4. DISCUSSION
Urolithiasis is one of the common diseases of the urinary system,
manifesting with severe pain that causes patients to frequently refer to
ED.8 Although most ureteral stones pass spontaneously
without intervention, the main challenge for emergency physicians is to
identify patients at high risk for complications, such as obstructive
uropathy. In our study, we found that patients with urolithiasis and
without microscopic hematuria in UA had clinically more significant
ureteral stones. In addition, emergency patients without microscopic
hematuria had a higher risk of moderate to severe hydronephrosis than
those with microscopic hematuria.
The investigation of microscopic hematuria in UA is a good screening
test in patients with suspected renal colic, but its sensitivity varies
between 69% and 84%.9 Kim et al.10found the sensitivity, specificity, positive predictive and negative
predictive values of microscopic hematuria as 89.4%, 41.1%, 88.9%
and 42.1%, respectively in the diagnosis of urolithiasis. They showed
that 10.6% of the patients diagnosed with urolithiasis did not have
hematuria. Luchs et al. reported that the incidence of a negative UA
test was 16% in patients with renal colic caused by stones that were
definitively diagnosed based on non-contrast abdominopelvic
CT.9 Similarly, Gulacti et al. determined that
hematuria was not observed in 12% of patients diagnosed with
urolithiasis.11 In our study, we found renal colic due
to ureteral stone without hematuria in 17.9% of the cases. Our data
show that the absence of hematuria in UA does not rule out the diagnosis
of urolithiasis.
Inci et al.12 reported no relationship between stone
volume and microscopic hematuria. They found that the frequency of
microscopic hematuria was 42% if the stone volume was 1-10
mm3, and 83% if 75-100 mm3. Mefford
et al.6 determined that the presence or absence of
microscopic hematuria was not related to the size of the stone and that
patients without microscopic hematuria had a higher rate of moderate to
severe hydronephrosis (42%) compared to those with microscopic
hematuria. In addition, that study revealed that the incidence of
moderate to severe hydronephrosis was 49% for ureteral stones of 5 mm
or greater, while it was 14% for those smaller than 5 mm. In the
current study, the incidence of moderate and severe hydronephrosis was
higher in the patient group without microscopic hematuria than the
patient group with microscopic hematuria. Unlike other studies, we found
that pyuria and hematuria had an independent relationship.
CT has a very high diagnostic value for kidney stone disease (94-100%
sensitivity and 92-99% specificity). It also provides important data in
the planning of treatment by determining stone size and localization,
and degree of hydronephrosis.13,14 In a study
involving 1,824 patients with urolithiasis, Chang et
al.15 reported that the severity of hydronephrosis
before treatment was associated with the failure of shock wave
lithotripsy. Cho et al.16 reported that patients
suffering from urolithiasis without microscopic hematuria used
medication more often and were hospitalized more frequently than those
with microscopic hematuria. In our study, we detected a correlation
between the degree of hydronephrosis and the absence of microscopic
hematuria. Therefore, we suggest that rapid diagnosis and treatment are
required by promptly performing non-contrast CT in the patient group
without microscopic hematuria.