This issue of Critical Care Clinics focuses on Rapid Response Systems and Fluid Resuscitation, with topics including: RRS Now; Triggering Criteria; Surgery/Trauma RRT; Obstetric RRT; Difficult airway rapid response teams; Sepsis rapid response teams; Applied physiology of fluid resuscitation in critical illness; The microcirculation and endothelial function in critical illness; The role of fluid therapy in optimizing the high-risk surgery patient; Blood product administration in critical illness and perioperative settings; and the effect of fluid type and amount on kidney function in critical illness.