Early recognition of failure of oxygen delivery and knowledge of how medications can alter oxygen delivery allow clinicians to institute appropriate therapies in a timely manner and can result in improved patient outcomes. Oxygen delivery can be estimated and evaluated using a variety of methods, including arterial blood gas sampling, blood lactate quantification, echocardiography, and direct cardiac output measurement. Delivery can be enhanced by manipulating the components of the oxygen delivery formula. Cardiac output, hemoglobin concentration, oxygen saturation, and oxygen tension can all be improved through therapeutic or pharmacologic intervention.