Physiologic events were observed before, during, and after extensive surgical procedures for life-threatening illnesses in a series of 98 patients. Although there was a wide spectrum of illnesses, operations, and associated clinical factors, fairly well defined patterns that began early after onset of the causative event were associated with survival and death, but were not well related to the degree of hypotension. We described the cardiorespiratory pattern of the 67 survivors, which to a first approximation represents the optimal therapeutic goals, and contrasted these with the pattern of the 31 patients who died. Alterations in the latter group may be used as early warning, and include lower cardiac output and other measures of cardiac performance, higher pulmonary vascular resistance, reduced oxygen transport, acidosis, higher arterial carbon dioxide tension, and greater reductions in hematocrit reading and blood volume.
Shoemaker WC, Montgomery ES, Kaplan E, Elwyn DH. Physiologic Patterns in Surviving and Nonsurviving Shock PatientsUse of Sequential Cardiorespiratory Variables in Defining Criteria for Therapeutic Goals and Early Warning of Death. Arch Surg. 1973;106(5):630-636. doi:10.1001/archsurg.1973.01350170004003