By Caitlyn Armistead
No other tool is more closely associated with the practice of medicine than the stethoscope, but choosing the right one and using it well is not an easy task. A stethoscope is also a crucial diagnostic tool for assessing any patient in respiratory compromise and the patient’s response to treatments. A stethoscope, along with capnography, is essential for confirming placement of an endotracheal tube or a supraglottic airway.
Here are 10 things to consider when choosing and using your stethoscope.
1. Choose the right stethoscope
Make sure you have the right tool for the job. Disposable and cheap stethoscopes are often recommended for students, but many of these stethoscopes have poor sound profiles. If you have young ears, a cheap scope may be good enough, but if you have less-than-perfect hearing or need a full range of sounds for diagnostics, then you will need a good scope.
Double-lumen, Sprague scopes, can cause artifact when the tubes rub against each other. Shorter tubes, in theory, will have better volume, but longer tubes are nice when the patient starts coughing.
Diaphragms — the side of the head with a solid disc — are great for listening to relatively higher-frequency breath sounds and bowel sounds, but for low-frequency heart tones and murmurs you will want a bell — the side that’s hollow.
Whichever brand or model you choose, remember, you generally get what you pay for. And never buy what you cannot afford to lose.
2. Know your stethoscope
Is that a pediatric diaphragm or is it a bell? Is the bell pressure activated? Which of the provided earpieces work best for you?
After you’ve bought your scope, read the owner’s manual. Visit the company’s website. Check out YouTube for training videos. There are lots of great resources out there on how to get the most from your particular scope.
3. Keep things clean
Make sure your ears are clean. Ear wax blockages are one of the most common causes of hearing loss. If you keep your stethoscope in your pants pocket, make sure that lint and dirt hasn’t clogged the earpieces. Also bear in mind that stethoscopes are a potential vector disease transmission — disinfect it after every patient.
4. Check your scope’s condition
If you suddenly can’t hear through your scope, make certain the head is turned the correct way. Check to make sure that the diaphragm isn’t cracked and the rings aren’t loose. Also, make sure the cord is intact; oils from your neck can damage the material over time.
5. Use Solid auscultation technique
Move the earpieces into position. They should be angled slightly so that they point toward your nose. This way the earpieces are aligned with your ear canals.
Turn the stethoscope’s head to the correct side. If you are using a double-sided scope, the head will turn on a pivot that will allow the sound to travel from the operating side to the cord or tube. Check your owner’s manual to learn how to determine which side is activated. Usually, the flat side of the attachment — or the side with the hole — indicates which side is active.
When taking a patient’s blood pressure, make certain the stethoscope is directly over the brachial artery. You can find it by palpating the medial aspect of the antecubital fossa. Once you have the stethoscope in place, do not place your thumb on top to hold it — it can add artifact. Instead, secure it in place your fingers or cradle it between finger and thumb at the base with the cord draped over the back of your hand.
6. Skin contact is important
Sound loses quality when it travels through the patient’s clothing. You can buy the best stethoscope in the world, but if you use it over clothing, you are blocking sound from ever reaching it. Place the stethoscope directly on the patient’s skin, exposing the patient’s skin when necessary to auscultate a blood pressure, lung sounds or heart sounds.
7. Learn the stethoscope tricks of the trade
When taking a patient’s blood pressure, don’t rest the patient’s arm on the stretcher rail; vibrations will travel through the person and add to the artifact. Place your feet on the stretcher instead of the floor so fewer vibrations will pass through your boots. Sometimes simply lifting your heels is sufficient. If you need to, shut the whole truck down so you don’t have to listen over the engine rumble.
For hard-to-hear breath sounds, listen in the axillary region and press the patient’s arm down over the stethoscope to block ambient noise.
8. Do not adjust your ear pressure
Do not attempt to change the pressure in your ears to improve your earpiece positioning. Changes in pressure remain in the eustachian tubes unless you have a perforated tympanic membrane. It may feel different, but it has no real effect on earpiece placement. That pressure change is much more likely to affect sound conduction through your ear and make hearing more difficult.
9. Be honest
NEVER lie about the patient’s blood pressure.
NEVER be afraid to say you couldn’t hear what you were attempting to auscultate.
NEVER be afraid to ask your partner to listen in and confirm.
If you can’t hear the patient’s blood pressure, try palpating. It is better to have a palpated systolic BP than a wildly inaccurate systolic/diastolic. In the end, we are here for good patient care, not our own egos.
10. Get your hearing checked
If hearing through your stethoscope is a consistent problem or you are considering an electronic scope, get your hearing checked. There are many options for hearing support available, and many of them interface well with stethoscopes and radios. Your audiologist can help find the right stethoscope for you.
About the author
Caitlyn is a teacher, AEMT, and lifeguard. She has worked for large hospitals, several EMS services, and as a research librarian for a state Bureau of Emergency Medical Services.
This article, originally published May 9, 2016, has been updated.