Auscultation

AUSCULTATION (from Latin auscultatio — listening), one of the most important clinical methods of examination at the patient's bedside. By auscultation, one understands not the examination of the body in general by means of hearing, but a method of listening to the body with the ear placed close to it for the purpose of studying sound phenomena naturally arising in the organism. Auscultation was known in antiquity; as a method of listening to the heart, it is mentioned in the works of the Greek physician Aretaeus (Aretaios), but it was applied even before him, although in a more primitive form, by Hippocrates. A distinction is made between immediate auscultation, by applying the ear to the body, and mediate auscultation, by means of using instruments of various kinds and types, up to the latest models of electrostethoscopes. The stethoscope was introduced into clinical practice for the first time at the beginning of the 19th century by the Frenchman Laennec; although individual physicians, such as Auenbrugger and Corvisart, used auscultation even before him, Laennec was the first to develop auscultation in detail and scientifically. In France, immediate auscultation is still widespread. In the USSR and in most other countries, mediate auscultation is used, mainly. The stethoscope allows one to listen to a small, limited area of the body and thereby isolate sound phenomena from neighboring ones. This is especially important in relation to the cardiac region, where many different sounds are concentrated in a small area. Auscultation of supraclavicular spaces, depressions, and protrusions on the body under pathological conditions, for example, in kyphoscoliosis, auscultation of severely ill patients and young children, simultaneous listening by several persons at once, etc., are sometimes possible only with the help of apparatuses. Stethoscopes are prepared in various shapes and from various materials. Most commonly used are those in the form of a hollow tube made of wood, hard rubber, or metal, with a small bell at one end, applied to the patient's body, and with a wide plate with a hole in the middle for the examiner's ear at the other end (see Figure 1). In wide use, especially in pediatric practice and with severely ill patients, are soft, binaural stethoscopes, e.g., the Russian Filatov model, consisting of a hollow cone, the interior of which is connected to two long rubber tubes, the free ends of which are inserted into both ears of the examiner (see Figure 3). These instruments do not amplify sound but serve only as its conductor. Another group of stethoscopes is built on the principle of sound amplification. Resonators, as well as microphones of earlier construction, alter the sound so much that they have been abandoned by everyone. At the present time, the so-called phonendoscope is also used.

Figure 2. Phonendoscope.

Figure 3. Filatov's stethoscope.

An essential part of them is a hollow capsule with an amplifying membrane, applied to the patient's body (see Figure 2). Well-made phonendoscopes are found to be useful in the detailed study of sound phenomena, especially if these phenomena are weakened. In France and America, electrical devices are coming into use. Such electro-auscultation has proven particularly convenient for mass demonstrations in lecture halls. By means of auscultation, the organs of respiration and circulation are mainly examined. Auscultation of other areas has secondary importance, for example, of the esophagus, for the diagnosis of its strictures by determining so-called swallowing sounds; of the intestines, for determining the presence of peristalsis by auscultation of 'intestinal sounds,' which disappear in intestinal paresis, for example, in peritonitis, etc. Also heard are: the whistling 'sound of intestinal stricture'; 'peritoneal friction sound' in perivisceritis, e.g., in splenic infarcts, liver cirrhosis, chronic peritonitis; the so-called 'cranial sound,' heard in the head, e.g., in anemias, aneurysms of intracranial arteries, etc.; finally, in recent times, auscultation of joints has begun to be applied again, whereby this examination determines the 'machine-gun crackle sound,' indicating the friction of rough intra-articular surfaces of the epiphyses. Auscultatory percussion is a method in which sound phenomena in the patient's body are heard, arising not independently, as in ordinary auscultation, but from the tapping performed at that moment. It is used in the clinic to determine the boundaries of certain organs, mainly the liver and stomach. To find, for example, the lower border of the liver, a stethoscope is placed on the liver region and simultaneously one percusses or runs a finger along the abdomen, moving upward. In the stethoscope, a dull sound is initially heard, which sharply intensifies as soon as the finger aligns with the liver. The method provides satisfactory orientational data. For auscultation of pregnant women, see Obstetric examination.

V. Egorov.