TREATING SEVERE CARDIOGENIC-SHOCK BY LARGE COUNTERPULSATION VOLUMES

Background. Intraaortic balloon pumping is known to be ineffective in severe cardiogenic shock. The efficacy of balloon volumes larger than those commonly used is examined. Methods. In 18 dogs with severe exper imental cardiogenic shock (systolic aortic pressure <60 mm Hg, aortic flow <45 mL . min(-1) . kg(-1)) the effect of three intraaortic balloo n volumes (15, 30, and 45 mL) and a 60-mL paraaortic pump was examined . Results. The 45-mL balloon covering the full length of the aorta ind uced the highest (+12.4 +/- 2.2 mL . min(-1) . kg(-1)); mean +/- stand ard error of the mean) and the 15-mL balloon the lowest increase in ao rtic flow (F = 14.6, p < 0.0001). Only the 45-mL balloon increased < 0 .05) urine output and renal artery flow. The 60-mL paraaortic pump ind uced the highest (F = 10.72, p < 0.002) increase (+36.6 +/- 6.5 mL . m in(-1) . kg(-1)) in aortic flow compared to the three balloons. An 80- to 100-mL paraaortic pump maintained the life of 3 patients in severe cardiogenic shock for 4 hours, 8 days, and 54 days, whereas a 40-mL c onventional balloon was completely ineffective. Conclusions. Experimen tal and clinical data indicate that the effectiveness of intraaortic b alloon pumping in severe cardiogenic shock may be improved by increasi ng the volume of the balloon (ie, until it fully occupies the aorta).