Examination and neurological status
The physical examination of a patient begins with assessing their general condition and posture. In the early stages of kidney disease, patients are active. However, with the development of end-stage chronic renal failure (uremic coma), posture becomes passive, and consciousness is depressed. This extremely severe condition is typically characterized by labored Kussmaul breathing and a pronounced odor of ammonia. Patients undergoing maintenance hemodialysis may develop psychoses or specific dementia.
Forced posture is of particular diagnostic significance. If the patient lies on the affected side with the leg flexed at the knee and hip joints, it may indicate inflammation of the perirenal tissue (paranephritis), as this posture relaxes the psoas muscle. During renal colic, by contrast, the patient tosses about, cries out, and cannot find a comfortable position. In renal eclampsia or acute glomerulonephritis, hypertension and cerebral edema may cause agitation, brief convulsions, and even temporary loss of vision (amaurosis).
Skin and edema syndrome
Renal edema is a crucial symptom of nephropathies. It alters the patient's appearance, forming facies nephritica: a pale, puffy face with swollen eyelids and narrowed palpebral fissures. Severity ranges from mild pastosity to total anasarca with fluid accumulation in the serous cavities.
The physician must differentiate renal edema from cardiac edema:
- Rate and localization: Renal edema develops rapidly (sometimes suddenly), starting from the face and descending downwards. Cardiac edema develops slowly and ascends from bottom to top (starting from the ankles).
- Characteristics: Renal edema is soft, "watery," and easily displaced. Cardiac edema is dense and relatively immobile.
The skin also reacts to the disease. In acute glomerulonephritis, pallor results from vasospasm, while in nephrotic syndrome it is caused by capillary compression from edematous fluid. "Waxy" pallor is typical of amyloidosis. In chronic renal failure, the skin acquires a yellowish-green tint due to the accumulation of urochromes, becomes dry, and is covered with scratch marks. In addition, the physician should look for stigmata of dysmorphic development (skeletal anomalies) or cutaneous markers of systemic diseases, such as the malar "butterfly" rash in lupus or livedo reticularis.
Palpation and abdominal inspection
Normally, the abdomen is symmetrical, and the kidneys are not palpable. Abdominal asymmetry indicates severe hydronephrosis, a large tumor, or large cysts. Smoothing of the lumbar contours on one side is characteristic of paranephritis or a massive hematoma. A suprapubic bulge indicates acute urinary retention.
Palpation of the kidneys is performed bimanually, primarily in asthenic patients in the supine position. The physician places the left supporting hand under the patient's lower back and the right hand on the abdomen. The patient takes a deep breath, during which the palpating hand sinks inward, trying to grasp the organ. Upon expiration, the kidney slips upward.
- Nephroptosis: pathological mobility ("floating" kidney).
- Enlargement: unilateral (tumor, cyst, hydronephrosis) or bilateral (polycystic kidney disease).
It is important to distinguish an enlarged right kidney from the liver (the liver has a sharp edge and is palpable throughout) and the gallbladder, and the left kidney from the more superficial spleen.
Percussion and auscultation
Percussion methods in nephrology aim to detect pain and assess the condition of the urinary bladder.
- CVA tenderness (punch sign). The physician places the left palm on the patient's lower back and strikes it moderately with the fist or ulnar edge of the right hand. A positive sign (pain) indicates stretching of the renal pelvis (hydronephrosis), capsule (glomerulonephritis), or tissue inflammation.
- Pasternatsky's sign. Often confused with the previous one. It is tested by jarring the body: the patient drops sharply from toes to heels. The onset of pain also indicates pathology.
Percussion of the urinary bladder is performed from the umbilicus downward; dullness over the pubic bone reveals an overfilled organ.
Auscultation of the abdomen is mandatory for all nephrological patients and individuals with arterial hypertension. Auscultation of a systolic murmur in the projection of the abdominal aorta or renal arteries is a sign of congenital or acquired stenosis (atherosclerosis, aortoarteritis). This is an indication for mandatory angiography.
To avoid confusing edemas, remember the direction of their spread: renal edema "falls" from top to bottom (from the face to the body), it is rapid and soft. Cardiac edema "grows" from bottom to top (from the ankles to the abdomen), it is slow and dense.
Class and exam questions
How can occult renal edema be detected?
This is done by daily body weight control, comparing diuresis with fluid intake, and the Aldrich test—intradermal administration of 0.2 ml of saline (in cases of edema, the bleb is absorbed faster than 40 minutes).
What is the fundamental difference between CVA tenderness and Pasternatsky's sign?
CVA tenderness is checked by the physician striking the lower back through their own palm, whereas Pasternatsky's sign causes pain when the patient themselves drops sharply from toes to heels (jarring the entire body).
What does a systolic murmur during abdominal auscultation indicate in nephrology?
A systolic murmur in the projection of the renal arteries indicates narrowing (stenosis) of the vessel due to atherosclerosis or congenital pathology. This requires angiography to confirm the diagnosis.
What else to study on this topic
- Mechanisms of uremic coma development and differential diagnosis of impaired consciousness in nephrology
- The association of genetic stigmata of dysmorphic development with hereditary nephropathies
- Pathogenesis of occult edema formation and detailed methodology of the Aldrich test
- Differential palpation of the kidneys, liver, gallbladder, and spleen (clinical examples)
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