Time course and variability of the endocrine and metabolic response to severe sepsis

In trauma patients a specific pattern of the hormone endocrine response to injury has been described. Conflicting data exist regarding the hormonal changes during sepsis. We studied the time course and variability of the hormonal and metabolic responses to severe sepsis in twelve medical patients.

Hormone levels were measured every 6 hours. Urinary nitrogen and 3-methylhistidine excretion were measured daily. Indirect calorimetry was used to calculate energy production rate (EPR).

None of the hormones measured showed a time course in individual patients. Growth hormone (1.69 +/- 0.17 ng/ml) and insulin (48 +/- 5 mU/L) values were within normal range. Cortisol value (474 +/- 44 nmol/L) was in the upper normal range. Insulin-like growth factor 1 level (12.5 +/- 5.7 nmol/L) was decreased. Nitrogen balance was negative and did not change during the study period. Neither oxygen consumption (VO2) (318 +/- 20 ml/min), carbon dioxide output (283 +/- 10 ml/min), EPR (2064 +/- 435 kcal/day), nor fuel utilization showed a time course. The variability during the study period compared with values on admission ranged from 20% (insulin-like growth factor 1) to 74% (growth hormone). The variability of calculated fuel utilization ranged from 35% (protein) to 180% (fat). The variability of VO2, carbon dioxide production, and EPR was for less, 8%.

A specific pattern in the endocrine and metabolic responses as observed in trauma patients does not occur in medical patients with severe sepsis. Hormones and calculated fuel utilization show large variations when compared with values on admission. VO2 and EPR vary for less. Nutritional needs in patients with sepsis, therefore, can be calculated on admission and need not be recalculated during the first week after admission.