A possible relationship between hypermetabolism (energy expenditure expressed as percentage above the estimated basal metabolic rate) and clinical outcome was investigated in 29 artificially ventilated patients with infection and multiple organ failure following abdominal surgery. The average energy expenditure and hypermetabolism were 126 +/- 19 kJ (30 +/- 5 kcal)/kg/24 h and 36 +/- 12%, respectively. Survivors of the intensive care period (n = 20) had a 15% higher hypermetabolism (41 +/- 11 vs 26 +/- 8%, p less than 0.01) than patients who died in the intensive care unit (n = 9). Six of the patients died after intensive care. On comparing hypermetabolism in survivors (n = 14) and non-survivors (n = 15) of the period of hospitalization, no significant difference was discernible. The results demonstrate that patients with multiple organ failure have a moderate hypermetabolism and suggest that the hypermetabolism is comparatively reduced in patients with a fatal outcome during intensive care.