No abstract

The AVCO balloon pump (model 7) was used on 13 patients with cardiogenic shock and for circulatory support after open-heart surgery. Twelve patients survived, but one patient died of a cerebral embolism which had occurred before the use of the balloon pump. Mean systemic arterial pressure, mean pulmonary artery pressure, pulmonary wedge pressure and heart rate were measured in all patients, while cardiac index and arterio-venous oxygen difference were measured in seven. Average duration of counterpulsation was four days. Vasopressor treatment was reduced or discontinued in all patients, urinary output increased markedly and the clinical state improved. Although systolic pressure did not change significantly, MAP increased significantly by 25 mm Hg (P less than 0.005), with a mean diastolic pressure increase to 104 mm Hg. The pulmonary artery pressure, the pulmonary wedge pressure and the mean pulse rate all decreased significantly by 25 mm Hg, 16 mm Hg and 24 beats/min, respectively. A fall in arterio-venous oxygen difference of 2.6 ml/100 ml (P less than 0.025) was associated with a significant increase in cardiac index by 0.62 l/min-m2 (P less than 0.025). It is concluded from these results that intra-aortic balloon counter-pulsation may be an effective means of providing circulatory support in cardiogenic shock and after open-heart surgery.