[Changes in oxygen delivery and consumption in different stages of chronic cor pulmonale]

To observe the changes of oxygen dynamic status in the development of chronic cor pulmonale, we studied early chronic cor pulmonale (group A, 13 cases), late chronic cor pulmonale in remission stage (group B, 15) and late chronic cor pulmonale in acute exacerbation stage (group C, 10) with Swan-Ganz thermodilution catheter and arterial and mixed venous blood gas analysis for detecting the oxygen delivery (DO2) and consumption (VO2). In group C, amrinone was given intravenously (15 micrograms.kg-1/min) and the examinations were repeated. DO2 (465 +/- 72 ml.min-1/m2) and VO2 (114 +/- 11 ml.min-1/m2) were at low level of normal range. No correlation was noted between them (r = 0.282, P > 0.05) in group A. It is suggested that the patient of early stage was in low oxygen delivery and consumption and no tissue oxygen deficit existed. In group B, DO2 and VO2 increased (592 +/- 111 and 145 +/- 32 ml.min-1/m2 respectively, P < 0.05 versus group A) but no significant correlation was found (r = 0.189, P > 0.05). Hence, the body of the patient was in high metabolic status and no tissue oxygen deficit existed in remission stage. DO2 and VO2 in group C (622 +/- 150, 139 +/- 44 ml.min-1/m2 respectively) were similar to those in group B (P < 0.05). After amrinone administration, a significant correlation was found between DO2 and VO2 (r = 0.39, P < 0.05). It is suggested that in the exacerbation stage, the patient's body was in highly metabolic status, the oxygen delivery-consumption compensation mechanism failed, and tissue oxygen deficit existed.