Clinical experiences with assisted circulation

Of primary importance in the clinical application of mechanical support for the failing circulation are the selection of patients and definition of criteria for assessing the therapeutic results. Experimental and clinical observations suggest that serial measurements of arteriovenous oxygen difference are a reliable rough measurement of the adequacy of the existing cardiac output to meet the oxygen requirements of the tissues. Patients with a decreasing cardiac output may profit from assisted circulation. Thirteen such patients are presented, all of whom were in intractable heart failure. Seven "medical" patients underwent common femoral vein-to-artery perfusion with an oxygenator for an average of 135 minutes. Of these, one patient who had already had two cardiac arrests died, six patients showed striking clinical and biochemical improvement for hours to days, and two patients were discharged from the hospital. Of particular interest were five in whom the indication for assisted circulation was irreversible cardiac arrest. Three patients were resuscitated, and one, who had neurological signs usually accepted as those of anoxic cerebral damage for 45 minutes, recovered completely.