to clinical variables for 72 hours afterward (including CVP and ScVO2). In Process, Promise, and Arise ICU physicians took over care and were not blinded. Since usual care now includes knowledge of poor outcomes with patients who have low CVPs and SVO2s of 40%, were these ever measured in the usual care group or were clinicians prohibited from measuring these? Do you think the differences in blinding between Rivers and PRISM underemphasized a possible effect in the sickest patients – clearly not based on APACHE-II or Lactate, but possibly based on ScVO2 and CVP?