Материал: General propedeutics of internal diseases_Nemtsov-LM_2016

airless organs and tissues (liver, muscles), liver dullness. But the absolute dullness identical to the percussion sound of the liver can only be heard in the presence of a large amount of fluid in the pleural cavity.

The amount of air in the lung increases in emphysema. The percussion sound in lung emphysema is louder than the dull tympanic sound because of the increased airiness of the pulmonary tissue and decreased elasticity of the tense pulmonary tissues; but the tympanic character is preserved. The percussion sound resembles the one produced by a stroke on a box; hence the name bandbox sound.

The amount of air held inside the lung increases with formation in it of a smooth-wall cavity filled with air and communicated with the bronchus (abscess, tuberculosis cavern). The percussion sound over this area will be tympanic. If the cavity is small and situated deeply in the chest, vibrations of the pulmonary tissue will not reach this cavity and no tympanic sound will be heard. Such a cavity will only be revealed by roentgenoscopy. The sound over a very large smooth-wall cavity in the lung (6—8 cm in diameter) will be tympanic, resembling a stroke on a metal (metallic percussion sound). If this cavity is located superficially and is communicated with the bronchus through a narrow slit, the percussion sound will be soft and will resemble that of a cracked pot (hence the name - cracked-pot sound).

Topographic percussion of lungs

Topographic percussion is used for delimitation (1) the upper borders of the lungs or the upper level of their apices and their width (Kroenig's area);

(2) the lower borders of the lungs, and (3) variation mobility of the lower border of the lung.

The topographic percussion is always performed from a clear note in the direction of dull sound. Percussion begins from the level of II-d intercostal space to reach a dull note. The border of a lung is marked on that side of a finger-pleximeter which is reversed to more clear sound. The upper edge of the pleximeter lying in intercostal space will correspond to the inferior edge of the superposed rib which is considered to be the lower border of a lung.

The position of the upper borders (apices) of the lungs is determined both anteriorly and posteriorly. In order to locate the apex of the lung, the pleximeter finger is placed parallel to the clavicle and percussion is effected from the middle upwards and slightly medially along the edge of m. scalenus med. to dullness. The upper level of the apices in healthy persons is 3-4 cm above the clavicles. The upper posterior border of the lungs is always determined by their position with respect to the spinous process of the 7th cervical vertebra. The pleximeter finger is placed over the supraspinous fossa parallel to the scapular spine and stroked from the middle. The pleximeter finger is moved gradually upward to the point located 3—4 cm laterally to

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the spinous process of the 7th cervical vertebra, at its level, and percussion is then continued until dullness. Normal height of the lung apices (posterior) is about at the level of the spinous process of the 7th cervical vertebra.

The so-called Kroenig's area is a band of clear resonance over the lung apices. The width of these areas is determined by the low anterior border of the trapezius muscle and is (on an average) 5-6 cm wide, but its width can vary from 4 to 7 cm, at the right side it is lesser on 1-1.5 cm. The anterior border of the trapezius muscle divides the Kroenig's area into its anterior field which extends to the clavicle, and the posterior one that widens toward the supraspinous fossa. Light (quiet) percussion is used to determine the width of the lung apex. The position of a physician is in back and some right of a patient. The pleximeter finger is held over the middle portion of m. trapezius, perpendicular to its anterior margin, and percussion is first carried out medially, and then laterally, to dullness. The distance between the points of transition of the clear pulmonary resonance to dullness is measured in centimeters.

The upper border of the lungs and the width of the Kroenig area can vary depending on the amount of air in the apices. If the amount of air is high (which may be due to emphysema) the apices increase in size and move upwards. The Kroenig's area widens accordingly. The presence of connective tissue in the lung apex (which usually develops during inflammation as in tuberculosis or pneumonia or inflammatory infiltration) decreases the airiness of the pulmonary tissue. The upper border of the lung thus lowers and the width of the Kroenig's area decreases.

To outline the lower borders of the lungs their percussion is carried out in the downward direction along conventional vertical topographical lines (Table 2). The lower border of the right lung is first determined anteriorly along the parasternal and the medioclavicular lines, then laterally along the anterior, medial and posterior axillary lines, and posteriorly along the scapular and paraspinal lines. The lower border of the left lung determined only laterally, by the three axillary lines, and posteriorly by the scapular and paraspinal lines. The lower border of the left lung is not determined anteriorly because of the presence of the heart. The pleximeter finger is placed in the interspaces, parallel to the ribs, and the plexor finger produces slight and uniform strokes over it. Percussion of the chest is usually begun anteriorly, from the second costal interspace (with the patient in the lying or upright position).

