Evaluation of the Success of POCUS Usage in Addition to STONE Criteria in Diagnosing Nephrolithiasis and Predicting Readmission Within One Month in Patients Presenting to the Emergency Department With Suspected Nephrolithiasis

Our study is a prospective study that will be conducted in the Emergency Medicine Clinic of Kocaeli City Hospital. Patients aged 18 and above who present to the emergency department of Kocaeli City Hospital with symptoms suggestive of renal colic will be included in the study if they volunteer. After examination by a resident physician working in the emergency department, patients for whom nephrolithiasis is considered among the preliminary diagnoses will be notified to the principal investigators. After obtaining written consent, demographic data, vital signs, and physical examination findings will be recorded on previously prepared standard data forms.

Patients scoring 8 points or higher according to the STONE criteria based on history, physical examination, and laboratory results will undergo bedside ultrasound. The ultrasound will be performed by 4 resident physicians with a basic ultrasound course certificate from the Turkish Emergency Medicine Association, who have 2 years of experience. The bedside urinary ultrasound will be performed using the 'Esaote Mylab Gamma® device (Genoa, Italy)' ultrasound machine with the 'Esaote AC2541 curved array (1-8 MHz) probe (Genoa, Italy)' while the patient is in the supine position.

During renal ultrasound, the convex ultrasound probe will be placed in the right upper quadrant of the patient, intersecting the right lower intercostal area and the mid-axillary line. In the left upper quadrant, the probe will be placed in the lower intercostal area along the posterior axillary line. The ultrasound probe will be positioned longitudinally with the indicator pointing towards the patient's head. Subsequently, the same area will be imaged transversely with the indicator pointing towards the patient's right.

In these sections, images of the kidneys will be evaluated for the presence of hydronephrosis, the degree of expansion of pelvic-calyceal structures, stone size, kidney dimensions, parenchymal echogenicity, and the presence of primary stones or acoustic shadowing from stones. Then, from the suprapubic region, the probe will be positioned transversely and longitudinally, sequentially showing the patient's right and head; the presence of globules in the bladder, bladder dimensions, the presence of stones, and the degree of jet flow at the junction of the ureters with the bladder will be assessed using color frequency mode (CFM). The presence of twinkling artifacts with color frequency mode (CFM) will be evaluated when a stone is suspected. The data obtained will be recorded on the study form by the resident physician performing the ultrasound. The recorded data will later be compared with the gold standard diagnostic method, computed tomography routinely performed in patients with nephrolithiasis, for effectiveness.