A 72-year-old man with diabetes, renal insufficiency, and coronary aery disease presents in septic shock from emphysematous cholecystitis. His oxygen saturation is 100% on 6-L nasal cannula and his hemoglobin is 7.2 mg/dL. His mixed venous oxygen saturation is 58%. Which of the following treatment options will improve his oxygen delivery the most?
Increase his inspired oxygen concentration Transfer him to a hyperbaric chamber Administer an erythropoietic agent Transfuse two units of packed red blood cells