Effect of pentaglobin and piperacillin on survival in a rat model of faecal peritonitis: importance of intervention timings

Antibody Production in Murine Polymicrobial Sepsis-Kinetics and Key Players

Although antigen-specific priming of antibody responses is impaired during sepsis, there is nevertheless a strong increase in IgM and IgG serum concentrations. Using colon ascendens stent peritonitis (CASP), a mouse model of polymicrobial abdominal sepsis, we observed substantial increases in IgM as well as IgG of all subclasses, starting at day 3 and peaking 2 weeks after sepsis induction. The dominant source of antibody-secreting cells was by far the spleen, with a minor contribution of the mesenteric lymph nodes. Remarkably, sepsis induction in splenectomized mice did not change the dynamics of the serum IgM/IgG reaction, indicating that the marginal zone B cells, which almost exclusively reside in the spleen, are dispensable in such a setting. Hence, in systemic bacterial infection, the function of the spleen as dominant niche of antibody-producing cells can be compensated by extra-splenic B cell populations as well as other lymphoid organs. Depletion of CD4+ T cells did not affect the IgM response, while it impaired IgG generation of all subclasses with the exception of IgG3. Taken together, our data demonstrate that the robust class-switched antibody response in sepsis encompasses both T cell-dependent and -independent components.

A double blind randomized experimental study on the use of IgM-enriched polyclonal immunoglobulins in an animal model of pneumonia developing shock

BACKGROUND

Patients with severe pneumonia often develop septic shock. IgM-enriched immunoglobulins have been proposed as a potential adjuvant therapy for septic shock. While in vitro data are available on the possible mechanisms of action of IgM-enriched immunoglobulins, the results of the in vivo experimental studies are non-univocal and, overall, unconvincing. We designed this double blinded randomized controlled study to test whether IgM-enriched immunoglobulins administered as rescue treatment in a pneumonia model developing shock, could either limit lung damage and/or contain systemic inflammatory response.

METHODS

Thirty-eight Sprague Dawley rats were ventilated with injurious ventilation for 30min to prime the lung. The rats were subsequently randomized to received intratracheal instillation of either lipopolysaccharide (LPS) (12mg/kg) or placebo followed by 3.5h of protective mechanical ventilation. IgM-enriched immunoglobulins at 25mg/h (0.5mL/h) or saline were intravenously administered in the last hour of mechanical ventilation. During the experiment, gas exchange and hemodynamic measurements were recorded. Thereafter, the animals were sacrificed, and blood and organs were stored for cytokines measurements.

RESULTS

Despite similar lung and hemodynamic findings, the administration of IgM-enriched immunoglobulins compared to placebo significantly modulates the inflammatory response by increasing IL-10 levels in the bloodstream and by decreasing TNF-α in bronchoalveolar lavage (BAL) fluid. Furthermore, in vitro data suggest that IgM-enriched immunoglobulins induce monocytes production of IL-10 after LPS stimulation.

CONCLUSIONS

In an in vivo model of pneumonia developing shock, IgM-enriched immunoglobulins administered as rescue treatment enhance the anti-inflammatory response by increasing blood levels of IL-10 and reducing TNF-α in BAL fluid.

Early therapy with IgM-enriched polyclonal immunoglobulin in patients with septic shock

PURPOSE

To determine whether there was an association between adjunctive therapy with IgM-enriched immunoglobulin (IgM) and the 30-day mortality rate in patients with septic shock.

METHODS

In 2008 we introduced IgM as a possible adjunctive therapy to be provided within 24 h after shock onset in the management protocol for patients with septic shock. In this retrospective study we included the adult patients suitable for IgM therapy admitted to our ICU from January 2008 to December 2011. An unadjusted comparison between patients who did or did not receive IgM therapy, a multivariate logistic model adjusted for confounders and propensity score-based matching were used to evaluate the association between early IgM treatment and mortality.

