Direct Calorimetry Using Swan-Ganz Catheter for Evaluation of General Metabolic Expenditure in Acute Cerebrovascular Disease

—Comparison Between Direct Fick Method and Indirect Calorimetry Technique—

Abstract

Oxygen consumption calculated by the direct Fick method using a Swan-Ganz catheter (D-VO₂) and indirect calorimetry using a metabolic computer (ID-VO₂), carbon dioxide production calculated by the latter method, and respiratory quotient were determined pre and postoperatively in 12 patients with acute hypertensive intracerebral hemorrhage and eight patients with acute ruptured intracranial aneurysm. The mean D-VO₂ value was slightly lower than the mean ID-VO₂ value, but had a significantly positive correlation. The regression curve was very close to the line of identity. The total metabolic expenditure can be calculated from D-VO₂ and daily urinary nitrogen excretion. Direct calorimetry using a Swan-Ganz catheter is a simple method to evaluate metabolic expenditure in acute hemorrhagic cardiovascular disease.