Oxygen transport-dependent splanchnic metabolism in the sepsis syndrome
C. P. Steffes, M. S. Dahn and M. P. Lange
Department of Surgery, Veterans Affairs Medical Center, Allen Park, Mich.
OBJECTIVE: Total body oxygen consumption (VO2) may be pathologically oxygen
delivery (DO2)-dependent in critically ill patients exhibiting the sepsis
syndrome. This observation has been used to infer the presence of occult
tissue or organ ischemia that potentially can be eradicated by augmenting
DO2. We examined this hypothesis by determining the VO2-DO2 relationship
and lactate metabolism in the splanchnic region. DESIGN: Before and after
intervention trial. SETTING: University-affiliated Veterans Affairs Medical
Center, Allen Park, Mich. PATIENTS: Eighteen surgical patients exhibiting
the sepsis syndrome. INTERVENTION: Systemic and splanchnic oxygen exchange
and lactate uptake measurements before and after augmentation of DO2 with
blood transfusion. MAIN OUTCOME MEASURES: Changes in oxygen exchange and
lactate metabolism. RESULTS: The splanchnic VO2 index rose 9% in
association with a 26% regional DO2 index increase indicating an oxygen
transport dependency (P < .05). Splanchnic O2 extraction (0.47 +/- 0.04)
was significantly greater than the mean systemic level (0.31 +/- 0.02) and
showed a greater decline following DO2 index augmentation (0.41 +/- 0.04 vs
0.28 +/- 0.03, respectively). However, splanchnic lactate uptake was not
changed significantly in response to the increased DO2 index. CONCLUSIONS:
Although splanchnic oxygen transport dependency and elevated extraction
ratios suggest the presence of regional ischemia that should be relieved
with an increased DO2 index, the observed changes in lactate uptake do not
support this conclusion. The significance of the VO2-DO2 relationship, its
role in the pathophysiology of the sepsis syndrome, and its place in the
clinical care of the septic surgical patient are in doubt.
