Mixed venous oxygen saturation as a guide to tissue oxygenation and prognosis in patients with acute myocardial infarction.
The relation of mixed venous oxygen saturation and the cardiac index to tissue oxygenation and prognosis was investigated in 119 patients with acute myocardial infarction. There was a positive correlation between mixed venous oxygen saturation and the cardiac index in 97 survivors and 22 nonsurvivors, but a significantly lower mixed venous oxygen saturation level at the same level of cardiac index was observed in nonsurvivors compared with survivors. Results of multivariate analysis with mixed venous oxygen saturation and the cardiac index indicated that only mixed venous oxygen saturation was significantly related to survival and to hyperlactacidemia. Oxygen delivery to tissues declined significantly in nonsurvivors because of a lower cardiac index and a lower hemoglobin concentration in these patients than in survivors. However, at the same level of oxygen delivery to tissues, nonsurvivors had a significantly higher rate of oxygen consumption leading to a correspondingly greater decrease in mixed venous oxygen saturation, suggesting that a greater increase in oxygen demand was also observed in nonsurvivors than in survivors. Thus mixed venous oxygen saturation after acute myocardial infarction is a better predictor of hyperlactacidemia and survival than the cardiac index, and this may be associated with an increased oxygen demand and an impaired oxygen transport system in seriously ill patients.
Sumimoto
T
T
Second Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
Takayama
Y
Y
Iwasaka
T
T
Sugiura
T
T
Takeuchi
M
M
Hasegawa
T
T
Tarumi
N
N
Takashima
H
H
Nakamura
S
S
Taniguchi
H
H
D000368:Aged; D002302:Cardiac Output; D005260:Female; D006801:Humans; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000378:metabolism* / Q000401:mortality; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D011379:Prognosis; D016019:Survival Analysis; D014680:Veins
D007773:Lactates; D019344:Lactic Acid; D010100:Oxygen