Critical Care Medicine www.ccmjournal.org e721 populations of critically ill patients, several RCTs are underway. Fortunately, most have safeguards in place, including the exclusion of patients with known G6PD deficiency and oxalate nephropathy ("primum non nocere") and for patients with unknown G6PD status, monitoring for serious adverse events and using enhanced point-of-care techniques ("secundum cavere").