Few methods assist the physician make a differential diagnosis better than listening with a stethoscope, a skill known as auscultation. According to Modern Medicine, mastering auscultation takes time but is well worth the effort. Infants pose a challenge because of their anatomic structure, and their relative non-compliance with the test. A few adjustments in technique and preparation can make the examination easier.
Preparation
Warm your stethoscope to body temperature or slightly warmer. According to Emedicine, listening to the lungs is most important when examining a child with respiratory symptoms, and it is best performed with warm hands and stethoscope. Placing a cold stethoscope diaphragm on the skin will cause the infant to cry making it more difficult for you to hear. You can warm the instrument by using your own body heat. Rub your hands together and then cup the diaphragm. Keep the diaphragm cupped until you are ready to listen.
Technique
Gently expose the area of the infant's body you plan to listen to. The stethoscope is typically used for listening to breath sounds, though it can be used for other examining other things. According to Pediatric Education for Prehospital Providers, assess air movement by placing the stethoscope on the infant's chest and listen for air movement. Listening through clothing should be avoided as this may cause sounds that interfere with the examination. Use an appropriately sized stethoscope designed for listening to infants. Using too large of a diaphragm will allow excessive noise.
Place the diaphragm of the stethoscope on the area you want to listen to. If the infant does not react, you can then place the ear pieces. If the infant does react, all you will hear is crying. Wait until the infant becomes accustomed to the feeling of the stethoscope and stops crying, then wear the ear pieces. A pacifier can be used to quiet the infant.
Position
Check for symmetry with the lung sounds. According to Medscape, compare the left and right sides, listen to the front, sides and back, and work from the top to the bottom of the chest. For the front, place the diaphragm above the nipple, but below the collar bone, on both sides. For the sides, place the diaphragm under the armpit and about nipple line. For the back, listen beneath both shoulder blades.
Duration
Listen for approximately 30 to 60 seconds in each position. An infant's internal organs are all in close proximity, so listening to one area may be masked by sounds of another. For example, while listening for bowel sounds, the infant's breathing might seem louder. Listening longer provides a better opportunity to distinguish between different sounds.
Medical Attention
There are some lung sounds that may require immediate medical attention. According to University Hospitals, the four most common include rales, rhonchi, stridor and wheezing. Rales are caused by air suddenly opening closed air spaces, and are compared to the sound of rubbing hair between your finger tips. Rhonchi are caused by a blockage of the large airways by mucous and resemble a snoring sound. Stridor is a wheeze-like sound caused by a blockage of the upper airway , usually by a foreign body. Wheezing is a high-pitched sound heard in the lower airways and suggests inflammation.
References
- Modern Medicine: Heart and Breath Sounds -- Listening with Skill
- Emedicine: Pediatrics, Pneumonia
- "Pediatric Education for Prehospital Providers"; American Academy of Pediatrics; 2006.
- Medscape: Systematic Physical Assessment Guide -- Auscultation
- University Hospitals: Newborn Infant Disorders
