Use of Earlier-Reported Rotational Thromboelastometry Parameters to Evaluate Clotting Status, Fibrinogen, and...

Rotational thromboelastometry (ROTEM) can provide clinical information in 10-20 minutes for guiding administration of fibrinogen, platelets, and fresh frozen plasma products. While ROTEM testing is well established for cardiac and other surgeries, it is less characterized for use in postpartum hemorrhage (PPH) patients. We wanted to determine if the earlier-measured ROTEM parameters (α-angle and amplitude at 10 minutes [A10]) could replace the later parameters (amplitude at 20 minutes and maximum amplitude [maximum clot firmness {MCF}]) in all patient groups studied. We also correlated the A10 and α-angle of the EXTEM and FIBTEM tests to the fibrinogen levels and platelet counts in these patients.

We retrospectively analyzed 100 sets of EXTEM and FIBTEM results ordered on patients undergoing operations for PPH, patients in intensive care units (ICU), and those undergoing cardiothoracic surgery (cardiothoracic operating room [C/T OR]). We determined if the correlations among the various parameters were similar among the PPH, ICU, and C/T OR patients.

As expected, the EXTEM A10 (A10EX) and FIBTEM A10 (A10FIB) correlated highly to the EXTEM MCF and FIBTEM MCF in all patient groups. The A10EX parameter correlated significantly to both fibrinogen and platelet levels, and the A10FIB correlated to the fibrinogen levels. The difference between the A10EX and the A10FIB (PLTEM) is related to platelet activity, and we found that the PLTEM and platelet count correlated highly for all 100 PPH patients (r = 0.80), C/T OR patients (r = 0.70), and ICU patients (r = 0.66), despite 4 high platelet counts with relatively low PLTEM values in the ICU group. The earlier-reported parameter EXTEM α angle (α-EX) is an excellent indicator of the A10EX, with an α-EX ≥65° (ie, normal) giving a >96% probability that the A10EX was ≥44 mm, and an α-EX value below 65 mm giving an 86% probability that the A10EX was <44 mm.

The correlations among the ROTEM parameters for the PPH comparisons were equivalent to the C/T OR patients studied, and the A10EX and A10FIB could replace the MCF results in all patient groups. Also, the α-EX was an early indicator of the A10EX and had good correlations to the A10FIB and the fibrinogen in all patient groups. Finally, in a separate group of 62 comparisons, the FIBTEM α angle showed promise as an early indicator of the A10FIB and the fibrinogen levels.