진료실 참고자료 - 혈뇨/단백뇨 진료 알고리즘
Evaluation of Proteinuria
Evaluation of Hematuria
소변 1L 당 1mL blood 가 있어도 색깔이 붉게 보일 수 있다.
Microscopic hematuria (defined as 3 RBCs or more per high-power field)
- Although abnormal hematuria is commonly defined as the presence of three or more RBCs per high-power field in a spun urine sediment, there is no "safe" lower limit below which significant disease can be excluded
Urine dipstic 위양성
(dipstick detects hemoglobin but no RBCs are visible)
(1) Semen, which is present in the urine after ejaculation and may cause a positive heme reaction on the dipstick
(2) An alkaline urine with a pH greater than 9 or contamination with oxidizing agents used to clean the perineum.
(3) The presence of myoglobinuria or hemoglobinuria.
드물게는 매우 희석된 소변이 RBC 의 osmotic lysis 를 일으켜 위양성이 발생하는 경우도 있다.
* 위음성의 경우 매우 드물지만 많은 양의 vitamin C 를 복용했을 때 나타났다는 것이 보고된바 있다.
< Causes of hematuria >
Microscopic hematuria identified in a woman during her menses, or in a patient shortly after vigorous exercise or acute trauma, should be confirmed by repeating the urinalysis.
In patients who had hematuria identified in the setting of vigorous exercise, the urinalysis should be repeated approximately four to six weeks later during a period of no exercise.
Patients who present with hematuria and unilateral flank pain suggestive of obstructive nephrolithiasis should undergo imaging (noncontrast computed tomography [CT] or ultrasound with or without an abdominal radiograph) as the first test in the evaluation
Patients who have findings suggestive of urinary tract infection (eg, fever, dysuria, presence of white blood cells [WBCs] in the urine, positive dipstick for nitrite) should undergo urine culture to evaluate for urinary tract infection.
< Evaluation of the adult with asymptomatic hematuria >
< Approach to the patient with red or brown urine (Gross hematuria) >
< Causes of heme-negative red urine >
< Major causes of hematuria by age and duration >
Blood clots, if present, are almost always due to nonglomerular bleeding
56000 명의 성인 환자 중 (평균 f/u 기간은 5.8 년)
432 명의 경우 무증상, 단백뇨 없는 혈뇨
44% : hematuria 사라짐
44% : proteinuria 없는 hematuria 지속
11% : hematuria 지속, proteinuria 발생
Renal insufficiency 가 발생한 경우는 없었음. (eGFR 60 미만, Cr 1.5 이상)
134 명은 무증상 혈뇨 with 단백뇨
예후는 더 좋지 않음.
16% 에서만 hematuria 사라짐.
Renal insufficiency 는 15% 에서 발생.
한 연구에서 2421585 명의 사람에서 40% 의 사람에서 asymptomatic microscopic hematuria 가 있었고, 그 사람들을 대상으로 재검을 했을 때, asymptomatic microscopic hematuria 가 또 나오는 경우가 66% 였다. 즉 초기 소변검사에서 혈뇨가 있는 사람 중 대략 1/3 의 사람이 혈뇨가 사라지는 transient hematuria 였다.
* RISK FACTORS FOR MALIGNANCY
Age >35 years
Past or current smoking history in which the risk correlates with the extent of exposure
Occupational exposure to chemicals or dyes (benzenes or aromatic amines), such as printers, painters, and chemical plant workers
History of gross hematuria
History of irritative voiding symptoms
History of chronic urinary tract infection
History of pelvic irradiation
History of exposure to cyclophosphamide
History of a chronic indwelling foreign body
History of exposure to aristolochic acid
History of analgesic abuse, which is also associated with an increased incidence of carcinoma of the kidney
Role of renal biopsy
Indications — The main indication for performing a kidney biopsy in patients with glomerular hematuria (defined by the presence of dysmorphic RBCs and/or RBC casts) is the presence of risk factors for progressive disease such as proteinuria and/or an elevation in the serum creatinine concentration.
We typically biopsy patients with glomerular hematuria and a urine albumin excretion above 30 mg/day, except for those who have a clinical presentation consistent with diabetic nephropathy.
