Aggressive methods of decreasing oxygen consumption, such as therapeutic musculoskeletal paralysis, are used in patients with marginal oxygen delivery associated with cardiac and respiratory insufficiency. This is especially true of new mechanical ventilation methods designed to decrease tidal volume and peak airway pressures. Agitation and delirium associated with brain failure also have become an important source of abnormally increased oxygen consumption in ICU patients. Hemodynamic deterioration from the effects of musculoskeletal hyperactivity can precipitate angina, heart failure, and cardiac arrhythmias by increasing myocardial work and oxygen consumption in the face of a fixed coronary artery output. Escalated doses of sedatives, followed by oppressive hemodynamic and ventilatory side-effects, sometimes indicate the need for therapeutic musculoskeletal paralysis to quickly control life-threatening agitation syndromes. Cerebral-function monitoring with portable, noninvasive, computer-processed monitors allows quick recognition of brain functions under titrated, suspended animation in real time, facilitating modulation of therapy when the visual clues of neuronal function disappear.