Cs2100i

Serial coagulation samples were taken as part of routine care. Arterial samples were taken when peripheral or umbilical arterial catheters were in situ, otherwise peripheral venous samples were obtained including precautions to prevent heparin sample contamination (13 (link)). Coagulation screens were analyzed using the Sysmex CS-2100i coagulation analyser and full blood counts as part of validated laboratory practices.

All patients who had a D-dimer assay and CDUS had their data analysed. The Biopool Autodimer quantitative immunoturbidometric microparticle latex assay (Diagnostica Stago, UK) was used for D-dimer level estimation. A D-dimer result below 230 ng/mL was considered to be negative.
During our reaudit the D-dimer assay was changed to Innovance D-dimer (Sysmex UK, Milton Keynes, UK) [19 (link)] and a D-dimer value of below 0.50 mg/L FEU (fibrin equivalent units) was considered negative.
All D-dimer assays were performed on a Sysmex CS2100i automated coagulation analyser (Sysmex UK, Milton Keynes, UK).
Patients who had a negative D-dimer result were then classified into 3 groups with pretest clinical probability score according to Wells et al.: low (score 0), medium (score 1 or 2), or high (score 3) [11 ]. Doppler US results of patients with a negative D-dimer test and low Wells score were assessed. Our standard US technique for evaluating above knee DVT included a combination of compression B-mode US and Doppler study (CDUS) evaluating flow augmentation with respiration and calf compression.

AFXa and ATIII activity were measured using a Sysmex CS-2100i clotting analyser [51 , 52 (link)]. Biophen-Hyphen reagents (Biophen, Neuville-sur-Oise, France) were used for calibrator, control and plasma controls. Internal quality control of all assays were performed to ensure correct calibration and assay accuracy.
AFXa levels were measured using the Biophen Heparin LRT chromogenic assay (Ref No: 221013, Lot No: F1801686P3), which is a kinetic method based on the inhibition by ATIII of factor Xa (FXa). The remaining FXa is then measured by its amidolytic activity on a FXa specific chromogenic substrate, which releases p-nitroaniline (pNA). The amount of pNA generated is inversely proportional to the concentration of UFH or LMWH in the tested plasma. This is suitable for heparin, heparin analogues and other direct FXa inhibitors.
ATIII activity was measured using the Biophen AT anti-(h)-Xa LRT assay (Ref No: 221123, Lot No: F1900074) based on the inhibition of FXa by anti-thrombin in presence of heparin. The remaining FXa is then measured by its amidolytic activity on a FXa-specific chromogenic substrate, which releases pNA. The amount of pNA generated is inversely proportional to the ATIII concentration present in the tested plasma. The assay is insensitive to heparin, therefore plasmas from patients on heparin therapy can be tested.

The animal study was approved by the Institutional Animal Care and Use Committee (IACUC-19-174) at the National Defense Medical Center (Taipei, Taiwan). Twelve 8-week-old male Sprague–Dawley rats were purchased from Bio-LASCO Co. Ltd. (Taipei, Taiwan) and divided into two groups, namely healthy rats (n = 6) and rats with heparin consumption (n = 6). Blood samples were collected from both groups and transferred to vials containing 3.2% (w/v) sodium citrate. The blood was then incubated with the chitosan or regular gauze dressing at 25 °C and 37 °C; blood without dressing material served as the control and was subjected as ratio. For PT and aPTT analysis, the dressings were removed, and sera were collected and fed into an automated blood hemostasis analyzer (CS-2100i; Sysmex Corp., Kobe, Japan). Each experiment was performed in triplicate.

Patient baseline data, including age, sex, site of infection, APACHE II, and SOFA scores, were collected from the Electronic Medical Record System (EMRS). Underlying medical history was also obtained, including ischemic heart disease, chronic heart failure, chronic obstructive pulmonary disease, cerebrovascular accident, and diabetes mellitus. The levels of coagulation indices (prothrombin time [PT], thrombin time [TT], activated partial thromboplastin time [APTT], fibrinogen [FIB] and D-dimer, platelet count [PLT], and lactate were collected. Blood coagulation, including those for PT, TT, APTT, and FIB, was assayed using the CS-2100i automatic coagulation analyzer (Sysmex).