RESULTS

One hundred and sixty-eight patients were included in the study. Of these, 92 (54.8%) received IgM therapy. Patients who did or did not receive IgM were similar with regards to infection characteristics, severity scores and sepsis treatment bundle compliance. Patients who received IgM were more likely to have blood cultures before antibiotics and to attain a plateau inspiratory pressure less than 30 cmH2O (p < 0.05). The 30-day mortality rate was reduced by 21.1% (p < 0.05) in the group that received IgM compared to the group that did not. The multivariate adjusted regression model (OR 0.17; CI 95% 0.06-0.49; p = 0.001) and the propensity score-based analysis (OR 0.35; CI 95% 0.14-0.85; p = 0.021) confirmed that IgM therapy was associated with reduced mortality at 30 days after the onset of septic shock.

CONCLUSIONS

Our experience indicates that early adjunctive treatment with IgM may be associated with a survival benefit in patients with septic shock. However, additional studies are needed to better evaluate the role of IgM therapy in the early phases of septic shock.

Relationship between the timing of administration of IgM and IgA enriched immunoglobulins in patients with severe sepsis and septic shock and the outcome: a retrospective analysis

PURPOSE

Because the use of IgM and IgA enriched polyclonal intravenous immunoglobulins (eIg) is a standard of care in critically ill patients admitted to our intensive care unit (ICU) with the diagnosis of severe sepsis or septic shock, we investigated if the delay from the onset of severe sepsis and septic shock and their administration could influence the outcome.

MATERIALS AND METHODS

The medical records of all patients with severe sepsis or septic shock admitted to our ICU from July 2004 through October 2009 and treated with eIg (Pentaglobin®; Biotest, Dreieich, Germany) were retrospectively examined.

RESULTS

A total of 129 adult patients with severe sepsis or septic shock were considered eligible. Thirty-two percent of patients died during the ICU stay. Survivors were given eIg significantly earlier than nonsurvivors (23 vs 63 hours, P < .05). The delay in the administration of eIg and the Simplified Acute Physiology Score II were the only variables that entered stepwise a propensity score-adjusted logistic model. The delay in the administration of eIg was a significant predictor of the odds of dying during the ICU stay (odds ratio for 1 hour of delay, 1.007; P < .01; 99% confidence interval from 1.001 to 1.010) and proved to be independent from the Simplified Acute Physiology Score II and other variables.

CONCLUSIONS

The efficacy of eIg, being maximal in early phases of severe sepsis and/or septic shock, is probably time dependent.

Preconditioning with ozone/oxygen mixture induces reversion of some indicators of oxidative stress and prevents organic damage in rats with fecal peritonitis

OBJECTIVE AND DESIGN

Reactive oxygen and nitrogen species are involved in the pathogenesis of sepsis syndrome with peritonitis and the septic shock. The aim of this study was to determine whether ozone oxidative preconditioning (OOP) may exert beneficial effects in the prevention and treatment of sepsis syndrome in rats inoculated by the intraperitoneal route (i.p.) with fecal material and also to determine if antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) may exert protective effects against this systemic inflammatory disorder.

MATERIALS AND METHODS

Male Wistar rats were used. SOD and GPx activities were determined in erythrocytes. Thiobarbituric acid reactive substances (TBARS) content as biomarkers of oxidative stress, alanine amino transferase (ALT), aspartate amino transferase (AST) and creatinine (CRE) were measured in blood serum and myeloperoxidase (MPO) in lung tissue as markers of organs damage.

RESULTS

In rats submitted to OOP, SOD and GPx activities were significantly increased and it was accompanied by significant decrease of TBARS content in blood serum. OOP also significantly reduced levels of ALT, AST and CRE in blood serum as well as MPO in rat lung.

CONCLUSION

The results support the important role of SOD and GPx in the protective effects of OOP against organ damage induced by fecal peritonitis in rats.

