The cytokine network in the critically ill

Arctigenin protects mice from thioglycollate-induced acute peritonitis

Acute peritonitis is an acute inflammatory response of the peritoneal cavity to physical injury and chemical stimulation. Timely resolution of this response is critical to prevent further damage to the body, which can eventually lead to more severe chronic inflammation. Arctigenin (ATG) is the main active ingredient of the Chinese medicine Arctium lappa. In recent years, there have been an increasing number of studies on the anti-inflammatory effect of ATG, but there have been few studies on the effect of ATG on acute inflammation, especially in acute peritonitis, which has not been reported. In this study, a mouse model of experimental acute peritonitis induced by thioglycolate (TG) solution was used to study the protective anti-inflammatory effect of ATG against acute peritonitis and the relevant mechanism. Our results showed that, after 12 hours of TG treatment, ATG significantly reduced inflammatory cell infiltration in mouse tissues and inhibited the secretion and expression of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in mice. ATG significantly reduced the percentage of CD11b+ Ly6G+ neutrophils and F4/80+ macrophages in the spleen and peritoneal exudate. In addition, ATG significantly inhibited the expression of the chemokines CCL3 and CCL4 and the adhesion molecule CD62L on the surface of CD11b-positive monocytes. ATG was observed to inhibit the phosphorylation of p65 and p38 in LPS-stimulated RAW264.7 cells. In conclusion, ATG can improve the symptoms of TG-induced acute peritonitis through immune regulation. ATG can reduce the inflammatory response in TG-induced acute peritonitis in mice.

Tumor necrosis factor-α -308G/A and -238G/A polymorphisms are associated with increased risks of sepsis: evidence from an updated meta-analysis

Previous studies have reported the relationship between tumor necrosis factor-α (TNF-α) -308G/A and -238G/A polymorphisms and sepsis risk with inconsistent results. The aim of this study was to estimate the association of the two polymorphisms with risk of sepsis or sepsis-related mortality using a meta-analysis. PubMed, Embase, and Web of Science databases were searched up to June 20 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effect model. Twenty-six studies were included in this meta-analysis. Overall, an increased sepsis risk of TNF-α -308G/A was observed (GA vs GG: OR = 1.43, 95% CI: 1.07-1.92; GA/AA vs GG: OR = 1.42, 95% CI: 1.06-1.89). Subgroup analyses showed that the significant association was found in Asians (GA vs GG: OR = 1.63, 95% CI: 1.01-2.63) and adult patients. Similarly, an increased sepsis risk of TNF-α -238G/A was observed in overall and subgroup analyses. However, no significant association was found between TNF-α -308G/A and -238G/A polymorphisms and sepsis-related mortality. These findings indicate that both TNF-α -308G/A and -238G/A polymorphisms were associated with increased risks of sepsis but not sepsis-related mortality. Further studies with larger sample size are needed to confirm these results.

Neutrophil-Related Inflammatory Mediators in Septic Acute Respiratory Distress Syndrome

To disclose the participation of neutrophils in septic acute respiratory distress syndrome (ARDS), characteristics of various inflammatory mediators were examined in septic patients. Forty-seven gram-negative septic patients were divided into ARDS (n = 23) and non-ARDS (n = 24) groups at the transferred point to the intensive care unit. The mediators were measured simultaneously at the transferred point, and then subsequently on days 1, 3, and 5. At the transferred point, the ARDS group showed significantly higher levels of interleukin-8 (IL-8), macrophage inflammatory peptide-1-alpha (MIP-1-α), soluble intercellular adhesion molecule-1 (sICAM-1), and neutrophil elas-tase despite lower neutrophil counts compared to the non-ARDS group. The ARDS group sustained significantly higher levels of sICAM-1 until day 5 and neutrophil elas-tase until day 1 compare to the non-ARDS group. Furthermore, nonsurviving ARDS patients (n = 8) showed significantly higher levels of tumor necrosis factor-alpha, IL-6, IL-8, and IL-10 compared to surviving ARDS patients (n = 15) at the transferred point. In conclusion, neutrophil-related inflammatory mediators, IL-8, MIP-1-α, sICAM-1, and neutrophil elastase, appear to possibly participate in septic ARDS. Cytokines might also play an important role in the mortality of such cases.