New-onset hypertension or a significant elevation in blood pressure above a previous stable baseline that does not exceed 140/90 mmHg (eg, from 100/60 to 130/80 mmHg) is also associated with a greater likelihood of progressive disease but is primarily seen in patients who also have one or both of the other adverse predictors.
Kidney biopsy is not usually performed for isolated glomerular hematuria (ie, no abnormal proteinuria [or albuminuria and a negative or trace dipstick result], no elevation in serum creatinine, no elevation in blood pressure about a previous stable baseline, and no systemic manifestations or family history of renal disease), since there is no specific therapy for these conditions and since the renal prognosis is excellent as long as there is no evidence of progressive disease.
Monitoring if renal biopsy is not performed — If kidney biopsy is not performed in a patient with isolated glomerular hematuria, periodic monitoring is warranted during follow-up to detect progressive disease. Serum creatinine, urinalysis, and urine protein excretion should be monitored yearly for at least five years.
Once glomerular bleeding has been excluded in a patient with otherwise unexplained hematuria, the diagnostic evaluation is directed to the kidney, ureters, bladder, urethra, and prostate.
일반 복부 CT 혹은 CT urography 가 선호되는 modality
CTU has largely replaced IVP
Ultrasound of the kidneys and bladder, when compared with CTU, demonstrates lower diagnostic yield and is less sensitive in detecting urothelium transitional cell carcinoma, small renal masses, and calculi
대신 higher sensitivity for the diagnosis of upper urinary tract causes of hematuria
For detection of cancer, ultrasound rather than CT is more cost effective when combined with cystoscopy
* 고려해야할 상황
In a young patient (eg, age <35 years) with no risk factors for urinary tract malignancy, post-contrast images should not be routinely acquired. (nephrolithiasis 가 non contrast image 에서 확실히 보인다면.)
All patients who have gross (macroscopic) hematuria and no evidence of glomerular disease or infection should undergo cystoscopy
All patients with microscopic hematuria who have no evidence of glomerular disease, infection, or a known cause of hematuria such as exercise and who are at increased risk for malignancy should undergo cystoscopy.
The diagnostic yield of cystoscopy is lower in patients who have microscopic hematuria, negative imaging, negative urine cytology, and who are at low risk for malignancy.
Immunoglobulin A (IgA) nephropathy (20~30%)
Thin basement membrane nephropathy (4~43%)
- gross hematuria is unusual
- the family history may be positive (with an autosomal dominant pattern of inheritance)
- not for renal failure
Mesangioproliferative glomerulonephritis without IgA deposits (10%)
Alport syndrome (hereditary nephritis)
- gross hematuria can occur in association with a positive family history of renal failure
Hypercalciuria and hyperuricosuria
idiopathic hematuria 가 있는 어린이의 30~35% : Hypercalciuria
5~20% 는 hyperuricosuria
대개 가족력이 있으며, 훗날 kidney stone 의 위험성을 가지고 있다.
Hypercalciuria 의 경우 Lowering calcium excretion with a thiazide diuretic 으로 hematruia 가 호전된다. hyperuricosuria 의 경우 allopurinol 로 hematuria 가 호전된다.
hereditary hemorrhagic telangiectasis, radiation cystitis, schistosomiasis (which is not rare in endemic areas), arteriovenous malformations (AVMs) and fistulas, nutcracker syndrome, and the loin pain-hematuria syndrome.
Follow-up of patients with persistent hematuria
Potentially, the most serious disorder in the patient with unexplained persistent hematuria is the presence of an undiagnosed carcinoma of the urinary tract.
negative computed tomography (CT) of the abdomen and pelvis, negative cytology, and negative cystoscopy is usually sufficient to exclude malignancy in the urinary tract.
As a result, monitoring with annual urinalyses is recommended for patients with asymptomatic microhematuria; if persisting for three to five years, repeating the initial urologic workup is a reasonable consideration. Some clinicians also recommend repeat ultrasound and cystoscopy at one year in high-risk patients
* 관련포스팅 :
2019. 3. 12 - SJH