When percussing on a line parasternalis dextra the more precise determination of position of border of the lung is performed by means of immediate percussion according to Obraztsov. The immediate percussion is carried out on two superposed ribs above the dullness. The upper rib lies obviously above a pulmonary tissue and serves as the control, it generates clear pulmonary sound. Next the second rib lied directly above a dull sound

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is percussing. If at percussion of this rib it is obtained the same sound as above overlying control rib, it means the border lays on the inferior edge of this rib. If above the lower rib the sound will be a little dulled hence the liver lies under this rib, and the border of the lung will be on the upper edge of the rib that most often happens.

The examination of the lateral surface of the chest is performed from the axillary fossa (armpit). The patient either sits or stands with the hands behind the back of the head. The examination ends with the posterior percussion from the seventh costal interspace, or from the scapular angle, which ends at the seventh rib.

The lower border of the right lung is as a rule at the point of transition of the clear pulmonary resonance to dullness (lung-liver border). In exceptional cases, when air is present in the abdominal cavity (e.g. in perforation of gastric or duodenal ulcer), liver dullness may disappear. The clear pulmonary resonance will then convert to tympany. The lower border of the left lung by the anterior and midaxillary lines is determined by the transition of clear pulmonary resonance to dull tympany. This is explained by the contact between the lower surface of the lung (through the diaphragm) and a small airless organ, such as the spleen and the fundus of the stomach, which give tympany (Traube's space).

The lower borders of the lungs in normosthenic persons usually occur as given in Table 2. The position of the border varies depending on the constitutional properties of the body. The lower border of the lungs in asthenic persons is slightly lower than in normosthenics and is found at the interspace (rather than on the rib as in normosthenics) whereas this border is slightly higher in hypersthenic persons. The lower border of the lungs rises temporary during late pregnancy.

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The position of the lower border of the lungs can vary in various pathological conditions that develop in the lungs, the pleura, the diaphragm, and the abdominal viscera. The border can both rise and lower from the normal level. This displacement can be unior bilateral.

Bilateral lowering of the lower border of the lungs can occur in acute and chronic dilation of the lungs (attack of bronchial asthma and emphysema of the lungs, respectively) and also in sudden weakening of the tone of the abdominal muscles and lowering of the abdominal viscera (splanchnoptosis). Unilateral lowering of the lower border of the lungs can be due to vicarious (compensatory) emphysema of one lung with inactivation of the other lung (pleurisy with effusion, hydrothorax, pneumothorax, hemiparesis of the diaphragm).

The elevation of the lower border of the lungs is usually unilateral and occurs in (1) restriction of the lung due to development of connective tissue (pneumosclerosis); (2) complete obstruction of the lower-lobe bronchus by a tumour which causes gradual collapse of the lung, atelectasis; (3) accumulation of fluid or air in the pleural cavity which displace the lung upwards and medially toward the root; (4) marked enlargement of the liver (cancer, echinococcosis), or of the spleen (chronic myeloleukaemia). Bilateral elevation of the lower borders of the lungs occurs in the presence of large amounts of fluid (ascites) or air in the abdomen due to an acute perforation of gastric or duodenal ulcer, and also in acute meteorism.

After determining the lower border of the lungs at rest, active respiratory mobility of pulmonary borders should be determined by percussion during forced inspiration and expiration. This mobility is called active, and is usually measured by the difference in the position of the lower border of the lungs between the two extremes. Measurements are done by three lines on the right side (midclavicular, axillary, and scapular lines) and two lines on the left side (midaxillary and scapular lines). The normal mobility of the lower border of the lungs is described by the figures given in Table 3. Mobility of the lower border of the left lung by the midclavicular line cannot be determined because of the interference of the heart.

The respiratory mobility of the lungs is determined as follows. The lower border of the lungs in normal respiration is first determined and marked by a dermograph. Further the patient is asked to make a forced inspiration and to keep breath at the height. The pleximeter finger should at this moment be held at the lower border of the lung (determined earlier). Percussion is now continued by moving the pleximeter downwards to complete dullness, where the second mark should be made by a dermograph at the upper edge of the pleximeter finger. Next the patient is then asked to maximum air from the lungs and to keep breath again. The percussion is now continued in the downward direction from starting point until the clear vesicular resonance disappears. The third dermographic mark should be made

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