Comparison Two Point of Care Coagulation Monitoring Systems - the ROTEM Sigma and the Quantra Devic

Comparison of Methods for Coagulation Analysis Between Rotem Sigma (Instrumentation Laboratory, Bedfort, MA, USA) and Quantra System (Hemosonics, Charlottesville, VA USA) in Cardiac Surgery

Human Research Project Risk Category A. In this study no additional intervention or treatment are performed. The whole blood samples are taken from a routinely placed arterial catheter. The blood loss caused by the two additional blood samples is estimated with 2x 2.7ml. The Risk for the patients to participate in this study is minimal.

Clinical observational study of a point of care in vitro diagnostic device, the Quantra®system (Quantra), that received the CE Mark in April 2017 and is approved by the Swiss Medic for clinical use. The Quantra estimates the coagulation strength of whole blood by sonorheometry technology applying a series of ultrasound pulses to a whole blood sample and measuring its stiffness by returning echoes.

The purpose of this study is to investigate to what extent the results of the Quantra corresponds to those of the ROTEM® Sigma (ROTEM). Additionally, the time required for delivery of final results (turnaround time) of all parameters of the Quantra will be examined. Significant differences in the turnaround time between both devices are of high interest as timing is a crucial factor in the diagnosis-based treatment.

Comparison of the coagulation process measurements in turnaround time and results of the ROTEM INTEM CT, HEPTEM CT, EXTEM A10 FIBTEM A10 with corresponding Quantra parameters such as CT, CTH, CTR, CS, PCS, FCS.

The primary aim of the study is to examine whether the two methods of hemostasis analysis are equivalent and how far they correlate.

Secondary aims are to examine the turnaround time of test results in both devices and to examine whether these results would have led to the same therapeutic decisions in a retrospective review of data.

For both devices following data is documented:

• Time for cartridge insertion
• Time first results available
• Time measurement finished

Parameters measured ROTEM Quantra

• INTEM CT Clot Time (CT)
• HEPTEM CT Heparinase Clot time
• (CTH)
• INTEM CT/HEPTEM CT Clot Time Ratio (CTR)
• EXTEM A10 Clot Stiffness (CS)
• FIBTEM A10 Fibrinogen Contribution
• to Clot Stiffness (FCS)
• EXTEM A10 - FIBTEM A10 Platelet Contribution to
• Clot Stiffness (PCS)

Blood loss estimated (mL/6h; mL/12h; mL/24 h) RCP transfused FFP packages transfused Platelet packages transfused Fibrinogen applied F XIII applied

Quantra clot stiffness values are expressed in hectoPascals (hPa), whereas corresponding ROTEM values are expressed as an amplitude in mm. The relationship between amplitude (A in mm) and shear modulus (G in Pascals) is not linear. For a proper comparison the ROTEM amplitude (mm) needs to be converted to Pascals by following formula:

G (Pascals) = (500 x A) / (100 - A),

as described by Solomon C et al, Anaesth Analg 2015; 121:868-78.

The Quantra data that are collected during the study are only observational and will not be used to guide therapeutic interventions

Inclusion Criteria:

• Patients scheduled for cardiac surgery needing a cardiopulmonary bypass
• Age older than18 years
• Written consent of the participation after clarification about the study

Exclusion Criteria:

• No consent to participate
• No German comprehension
• Known coagulation disorder