Prevalence of heparin-induced thrombocytopenia and heparin-induced thrombocytopenia-related thrombosis among extracorporeal membrane oxygenator patients at our institution is relatively high. Using platelet count trends to guide decision to test for heparin-induced thrombocytopenia is not an optimal strategy in extracorporeal membrane oxygenator patients. Without a validated pretest probability clinical score, serosurveillance in a defined high-risk group of extracorporeal membrane oxygenator patients may be needed.

Continuous bedside pulse oximetry (SpO2) is universally used to monitor oxygenation for patients supported on veno-venous extracorporeal membrane oxygenation (VV-ECMO). Yet, elevated carboxyhemoglobin (COHb), a known event in VV-ECMO, diminishes the reliability of SpO2. This retrospective cohort study aims to assess the accuracy of SpO2 compared with oxyhemoglobin (SaO2) and quantify COHb levels by co-oximetry in the VV-ECMO population. Forty patients on VV_ECMO from 2012 to 2017 underwent 1,119 simultaneous SaO2 and SpO2 measurements. Most patients were male (60%) with average age of 46 years. SpO2 overestimated SaO2 values by 2.35% at time of cannulation and 0.0061% for each additional hour on VV-ECMO (p < 0.0001). Twenty-nine (72.5%) patients developed elevated COHb (>3% of hemoglobin saturation) at least once during VV-ECMO support and 602 (40.2%) arterial blood gases yielded elevated COHb levels. Mean duration for ECMO with elevated COHb was 244 hours compared with 98 hours in patients without (p < 0.0048). Patients who developed COHb were younger (mean age 40 vs. 55 years, p < 0.024) and had single-site double-lumen cannulation (odds ratio = 4.5, p = 0.23). At time of cannulation, mean COHb was 2.18% and increased by 0.0054% for each additional hour (p < 0.0001). For every 1% increase in COHb, SaO2 decreased by 1.1% (p < 0.0001). During VV-ECMO, SpO2 often overestimates SaO2 by substantial margins. This is attributable to rising COHb levels proportional to duration on VV-ECMO. In this population where adequate oxygen delivery is often marginal, clinicians should be wary of the reliability of continuous pulse oximetry to assess oxygenation.

Transfusion-related acute lung injury (TRALI) remains the deadliest complication of transfusion. Consensus definitions of TRALI have been developed but remain controversial. Recent evidence supports a strong relationship between blood transfusion and the development of acute lung injury in the critically ill and trauma population. Plasma and platelet transfusions have been the most commonly implicated blood products. The 'two hit' model may best explain the immune and nonimmune pathogenesis of TRALI. Current treatment remains largely supportive; effective measures for decreasing the incidence of TRALI include the use of predominantly male plasma and apheresis platelets. Greater understanding of the blood component and patient risk factors for TRALI will hopefully lead to novel treatment and preventive strategies for reducing the risk of this life-threatening syndrome.

METHODS Hemodynamic data were available for 140/302 patients in the SHOCK trial and 260/1189 in the SHOCK registry. We explored the number of patients meeting criteria for RVD as defined by: CVP>10mmHg, CVP/PCWP>0.63, PAPi<2.0 and RVSWI<450 mmHg$mL/m2. Next, we explored the number of patients who met the RR-RVF criteria in the trial and registry. Finally, we examined whether RVD or the RR-RVF criteria were associated with 30 day mortality.RESULTS RVD was observed in 37% and 36% of patients in the SHOCK trial and registry respectively. RR-RVF criteria were observed in 45% and 38% of SHOCK trial and registry patients respectively. Among trial patients, RR-RVF criteria were not associated with increased 30-day mortality. Among registry patients, 30 day mortality was higher among patients who met RR-RVF criteria compared to those who did not (58% vs 44%, p¼0.03). RR-RVF criteria were associated with a hazard ratio of 1.46[1.03-2.07] (p¼0.04) for 30-day mortality among registry subjects.CONCLUSIONS RVD was commonly observed among patients in the SHOCK trial and registry. The RR-RVF criteria were associated with increased 30-day mortality in both the SHOCK trial and registry. These findings suggest that univentricular shock is uncommon in AMI-CS. Early recognition and aggressive management of RVD may improve clinical outcomes in AMI-CS. Future studies are required to further explore the potential clinical utility of the RR-RVF criteria.

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