In vivo modulation of human neutrophil function by pentoxifylline in patients with septic syndrome.

The influence of pentoxifylline on human polymorphonuclear granulocyte (PMN) respiratory burst activity (RBA) was studied in 23 patients fulfilling the established criteria of sepsis and in 10 healthy donors. Pentoxifylline (PTX) was administered (5 mg/kg) by intravenous infusion in 13 septic patients over a period of 180 min. The control group consisted of 10 patients with septic syndrome who received an infusion of physiological saline. For determination of RBA, 10 mL of blood was drawn at respective time intervals before, during, and after treatment with PTX or a placebo. RBA measurements were performed using a chemiluminescence assay after stimulation of PMN with formyl-methionyl-leucyl-phenylalanine (FMLP), phorbol-myristate-acetate, and opsonized zymosan, respectively. RBA measurements of each patient were performed in replicate samples. CL was measured for 1 h at respective time intervals (1, 3, 5, 8, 10, 15 min etc). RBA of PMN of septic patients was compared with RBA of PMN of healthy donors and patients receiving PTX were compared with controls. Our results demonstrate that PMN of patients with sepsis had an increased oxidative response compared with healthy donors. We found that PTX administered intravenously was able to reduce this reactivity. RBA was significantly decreased during PTX infusion when PMN were stimulated with FMLP and phorbol-myristate-acetate, compared with the control group. No significant decrease was observed when PMN were stimulated with opsonized zymosan. These data suggest that PTX may be a valuable drug in septic state.

HSP70 expression in granulocytes and lymphocytes of patients with polytrauma: comparison with plasma glutamine.

Heat shock proteins (HSP's) are a set of conserved proteins which confer tolerance to stress. These proteins play a major role in the pathophysiology of infection and inflammation. Induction of HSP's before onset of sepsis is able to reduce or prevent organ damage and death. GLN is known to influence the expression of HSP70 in different cell types. In this work we tried to find out if there is an association between plasma GLN levels and HSP70 expression in immune cells. We investigated six polytraumatized patients and a control group of six healthy donors. HSP70 expression was investigated by western blot analysis and immune-histochemistry. We demonstrated that granulocytes and lymphocytes behave differently in the expression of HSP70 in polytraumatized patients. In healthy donors both lymphocytes and granulocytes showed a pronounced expression of HSP70. In contrast, most of the polytraumatized patients showed no HSP70 expression in granulocytes. In lymphocytes of these patients, however, a pronounced expression similar to that of healthy volunteers was observed. Plasma glutamine levels were reduced in all patients and at normal range in healthy donors. These results suggest that lymphocytes and granulocytes behave different when confronted with a reduction of plasma GLN levels.

Cardiovascular effects of 6% hetastarch and lactated Ringer's solution during spinal anesthesia.

BACKGROUND AND OBJECTIVES: The purpose of this prospective, randomized, double-blinded study was to compare the hemodynamic effects of 6% hetastarch with lactated Ringer's solution and to determine the main reasons for hemodynamic impairment following spinal anesthesia in elderly patients undergoing emergent hip surgery. METHODS: After receiving institutional approval and informed consent, we enrolled 24 ASA physical status III patients for this study. Hemodynamics were recorded with pulmonary artery and arterial catheters and an electrocardiogram. Following fluid administration with either 500 mL 6% hetastarch (group H) or 1500 mL lactated Ringer's solution (group R), spinal anesthesia was administered with 3.0 mL 0.5% bupivacaine (isobaric). Hemodynamic measurements were recorded prior to fluid administration, before spinal anesthesia, and 10, 20, and 30 minutes following spinal anesthesia and reported as relative changes relating to baseline. RESULTS: Although the hemodynamic measurements after spinal anesthesia remained stable in group H throughout the observation period, blood pressure, central venous pressure, pulmonary artery (PA) wedge pressure and systemic vascular resistance decreased significantly in group R (blood pressure: -7 +/- 10 vs - 14 +/- 8% 30 minutes after spinal anesthesia, P < .05 to group R; central venous pressure: 51 +/- 106 vs -26 +/- 27% 10 minutes, 63 +/- 89 vs -36 +/- 30% 20 minutes and 73 +/- 112 vs -33 +/- 29% 30 minutes after spinal anesthesia, P < .01 to group R; PA wedge pressure: 40 +/- 37 vs -5 +/- 40% 10 minutes, 40 +/- 35 vs -23 +/- 32% 20 minutes and 38 +/- 36 vs -23 +/- 32% 30 minutes after spinal anesthesia, P < .01 to group R; systemic vascular resistance: -10 +/- 16 vs -18 +/- 7% 20 minutes and -10 +/- 15 vs - 19 +/- 12% 30 minutes after spinal anesthesia, P < .05 to group R). CONCLUSIONS: Six percent hetastarch minimizes the hemodynamic responses during spinal anesthesia in elderly patients undergoing emergent hip surgery. In this study population, spinal anesthesia-induced hemodynamic impairment is caused by decreases in cardiac filling pressures and systemic vascular resistance.

