%0 Journal Article
%T Impact of C-reactive Protein on Anticoagulation Monitoring in Extracorporeal Membrane Oxygenation.
%A Madhok J
%A O'Donnell C
%A Jin J
%A Owyang CG
%A Weimer JM
%A Pashun RA
%A Shudo Y
%A McNulty J
%A Chadwick B
%A Ruoss SJ
%A Rao VK
%A Zehnder JL
%A Hsu JL
%J J Cardiothorac Vasc Anesth
%V 0
%N 0
%D 2024 Apr 5
%M 38960805
%F 2.894
%R 10.1053/j.jvca.2024.04.006
%X OBJECTIVE: To evaluate the impact of inflammation on anticoagulation monitoring for patients supported with extracorporeal membrane oxygenation (ECMO).
METHODS: Prospective single-center cohort study.
METHODS: University-affiliated tertiary care academic medical center.
METHODS: Adult venovenous and venoarterial ECMO patients anticoagulated with heparin/ MEASUREMENTS AND MAIN RESULTS: C-Reactive protein (CRP) was used as a surrogate for overall inflammation. The relationship between CRP and the partial thromboplastin time (PTT, seconds) was evaluated using a CRP-insensitive PTT assay (PTT-CRP) in addition to measurement using a routine PTT assay. Data from 30 patients anticoagulated with heparin over 371 ECMO days was included. CRP levels (mg/dL) were significantly elevated (median, 17.2; interquartile range [IQR], 9.2-26.1) and 93% of patients had a CRP of ≥5. The median PTT (median 58.9; IQR, 46.9-73.3) was prolonged by 11.3 seconds compared with simultaneously measured PTT-CRP (median, 47.6; IQR, 40.1-55.5; p < 0.001). The difference between PTT and PTT-CRP generally increased with CRP elevation from 2.7 for a CRP of <5.0 to 13.0 for a CRP between 5 and 10, 17.7 for a CRP between 10 and 15, and 15.1 for a CRP of >15 (p < 0.001). In a subgroup of patients, heparin was transitioned to argatroban, and a similar effect was observed (median PTT, 62.1 seconds [IQR, 53.0-78.5 seconds] vs median PTT-CRP, 47.6 seconds [IQR, 41.3-57.7 seconds]; p < 0.001).
CONCLUSIONS: Elevations in CRP are common during ECMO and can falsely prolong PTT measured by commonly used assays. The discrepancy due to CRP-interference is important clinically given narrow PTT targets and may contribute to hematological complications.