Determining the boundaries of the lungs is of great importance for the diagnosis of many pathological conditions. The ability to percussion to detect the displacement of the chest organs in one direction or another makes it possible to suspect the presence of a certain disease already at the stage of examining the patient without the use of additional research methods (in particular, radiological ones).
How to measure the borders of the lungs?
Of course, you can use instrumental diagnostic methods, take an X-ray and use it to evaluate how the lungs are located relative to the bone frame of the chest. However, this is best done without exposing the patient to radiation.
Determination of the boundaries of the lungs at the stage of examination is carried out by the method of topographic percussion. What it is? Percussion is a study based on the identification of sounds that occur when tapping on the surface of the human body. The sound changes depending on the area in which the study is taking place. Above the parenchymalorgans (liver) or muscles, it turns out to be deaf, over hollow organs (intestines) - tympanic, and over air-filled lungs it acquires a special sound (pulmonary percussion sound).
This research is carried out as follows. One hand is placed with the palm on the area of study, two or one finger of the second hand hits the middle finger of the first (plessimeter), like a hammer on an anvil. As a result, you can hear one of the percussion sounds mentioned above.
Percussion can be comparative (sound is evaluated in symmetrical areas of the chest) and topographic. The latter is just designed to determine the boundaries of the lungs.
How to conduct topographic percussion?
The finger-plesimeter is set to the point from which the study begins (for example, when determining the upper border of the lung along the anterior surface, it starts above the middle part of the clavicle), and then shifts to the point where this measurement should approximately end. The border is defined in the area where the pulmonary percussion sound becomes dull.
Finger-plessimeter for the convenience of research should lie parallel to the desired border. The displacement step is approximately 1 cm. Topographic percussion, unlike comparative, is performed by gentle (quiet) tapping.
Upper border
The position of the tops of the lungs is assessed both in front and behind. On the anterior surface of the chest, the clavicle serves as a reference point, on the back -the seventh cervical vertebra (it has a long spinous process, by which it can be easily distinguished from other vertebrae).
The upper borders of the lungs are normally located as follows:
- In front above the level of the collarbone by 30-40 mm.
- Behind usually at the same level with the seventh cervical vertebra.
Research should be done like this:
- Front, the plessimeter finger is placed over the clavicle (approximately in the projection of its middle), and then shifted up and to the inside until the percussion sound becomes dull.
- Behind, the study starts from the middle of the spine of the scapula, and then the finger-plessimeter moves up so as to be on the side of the seventh cervical vertebra. Percussion is performed until a dull sound appears.
Shift of the upper limits of the lungs
The upward displacement of the boundaries occurs due to excess airiness of the lung tissue. This condition is typical for emphysema - a disease in which the walls of the alveoli are overstretched, and in some cases their destruction with the formation of cavities (bulls). Changes in the lungs with emphysema are irreversible, the alveoli swell, the ability to collapse is lost, elasticity is sharply reduced.
The borders of the human lungs (in this case, the borders of the apex) can also move down. This is due to a decrease in the airiness of the lung tissue, a condition that is a sign of inflammation or its consequences (proliferation of connective tissue and wrinkling of the lung). Borders of the lungs (upper) locatedbelow the normal level - a diagnostic sign of such pathologies as tuberculosis, pneumonia, pneumosclerosis.
Lower border
To measure it, you need to know the main topographic lines of the chest. The method is based on moving the researcher's hands along the indicated lines from top to bottom until the pulmonary percussion sound changes to dull. You should also know that the border of the anterior left lung is not symmetrical to the right one due to the presence of a pocket for the heart.
In front, the lower borders of the lungs are determined along the line passing along the lateral surface of the sternum, as well as along the line descending down from the middle of the collarbone.
Sideways, three axillary lines are important landmarks - anterior, middle and posterior, which start from the anterior, center and posterior margin of the armpit, respectively. Behind the edge of the lungs is determined relative to the line descending from the angle of the scapula, and the line located on the side of the spine.
Shifting the lower limits of the lungs
It should be noted that in the process of breathing the volume of this organ changes. Therefore, the lower borders of the lungs are normally displaced by 20-40 mm up and down. A persistent change in the position of the border indicates a pathological process in the chest or abdominal cavity.