Receptor and non-receptor mediated formation of superoxide anion and hydrogen peroxide in neutrophils of intensive care patients.

Generation of reactive oxygen intermediates (ROI) has been implicated in tissue damage in a variety of disease states including sepsis and trauma. On the other hand, generation of ROI in polymorphonuclear granulocytes (PMN) presents a crucial element in the defence of the host against invading microorganisms. In the present study we investigated the generation of superoxide anions (O2-) and hydrogen peroxide (H2O2) by neutrophils (PMN)5 of 17 critically ill patients treated at a intensive care unit (ICU) after polytrauma (n = 6), heart operation (n = 6) or during septic shock (n = 5) using flow cytometry. O2- production of PMN from ICU patients was significantly lower (p < 0.01) than that in healthy volunteers (HV) during non-receptor mediated stimulation with phorbol-myristate-acetate (PMA) but higher (p < 0.001) during receptor mediated stimulation with formylmethionine-leucine-phenylalanine (FMLP). H2O2 generation of PMN from ICU patients was increased after stimulation with FMLP (p < 0.01) and remained unchanged after stimulation with PMA. Patients in septic shock had lower O2(-)-generation of PMN than did injured patients and patients after heart operations. We conclude that receptor mediated formation of O2- and H2O2 is stimulated in ICU patients. However, in patients in septic shock O2(-)-generation decreases, which potentially might contribute to the immunoparalysis present in septic shock.

Granulocytes of critically ill patients spontaneously express the 72 kD heat shock protein.

Polymorphonuclear neutrophils (PMN), through their ability to release oxygen-free radicals and other tissue-damaging molecules, play a major role in the pathogenesis of multiple organ failure syndrome (MOFS). There is evidence that heat shock proteins (stress proteins; HSPs) are involved in cellular repair mechanisms, and are protecting cells against oxidative injury. In this study, we analyzed the spontaneous expression of the 72 kD HSP (HSP72) in peripheral blood PMN of 20 critically ill patients (16 polytrauma victims, four patients after major surgery) admitted to an intensive care unit. The expression of HSP72 was investigated in PMN of patients and healthy donors by immunohistochemistry. We found spontaneous expression of HSP72 in PMN of 12 (60%) of 20 patients. No specific staining was detected in PMN of healthy donors (n = 10). In PMN of six of 12 patients expressing HSP72 without previous heat treatment, we found an impairment of respiratory burst activity (RBA) compared to the control population. These results demonstrate for the first time the in vivo expression of HSP72 in human leukocytes without previous heat treatment, and suggest a possible role of this protein in patients suffering from severe tissue injury.

Effects of pentoxifylline on hemodynamics and oxygenation in septic and nonseptic patients.

