[The characterization of a pattern of metabolic response and energy utilization in septic surgical patients]

To describe the energy-metabolic response pattern in septic surgical patients. Carried out in the Surgical Intensive Care Unit (SICU). Hospital Universitario.

Eighteen surgery patients. Inclusion criterion: sepsis according to the criteria of the American Intensive Care Society (1992).

Standard invasive and metabolic hemodynamic monitoring: sequential recording of direct measuring variables and calculation of derived variables.

Monitoring of the critical illness until final discharge due to improvement or death. We included 642 hemodynamic-metabolic evaluations, codified and incorporated into a data base specially designed for the purposes. Surviving and non-surviving groups (SG and NSG) were identified. Inter-group differences were analysed using the Student or MANOVA test, and intra-group analysis was done with the ANOVA test. Significant difference p less than 0.05.

On admission to the SICU, oxygen consumption (VO2) and carbon dioxide production (VCO2) were lower in the SG (198 mL/min vs 233 Ml/Min) and (105 mL/min vs 172 mL/min), while RQ was significantly higher (1.08 vs 0.43): the NSG showed lower arterial bicarbonate (HCO3) (11.8 mOsm/Lt vs 14.4 mOsm/Lt). At the end of monitoring, there were significant inter-group differences for RQ (0.85 vs 1.02), VO2 (346 mL/min vs 398 mL/min), VCO2 (271 mL/min vs 359 mL/min) and arterial HCO3 (18.0 mOsm/l vs 15.6 mOsm/L) when the SG was compared with the NSG. With the passage of time, in the SG, VO2 dropped progressively, the arterial HCO3 rose, and RQ rose to lipogenesis level (days 6 and 7). In the NSG, there was a late period of RQ in excess of 1.0, severe metabolic acidosis, and persistently high VO2 and VCO2. Caloric requirements were significantly higher in the NSG (1.64 kcal/min, vs 1.9 cal/min-p < 0.001).

There were major differences between the SG and NSG energy-metabolic pattern during surgical sepsis. Initially, the SG showed serious lesion parameters with RQ characteristic of a metabolism basically of the glucose oxidation type: the VO2 was high in the NSG, with persistent metabolic acidosis, and RQ initially explained by the accumulation of ketonic bodies and, subsequently, by lipogenesis. Definition of a metabolic pattern in the septic surgery patient establishes criteria of which are unquestionably useful in prognosis, suggesting that the therapeutic program be restructured at the moment when it is noted that the patient's pattern departs from that of the survivors.