Abstract Number: PB1422
Meeting: ISTH 2020 Congress
Background: Heparin-induced thrombocytopenia (HIT) is a potentially devastating consequence of heparin exposure. Prompt diagnosis with initiation of a non-heparin anticoagulant can prevent life-threatening thrombotic complications. In an institution-wide effort to increase early recognition, an alert in the electronic medical record (EMR) has been sent to providers for the last 15 months when a patient’s platelet count dropped by ≥50%.
Aims: Assess the effect of a platelet count-based alert on HIT diagnosis and management.
Methods: Retrospective evaluation of alert firings and subsequent actions at an academic medical center over a one-month period.
Results: An average of 3.3 alerts fired per day. Of 100 total alerts, 21 were considered inappropriate due to lack of heparin exposure, inaccurate platelet count due to clumping, or patient characteristics such hematopoietic stem cell transplant recipient (HSCT) or organ donor (n=10; excluded from further analysis). Characteristics of the remaining 90 alerts are outlined in Table 1. The majority (59%) of alerts fired in patients with low HIT probability with 4Ts scores ≤3. Immunoassays were ordered for 34 patients (38%); 18/34 (53%) had a low probability score (Figure 1). Seven (21%) immunoassays were positive and one patient was confirmed to have HIT with the serotonin release assay. Of the patients tested with the immunoassay, heparin was held in 11 (32%) and a non-heparin anticoagulant started in 4 (12%). Following a negative immunoassay result, heparin prophylaxis was not restarted in 6 and bivalirudin was continued in 5 for a total of 57 days. The average number of HIT immunoassays ordered in the 2 years prior to the alert creation was 50/month (SD 10); the number has since increased to 63 (SD 9).
Conclusions: An EMR alert based on a drop in platelet count may have increased HIT immunoassay ordering but did not contribute to appropriate testing and use of non-heparin anticoagulants.
| Medical service, n(%) | |
| Cardiovascular surgery | 25 (28%) |
| Intensive care unit | 19 (21%) |
| Trauma | 17 (19%) |
| Cardiology | 10 (11%) |
| Internal medicine | 9 (10%) |
| Others | 10 (11%) |
| Platelet count, mean(range) | |
| Peak prior to drop (x10^3/μL) | 304 (67-1077) |
| At the time of alert (x10^3/μL) | 136 (31-528) |
[Table 1: Patient characteristics]
[Figure 1: Diagram of electronic medical record alerts, selection for testing, and test results ]
To cite this abstract in AMA style:
May J, Taylor L, Varden PW, Wallace E, Marques M. The Utility of a Platelet Count-Based Electronic Medical Record Alert to Facilitate Diagnosis of Heparin-Induced Thrombocytopenia [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/the-utility-of-a-platelet-count-based-electronic-medical-record-alert-to-facilitate-diagnosis-of-heparin-induced-thrombocytopenia/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/the-utility-of-a-platelet-count-based-electronic-medical-record-alert-to-facilitate-diagnosis-of-heparin-induced-thrombocytopenia/