The article, “Failure to Oxygenate During Cardiopulmonary Bypass: Treatment Options and Intervention Algorithm,” examines the management of oxygenator failure during cardiopulmonary bypass (CPB), a rare but high-risk complication. It underscores the importance of preparation, emergency protocols, and advanced intervention techniques for managing this critical scenario. The study provides an updated intervention algorithm and emphasizes a novel venous piggyback technique for addressing oxygenator failure effectively.
Oxygenator failure, though infrequent, is a significant risk due to its potential for rapid patient deterioration. Historically, the traditional approach has been an oxygenator change-out, where the failed device is replaced mid-procedure. While effective, this technique often necessitates a temporary cessation of CPB, which can introduce additional risks depending on the patient’s status and the surgical stage. Furthermore, oxygenator change-outs can be time-consuming and require precise coordination to minimize disruption.
To address these challenges, the authors explore alternative methods such as the PRONTO (Parallel Replacement of an Oxygenator Not Transferring Oxygen) technique and various piggyback strategies. The PRONTO method, developed in 2002, enables oxygenator replacement without stopping CPB. However, it requires custom circuit modifications, including additional Y-connectors and specific tubing packs, which increase complexity and the potential for circuit-related complications. Despite its benefits, the method has not gained widespread adoption due to these logistical challenges.
The piggyback approaches, specifically arterial and venous piggyback oxygenation, provide innovative alternatives to traditional methods. These techniques involve incorporating a secondary oxygenator into the circuit to supplement oxygenation without completely replacing the primary device. The arterial piggyback method involves connecting the secondary oxygenator to the arterial circuit, allowing blood to be pre-oxygenated before passing through the failing primary oxygenator. While effective in certain cases, this approach is limited by the dependency of oxygenation on systemic blood flow.
In contrast, the venous piggyback technique sources blood from the venous circuit, passes it through a secondary oxygenator, and returns it to the cardiotomy reservoir. This method provides independent oxygenation support, reducing reliance on systemic flow and offering greater flexibility. The authors advocate for this technique as a first-line intervention for oxygenator failure, particularly in scenarios where immediate replacement of the primary device is not feasible.
A detailed case study highlights the practical application of these techniques. During a 7-hour CPB procedure for a pediatric patient with compromised pulmonary function, the team identified a gradual decline in oxygenation levels. With the patient nearing separation from CPB, the arterial piggyback method was employed as a temporizing measure. This intervention stabilized oxygenation without necessitating a full oxygenator change-out, allowing the procedure to continue uninterrupted.
The authors emphasize the importance of institutional readiness to manage such emergencies. They advocate for written protocols, regular simulation drills, and the inclusion of advanced techniques like venous piggyback oxygenation in emergency response plans. By proactively incorporating these measures, perfusion teams can enhance patient safety and reduce the risks associated with oxygenator failure.
The article also discusses the technical considerations and limitations of the venous piggyback technique. For instance, sufficient blood flow capacity from the venous circuit is essential to support the secondary oxygenator. The authors propose modifying standard circuit designs to include Y-connections instead of stopcocks, which would enhance flow capacity and facilitate venous-assisted oxygenation.
The findings are supported by a review of institutional data and literature. Over 15 years, the authors’ institution reported seven instances of suspected oxygenator failure among more than 13,000 CPB cases. While most incidents were managed without on-bypass oxygenator change-outs, the recent experience with the arterial piggyback method demonstrated its effectiveness as a bridging technique.
The authors conclude by presenting an updated intervention algorithm that incorporates venous piggyback oxygenation as a preferred response to oxygenator failure. This approach minimizes patient risk, avoids unnecessary interruptions to CPB, and allows for a more controlled response to emergencies. They encourage other institutions to adopt similar protocols and emphasize the importance of continuous training and protocol refinement to ensure optimal outcomes.
Overall, the study highlights the critical need for preparedness in managing oxygenator failure during CPB. By adopting innovative techniques and fostering a culture of proactive planning and training, perfusion teams can improve patient safety and surgical outcomes in these rare but high-stakes scenarios.
