Methods and compositions disclosed herein generally relate to methods of identifying, validating, and measuring clinically relevant, quantifiable biomarkers of diagnostic and therapeutic responses for blood, vascular, cardiac, and respiratory tract dysfunction, particularly as those responses relate to septic shock in pediatric patients. In particular, the invention relates to identifying one or more biomarkers associated with septic shock in pediatric patients, obtaining a sample from a pediatric patient having at least one indication of septic shock, then quantifying from the sample an amount of one or more of said biomarkers, wherein the level of said biomarker correlates with a predicted outcome.