Relationship between oxygen extraction (OER) and age in septic patients
KeywordsLactate Cardiac Output Oxygen Consumption Organ Failure Mitochondrial Dysfunction
A pathologic dependency between oxygen consumption (VO2) and oxygen transport (DO2) is characteristic of septic patients. Septic state appears to be associated with a defect in oxygen extraction (OER = VO2/DO2), causes possible cellular hypoxia, mitochondrial dysfunction and development of multiple organ failure. We studied the relationship between the mean OER and age in septic patients in a 12-bed ICU.
We investigated 53 septic patients (age range 20–93 years), invasively monitored in a descriptive study. DO2, VO2 and OR were obtained in each patient in triplicate during the first 24 h of sepsis diagnosis. Cardiac output (CO) was determined during thermodilution. Lactate concentrations were obtained in 46/53 patients (86%) and were elevated in 39%.
In this descriptive study, mean OER increases in elderly septic patients. These results are probably explained by the decrease of DO2 and VO2 in relation with age.