ABSTRACT
OBJECTIVES: This study examines whether patient outcomes were affected when the hemoglobin (Hb) transfusion threshold was lowered by 1 g/dL during COVID-19-related blood shortages. METHODS: Outcomes of lowered Hb thresholds (from <7 to <6 g/dL) were defined by 14-month intervals in 2 patient groups (prepandemic [January 2019-February 2020] and pandemic [April 2020-May 2021]). We evaluated patient admissions, pretransfusion (if transfused) or nadir admission (if not transfused) Hb levels between 5.0 and 8.0 g/dL, and total red blood cell (RBC) transfusions during admission (if transfused). Baseline variables and outcomes were selected from electronic health records. Primary COVID-19-related admissions were excluded. Regression analysis was conducted to determine outcomes. RESULTS: Those in the prepandemic group (1976) and pandemic group (1547) were transfused. Fewer RBCs (2186, vs 3337) were used in the prepandemic group than in the pandemic group, respectively. Those in the prepandemic group had significantly higher rates of hypertension and diabetes as well as more smokers. Significant differences were observed when comparing the number of procedures and incidence of sepsis between the patient groups. Similar patterns were observed for the not transfused and transfused subgroups. CONCLUSIONS: Patient outcomes were not affected after implementing lower Hb pretransfusion thresholds. Although confounding factors were mitigated, some may have been associated with procedures or sepsis. Proactive patient blood management strategies during COVID-19-related blood shortages may include adopting lower Hb thresholds.
ABSTRACT
BACKGROUND: Whole blood viscoelastic testing (VET) devices are routinely used in a variety of clinical settings to assess hemostasis. The Quantra QStat System is a cartridge-based point of care VET device that measures changes in clot stiffness during coagulation and fibrinolysis using ultrasound detection of resonance. The objective of this study was to assess the ability of the Quantra QStat System to detect coagulopathies in trauma patients. METHODS: A multicenter observational study was conducted on adult subjects at two level 1 trauma centers. For each subject, whole blood samples were drawn upon arrival to the emergency department and again, in some cases, after administration of blood products and/or antifibrinolytics. Samples were analyzed on the Quantra in parallel to ROTEM delta. The QStat cartridge provides measures of Clot Time (CT), Clot Stiffness (CS), Fibrinogen and Platelet Contributions to clot stiffness (FCS and PCS), and Clot Stability to Lysis (CSL). Data analyses included linear regression of Quantra and ROTEM parameters and an assessment of the concordance of the two devices for the assessment of hyperfibrinolysis. RESULTS: A total of 56 patients were analyzed. 42% of samples had a low QStat CS value suggestive of an hypocoagulable state. The low stiffness values could be attributed to either low PCS, FCS or combination. Additionally, 13% of samples showed evidence of hyperfibrinolysis based on the QStat CSL parameter. Samples analyzed with ROTEM assays showed a lower prevalence of low CS and hyperfibrinolysis based on EXTEM and FIBTEM results. The correlation of CS, FCS and CT versus equivalent ROTEM parameters was strong with r-values of 0.83, 0.79 and 0.79, respectively. DISCUSSION: This first clinical experience with the Quantra in trauma patients showed that the QStat Cartridge was strongly correlated with ROTEM parameters and that it could detect coagulopathies associated with critical bleeding. LEVEL OF EVIDENCE: Diagnostic test, Level II.