OBJECTIVE: To evaluate the effects of pentoxifylline on hemodynamics and systemic oxygenation in septic and nonseptic critically ill patients. DESIGN: Prospective clinical investigation. SETTING: Intensive care unit (ICU) of a university hospital. PATIENTS: Nineteen critically ill patients were included in the study 1 to 4 days after their admission to the ICU. A systemic inflammatory response syndrome was present in 12 patients, fulfilling at least two of the American College of Chest Physicians/ Society of Critical Care Medicine Consensus Conference criteria. The other seven patients did not fulfill these criteria and were classified as nonseptic. INTERVENTIONS: All patients were mechanically ventilated. The dosage of catecholamines was kept constant during the entire study period and at least during 15 mins before the start of the study. In both study groups, pulmonary and radial artery catheters were inserted and 5 mg/kg of pentoxifylline (diluted in 300 mL of physiologic saline) was intravenously administered over a period of 180 mins at a rate of 100 mL/hr. MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables, oxygen transport (DO2), oxygen uptake (VO2), and oxygen extraction ratio were determined before pentoxifylline, after 2.5 mg/kg of pentoxifylline, after 5 mg/kg of pentoxifylline, and 60 mins after the termination of pentoxifylline. Repeated-measures analysis of variance and Mann-Whitney test were used for statistical analysis. At baseline, there were significant differences between the septic and the nonseptic groups in mean pulmonary arterial pressure (septic: 31 +/- 5 mm Hg; nonseptic: 26 +/- 7 mm Hg, p < .05), and pulmonary vascular resistance index (PVRI) (septic: 344 +/- 121 dyne.sec/ cm5.m2; nonseptic: 233 +/- 100 dyne.sec/cm5.m2, p < .05). In the septic group, significant increases in heart rate and cardiac index were observed. Systemic vascular resistance index and PVRI decreased. No significant changes in hemodynamic variables occurred in the nonseptic group. In both groups, DO2 and VO2 increased significantly, while oxygen extraction ratio remained unchanged. CONCLUSIONS: The administration of pentoxifylline to septic patients results in a significant improvement in hemodynamic performance compared with critically ill nonseptic patients. The better hemodynamic state is accompanied by an increase in DO2 and VO2 with unchanged oxygen extraction ratio.

Three-in-one blocks with ropivacaine: evaluation of sensory onset time and quality of sensory block.

UNLABELLED: The purpose of this prospective, randomized, double-blinded study was to evaluate the sensory onset time and the quality of sensory block of ropivacaine, a new long-acting local anesthetic, compared with bupivacaine, for 3-in-1 blocks. Fifty ASA physical status I-III patients undergoing hip surgery after trauma were randomly assigned to two study groups of 25 patients each. The two study groups received a 3-in-1 block with either 20 mL of ropivacaine 0.5% or 20 mL of bupivacaine 0.5%. Blocks in both groups were performed using a nerve stimulator. The sensory onset time and the quality of sensory block was assessed by pinprick test in the central sensory region of each of the three nerves and compared with the same stimulation in the contralateral leg. We used a scale from 100% (normal sensation) to 0% (no sensory sensation). We did not find significant differences in sensory onset times between the ropivacaine group and the bupivacaine group (30+/-11 vs 32+/-10 min). The quality of sensory blocks was also comparable between the study groups (19%+/-20% vs 21%+/-15%). We conclude that the sensory onset time and quality of sensory block during 3-in-1 blocks performed with ropivacaine are comparable to those with bupivacaine. Ropivacaine is described as being less potent than bupivacaine, making this local anesthetic promising for 3-in-1 blocks because of its reportedly lower incidence of cardiovascular and central nervous system complications. IMPLICATIONS: Ropivacaine 0.5% has a sensory onset time and quality of sensory block during 3-in-1 blocks similar to that of bupivacaine 0.5%. Ropivacaine is described as being less potent than bupivacaine, making it a promising local anesthetic for 3-in-1 blocks because of its reportedly lower cardiovascular and central nervous system toxicity.

Polytrauma induces increased expression of pyruvate kinase in neutrophils.

Polytrauma (PT) leads to systemic activation of polymorphonuclear neutrophils (PMNs). Organ damage commonly found in these patients is ascribed to respiratory bursts of activated PMNs. With the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, PMN extracts from PT patients were found to contain a clear protein band not seen in control PMNs from healthy volunteers. This band was identified by amino acid sequencing and Western blotting as pyruvate kinase (PK). Enzymatic assays revealed a 600-fold increase in PK activity in PMNs of PT patients, with the highest levels occurring between the fifth and seventh posttraumatic day. In lymphocytes, no such increase was detectable. As PK is a major regulatory enzyme in glycolysis, glucose-dependent lactate production in PMNs from PT patients was assayed. These cells showed a higher glycolytic lactate production than controls. It was additionally demonstrated that acute activation of respiratory burst activity depends mainly on breakdown of glucose to lactate via the pentose-phosphate pathway and glycolysis. In PMNs from PT patients, this glucose-dependent respiratory burst activity was more than twofold higher than in controls. The increase in expression and activity of PK in PMNs from PT patients may contribute to the high glucose-dependent respiratory burst activity seen in these cells.