Assessment of Laboratory Parameters and Imaging Findings in Patients With Gastrointestinal Bleeding

METHODS 1.1. Study Design This prospective, cross-sectional, observational study was conducted in the Emergency Department of Süleyman Demirel University Hospital (Isparta, Turkey). From 55,328 annual adult ED admissions, 238 eligible gastrointestinal bleeding (GIB) patients were identified, with 76 enrolled after exclusions. Written informed consent was obtained, and the study is registered at ClinicalTrials.gov. 1.2. Participants Adult patients (≥18 years) with GIB who underwent bedside ultrasonography (May 2023-June 2025) were included. Exclusions: pregnancy, trauma, advanced organ failure, malignancy, inability to consent, or refusal. Flow Chart: Suspected GIB: 420 Excluded (no confirmed GIB): 182 Enrolled (confirmed GIB): 238 Included (met criteria): 76 Excluded: 162 (age \<18, pregnancy, trauma, comorbidities, no consent, refused hospitalization). 1.3. Sample Size Based on pilot data (effect size 0.5, power 95%, α=0.05), 70 participants were required for significance. 1.4. Data Collection Demographics, labs (Hb, Hct, lactate), hemodynamics (BP, HR, MAP), and outcomes (transfusion, ICU admission, mortality) were recorded. Ultrasonography: Performed by a certified resident (3 years' experience) using a Terason Usmart 3200T (7.5 MHz probe). IJV and CCA measurements were taken at the thyroid cartilage level. Scoring: Glasgow-Blatchford score (GBS) assessed bleeding severity. 1.5. Ethical Approval Approved by the local ethics committee (Decision #12, Meeting 92; Feb 20, 2025). 1.6. Quality Evaluation Conducted per Declaration of Helsinki and STROBE guidelines. 1.7. Statistical Analysis Normality: Kolmogorov-Smirnov test. Comparisons: T-test/Mann-Whitney U (2 groups), ANOVA/Kruskal-Wallis (≥3 groups), Chi-square/Fisher's exact test (categorical). Correlation: Pearson (GBS vs. US measurements). Predictive performance: ROC curves (AUC, Youden's Index for cut-offs). Survival analysis: Kaplan-Meier, Cox regression. Software: SPSS 27.0, MedCalc® 20.218