title: Relationships of oxygen uptake and oxygen delivery in respiratory failure not due to the adult respiratory distress syndrome.
abstract: Previous studies have suggested that oxygen uptake (VO2) may be dependent on oxygen delivery (QO2) at most levels of QO2 in patients with the adult respiratory distress syndrome (ARDS); however, the adequacy of substrate delivery in patients with non-ARDS respiratory failure is unclear. The purpose of the present study was to examine the relationship between VO2 and QO2 in a group of critically ill patients (n = 10) with non-ARDS respiratory failure (ie, cardiac pulmonary edema, chronic obstructive pulmonary disease [COPD], or pneumonia). For comparison, these relationships were also examined in a group of patients (n = 6) with ARDS. The data indicate that VO2 is dependent on QO2 in both patients with ARDS and non-ARDS respiratory failure. In contrast, regional venous oxygen tension differences varied considerably between the two groups of patients, indicating differences in local adaptations to critical reductions in QO2. Finally, over a similar range of QO2, oxygen extraction was greater in patients with ARDS compared to patients with non-ARDS respiratory failure (r = -0.67 and slope = -0.62 vs r = -0.45 and slope = -0.35; p less than 0.05). These data suggest that a linear relationship between VO2 and QO2 is not unique to patients with ARDS and may not predict regional adaptations to critical reductions in substrate availability.
authors.affiliation: Department of Medicine, Ohio State University, Columbus.
authors.forename: P M
authors.initials: PM
authors.lastname: Dorinsky
authors.forename: J L
authors.initials: JL
authors.lastname: Costello
authors.forename: J E
authors.initials: JE
authors.lastname: Gadek
mesh_terms: D006439:Hemodynamics; D006801:Humans; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D010313:Partial Pressure; D011175:Positive-Pressure Respiration; D011659:Pulmonary Gas Exchange; D012128:Respiratory Distress Syndrome / Q000503:physiopathology* / Q000628:therapy; D012131:Respiratory Insufficiency / Q000503:physiopathology* / Q000628:therapy
chemical_list: D010100:Oxygen