CRITICAL VALUES OF HEMOSTASIS PARAMETERS IN AN ONCOLOGY CENTER: A RETROSPECTIVE REGISTRY-BASED STUDY.

BACKGROUND AND OBJECTIVES: Patients with cancer are at high risk of hemostatic disorders due to tumor-related mechanisms, antineoplastic therapy, and surgical interventions. Critical laboratory values (CVs) represent life-threatening conditions requiring immediate clinical response and are essential indicators of laboratory quality and patient safety. OBJECTIVE: To analyze the frequency, structure, and distribution of critical values of hemostasis parameters (APTT and fibrinogen) in the clinical diagnostic laboratory of an oncology center. MATERIALS AND METHODS: A retrospective study of the electronic CV registry was conducted for the period January-December 2025. Critical thresholds were defined according to SOPs and international recommendations. Data were analyzed by month, clinical ward, and type of hemostatic disorder. Comparative statistical analysis using the χ² test was performed. During the study period, a total of 48,326 coagulation tests were performed, including 27,418 APTT assays and 20,908 fibrinogen measurements. The overall frequency of critical values was 27.5 per 1,000 coagulation tests. RESULTS: A total of 1,328 CVs were registered. The most frequent abnormalities were hypofibrinogenemia (<1.5 g/L) (60%), prolonged APTT (>78 s) (23%), and absent clot formation by APTT (10%). The distribution of CVs differed significantly across clinical departments (χ²(13)=726.51, p<0.001), with the highest burden observed in the hematobiochemistry department, ICU, and hematology wards. Extreme hypocoagulatory states (absence of clot formation by APTT or fibrinogen assays) accounted for 12% of all registered critical events, indicating a substantial proportion of patients at immediate risk of life-threatening hemorrhagic complications. Seasonal variation was statistically significant (χ²(10)=72.80, p<0.001), with peaks in March, July, and October. CONCLUSIONS: Critical hemostasis abnormalities are highly prevalent in oncology patients and are predominantly associated with hypocoagulatory states. Implementation of a structured electronic CV reporting system enables rapid clinician notification, optimization of laboratory workflow, and improved patient safety in high-risk oncology settings.