Doppler scatterers Jon-Emile S. Kenny MD [@heart_lung] “I am fearful, or suspicious of generalizations … they cannot guide me reliably in making decisions about particular individuals.” -Ruth Bader Ginsburg Between the 22nd and 24th of May, I participated in the “Hospitalist and the Resuscitationist” conference in Montreal, Canada. I spoke on the stanchions of physiology and evidence underpinning IVC collapse and hemodynamics. Additionally, I gave a brief overview on the principles of Doppler ultrasound for blood flow measurement. This lecture is included below; it is a truncated version of a talk that I gave to the UCLA pulmonary and critical care fellows in early January.