[Relation between oxygen delivery and consumption during septic states. Value of an early dobutamine test]

From previous studies it has been hypothesized that multiple organ failure and high level of mortality, seen in critically ill septic patients, may be due to defective oxygen extraction and tissue hypoxia occurring early in the course of sepsis. Oxygen flux test has been proposed as a method of revealing an occult oxygen debt. We used a one hour dobutamine infusion test, in septic patients, without increase in blood lactate. Fifty patients with sepsis syndrome entered a multicentric prospective study. After fluid loading to increase pulmonary artery occlusion pressure (Paop) to a minimum value of 10 mmHg, all the patients were given 10 mcg/kg.min of dobutamine for one hour. Hemodynamic and metabolic variables were recorded before, HO, and after the test, H1 (cardiac index, Paop, oxygen deliver, DO2, and consumption, VO2, oxygen extraction ratio, (OER), blood lactate). The dobutamine test allowed to identify responders (R) who increased VO2 by more than 15% and non-responders. R and NR differed significantly in mortality (8.5% vs 44.4%). The test has a good predictive value for surviving. Without respect of the result of the test, the patients were randomized in two groups. The group D+ was given conventional therapy and dobutamine at the same rate of infusion for 9 consecutive days and the D- group received only conventional therapy. The RD+ patients improved more rapidly when compared with RD-, NRD+, NRD-. We concluded that a one hour dobutamine test is able to identify R and NR critically ill septic patients. The response is associated with significant difference in outcome.(ABSTRACT TRUNCATED AT 250 WORDS)