Abnormal electrical stimulus of an intra-aortic balloon pump with concurrent support with continuous veno-venous hemodialysis

Malfunction of electronic medical support apparatus utilized in the ICU usu ally causes system failure. We report several occurrences of a potentially dangerous interaction between a continuous veno-venous hemodialysis (CVVHD) system and an intra-aortic balloon pump (IABP) counterpulsation device in four patients requiring both systems. The patients had acute renal failure in the face of multi-organ failure and were dependant upon the balloon pump for pressure support. Electrical interference created by the roller pump a ction of the CVVHD system was identified by the balloon pump as cardiac in origin, and it responded by inflation and deflation. As the blood pump rate was reduced, the interference reduced to the point of complete cessation w hen the blood pump was shut down. Whereas one patient transiently had a sig nificant drop of mean arterial pressure (from 70 +/- 4 to 40 +/- 2 mm Hg) t he other observed occurrences had no clinically significant sequelae. Elect rocardiogram (ECG) tracings identified the abnormal stimulus and systematic review identified as potential sources for the creation of this interferen ce static electricity buildup, piezoelectric properties of the polyvinyl ch loride tubing, and, possibly but less likely, radiofrequency interference. A newer generation ECC cable and advanced cardiac rhythm recognition softwa re (CardioSync) have been introduced with the Datascope System 98, and the ECG interference, although still occasionally present, does not cause errat ic inflation and deflation of the intra-aortic balloon pump. Interference b etween different electrical support systems may occur, and we suggest that the systems be tested for compatibility before combined use and that older equipment be more rigorously tested for potential clinically significant in terference.