No abstract

BackgroundCritical illness constitutes a serious derangement of metabolism. The aim of our study was to compare acute phase metabolic patterns in children with sepsis (S) or severe sepsis/septic shock (SS) to those with severe traumatic brain injury (TBI) and healthy controls (C) and to evaluate their relations to neutrophil, lymphocyte and monocyte expressions of CD64 and CD11b.MethodsSixty children were enrolled in the study. Forty-five children with systemic inflammatory response syndrome (SIRS) were classified into three groups: TBI (n = 15), S (n = 15), and SS (n = 15). C consisted of 15 non- SIRS patients undergoing screening tests for minor elective surgery. Blood samples were collected within 6 hours after admission for flow cytometry of neutrophil, lymphocyte and monocyte expression of CD64 and CD11b (n = 60). Procalcitonin (PCT), C-reactive protein (CRP), glucose, triglycerides (TG), total cholesterol (TC), high (HDL) or low-density-lipoproteins (LDL) were also determined in all groups, and repeated on day 2 and 3 in the 3 SIRS groups (n = 150).ResultsCRP, PCT and TG (p < 0.01) were significantly increased in S and SS compared to TBI and C; glucose did not differ among critically ill groups. Significantly lower were the levels of TC, LDL, and HDL in septic groups compared to C and to moderate changes in TBI (p < 0.0001) but only LDL differed between S and SS (p < 0.02). Among septic patients, PCT levels declined significantly (p < 0.02) with time, followed by parallel decrease of HDL (p < 0.03) and increase of TG (p < 0.02) in the SS group. Neutrophil CD64 (nCD64) expression was higher in patients with SS (81.2%) and S (78.8%) as compared to those with TBI (5.5%) or C (0.9%, p < 0.0001). nCD64 was positively related with CRP, PCT, glucose, and TG (p < 0.01) and negatively with TC, LDL, and HDL (p < 0.0001), but not with severity of illness, hematologic indices, length of stay or mechanical ventilation duration.ConclusionsIn sepsis, the early stress-metabolic pattern is characterized by a high (nCD64, glucose, TG) - low (TC, HDL, LDL) combination in contrast to the moderate pattern of TBI in which only glucose increases combined with a moderate cholesterol - lipoprotein decrease. These early metabolic patterns persist the first 3 days of acute illness and are associated with the acute phase CD64 expression on neutrophils.

Heat shock protein 72 (Hsp72) exhibits a protective role during times of increased risk of pathogenic challenge and/or tissue damage. The aim of the study was to ascertain Hsp72 protective effect differences between animal and human studies in sepsis using a hypothetical “comparative study” model. Forty-one in vivo (56.1%), in vitro (17.1%), or combined (26.8%) animal and 14 in vivo (2) or in vitro (12) human Hsp72 studies (P < 0.0001) were enrolled in the analysis. Of the 14 human studies, 50% showed a protective Hsp72 effect compared to 95.8% protection shown in septic animal studies (P < 0.0001). Only human studies reported Hsp72-associated mortality (21.4%) or infection (7.1%) or reported results (14.3%) to be nonprotective (P < 0.001). In animal models, any Hsp72 induction method tried increased intracellular Hsp72 (100%), compared to 57.1% of human studies (P < 0.02), reduced proinflammatory cytokines (28/29), and enhanced survival (18/18). Animal studies show a clear Hsp72 protective effect in sepsis. Human studies are inconclusive, showing either protection or a possible relation to mortality and infections. This might be due to the fact that using evermore purified target cell populations in animal models, a lot of clinical information regarding the net response that occurs in sepsis is missing.

Dear Editor, Advances in paediatric critical care have resulted in the increased survival of chronically ill patients. In many units, such patients represent [50 % of the workload and are often malnourished [1]. Prediction of energy expenditure (PEE) equations are simple alternatives to the gold standard of assessing resting energy expenditure (REE) by indirect calorimetry (IC). However, recent work has suggested that PEE equations fail to adequately predict REE. New paediatric intensive care unit (PICU)-oriented equations have been found to be no better than well-established tools, such as the Schofield-HW equation [2]. We have compared PICU-specialized and commonly used PEE equations with REE using a new modular metabolic monitor (E-COVX) in well-nourished and malnourished critically ill children. The E-COVX compact metabolic module has the advantage of not being influenced by uneventful open endotracheal suctioning [3]. It is suitable for repeated 30-min measurements in well-sedated mechanically ventilated children with stable respiratory patterns in a variety of ventilation modes [4]. We hypothesized that IC using the E-COVX would show that energy expenditure is unpredictable in malnourished children and that replacing REE with any PEE equation, including the new PICU-oriented equations, might not be applicable for estimating energy expenditure in patients suffering from malnutrition during a critical illness. The Ethics Committee of the Institutional Review Board approved this study, and parents or guardians of the children gave informed, written consent.Mechanically ventilated critically ill children, consecutively admitted to the PICU of the University Hospital, Heraklion, Crete, were enrolled in the study. Thirty consecutive 1-min gas exchange measurements (VO 2 and VCO 2 ) were taken and the respiratory quotient (RQ) and REE were calculated for each patient (results were blinded from the attending physician). The nutritional status was evaluated for the presence of proteinenergy malnutrition as defined by Waterlow [5]. The PEE was estimated and basal metabolic rate (PBMR) was predicted using the common Harris-Benedict, Schofield-HW, Seashore, Fleisch, CaldwellKennedy and Henrys formulas, as well as equations specifically developed for the PICU by White and by Meyer [2]. Patients were classified as hypermetabolic, normometabolic and hypometabolic when the REE was [110, 90-110 and \90 % of the Schofield-PBMR, respectively, and as overfed, adequately fed and underfed when the caloric intake was [110, 80-110 and \80 % of the REE, respectively.Forty-four patients (28 boys, 16 girls) were studied (total measurements 1,320). Four patients were admitted after an elective procedure; the remaining patients were admitted as a result of an acute illness or injury. Twelve (27.3 %) patients presented severe (4) or moderate (8) malnutrition. All patients survived.The REE did not differ between patients according to a body temperature of \37.1°C (1,068 ± 460 kcal/ day) or C37.1°C (824 ± 217 kcal/ day) or with a Ramsey s...