Ethics, equipoise, and evidence: when should investigators decide to not test their hypothesis

In an excellent investigation of endotracheal tube cuff pressure assessment, "Endotracheal Tube Cuff Pressures in Patients Intubated Prior to Transport," Chapman et al measured endotracheal tube cuff pressure in patients who arrive at their emergency department after being intubated in the field. This, the first published American study of this type, presents clear and convincing evidence that patients who undergo endotracheal intubation before transport have endotracheal tube cuff pressures that exceed safe limits. Although a study of this type has not been conducted on patients who are endotracheally intubated by emergency medicine physicians within the confines of an emergency department, we pose the question to the academic and clinical emergency medicine community, "Should such a study be conducted?" Instead, should the evidence offered by Chapman et al, in addition to that of other publications, be enough to prompt emergency physicians to abandon the practice of endotracheal intubation without measurement and/or control of endotracheal tube cuff pressure? To adequately understand the complexity of such an apparently simple question, it is necessary to consider 2 concepts: equipoise and evidence. Our hope is that readers will acknowledge the study of Chapman et al as a strong piece of evidence indicating that patients who undergo endotracheal intubation without measurement of endotracheal tube cuff pressure very likely have a pressure that exceeds the safe range. We hope this study, in conjunction with the other available evidence, will prompt readers to adopt measurement of endotracheal tube cuff pressure as a routine.