When 2 or more items of equipment are connected to a patient with a connection from one to an invaded point within the body, and especially adjacent to the myocardium, the danger of induced VF exists

1. Electrical (shock) hazard is possible when both:

a) There is a path by which the electrical current can flow from an electrical device through a patient to ground

b) There is some fault in the electrical grounding of the apparatus

2. If the circuit includes an intracardiac monitor such as a CVP line, the leakage current can be transmitted directly to the heart (microshock hazard)

a) Any equipment that bypasses skin resistance (epicardial pacemakers, CVC) should be handled with care (eg rubber gloves) to avoid any leakage current reaching the patient

3. The addition of more pieces of equipment directly increases the risk of exposure to electrical hazard due to to the fact that possible exposure to faults within the individual pieces of equipment increases

4. Equipotential grounding

a) A major problem in monitoring the patient with cardiac disease is the multiple connection to electrical devices

b) To provide safety through proper grounding, each device should be attached to a common ground wire, will drain all current leakage to a single ground point

c) A single ground reference eliminates current flow caused by slight variances in ground potential [“Cardiac protected area”]

d) A panel of outlets near the patient, connected to a common ground, should be the only outlets used

e) Connection to a remote outlet may result in current flow from one electrical device to another with a slightly different potential or ground which can pass through the patient even when the equipment is turned off

5. Capacitance leakage

a) Looping or kinking of electrical cable should be avoided to minimise resistive or capacitance leakage