Response to nutritional support and therapeutic approaches of amino acid and protein metabolism in surgical patients

The response to critical illness involves alterations in all aspects of metabolic control, favoring catabolism of body protein. In particular, body protein loss occurring as a result of the alteration of protein metabolism has been reported to be inversely correlated with the survival of critically ill patients. Despite the availability of various therapeutic modalities aiming to prevent loss of the body protein pool, such as total parenteral nutrition, enteral nutrition designed to provide excessive calories as a form of energy substrate, and protein itself, the loss of body protein cannot be prevented by any of these. Loss of the boyd protein store occurs as a consequence of the alteration of the intermediate metabolism that works for the production of energy substrate. This alteration of substrate metabolism may be linked to the alteration of protein metabolism. However, no specific factors regulating amino acid and protein metabolism have been identified. Thus, further investigations evaluating amino acid and protein metabolism are required to obtain better understanding of metabolic regulation in the body, which may lead to the development of novel and more effective therapeutic modalities for nutrition in the future.

Several Cytokines and Protein C Levels with the Apache II Scoring System for Evaluation of Patients with Sepsis

OBJECTIVE

We investigated whether determination IL-6, IL-8, IL-1beta and TNF-alpha at baseline, total protein C (PC) levels at time of admission and 48 hours after initiation could complement the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system to identify patients with sepsis, severe sepsis or septic shock for clinical outcome.

MATERIAL AND METHODS

The study was carried out prospectively. 60 consecutive patients with sepsis, severe sepsis or septic shock were included. Blood samples were obtained at baseline and 48 hours after initiation. Cytokines and PC levels in plasma were measured with an enzyme-linked immunoabsorbent assay (ELISA). APACHE II score was calculated on admission.

RESULTS

Baseline IL-6 levels and PC levels 48 hours after initiation were predictive of increased mortality (p=0.016, p=0.044 respectively). Baseline IL-6, IL-8 and TNF-alpha baseline levels correlate with the severity of physiologic insult, as determined by the APACHE II score. However, our multiple logistic regression analysis of these did not reveal any predictive value in combination with the APACHE II score.

CONCLUSION

Determination of baseline IL-6 and PC 48 hours after initiation were of predictive value for prognostic evaluation of septic patients, but did not significantly increase predictive power of the APACHE scoring system to identify patients with sepsis for fatal clinical outcome.

Molecular cloning of interleukin-1β, interleukin-8, and tumor necrosis factor-α of bighorn sheep (Ovis canadensis) and comparison with those of other species

The susceptibility to, and pathology induced by, Mannheimia haemolytica infection in bighorn sheep (BHS) and domestic sheep (DS) are distinctly different. Bighorn sheep are particularly susceptible to pneumonia caused by M. haemolytica, and the pneumonic lesions in infected BHS are more severe than those in DS. The molecular basis for this disparity has not been elucidated. Proinflammatory cytokines have been implicated in the pathogenesis of multiple lung diseases of humans and animals. It is possible that the enhanced pathology observed in the pneumonic lungs of M. haemolytica-infected BHS, in comparison to that of DS, is due to comparatively higher levels of proinflammatory cytokine expression in BHS. As the first step towards elucidating this concept, we have cloned and sequenced the cDNA encoding the cytokines interleukin-1β (IL-1β), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) of BHS. The cDNA of BHS IL-1β, IL-8, and TNF-α consists of 801, 306, and 705 base pairs encoding 266, 101, and 234 amino acids, respectively. The availability of cDNA encoding IL-1β, IL-8, and TNF-α of BHS should facilitate the elucidation of the role of these cytokines in the differential pathology induced by M. haemolytica infection in BHS and DS.

Induction of muscle weakness by local inflammation: an experimental animal model

OBJECTIVE AND DESIGN

The objective of this study was to characterize the response of skeletal muscle to a localized inflammation induced by the inflammatory agent casein.

METHODS

An inflammatory agent, casein, was injected into the right hindlimb and saline was injected into the left hindlimb of normal adult mice, once daily for six consecutive days. Inflammatory response was monitored by immunohistochemical labeling of leukocytes. Muscle protein levels were determined by electrophoresis and muscle function was determined by isometric force measurements.

RESULTS

Local inflammation was induced by casein in association with the accumulation of extensive neutrophils and macrophages in the soleus muscle. This local inflammation resulted in a shift in myosin heavy chain (MHC) isoform expression and a significant reduction in total MHC concentration in the soleus. Maximal twitch and tetanic forces were significantly reduced in the inflamed soleus. Contractile function in soleus was fully restored after two weeks of recovery, along with the restoration of protein concentration and the disappearance of inflammatory cells.

CONCLUSION

This study establishes a unique and robust model in which mechanisms of local inflammation induced muscle protein degradation, reduction of contractile force, and subsequent recovery from this condition can be further studied.

