A stethoscope is virtually a standard symbol of doctors and nurses. Everyone knows how to use the stethoscope: that is, put the thing in your ears and place the other end on a patient then listen. However, the truth is that the stethoscope can do much more. Do you know how it works?
The diaphragm will move the column of air inside the stethoscope tube up and down. That, in turn, moves air out and in of the ear canal. Relying on that, you are able to listen to the sound. It’s because the surface area of the diaphragm is much greater than the column of air which moves in the tube. The air inside the tube will travel more than the diaphragm creating an enlargement of the pressure waves that will leave the ear tip. Meanwhile, you will receive louder sounds in your ear thanks to larger pressure waves. That’s why how the stethoscope amplifies sounds.
Stethoscopes and their function
- Measure the liver’s span
A physician can use percussion (tapping the belly) to measure the span of the liver. However, using the stethoscope is considered as another clever alternative. Just put it under the right nipple with the other index finger above the belt line according to the nipple and then scratch the skin up toward the stethoscope’s chest piece. The sound will be duller when you are over the liver. Try to place it about 10 cm from the nipple line.
- Measure blood pressure
It might be a common function for the stethoscope, but it’s often performed poorly. Keep in mind that placement of the blood pressure cuff is important. Students are taught that diastolic blood pressure (e.g. 12/80) is the position in which they can no longer listen to the brachial artery’s thump. More correctly, diastolic blood pressure is the number where the volume of the thumb decreases seriously. It’s often 4-10 mm Hg higher than when the sound exits totally.
- Assess heart sounds
You can listen to type, rate and rhythm of the heart sound as well as any accidental sounds as gallops, murmurs or clicks. Perhaps, the heart sounds might be the same the first time. Nevertheless, after hearing many hearts, ultimately distinct sounds will seem to jump out at you. You need to hear the four main positions, including right and left of the sternum at the level of the second rib, on the left nipple line at the level of the fifth rib and the left of the sternum at the level of the fourth rib.
- Assess lung sounds
With the stethoscope, you can discover the rhythm, rate and quality of breathing, any blockage of the airways as well as rubs that demonstrate inflammation of the pleura. Avoid placing it above the clavicle because lung tissue expands that high. If you are listening to the back, you should get the patient to lean forward gently to display the triangle of auscultation. Remember to listen to the left and right sides at the same level before moving down to the next level.
- Discover bruits
A bruit is an unusual whooshing sound of blood via an artery that usually has been narrowed creating a turbulent flow. The bruit can be discovered in the neck (carotid bruits), kidneys (renal bruits), iliac, umbilicus (abdominal aortic bruits), temporal arteries and femoral area.
Which stethoscope should you purchase?
With $60, you are able to get a quality stethoscope.
Of course, you can buy one for less than this price but it might not be durable and have ineffective sound profiles.
The 3M Littman Cardiology III is used by most doctors and nurses. Avoid spending too much money on a digital instrument unless you are working in cardiology. All in all, you need to determine what you want from the stethoscope so that you can pick up the right one for your needs.
Last updated 08/2016