The lungs are excessively enlarged in emphysema, which leads to a bilateral downward displacement of the borders. Other causes may be hypotension of the diaphragm and pronounced prolapse of the abdominal organs. The lower limit is shifted downward from oneside in case of compensatory expansion of a he althy lung, when the second is in a collapsed state as a result, for example, of total pneumothorax, hydrothorax, etc.
The borders of the lungs usually move upward due to wrinkling of the latter (pneumosclerosis), a fall in the lobe as a result of obstruction of the bronchus, accumulation of exudate in the pleural cavity (as a result of which the lung collapses and is pressed against the root). Pathological conditions in the abdominal cavity can also shift the lung boundaries upward: for example, accumulation of fluid (ascites) or air (during perforation of a hollow organ).
Lung borders are normal: table
| Lower limits in an adult | ||
| Research area | Right lung | Left lung |
| Line at the lateral surface of the sternum | 5 intercostal space | - |
| Line descending from the middle of the collarbone | 6 rib | - |
| Line originating from the front edge of the armpit | 7 rib | 7 rib |
| A line from the center of the armpit | 8 rib | 8 rib |
| Line from the rear edge of the armpit | 9 rib | 9 rib |
| Line descending from the angle of the shoulder blade | 10 rib | 10 rib |
| Line on the side of the spine | 11 thoracic vertebrae | 11 thoracic vertebrae |
The location of the upper lung borders is described above.
Change in the indicator depending on the physique
In asthenics, the lungs are elongated in the longitudinal direction, so they often fall slightly below the generally accepted norm, ending not on the ribs, but in the intercostal spaces. For hypersthenics, on the contrary, a higher position of the lower border is characteristic. Their lungs are wide and flattened in shape.
How are the lung borders in a child?
Strictly speaking, the boundaries of the lungs in children almost correspond to those of an adult. The tops of this organ in children who have not yet reached preschool age are not determined. Later, they are detected in front 20-40 mm above the middle of the clavicle, behind - at the level of the seventh cervical vertebra.
The location of the lower bounds is shown in the table below.
| Lung borders (table) | ||
| Research area | Under 10 years old | Age over 10 |
| A line from the middle of the collarbone | Right: 6 rib | Right: 6 rib |
| Line originating from the center of the armpit |
Right: 7-8rib Left: 9th edge |
Right: 8 rib Left: 8 rib |
| Line descending from the angle of the shoulder blade |
Right: 9-10 rib Left: 10 rib |
Right: 10 rib Left: 10 rib |
The reasons for the displacement of the pulmonary borders in children up or down relative to normal values are the same as in adults.
How to determine the mobility of the lower edge of the organ?
It has already been said above that when breathing, the lower limits shift relative to normal values due to the expansion of the lungs on inspiration and decrease on exhalation. Normally, such a shift is possible within 20-40 mm upwards from the lower border and the same amount downwards.
Determination of mobility is carried out along three main lines starting from the middle of the clavicle, the center of the armpit and the angle of the scapula. The study is carried out as follows. First, the position of the lower border is determined and a mark is made on the skin (you can use a pen). Then the patient is asked to take a deep breath and hold his breath, after which the lower limit is again found and a mark is made. And finally, the position of the lung during maximum expiration is determined. Now, focusing on the marks, we can judge how the lung is shifting relative to its lower border.
In some diseases, lung mobility is markedly reduced. For example, this happens with adhesions or a large amount of exudate in the pleural cavities, loss of elasticity in the lungs with emphysema, etc.
Difficulties in conductingtopographic percussion
This research method is not easy and requires certain skills, and even better - experience. The difficulties that arise in its application are usually associated with improper execution technique. As for the anatomical features that can create problems for the researcher, this is mainly severe obesity. In general, it is easiest to perform percussion on asthenics. The sound is clear and loud.
What needs to be done to easily determine the boundaries of the lung?
- Know exactly where, how and exactly what borders to look for. Good theoretical preparation is the key to success.
- Move from clear to dull sound.
- The finger-plessimeter should lie parallel to the defined border, but move perpendicularly to it.
- Hands should be relaxed. Percussion does not require much effort.
And, of course, experience is very important. Practice builds confidence.
Summarize
Percussion is a very important diagnostic method of research. It allows you to suspect many pathological conditions of the chest organs. Deviation of the boundaries of the lungs from normal values, impaired mobility of the lower edge are symptoms of some serious diseases, the timely diagnosis of which is important for proper treatment.