Clinical relevance of pharmacokinetics and pharmacodynamics in cardiac critical care patients

Pharmacokinetics is a discipline aimed at predicting the best dosage and dosing regimen for each single drug in order to ensure and maintain therapeutically effective concentrations at the action sites. In cardiac critical care patients, various pathophysiological conditions may significantly alter the pharmacokinetic behaviour of drugs. Gastrointestinal drug absorption may be erratic and unpredictable in the early postoperative period, and so patients may be unresponsive to oral therapy; thus the intravenous route should be preferred for life-saving drugs whenever feasible. Variations in the extracellular fluid content as a response to the trauma of surgery and the fluid load or significant drug loss through thoracic drainages may significantly lower plasma concentrations of extracellularly distributed hydrophilic antimicrobials (beta-lactams, aminoglycosides and glycopeptides). Drug metabolism may be altered by the systemic inflammatory response and/or multiple organ failure and/or drug-drug pharmacokinetic interactions that can potentially occur during polytherapy, especially in immunosuppressed cardiac transplant patients. Instability of renal function may promote significant changes in body fluid concentrations of renally eliminated drugs, even in a brief period of hours. Finally, the application of extracorporeal circulation by means of cardiopulmonary bypass may significantly alter the disposition of several drugs during the operation because of acute haemodilution, hypoalbuminaemia, hypothermia and/or adsorption to the bypass equipment. Accordingly, to avoid either overexposure and the consequent increased risk of toxicity or underexposure and the consequent risk of therapeutic failure in critically ill cardiac patients, the dosing regimens of several drugs are expected to be significantly different from those suggested for clinically stable patients. Additionally, therapeutic drug monitoring may be helpful in the management of drug therapy and should be routinely used to guide individualized dose adjustments for (i) immunosuppressants whenever cytochrome P450 3A4 isoenzyme inhibitors (e.g. macrolide antibacterials, azole antifungals) or inducers (e.g. rifampicin [rifampin]) are added to or withdrawn from the regimen; and (ii) glycopeptide and aminoglycoside antibacterials whenever haemodynamically active agents (such as dopamine, dobutamine and furosemide [frusemide]) are added to or withdrawn from the regimen, and also whenever significant changes of haemodynamics and/or of renal function occur.

A comparison of the effect of total intravenous anaesthesia with propofol and remifentanil and inhalational anaesthesia with isoflurane on the release of pro- and anti-inflammatory cytokines in patients undergoing open cholecystectomy

The aim of the study was to investigate the effects of two anaesthetic techniques (total intravenous technique vs. inhalational technique) on changes in pro- and anti-inflammatory cytokine levels during open cholecystectomy. Forty ASA PS I-II patients undergoing open cholecystectomy were randomly assigned to two groups. Group R received total intravenous anaesthesia with propofol and remifentanil and group F received balanced inhalational anaesthesia with isoflurane. The plasma levels of tumour necrosis factor-alpha (TNF-alpha), interleukin IL-6 and interleukin IL-10 were measured during and after surgery. The pro-inflammatory cytokine levels (TNF-alpha and IL-6) and the anti-inflammatory cytokine (IL-10) showed a significant increase in their concentrations compared with pre-induction levels in both groups (P < 0.05). By the end of anaesthesia and surgery, TNF-alpha and IL-6 were significantly lower in group R than in group F (P < 0.05). At the end of anaesthesia and 12 hours postoperatively, IL-10 levels in group R were higher than in group F (P < 0.05). These findings suggest that total intravenous anaesthesia using propofol and remifentanil suppresses the inflammatory response caused by surgery to a greater extent than a balanced inhalation technique using isoflurane.

Costs and length of stay associated with antimicrobial resistance in acute kidney injury patients with bloodstream infection

INTRODUCTION

Antimicrobial resistance negatively impacts on prognosis. Intensive care unit (ICU) patients, and particularly those with acute kidney injury (AKI), are at high risk for developing nosocomial bloodstream infections (BSI) due to multi-drug-resistant strains. Economic implications in terms of costs and length of stay (LOS) attributable to antimicrobial resistance are underevaluated. This study aimed to assess whether microbial susceptibility patterns affect costs and LOS in a well-defined cohort of ICU patients with AKI undergoing renal replacement therapy (RRT) who developed nosocomial BSI.

METHODS

Historical study (1995-2004) enrolling all adult RRT-dependent ICU patients with AKI and nosocomial BSI. Costs were considered as invoiced in the Belgian reimbursement system, and LOS was used as a surrogate marker for hospital resource allocation.

RESULTS

Of the 1330 patients with AKI undergoing RRT, 92 had microbiologic evidence of nosocomial BSI (57/92, 62% due to a multi-drug-resistant microorganism). Main patient characteristics were equal in both groups. As compared to patients with antimicro-4 bial-susceptible BSI, patients with antimicrobial-resistant BSI were more likely to acquire Gram-positive infection (72.6% vs 25.5%, P<0.001). No differences were found neither in LOS (ICU before BSI, ICU, hospital before BSI, hospital, hospital after BSI, and time on RRT; all P>0.05) or hospital costs (all P>0.05) when comparing patients with antimicrobial-resistant vs antimicrobial-susceptible BSI. However, although not statistically significant, patients with BSI caused by resistant Gram-negative-, Candida-, or anaerobic bacteria incurred substantial higher costs than those without.

