Cardiorespiratory and metabolic adequacy and their relation to survival in sepsis

Cardiorespiratory and metabolic data were collected in 36 septic patients and 80 patients critically ill after nonseptic general surgery or trauma. Septic patients, particularly nonsurviving septics, showed early and sustained increases in metabolic rate, oxygen consumption, cardiac work, and minute ventilatory volume. They had lower levels of respiratory quotient and total peripheral resistance than nonseptic patients. High cardiac work was related to increasing oxygen transport. Both increases in metabolic utilization with high CO2 production, and abnormal increases in VD/VT appeared responsible for the higher minute ventilatory volumes. Respiratory quotient was negatively related to metabolic rate; this relation was modulated by the rate of caloric intake and, in nonseptic patients, was also influenced by the hemodynamic state. These data suggest that poor prognosis in sepsis is characterized by an early sustained stress response with more severe abnormalities in cardiovascular, metabolic, and respiratory function than is seen in the nonseptic stress response. The need for early support of physiologic functions and early and aggressive nutritional intervention is emphasized.