[Intrathoracic blood volume index as an indicator of fluid management in septic shock].

OBJECTIVE: To investigate the value of intrathoracic blood volume index (ITBVI) monitoring in fluid management strategy in septic shock patients. METHODS: In a prospective study, 33 patients who were diagnosed to be suffering from septic shock in the intensive care unit (ICU) were enrolled . Seventeen patients who received pulse indicator continuous cardiac output (PiCCO) monitoring, and ITBVI was used as indicator of fluid management, were enrolled into ITBVI group; 16 patients who received traditional fluid management strategy [directed by central venous pressure (CVP)] were enrolled into control group. Acute physiology and chronic health evaluation II (APACHEII) score, sepsis related organ failure assessment (SOFA) score and vasopressor score were compared between 1 day and 3 days of treatment. The characteristics of fluid management were recorded and compared within 72 hours. RESULTS: (1)In 3 days of treatment, APACHEII, SOFA and vasopressor score were significantly lower in ITBVI group compared with that of in 1 day of treatment[21.3±6.2 vs. 25.4±7.2, 6.1±3.4 vs. 9.0±3.5, 5 (0, 8.0) vs. 20.0 (8.0, 35.0), respectively, all P<0.01], whereas there were no changes in control group. (2)Although fluid output (ml) was higher in ITBVI group during 48-72 hours period (2 421± 868 vs. 1 721±934, P=0.039), there was no difference in fluid intake, fluid output or fluid balance (ml) within 0-72 hours between two groups (fluid intake: 9 918±137 vs. 10 529±1 331, fluid output : 6 035±1 739 vs. 5 827±2 897, fluid balance: 3 882±1 889 vs. 4 703±2 813, allP>0.05). (3)Comparing the fluid volume (ml) used for fluid replacement period, except that there was no significance in fluid challenge with colloid during 0-6 hours between two groups [ml: 250 (125, 500) vs. 250 (69,250), P>0.05], more fluid intake (ml) was found in ITBVI group [0-6 hours crystalloid: 250(150,250) vs. 125 (105,125), 6-72 hours crystalloid: 125 (125, 250) vs. 100 (56, 125), 0-72 hours crystalloid: 250(125, 250) vs. 125 (75, 125), 6-72 hours colloid: 125 (106, 250) vs. 75 (50, 125), 0-72 hours colloid: 200 (125, 250) vs. 100 (50, 125),all P<0.01]. CONCLUSION: Clinical picture in patients with septic shock is improved after 3 days of treatment than 1 day of treatment under fluid management directed by ITBVI, compared with by CVP. This improvement may be attributable to accurate assessment of preload and appropriate infusion rate in fluid challenge.

[Study on the natural ligand(s) of triggering receptor expressed on myeloid cell-1 on bacteria cell wall].

OBJECTIVE: To look for the natural ligand(s) of human triggering receptor expressed on myeloid cell-1 (TREM-1), in order to provide the theoretical basis for elucidation of the pathogenesis of sepsis. METHODS: Neutrophils and monocytes isolated from human peripheral blood were treated with heat-inactivated Staphylococcus aureus, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Staphylococcus aureus L-form or Pseudomonas aeruginosa L-form respectively for 24 hours. The cell wall was extracted from Staphylococcus aureus, Pseudomonas aeruginosa and Mycobacterium tuberculosis by ultrasound. Neutrophils and monocytes were isolated and treated with the cell wall respectively for 24 hours. Neutrophils and monocytes were isolated and treated with three main components from bacterial cell wall (polysaccharides, lipids and proteins) respectively for 24 hours. The level of TREM-1 mRNA was measured with fluorescent quantitative polymerase chain reaction (PCR), and the concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) were measured with enzyme-linked immunosorbent assay (ELISA). RESULTS: The TREM-1 mRNA level and the concentrations of TNF-alpha and IL-1 beta in cell supernatant of neutrophils and monocytes were upgraded when treated with cell, cell wall and cell wall polysaccharides of Staphylococcus aureus and Pseudomonas aeruginosa. Compared with the blank control group, the TREM-1 mRNA level of neutrophils and monocytes was upgraded to (3.86+/-0.20)-fold and (5.15+/-0.56)-fold respectively when treated with cell wall polysaccharides of Staphylococcus aureus (both P<0.05); the TREM-1 mRNA level of neutrophils and monocytes was upgraded to (4.03+/-0.15)-fold and (7.22+/-0.73)-fold respectively when treated with cell wall polysaccharides of Pseudomonas aeruginosa (both P<0.05). The effect could be attenuated by the addition of LP17 which could bind TREM-1 ligand. This attenuating effect was not found when the cells were treated with cell, cell wall or cell wall polysaccharides of Mycobacterium tuberculosis. CONCLUSION: The study provides the evidence that TREM-1 natural ligand(s) is present on cell wall of bacteria including Staphylococcus aureus and Pseudomonas aeruginosa, and it might be polysaccharides.