The effect of methylprednisolone on treatment in rats with induced sepsis

In this study, an appropriate sepsis model was created in rats. Additionally, the effects of steroid treatments on survival, in connection with antibiotic treatment, were investigated. The sepsis model performed via intraperitoneal injection of 3 ml/kg fecal suspension was determined as the most appropriate model for our study. Fifteen rats were used to investigate the effect of piperacillin-tazobactam on sepsis treatment. Forty-five randomly selected rats were used to investigate the efficacy of the antibiotic-plus-steroid combination. The rats were divided into three groups of 15 rats each. Twelve hours after the administration of fecal suspension, methylprednisolone (MP) at the dose of 0.25, 0.5, and 2 mg/kg/day was given to each group, respectively, in addition to an antibiotic administered intravenously. In order to investigate the effect of steroids alone in the treatment of sepsis, 0.5 mg/kg/day MP was given intravenously to 15 rats, 12 h after the fecal suspension was administered. It was concluded that administration of MP alone shortens survival time in rats with sepsis, whereas antibiotic therapy alone increases survival time significantly in rats with sepsis. It was seen that the antibiotic-plus-steroid treatment increases survival significantly compared to rats with no treatment (p < 0.05). In addition, steroids, when added to an antibiotic treatment in sepsis, affect survival positively when compared to the group with antibiotic therapy alone, depending on the dose given. Although, not statistically significant, high doses decrease survival (p > 0.05), and very low doses increase survival and mean survival time (p > 0.05) on the basis of clinical observation and average life time. However, low doses were found to increase survival significantly (p < 0.05). We concluded that low-dose MP, in addition to the appropriate antibiotic therapy, is the optimal in the treatment of rats with intraabdominal sepsis.

Immunoglobulin M-enriched human intravenous immunoglobulins reduce leukocyte-endothelial cell interactions and attenuate microvascular perfusion failure in normotensive endotoxemia

Clinical studies indicate potential differences in the efficacy of immunoglobulin (Ig) preparations in patients with sepsis. A recent meta-analysis showed improved survival rates with IgM-enriched Igs. It was the objective of the present study to characterize microcirculatory actions of different clinically used Ig preparations in a rodent endotoxin model by intravital microscopy. Male Syrian golden hamsters 6 to 8 weeks old with a body weight of 60 to 80 g were investigated by intravital fluorescence microscopy. Endotoxemia was induced by administration of 2 mg/kg (i.v.) endotoxin (LPS, Escherichia coli). Two different Ig preparations containing IgM, IgA, and IgG (intravenous IgM group; n = 6; 5 mL Pentaglobin/kg body weight, i.v.) or exclusively IgG (intravenous IgG group; n = 5; 5 mL Flebogamma/kg body weight, i.v.) were applied 5 min before LPS. Saline-treated endotoxemic animals served as controls (control; n = 8). In controls, LPS induced massive leukocyte-endothelial cell interactions, pronounced microvascular leakage, a decrease of systemic platelet count, and distinct capillary perfusion failure (P < 0.05). Both intravenous IgM and IgG reduced venular leakage (P< 0.05) and ameliorated the decrease in platelet count (P < 0.05). Of interest, intravenous IgM was capable of significantly (P< 0.05) reducing leukocyte adhesion in venules. This was associated with normalization of capillary perfusion at 24 h of endotoxemia, whereas intravenous IgG could not prevent LPS-mediated microvascular perfusion failure. We demonstrate that IgM-enriched Igs are superior to IgG alone in attenuating LPS-induced leukocytic inflammation and microcirculatory dysfunction. Our findings can explain better efficacy of IgM-enriched Igs in patients with severe sepsis.

Community-acquired septic shock: early management and outcome in a nationwide study in Finland

AIM

To determine how the early treatment guidelines were adopted, and what was the impact of early treatment on mortality in septic shock in Finland.

METHODS

This study was a sub-analysis of a prospective observational investigation of severe sepsis and septic shock in Finland (Finnsepsis). All patients with severe sepsis over 4 months in 24 intensive care units were included in the Finnsepsis study. Patients with community-acquired septic shock, admitted directly from the emergency department to the intensive care unit, were included in the sub-study. The following treatment targets were evaluated: measurement of lactate during the first 6 h; analysis of blood culture before antibiotics; commencement of antibiotics within 3 h; attainment of a mean arterial pressure of > or =65 mmHg, central venous pressure of > or =8 mmHg and central venous oxygen saturation of > or =70% or mixed venous oxygen saturation of > or =65% during the first 6 h.

