You use your stethoscope countless times each shift. As an indispensable tool for rapid patient assessment, your stethoscope has a constant presence with you as you care for patients. Now that it’s time to purchase your first or a replacement, how do you choose between the many styles and options available?
What should you look for in a stethoscope?
A quality stethoscope is durable, comfortable to use, and provides good acoustics for accurate assessment of heart, lung, and gastrointestinal sounds. The classic adage, you get what you pay for
, is true for stethoscope performance and longevity. Because a quality stethoscope might last 10-15 years, the choice of a reliable high or medium performance model could be a good long-term investment if you work in a hospital setting. If you are a student on a tight budget, there are basic models that will cover your assessment needs.
A stethoscope is made up of a head/chest piece, tubing, and ear buds. Let’s take a look at each of these components:
Stethoscopes will use one of three different heads – dual head, single head, or electronic head.
- A dual head model includes the diaphragm (for high frequencies) and the bell (for low frequencies). Some dual head stethoscopes include an accessory kit with adult, pediatric, and infant bells.
- Cardiology single head stethoscopes have a pressure-sensitive tunable head that functions as both a diaphragm and bell depending on the applied pressure. This tunable diaphragm allows for easy shift between high and low frequency sounds. To hear low-frequency sounds, you rest the chest piece lightly on the patient; to hear high-frequency sounds, you apply firm contact pressure to the chest piece. There are also very inexpensive single head stethoscopes that are only used to measure blood pressure.
- Electronic models provide sound amplification and ambient noise reduction. They also allow saved recordings with the capability of sending recordings to a computer using wireless connectivity. However, these models are very expensive ($240-$550), and the magnitude of sound improvement is small relative to the best acoustic stethoscopes.
Most stethoscopes come in 22-inch or 27-inch tube lengths. Shorter tubing, in theory, offers better sound volume, but the human ear does not detect the difference in acoustical performance between a stethoscope with shorter tubing versus one with longer tubing. Practical factors come into play when considering tubing length. Longer tubing allows more distance from sick patients when auscultating and improves ergonomics as there is less bending over patients.
Double or single lumen
Single lumen tubing has one tube connected to the chest piece, which then splits into two tubes, with each one going into one ear. Single lumen, single head stethoscopes are inexpensive and often used for taking blood pressures and in isolation rooms or other situations when disposable models are more practical. Double lumen stethoscopes are more sensitive than single lumen stethoscopes because they provide an individual sound channel to each ear. This allows you to hear the subtle characteristics of heart sounds and murmurs more distinctly. Most companies make “dual-channel” stethoscopes with two lumens inside a single tube.
A good fit is essential to avoid audio leak and minimize ambient noise. Earpieces are angled forward to match the direction of your external auditory canal. Soft gel or rubber earpieces are comfortable and ensure good coupling between the scope and the examiner’s ears. Most high-quality stethoscopes come with several different sizes and shapes of ear tips, which enables the user to select the best-fitting and most comfortable tips.
How do you know which stethoscope you need?
Think about what level of acoustic performance you need. If you practice in a specialty such as critical care or cardiology that requires precise auscultations, a high-performance model may be best for you. High performance stethoscopes include the 3M™ Littmann® Master Cardiology™
or Cardiology Series III/IV
, ERKA Finesse
, ERKA Precise
, Welch Allyn Harvey Elite
, MDF Classic Cardiology
, or ADC 600 Cardiology
. These models range in price from $130-$240.
If you practice in an outpatient setting or general medical/surgical units, a medium performance stethoscope may be adequate. Examples of models in this category include the Littman Classic series
, ERKA Sensitive
, MDF MD One
, Welch Allyn Professional
, and ADC Adscope 601
. These models range in price from $80-130.
Basic, entry level stethoscopes are the most economical, making them a good choice for medical, nursing, or EMT students. These models allow you to make general diagnoses and perform basic auscultations. Their limitations include the inability to detect murmurs of Grade 1 and S3/S4 heart sounds, as well as lack of durability. Basic models include Littmann Select
, Littmann Lightweight II S.E.
, MDF Acoustica Lightweight
, and Welch Allyn Lightweight
If your specialty is exclusively pediatrics, you should consider pediatric models such as the ERKA Finesse2 Child
, Littmann Classic II Infant
and the Littmann Classic II Pediatric
. If you work with varying age ranges, there are models with multiple interchangeable heads for adults, children and neonates, such as the MDF ProCardial C3 Cardiology
and MDF ProCardial ERA
Once you have purchased your ideal stethoscope, take the proper steps to make it last as long as possible. Wipe tubing and earpieces regularly with 70% isopropyl alcohol solution. Do not immerse your stethoscope in liquid, or subject it to any sterilization process. Keep it away from extreme cold or heat, oils, and solvents. Replacement earpieces, diaphragms, and bell covers are available should these components wear out.
To prevent loss or theft, consider engraving the metal part of the diaphragm with your name or choosing a distinctive tubing color.
Choosing the best stethoscope for you comes down to determining your day-to-day needs and your budget. Invest in the best stethoscope you can afford. It will help you provide better patient care and will be your clinical companion for many years.