A prospective study was conducted on 34 stable septic patients to determine whether mild hyperlactatemia is a marker of lactate overproduction or an indicator of lactate underutilization during sepsis. Plasma lactate clearance and lactate production were evaluated by modeling the lactate kinetic induced by an infusion of 1 mmol/kg L-lactate over 15 min. The patients were divided in two groups depending on their blood lactate: < or = 1.5 mmol/L (n = 20, lactate = 1.2+/-0.2 mmol/L) or > or = 2 mmol/L (n = 10, lactate = 2.6+/-0.6 mmol/L). The hyperlactatemic patients had a lower lactate clearance (473+/-102 ml/kg/h) than those with normal blood lactate (1,002+/-284 ml/kg/h, p < 0.001), whereas lactate production in the two groups was similar (1,194+/-230 and 1,181+/-325 micromol/kg/h, p = 0.90). A second analysis including all the patients confirmed that the blood lactate concentration was closely linked to the reciprocal of lactate clearance (r2 = 0.73, p < 0.001) but not to lactate production (r2 = 0.03, p = 0.29). We conclude that a mild hyperlactatemia occurring in a stable septic patient is mainly due to a defect in lactate utilization.

The aim of the present prospective study was to determine if malnutrition, measured using a simple validated score, is an independent risk factor for nosocomial infections (NI) in non-selected hospital in-patients. Between 29 and 31 May 2001, a survey on the prevalence of NI was conducted on all 1637 in-patients (61 (SD 25) years old) in a French university hospital as part of a national survey. Actual and usual body weights were recorded in all in-patients, and serum albumin levels were measured on all blood samples taken during the week before the study. Nutritional status was evaluated by using the nutritional risk index (NRI). Albumin values were obtained in 1084 patients, and complete weight information was obtained in 911. Therefore, NRI was calculated in 630 patients (61 (SD 20) years old): 427 (67·8 %) were malnourished. NI prevalence was 8·7 %: 4·4 % in non-malnourished patients, 7·6 % in moderately malnourished patients and 14·6 % in severely malnourished patients. In univariate analysis, the odds ratios for NI were 1·46 (95 % CI 1·2, 2·1) in moderately malnourished patients and 4·98 (95 % CI 4·6, 6·4) in severely malnourished patients. In multivariate analysis, age, immunodeficiency and NRI class influenced NI risk. Vascular and urinary catheters, and surgical intervention, were the extrinsic factors associated with NI, with odds ratios ranging from 2·0 (95 % CI 1·8, 2·6) for vascular catheters to 10·8 (95 % CI 8·8, 12·6) for association of the three factors. In conclusion, in non-selected hospitalized patients, malnutrition assessed with a simple and objective marker is an independent risk factor for NI. An early screening for malnutrition may therefore be helpful to reduce the high prevalence of NI.

Continuous venovenous hemofiltration with dialysis cannot mask lactate overproduction, and its blood concentration remains a reliable marker of tissue oxygenation in patients receiving this renal replacement technique.