How to Use a Stethoscope

cardiology_III_symbols_redYour stethoscope is your constant companion in medicine, so it’s really important to know how to use it.

While the technology required to listen in on our internal noises is very simple, learning how to perform effective auscultation takes a while. The sooner you learn to use a stethoscope effectively, the sooner you’ll be on your way to understanding the sounds made by the human body.

Different types of stethoscope

While they all perform the same function, a variety of different stethoscopes have been developed for various specialties. Some are designed specifically for cardiology or paediatricians. General purpose stethoscopes are ideal for students and nurses, while electronic stethoscopes can enhance traditional auscultation through the use of digital technology.

The right stethoscope for you is the model that gives you the best insight into the patient’s condition. Along with the type of stethoscope you use, your budget will also make a difference, with the quality of sound generally reflected in the price you pay.

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This article covers traditional or acoustic stethoscopes, as these are much more common than electronic or digital devices.

Using your stethoscope

Starting from the top of the stethoscope, the ear pieces should be inserted so that they point towards the bridge of your nose. A good stethoscope is designed with binaurals (the two tubes that end with the ear pieces) that point slightly forwards.

This is because your ear canals are angled slightly forwards. You’ll know that you have a good fit because all the noise around you becomes very faint when the ear pieces are inserted, allowing you to concentrate on the sounds coming through the stethoscope.

If you’re not sure whether you’ve got the stethoscope the right way round, put the two ear pieces together and you’ll see that they form the point of a shallow ‘V’. If the V is directed towards you, it’s the wrong way around.

If you can see the holes in the ear piece, it's the wrong way around.
If you can see the holes in the ear piece, it’s the wrong way around
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Can’t see the holes? This is the right way around.

Another useful guide is to hold the stethoscope headset in front of your face and see whether you can see the holes in the earpieces. If you can, again it’s the wrong way around. Because the earpieces should face slightly away from you, the holes will be out of sight.

Choose ear pieces that fit snugly and comfortably, based on their size, design and material.

Getting the fit right is important for both acoustic performance of the stethoscope and your comfort. Discomfort could be a distraction that prevents you from using your stethoscope effectively.

Ear pieces are replaceable.

 

The diaphragm and the bell

bubblegum_engraved_symbolsMost stethoscopes have two elements to the chest piece, a diaphragm and a bell. The diaphragm is used to listen for higher frequency sounds while the bell picks up lower frequencies.

On some models these are on opposite sides, requiring the chest piece to be rotated to switch between the two. This is done by twisting the tube just before the point where it enters the chest piece.

If you’re not sure which side is currently active, or you want to be sure that you’ve switched between modes, tap the diaphragm lightly with your fingertip. In diaphragm mode you’ll hear the tapping very loudly through the earpieces. It’s a good idea to learn the difference and practice changing mode before working with patients, because using the wrong side of the stethoscope with a patient, and having to switch it round while admitting you made a mistake, could undermine their confidence in you as a medical professional.

Littmann stethoscopes, which are extremely popular, have a tuneable diaphragm, meaning that a change in pressure is all that’s required to switch from diaphragm to bell. Holding the stethoscope lightly against the skin puts it in bell mode, while pressing it against the skin switches to diaphragm mode.

Depending on what you are listening for, the stethoscope should be placed against different points on the body. Ideally it should always be against the skin because even a thin layer of clothing will impede performance.

Knowing how to use a stethoscope is, of course, only the beginning of your education in how to assess a patient’s condition. You’ll need to learn how to recognise different sounds and understand their significance in the light of the patient’s medical history.

Cleaning your stethoscope

From time to time, take a moment to check that your ear pieces are free of obstructions. Depending on how you use and store your stethoscope, it’s possible for dirt and fluff to accumulate, which will impair auditory performance.

The entire stethoscope can be cleaned with disinfectant or alcohol wipes. Application of liquid is to be avoided, particularly solvents, as these can cause permanent damage. When cleaning, it’s also worth checking for cracks or other damage, because these can also impair performance. Replacement parts are usually available.