Performance of functional fibrinogen thromboelastography in children undergoing congenital heart surgery

• Published in: Pediatric anesthesia 2017-02, Vol.27 (2), p.181-189
• Main Authors: Gautam, Nischal K., Cai, Chunyan, Pawelek, Olga, Rafique, Muhammad B., Cattano, Davide, Pivalizza, Evan G., Ramamoorthy, Chandra
• Format: Article
• Language: English
• Subjects: Blood platelets; cardiac surgery; Cardiopulmonary Bypass; Child, Preschool; coagulation; congenital heart disease; Female; fibrinogen; Fibrinogen - analysis; Heart Defects, Congenital - surgery; Heart surgery; Humans; Infant; Infant, Newborn; Laboratories; Male; Pediatrics; Plasma; Platelet Count - statistics & numerical data; Prospective Studies; Thrombelastography - methods; thromboelastography
• ISSN: 1155-5645; 1460-9592
• DOI: 10.1111/pan.13048

Summary Background Functional Fibrinogen assay of the Thromboelastography (FFTEG), a whole blood viscoelastic hemostatic assay, has been used to estimate fibrinogen levels in adult patients undergoing major surgery but its performance in pediatric patients undergoing cardiac surgery requires evaluation. In this study, we evaluate the correlation between FFTEG parameters and standard laboratory tests for fibrinogen and platelet counts before and after cardiopulmonary bypass in children undergoing repair for congenital heart disease. Methods In this prospective observational study, whole blood samples were obtained from children less than 5 years of age undergoing congenital heart surgery with cardiopulmonary bypass before surgical incision and immediately after administration of protamine. Blood samples were analyzed for Thromboelastography, Functional Fibrinogen level measured by FFTEG (FLEV), complete blood counts with platelet count and plasma fibrinogen assay (LFib, Clauss). The primary outcome of this study was to assess the correlation between FFTEG parameters, LFib and platelet counts in neonates, infants, and small children less than 5 years old. Additionally, we studied if postbypass FFTEG parameters could predict critical thresholds of hypofibrinogenemia LFib ≤200 mg·dl−1. Results One hundred and five children (22 neonates, 51 infants, and 32 small children) were included in the final analysis. FLEV estimated higher fibrinogen levels than LFib in all patients. Before bypass, FLEV was on average 133 mg·dl−1 higher than LFib (95% confidence interval, CI, 116–150, P < 0.001) for all the patients; after bypass, FLEV was 48 mg·dl−1 (95% CI: 37–59, P < 0.001) higher than LFib for all the patients. Linear correlation coefficients between FLEV and LFib in all patients were R = 0.41 (95% CI: 0.24–0.56, P < 0.001) before bypass and increased to R = 0.63 (95% CI: 0.51–0.74, P < 0.001) after bypass. Bland Altman analysis performed on postbypass values of FLEV and LFib showed a positive bias of FLEV in estimation of LFib. The magnitude and the variability of the bias for all the patients group was decreased with lower mean of the difference of FLEV and LFib when the average values of FLEV and LFib were