Ethical Implications for Potential Placebo Effects of Point of Care Ultrasound

Anecdotally, practitioners of point of care ultrasound (POCUS) describe instances where patients appear to experience a placebo-like response after the examination, also described as a positive care effect. Extensive study of therapeutic ultrasound has yet to reveal differences between intervention and placebo, both of which respond to therapy. Indeed, POCUS is exemplary in incorporating many components known to modulate placebo-like effects. Patient expectations, ritualistic aspects of hands-on care, symbolic power of sophisticated medical instruments, the power of real-time POCUS images, therapeutic practitioner-patient communication, and the effect of cultural and linguistic concordance all have significant potential to modulate positive or negative care effects of POCUS. Drawing from complementary and alternative medicine's discussion of characteristic and incidental factors, this review argues that POCUS should be studied as a complex medical intervention intertwined with and inextricable from diagnostic and care processes in the hospital setting. Since POCUS is a diagnostic tool with care effect potential, its similarity to the physical exam can guide preliminary ethical guidance on disclosure of potential placebo effects or efforts to maximize that potential effect. However, more data is needed to balance the benefits and risks of effective diagnosis and overdiagnosis, respectively.