Frequency of Thrombocytopenia and Heparin-Induced Thrombocytopenia in Patients Receiving Extracorporeal Membrane Oxygenation Compared With Cardiopulmonary Bypass and the Limited Sensitivity of Pretest Probability Score

Abstract

Objectives: To ascertain: i) the frequency of thrombocytopenia and heparininduced thrombocytopenia (HIT), ii) positive predictive value (PPV) of the pre-test probability score (PTPS) in identifying HIT iii) clinical outcome of HIT in adult patients receiving veno-venous (VV)-extracorporeal membrane oxygenation (ECMO) or veno-arterial (VA)-ECMO, compared to cardiopulmonary bypass (CPB). Design: A single-centre, retrospective, observational cohort study from January 2016 to April 2018 Setting: Tertiary referral centre for cardiac and respiratory failure Patients: Patients who received ECMO for >48hrs or had CPB during specified period Interventions: None. Measurements and Main Results: Clinical and laboratory data were collected retrospectively. PTPS and HIT testing results were collected prospectively. Mean age (standard deviation) of the EMCO and CPB cohorts were 45.4 (±15.6) and 64.9 (±13), p< 0.00001. Median duration of CPB was 4.6 [2-16.5] hrs compared to 170.4 [70-1008] hrs on ECMO. Moderate and severe thrombocytopenia were more common in ECMO compared to CPB throughout (p<0.0001). Thrombocytopenia increased in CPB patients on day 2 but was 4 normal in 83% compared to 42.3 % of ECMO patients at day 10. Patients on ECMO also followed a similar pattern of platelet recovery following cessation of ECMO. The incidences of HIT in ECMO and CPB were 6.4% (19/298) and 0.6% (18/2998) respectively p<0.0001). There was no difference in prevalence of HIT in patients on VV-ECMO (9/156, 5.7%) vs VA-ECMO (11/142, 7.7%), p=0.81. The PPV of the PTPS in identifying HIT in patients post-CPB and on ECMO were 56.25% (18/32) and 25% (15/60) respectively. Mortality was not different with (6/19, 31.6%) or without (89/279, 32.2%) HIT in patients on ECMO, p=0.79. ConclusionsThrombocytopenia is already common at ECMO initiation. HIT is more frequent in both VVand VA-ECMO compared to CPB. PPV of PTPS in identifying HIT was lower in ECMO patients.HIT had no effect on mortality.

Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia

“…Interestingly, thrombocytopenia does not seem to be common and was present in only 37/201(18.8%) compared with >50% patients presenting with ARDS from other causes such as bacterial and other viral infections. 4 We would like to highlight the implications of Coagulation abnormalities associated with Covid-19 in patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO) as the high proportion of Covid-19 patients developing ARDS means that many will also require VV-ECMO. We have previously reported on the high frequency of intracranial hemorrhage in patients receiving VV-ECMO and so the high frequency in COVID19 is of concern.…”

Outcomes and factors associated with early mortality in pediatric postcardiotomy veno‐arterial extracorporeal membrane oxygenation

“…Although not a factor in this study, thrombocytopenia is a symptom of infection, 25 reducing the body's resistance and mAKIng it easier to become infected 26 . It’s worth mentioning that the prevalence of HIT in pediatric patients who received VA‐ECMO is extremely low, with little effect on mortality 27 …”

Quantitative and Qualitative Platelet Derangements in Cardiac Surgery and Extracorporeal Life Support

“…Thirdly, as systemic anticoagulation is required, patients are likely to develop heparininduced thrombocytopenia (HIT) [54]. The Extracorporeal Life Support Organization (ELSO) anticoagulation guideline recommends the administration of antithrombotic therapy during ECMO; unfractionated heparin (UFH) is widely administered [54,55]. The prevalence of HIT in adult ECMO patients is estimated at 3.7% with a similar prevalence between V-A and V-V ECMO [55,56].…”

“…It can induce conflicting mechanisms at the same time; platelet activation, aggregation and generation of procoagulant microparticles as well as platelet dysfunction, loss of surface receptors and bleeding complications [64,65]. Furthermore, patients receiving surgical bioprostheses are exposed to the adverse effect of the CPB [54]. The CPB duration seems to be a major determinant for the development of postoperative thrombocytopenia [66].…”