Studies are planned of hemodynamics, metabolism, and respiratory function in man and in laboratory animals in shock. Data will be recorded at the bedside from selected patients with hemorrhage or who are in shock from a variety of causes, including hypovolemia, sepsis, cardiac disease, pulmonary embolism and others. Adjuncts to the therapy of shock in man are being evaluated. Of particular interest are the effects of controlled hypotension in selected cases of continuing hemorrhage, and the influence of changes in hematocrit on viscosity of blood and rates of bleeding. Hypotheses derived from observations in man will be tested in the experimental laboratory. Observations being made in the experimental laboratory include studies of the effects of hematocrit on viscosity of blood, flow rates, and bleeding rates in vitro and in experimental animals. The hemodynamics of inflammation and endotoxin are being studied in dogs. Effects of hemorrhage on adenosine nucleotides in the canine liver are being evaluated. Observations are being made of ultramicroscopic changes in the brain in severe hemorrhage.