A Real Circuit Breaker: Hyperhemolysis Syndrome Related to the VA-ECMO Circuit?

Introduction: Myocarditis is an inflammatory disease of cardiac muscle caused by a variety of infectious and non-infectious conditions. Viral infection is the most frequent cause of myocarditis;however, herpes simplex virus 1 (HSV-1) infection causing myocarditis has been rarely described. We present a case of a young woman with HSV-1 viremia and fulminant myocarditis presenting with cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation (VA-ECMO), complicated by hyperhemolysis. Case Report: A 35 year-old immunocompetent woman with moderate alcohol consumption presented to hospital with a 4-day history of fever and flu-like symptoms. She was fully vaccinated for COVID-19 two months prior to symptom onset. Her COVID-19 testing was negative and she was discharged home. She returned to hospital 4 days later in cardiogenic shock. Transthoracic echocardiogram demonstrated LVEF of 30% with a small pericardial effusion. Coronary angiogram revealed normal coronaries. She was placed on peripheral VA-ECMO for worsening cardiogenic shock. Due to inadequate LV unloading, she underwent atrial septostomy. Five days after VA-ECMO cannulation, HSV-1 was detected in the blood and she was started on intravenous acyclovir. Her ECMO course was complicated by acute kidney injury requiring dialysis, and hyperhemolysis with a peak LDH of 12,000 U/L. The mechanism of hemolysis was attributed to an intravascular process (plasma free hemoglobin 7487 mg/L, normal < 150 mg/L) likely from a combination cold agglutinins and the mechanical circuit. Interestingly the membrane pressure gradient was within normal. The patient received treatment with plasmapheresis (Table 1), and was eventually decannulated after 12 days following hemodynamic improvement. This case report highlights a rare viral cause of fulminant myocarditis and emphasizes the need for collaboration among various specialists in the management of complex cases.

Preparing for Platelet Shortages: Which Surgeries Should be Cancelled?

Introduction: Due to their short shelf-life, platelet concentrates are particularly susceptible to the product shortages which may result from shortfalls in donor collections or disruptions to the manufacturing and supply chain. Mechanisms to address shortages are particularly important in light of the ongoing COVID-19 pandemic. Canadian Blood Services (CBS), the national blood center serving Canada except Quebec, called a national Green Advisory Phase from May to June 2020 on platelet products and O negative red blood cells, requesting daily hospital inventory reports. When such shortages occur, it may be challenging to identify which surgical procedures are likely to require platelet transfusion support and should therefore be rescheduled. Methods: Information systems maintained by the Blood Transfusion Service (Wellsky®) and the Department of Surgical Services (ORSOS®) were cross-referenced for the 2019 calendar year at a large adult teaching hospital in Toronto with active cardiovascular and transplant programs. Only procedures that were performed more than 25 times during this period were included in the analysis. Average platelet consumption on the day of surgery, 1 week post-operatively and 30 days post-operatively was calculated. Results: 50 procedures with a potential for requiring intra-operative platelet transfusion support were identified, with the greatest demand being those involving cardiopulmonary bypass (CBP) support (27% of cases transfused, median of 2.7 units per case) and heart, liver and lung transplantation (24% of cases transfused, median of 4.2 units per case). Although spinal surgery as a group was not a high platelet consumer (4% of cases transfused, median of 0.3 units per case), certain complex procedures such as thoracic-lumbar laminectomy and thoracic-lumbar decompression and fusion were more at risk of requiring platelet support during and in the post-operative period. Due to their frequency, procedures on CPB created the highest demand in platelets with close to 4500 units distributed during the year. Standard deviations for many procedures was large, up to 10 units in the intra-operative period. Other procedures with low-risk of intra-operative platelet transfusion support but a possibility of requiring platelet transfusion in the 30-day post-operative period included renal transplantation and neurosurgical procedures. Interestingly, renal transplant patients generally did not require transfusion support during surgery or in the immediate post-operative period but only when looking at 30-day requirements. For most patients, these procedures would therefore be at risk only in the setting of very prolonged shortages. Conclusion: Data-driven demand forecasting for intra-operative and post-operative platelet transfusion support may be of value in risk-benefit analysis of proceeding with specific surgical procedures in the setting of platelet shortages. However, some of the procedures with the highest platelet consumption serve the sickest patients and cannot be postponed. [Formula presented] Disclosures: No relevant conflicts of interest to declare.