Hidden risk in operating room. Micro-shock.

The risk of electrical micro-shock is recognised in patients undergoing cardiac catheterisation or connected to electronic equipment instruments. The work reported here investigates the possibility of injury by electrical micro-shock when monitoring the central venous pressure as commonly done during surgical procedures. The studies were done on dogs catheterised for the measurement of central venous pressure with the catheter advanced into the right ventricle. It was found that currents less than 500 micro-amperes caused interference with heart rhythm, and in some of the dogs ventricular fibrillation developed. In view of these findings it appears that greater consideration should be given to the risk of electrical micro-shock in patients in whom the central venous pressure is measured.