LAUSR

Surges in cases of coronavirus disease (COVID-19)–associated respiratory failure have caused acute regional shortages of ventilators. Repurposing of anesthesia machines and noninvasive ventilators unquestionably has helped support additional patients but may be insufficient during dramatic increases in caseload. Proposed actions to address acute shortages have included ventilator rationing, manual bag ventilation, and “splitting” the external ventilator circuit to support multiple patients simultaneously. None of these options is ideal. None is risk-free. None negates the need for more ventilators. However, these were the options we were forced to consider in New York City just a few months ago (1). In our view, rationing ventilators among multiple potentially rescuable patients is a last resort and should be considered only if all reasonable alternatives are exhausted. Extended-duration manual bag ventilation requires prolonged exposure with high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission to those performing the ventilation, and yet it still seems unlikely to provide appropriate support to severely lung-injured patients. With these considerations in mind, ventilator sharing seems a more palatable stopgap. When developing our ventilator-sharing protocol (2), we followed several guiding principles: 1) maximization of safety for each patient, 2) maintenance of lung-protective ventilation, 3) prevention of harm during equipment issues or clinical events, 4) potential for human error, and 5) practical scalability in context. The context in New York included extremely high patient-toclinician ratios, adoption of a tiered staffing strategy in ICUs, clinicians practicing outside their specialty, caring for critically ill patients in makeshift ICUs, and minimal lead time for planning or onboarding. There are many potential engineering solutions to share one ventilator among two or more patients, including those advocated by Chase and colleagues and Milner and colleagues. Proposals that increase circuit complexity also may increase risk of (potentially fatal) adverse events from equipment issues, clinical events, or human error (3). Reliance on components that are not routinely used in similar clinical applications, are not medical grade, and/or have not undergone rigorous testing increases these risks; this is especially true for mechanical components that regulate airflow, in which component failure could cause abrupt cessation of ventilator support for one or both patients. Circuit configurations that require unconventional ventilator settings, such as a neardoubling of preset VT or respiratory rate, increase these risks even further. We do not question the altruistic intent with various proposals for configuring a shared ventilator. However, the extent to which complex configurations offer meaningful benefits to patients over simpler circuitry should be carefully weighed against their potential to cause unintended harm. Regardless of the circuit configuration, responsible implementation requires adequate safeguards (including patient monitoring), multidisciplinary planning, and a carefully detailed clinical protocol. Experts can disagree reasonably on the best approach to ventilator sharing or whether it should even be entertained. However, we hope broad consensus exists for the most important issue: regional (and global) coordination is needed to respond to acute ventilator shortages (4). The problem in New York was unequivocally regional; ventilators elsewhere in the United States sat idle as New York hospitals began preparations to implement rationing protocols. Had New York hospitals reached the point of rationing ventilators, it would have signified a moral failure of our profession and our healthcare system. We came frighteningly close. We must work together to ensure future crises cannot get to that point again. n