Left ventricular opacification after intravenous injection of Albunex. The effect of different administration procedures.

A clinical study has been performed to investigate the influence of different administration procedures on the degree of contrast enhancement of the left ventricle. The administration variables assessed included Albunex injection rate, arm position, flushing rate and flushing fluid. Twenty-four healthy male volunteers were included. Compared to an injection rate of 1 ml/sec an injection rate of Albunex of 2 ml/sec caused an earlier appearance of contrast in the right ventricle (1 heart beat), whereas transpulmonary passage was not influenced. Horizontal arm position caused a delay in time to peak intensity of 2 to 3 heart beats in both systole and diastole as compared to elevated arm position. Injection rate of 1 ml/sec compared to 2 ml/sec caused a higher peak intensity and mean area under the curve and a longer mean time to peak intensity and transit time. Differences varied from 6 to 230 grey level units out of mean values of 2500. All the observed differences were small and thus probably of no clinical importance. The present study indicates that improvements in the pressure stability characteristics of the albumin microspheres in Albunex have been achieved. This implies that a simple administration procedure can be used. It is recommended that the contrast agent, after resuspension, is injected through a three-way stop cock cannula, followed by 10 ml of saline for flushing. The cannulas or syringes used should be no smaller than 20 G. The injection rate should be 1-2 ml/sec, depending on the diameter of the cannula. By using this procedure, a reliable transpulmonary passage and left ventricular opacification may be obtained.