A prospective study of the use of a dobutamine stress test to identify outcome in patients with sepsis, severe sepsis, or septic shock

Objective: To more clearly define the relationship between an oxygen flux t est, oxygen supply dependency, and outcome in patients with sepsis, severe sepsis, or septic shock. Design: Prospective, interventional clinical trial. Setting: A teaching hospital general intensive care unit in London, UK. Patients: A total of 36 patients with sepsis, severe sepsis, or septic shoc k were studied during a 10-month period. Interventions. After resuscitation, patients were given an intravenous infu sion of dobutamine at 10 mu g/kg/min for 1 hr. Cardiac and respiratory vari ables were measured before the infusion and then while the infusion was in progress. Any patient who was able to increase his or her oxygen consumptio n by >15% was designated a responder to the test. Measurements and Main Results: Hemodynamic, oxygen transport, and lactate m easurements were made at baseline and after 1 hr of the dobutamine infusion . All patients were then followed up until hospital discharge. Responders t o this test had a hospital mortality of 14%, whereas nonresponders had a mo rtality of 91% (p < .01). The responders were characterized by being younge r (p < .05), having higher Acute Physiology and Chronic Health Evaluation I II scores (p < .05), and having a greater requirement for inotropic support (p < .05). After the test, the responders had significantly higher oxygen delivery (p < .01) and oxygen consumption (p < .05) than the nonresponders, as well as a significantly greater temperature increase as a result of the infusion (p < .05). The nonresponders were unable to increase either oxyge n delivery or oxygen consumption to the dobutamine. This test was highly pr edictive of outcome (p < .0001). The identification of an increase in both oxygen delivery and oxygen consumption (oxygen supply dependency) was not a ssociated with a poor outcome. Conclusion: A dobutamine oxygen flux test provides evidence of the intrinsi c function of cells. The inability of these cells to increase oxidative met abolism during sepsis, as indicated by the dobutamine test, is associated w ith a high mortality.