RESULTS

Of the 92 patients who fulfilled the inclusion criteria, six reached all treatment targets and 33 reached four or more targets (group > or =4). The hospital mortality of group > or =4 was 24% (8/33), compared with 42% (25/59) for those who reached three or fewer targets (group < or =3) (P= 0.08). The 1-year mortality rates of group > or =4 and group < or =3 were 36% and 59% (P= 0.04), respectively. In logistic regression analysis, a delayed initiation of antimicrobials was associated with an unfavourable outcome (P= 0.04).

CONCLUSIONS

Compliance with international guidelines for the early treatment of septic shock was poor in Finnish hospitals. A failure to diagnose early and to start appropriate treatment was reflected in the high mortality. The delayed start of antibiotics was the most important individual variable leading to a high mortality in this nationwide study.

Efficiency of tazobactam/piperacillin in lethal peritonitis is enhanced after preconditioning of rats with O3/O2-pneumoperitoneum

Insufflation of ozonized oxygen into the peritoneum (O3/O2-pneumoperitoneum [O3/O2-PP]) of rats reduced the lethality of peritonitis. We evaluated the prophylactic effect of O3/O2-PP combined with tazobactam/piperacillin (TZP) in polymicrobial lethal peritonitis. Wistar rats were conditioned by daily repeated insufflation of ozone for 5 days, and hematologic parameters were determined. Sepsis was induced by i.p. injection of cecal material derived from donor rats. Simultaneously, TZP was applied at a single dosage of 65 mg/kg or at two dosage schedules of 65 mg/kg each at an interval of 1 h. The conditioning effect of O3/O2-PP on the number of blood cells was measured before inoculation of bacteria. The mRNA levels of proinflammatory cytokine IL-lbeta and TNF-alpha were determined at 4 h post infection in spleen and liver by semiquantitative in situ hybridization analysis. Preconditioning of rats by O3/O2-PP enhanced the number of blood leukocytes and granulocytes and increased the survival rate of septic rats up to 33%. The combination of O3/O2-PP and TZP further enhanced the survival rate up to 93%. This effect was accompanied by a reduced amount of IL-1beta and TNF-alpha mRNA in spleen and liver. In contrast, in non-infected animals the combination of O3/O2-PP and TZP enhanced IL-1beta and TNF-alpha mRNA in the spleen and IL-1beta mRNA in liver when compared with TZP- and sham-treated controls. The preconditioning effect of O3/O2-PP seems to support the biological effectiveness of TZP by altering the immune status before and during the onset of sepsis. The combined therapy could be a simple, preoperative intervention for abdominal surgery to reduce postoperative morbidity and mortality.

Effect of intraperitoneal application of an endotoxin inhibitor on survival time in a laparoscopic model of peritonitis in rats

Gram-negative sepsis due to fecal peritonitis is a hazardous disease with a high percentage having a lethal course. The inflammatory effects are induced by endotoxin release. We performed this study to evaluate the potential of direct intraperitoneal application of an endotoxin inhibitor in a laparoscopic peritonitis model in rats. The human feces specimen was prepared, and a standard fecal specimen (0.5 ml/kg b.w.) was applied via minilaparotomy. The rats were randomized to two studies. First, rats were randomized to three groups to define the survival time: (1) rats without further manipulation; (2) rats with laparoscopic lavage using NaCl; (3) rats with laparoscopic lavage using endotoxin inhibitor. Second, rats underwent the same procedure used in the first part of the study and an additional group with only NaCl lavage without peritonitis was randomized. To evaluate the immunologic or biochemical effects, animals were killed at a standard time of 20 hours until the postmortem examination was established. Interleukins 6 and 10 (IL-6, IL-10), malondialdehyde, and protein carbonyl group levels in plasma and particularly in peritoneal fluid were assayed. The first part of the experiment showed significantly increased survival after endotoxin inhibitor lavage. In the second part, administration of endotoxin inhibitor intraperitoneally caused a significant reduction of IL-6 in the peritoneal fluid, in contrast to that in the other groups. Laparoscopic application of endotoxin inhibitor intraperitoneally thus produced a beneficial effect on survival and reduction of IL-6 in peritoneal fluid. Hence, it is possible to influence the inflammation cascade by causing intraperitoneal endotoxin inhibition.