Cryptic shock (shock with normal vital signs) is a frequent occurrence in early severe sepsis and septic shock. Despite resuscitation to the goals for mean arterial blood pressure and CVP, almost 40% of control patients continued to exhibit global tissue hypoxia (decreased ScvO 2 and increased lactate levels); in these patients, there was a twofold increase in hemodynamic deterioration, requiring more mechanical ventilation, pulmonary artery catheterization, and vasopressor use in the subsequent 72 hours.