Which of the following statement(s) is/are true concerning oxygen kinetics in a critically ill, febrile patient?

b. The high cardiac output and pulse rate are designed to increase oxygen delivery

d. The patient can maintain adequate compensation as long as the oxygen delivery/oxygen consumption rate is greater than 2:1 

In critically ill patients oxygen consumption may be elevated or depressed, but slight to moderate elevations in oxygen consumption is the most common abnormality in critically ill patients. Oxygen consumption will be elevated in proportion to the amount of inflammation. A febrile patient with significant signs of septic toxicity will typically have an oxygen delivery at 1.5 to 2 times normal. It is very unusual for a critically ill patient to experience oxygen consumption greater than twice normal. This occurs only in situations of severe muscular exercise such as seizures or tetanus. During hypermetabolism, a change in oxygen consumption is followed promptly by a proportionate change in oxygen delivery. Hence, it is “normal” for a hypermetabolic patient to have a high cardiac output and pulse rate. Rarely the hyperdynamic response exceeds the increase in oxygen consumption, reflected in a ratio higher than 5:1 and venous saturation greater than 80%. Some patients cannot mount an increased oxygen delivery in response to increased oxygen consumption because of the combination of hypoxemia, anemia, and myocardial failure. If this occurs, then the oxygen delivery/oxygen consumption ratio will be less than 5:1. The patient will compensate for this by increased oxygen extraction, however, and the patient will remain stable as long as the ratio is greater than 2:1.