Background: Temporary right ventricular assist device (RVAD) support is used during selected high-risk cardiac operations, including durable left ventricular assist device implantation, orthotopic heart transplantation, and procedures complicated by anticipated right ventricular failure. When RVAD implantation is planned during cardiopulmonary bypass (CPB), the RVAD circuit is commonly primed with crystalloid solution. Although 500-600 mL may appear modest in many adult patients, this secondary circuit prime may produce clinically meaningful hemodilution in patients who are frequently anemic, volume loaded, and near transfusion thresholds, where relatively small changes in hematocrit may alter clinical management. Technique: This report describes an autologous priming technique that uses patient blood available during CPB to displace crystalloid from the RVAD circuit before completion of the outflow connection. The technique requires no change to the conventional RVAD circuit, adds minimal time, and can be discontinued at any point if patient conditions do not safely permit further displacement. Discussion: This technique applies established autologous priming principles to a secondary extracorporeal circuit introduced after CPB has already been established. The objective is to avoid an unnecessary crystalloid load, minimize secondary hemodilution, and preserve hematocrit at the margin where transfusion decisions are commonly made. Conclusion: Autologous priming of the RVAD circuit during planned implantation is a simple, reproducible, patient-directed technique for minimizing secondary hemodilution while preserving conventional RVAD deployment.
Mechanical circulatory support in sickle cell anemia patients undergoing complex cardiovascular surgery remains a subject of controversy. This is due to the risk of vaso-occlusive and prothrombotic phenomena associated with hypoxia, acidosis, inflammation, and contact with non-endothelialized surfaces. However, veno arterial extracorporeal membrane oxygenation (VA-ECMO) is employed as a rescue therapy in refractory shock scenarios. We describe the case of a 62-year-old patient with a history of sickle cell anemia and thoracic endovascular aortic repair (TEVAR), who was admitted for massive hemoptysis and severe hypoxemic respiratory failure. Imaging findings suggested infection of the aortic endoprosthesis. The patient underwent complex reconstruction of the aortic arch and ascending aorta, complicated by massive bleeding, requiring emergency left pneumonectomy. Patient developed refractory shock and deoxygenation requiring VA-ECMO. Thirty minutes later, the circuit presented massive thrombosis, resulting in a fatal outcome. This case underscores the profound risks associated with the convergence of sickle cell anemia, complex aortic surgery, and VA-ECMO.
Background Maintaining adequate oxygen delivery is critical in extracorporeal membrane oxygenation (ECMO), yet monitoring oxygenator performance remains largely dependent on reactive blood gas analysis (BGA) and subjective visual inspections. While Hamilton et al. developed a methodology to quantify gas exchange efficiency for short-term cardiopulmonary bypass (CPB), its applicability to long-term ECMO support has not been established. This study aimed to adapt and validate this model for real-time monitoring of ECMO oxygenator degradation. Methods In this monocentric, retrospective study, we analyzed 2,441 pre- and post-oxygenator BGA pairs from 164 patients treated with either the Quadrox PLS® (n=66) or A.L.ONE® (n=101) oxygenator. We adapted the Hamilton equation to calculate a corrected fraction of inspired oxygen FiO2 (cFiO2), normalizing performance to a target arterial partial pressure of oxygen (PaO2) of 150 mmHg. Statistical equivalence between measured and predicted oxygen transfer (VO2) was assessed using Two One-Sided Tests (TOST) and linear regression stratified by oxygenator runtime. Results Both oxygenator models demonstrated high correlation between VO2 and cFiO2. Performance degradation over time was successfully quantified through shifting regression slopes. TOST analysis confirmed statistical equivalence (α = 0.05) between the model’s predictions and clinical BGA data, indicating high predictive accuracy across various clinical states. Conclusion The Hamilton methodology can be effectively transferred to the ECMO setting, providing an objective, real-time tool to monitor membrane efficiency. By normalizing for patient-side variables, this mathematical framework allows for the early detection of oxygenator dysfunction, potentially facilitating proactive device exchange and improving patient safety.
