The ECG machine was originally designed for quiet hospital settings in which a cardiologist or team of cardiologists were able to to negotiate and interpret the ECG rhythym strips for signs of myocardial ischaemia, infarction or conduction disturbances. Over the years the role of the ECG machine has expanded to include out of hospital use by paramedics to more accurately identify and interpret cardiac presentations by paramedics. Unfortunately, the ECG machine is designed to catch the most minimal sounds and movements as electrical activity of the heart, which means that, the noisy environment that paramedics generally work within is likely to cause the ECG machine to interpret many areas of the environment as artefact.
It is difficult to ever completely remove the causes of ECG artefact in the prehospital environment, but these tips for reducing ECG artefact may help.
Tips for Reducing ECG artefact in an Ambulance:
- Make sure the engine of the Ambulance is turned off.
- Ensure that the patient is comfortable and laying at rest.
- Make sure the leads are on correctly and that all hair has been adequately removed prior to electrode placements.
- Turn of the air conditioner.
- Make sure the ECG leads are not touching each other because this may cause artefact.
- Make sure the ECG leads are laying flat on the patient and aren’t dangling/bouncing around.
- In the patient who has a continuous shake or tremor (such as Parkinson’s Disease) you may never get a perfect ECG, but should be able to get a better ECG if you perform a modified ECG with the 4 Limb leads placed on the torso (right shoulder, left shoulder, right lower quadrant of the abdomen, left lower quadrant of the abdomen) – this is not going to produce a perfect ECG, but may be better than nothing. As with any other changes from the norm, it is important to document on the ECG where you have placed the electrodes if you have made any modifications. This will avoid future confusions by medical staff in hospital. If you really can’t get a good ECG tracing, make sure you document this too.
- Make sure any hair has been cleanly shaved so that the electrodes have better conduction through the patients’s skin.