چاپ صفحه |  صفحه نخست سامانه |  نویسندگان |  اطلاعات تفضیلی |  دانلود مقاله | دانشگاه علوم پزشکی تبریز |
| نویسنده | نفر چندم مقاله |
|---|---|
| افشین قلعه گلاب بهبهانی | اول |
| عنوان | متن |
|---|---|
| کلمات کلیدی | Crystalluria, Urinalysis |
| خلاصه مقاله | Introduction It is common to find crystals on microscopic examination of the urine (about 8%). the presence of crystals may be normal or pathologic. Usually, the presence of crystals in the urine is of limited clinical significance. Supersaturation of the solute components of the crystals must occur for crystallization to initiate. Factors affecting supersaturation, include: Solute concentration, Ionic strength (solubility), Urine pH and the presence of promoters or inhibitors. Causes of Supersaturation include: Low fluid intake (dehydration), Hi dietary intake – drug ingestion, body metabolism, and prolonged interval between urine collection and urine examination. Discussion In most instances, crystalluria is an occasional finding without clinical importance because it reflects transient supersaturation of urine, these are called Common Crystals. Some crystals that almost always correlate with a known pathology if they are seen in a child’s urine, are called Pathological Crystals. Common crystals may be seen in some pathologic situations as well. Persistent Calcium Oxalate Crystalluria in repeated samples of the same subject should raise the suspicion of a possible disorder including: Hypercalciuria, Hyperoxaluria, Hypocitraturia (as citrate is a crystallization inhibitor), Ethylene Glycol Intoxication, Ingestion of the Exotic Star Fruit, Drug ingestion (Vitamin C, Naftidrofuryl Oxalate, and Orlistat). Persistent Uric Acid Crystalluria in repeated samples of the same subject should raise the suspicion of a possible disorder: Hyperuricosuria (with or without Hyperuricemia), acute uric acid nephropathy and persistent dehydration. Persistent Triple Phosphate, or Struvite Crystalluria in repeated samples of the same subject should raise the suspicion of a possible disorder: Infections due to urease-producing bacteria, typically associated with Proteus species and alkaline urine. Triple phosphate crystals have the shape of “coffin lids”: 3 to 4 to 6 – sided prism , composed of magnesium ammonium phosphate. Pathologic crystals seen in pathologic situations: Cystine Crystals that are always abnormal and are pathognomonic of the inherited disease: Cystinuria, patients often have kidney stones, found only in fresh urine, because if there is delay, they are soluble and not seen, may also be seen in transient acute phase of pyelonephritis. Cystine Crystals are Flat, hexagonal plates with well-defined edges, colorless, and highly retractile. Tyrosine and Leucine Crystals are also abnormal and suggest liver disease. Bilirubin Crystals are seen in all conditions associated with Conjugated Hyperbilirubinemia and Hyperbilirubinuria, such as Cholestasis. Cholesterol Crystals are found in patients with marked proteinuria. 2,8-Dihydroxyadenine Crystals are a highly sensitive marker of homozygotic deficiency of the enzyme adenine phosphoribosyl-transferase (APRT), found in about 96% of untreated patients. Drug Crystals in Urine; as a general rule, one should always suspect drug crystalluria when finds Atypical Crystals, because: most drugs cause atypical and/or pleomorphic crystals, which differ remarkably from common or pathological crystals. Factors causing Drug-crystals precipitation in urine, include: Drug overdose, Rapid intravenous bolus administration, Hypoalbuminemia, Dehydration, Urine pH; e.g.: Indinavir at pH > 6.0, Amoxicillin at pH ≤ 4.0 or >7.0 with “U” shaped behavior, Ciprofloxacin at pH>7.3, If confirmed, this should always prompt the check of renal function because acute renal failure can occur, especially in patients with impaired renal function. When crystalluria is caused by drugs, this may be the only urinary abnormality or it may be associated with: hematuria (either gross or microscopic), acute tubular necrosis caused by precipitation of crystals within renal tubules and obstructive uropathy caused by drug stones. If confirmed, this should always prompt the check of renal function because acute renal failure can occur, especially in patients with impaired renal function. It is advisable to: Withdraw the drug or decrease the dosage, Reestablish euvolemia, Stimulate a high urine flow, Manipulate urine pH in reverse direction. |
| نام فایل | تاریخ درج فایل | اندازه فایل | دانلود |
|---|---|---|---|
| Certificate 1.pdf | 1399/09/25 | 92343 | دانلود |
| Crystalluria in Urinalysis.docx | 1399/09/28 | 19017 | دانلود |
