Mechanical ventilation: A necessary evil?

To the Editor:

The author reported no conflicts of interest.

The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.

The avoidance of ventilator-associated lung injury has been a hallmark of acute respiratory distress syndrome management for the past 50 years.¹ Although recent clinical trials have failed to establish the superiority of mechanical circulatory support over mechanical ventilation in these patients,² extracorporeal membrane oxygenation (ECMO) has traditionally been reserved for refractory cases and most often performed through femoral cannulation.

With a surgical volume of over 80 cases, our program has one of the largest experiences with the Protek Duo right ventricular assist device cannula (LivaNova, London, United Kingdom). Percutaneous cannulation via the right internal jugular vein allows for full right ventricular and pulmonary support in which blood is withdrawn from the right atrium, oxygenated, and returned directly to the pulmonary artery (Figure 1 ). As with other disruptive transcatheter technologies, the skill set required for procedural success exists at the intersection of interventional cardiology and cardiac surgery. A collaborative approach between these disciplines was critical during our initial 10 implants and can effectively negate the risks of inexperience.

Figure 1.

The LivaNova TandemLife Protek Duo catheter is inserted via the right internal jugular vein and placed into the main pulmonary artery.

Early in our experience, we observed that right ventricular dysfunction was frequently attributed to distributive shock.³ Recognizing that acute respiratory distress syndrome in the context of COVID-19 frequently leads to increasing pressor requirements and progression to multiple organ dysfunction syndrome, we hypothesized that early intervention with a percutaneous right ventricular assist device/ECMO approach might improve outcomes in these patients. In 9 consecutive patients, we have not had any secondary organ failure, with only 1 mortality. Pressor requirements have been eliminated with this approach, and our practice has been to extubate while on ECMO support to facilitate rehabilitation and avoid ongoing barotrauma. At the time of this submission, 6 of the patients have been decannulated. Although all the patients met Extracorporeal Life Support Organization criteria for support, attempts were made to intervene at the time of intubation to minimize the adverse effects of mechanical ventilation.

Cost considerations weigh heavily on the decision to proceed with any form of mechanical circulatory support, and the pandemic-induced economic uncertainty facing hospitals has only added to the complexity of these decisions. Charges for a 9-day hospital stay in 1 of our patients totaled $224,718. Although supply chain limitations would likely impair the widespread adoption of this approach, the current spoke-hub model for ECMO referral potentially could mitigate many of the economic disparities between hospitals.

Anecdotal evidence should always be viewed with a degree of skepticism, and our team is currently preparing for a multicenter prospective randomized clinical trial to evaluate the merits of this approach compared with conventional management strategies. Nevertheless, cardiothoracic surgeons who are asked to cannulate a patient for COVID-19 in the setting of increasing pressor requirements or secondary organ failure should carefully evaluate the potential for right ventricular dysfunction as a contributor.