Routine blood tests, urine tests, renal ultrasound, and renal function tests should typically be performed. Combined with clinical symptoms, a preliminary diagnosis can be made.
1. Blood Tests:
- Increased levels of serum creatinine and blood urea nitrogen;
- Hemoglobin is generally below 80g/L; in the later stages of uremic poisoning, it may drop to 20-30g/L, possibly accompanied by reduced platelet count or elevated white blood cell count;
- In the late stage of uremic poisoning, there is often a decrease in PH value, AB, SB, and BE are all reduced, PaCO2 shows compensatory reduction;
- Plasma protein is normal or reduced;
- Electrolyte measurements may show abnormal indicators.
2. Urine Tests:
- Due to different causes of uremic poisoning (for example, some uremic poisoning patients develop from chronic glomerulonephritis, while others develop from diabetes, hypertension, purpura, etc.), proteinuria, white blood cells, or casts in urine may appear;
- The specific gravity of urine is mostly below 1.018, fixed at 1.010~1.012 during uremic poisoning, and nighttime urine volume is greater than daytime urine volume.
3. Ultrasound Examination:
- Determine the position and mobility of the kidneys. If the kidney position drops, it is commonly seen in nephroptosis.
- Measure the size of the kidney. Enlarged kidneys are seen in polycystic kidney disease, kidney tumors, acute renal failure, etc., while shrunken kidneys are commonly seen in chronic renal failure.
- Determine intrarenal diseases. Such as hydronephrosis, kidney stones, kidney cysts, polycystic kidney disease, kidney tumors, etc., each has its own specific imaging. Ultrasound is significant for diagnosing these diseases, especially for non-functional kidneys such as late-stage hydronephrosis, polycystic kidney disease, and kidney tumors. X-ray intravenous pyelography cannot display the image of the kidney, and at this time, based on the findings of the ultrasound combined with clinical presentation, it helps improve diagnostic accuracy.
- When changes in kidney size and shape are found during renal ultrasound, it generally indicates serious kidney problems, and early treatment should be sought.
4. Renal Function Tests:
- Decreased glomerular filtration rate and endogenous creatinine clearance rate;
- Both phenol red excretion test and urine concentration dilution test are reduced;
- Abnormal pure water clearance rate measurement;
- Radionuclide renogram, renal scanning, and scintigraphy help understand renal function.