CONCLUSION

In a cohort of ICU patients with AKI and nosocomial BSI undergoing RRT, patients with antimicrobial-resistant vs antimicrobial-susceptible Gram-positive BSI did not have longer hospital stays, or higher hospital costs. Patients with resistant "other" (i.e. Gram-negative, Candida, or anaerobic) BSI were found to have a distinct trend towards increased resources use as compared to patients with susceptible "other" BSI, respectively.

Pulmonary hypertension due to unknown causes in liver resection

A 16-year-old male underwent transcatheter arterial embolization against a large hepatic tumor, and was subsequently scheduled for removal of the tumor. Sudden hypotension and tachycardia were observed on removal of the tumor. Massive bleeding or obstruction of the inferior vena cava was expected to develop, but this did not occur because of simultaneous pulmonary hypertension (PH). The development of acute PH due to pulmonary vasoconstriction was suspected. Milrinone and prostaglandin E1 were effective. The same type of PH was again observed during manipulation of the residual portion of the liver. The acute PH was reproducible each time the liver was manipulated, which could suggest that this series of PH was specifically related to the hepatic lesion. A necrotic hepatic lesion might play an important role in disturbing the pulmonary circulation and causing the development of acute PH.

The changes and effects of the plasma levels of tumor necrosis factor after coronary artery bypass surgery with cardiopulmonary bypass

BACKGROUND

Systemic inflammatory response after cardiopulmonary bypass (CPB) is thought to result from contact of cellular and humoral blood components with the synthetic material of the extracorporeal circulation system, leukocyte and endothelial activation caused by ischemia and reperfusion or endotoxins, or by surgical trauma. Proinflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8, play an important role in the inflammatory processes after CPB and may induce cardiac and lung dysfunction. This study examined the association of the increased release of TNF-alpha with increased myocardial and lung injury after CPB and its effect on postoperative morbidity.

METHODS

Twenty patients undergoing elective coronary artery bypass grafting (CABG) were included in the study. Four intervals of blood samples were obtaind and assayed for TNF-alpha, white blood cells, C-reactive protein, and erythrocyte sedimentation rate.

RESULTS

All patients were similar with regards to preoperative and intraoperative characteristics, and clinical outcomes were comparable. Plasma levels of TNF-alpha rose more than 20 pg/mL during and after standard CPB in 13 patients (group 1), whereas the plasma levels were less than 20 pg/mL in the remaining 7 patients (group 2) after CPB. The patients of the first group had increased mediastinal bleeding and prolonged intubation time compared to the other group.

CONCLUSION

Cardiac surgery and CPB stimulate systemic inflammatory processes characterized clinically by changes in cardiovascular and pulmonary function. Significant morbidity is rare, but most patients undergoing CPB exhibit some degree of organ dysfunction due to activation of the inflammatory response. This study showed that there were no major clinical results of TNF-alpha and white blood cell level, C-reactive protein, and erythrocyte sedimentation rate after the operation, but in patients with a high level of TNF-alpha (more than 20 pg/mL), increased mediastinal bleeding and longer orotracheal intubation time was observed. A number of studies have shown the increase of TNF-alpha after open heart surgery; however, the specific level of TNF-alpha was first described as 20 pg/mL in this study.

Effect of Ligustrazine on liver injury after burn trauma

This study was designed to investigate the effect of Ligustrazine on burn-induced liver injury as well as the activation of nuclear factor kappaB (NF-kappaB) in severely burned rats. Sprague-Dawley rats were divided into three groups: (1) sham group, rats who underwent sham burn; (2) control group, rats given third-degree burns over 30% total body surface area (TBSA) and lactated Ringer solution for resuscitation; (3) Ligustrazine group, rats given burn and lactated Ringer's solution with Ligustrazine inside for resuscitation. Liver injury was assessed at 24 h post-burn by serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), as well as liver wet/dry weight ratio. Liver myeloperoxidase (MPO) activity was also analyzed. Hepatic NF-kappaB activity was examined by electrophoretic mobility shift assay (EMSA). Burn results in hepatic dysfunction and increased hepatic NF-kappaB activity, elevated liver wet/dry ratio and hepatic MPO activity. Ligustrazine inhibited these changes and alleviated burn-mediated hepatic dysfunction. The data indicated that Ligustrazine has a protective effect on burn-induced liver injury and possible mechanism may be attributed to its inhibitory action on the activation of NF-kappaB following burn trauma.

Sepsis: Still Going Strong

Sepsis definitions help to understand and to better define a group of syndromes secondary to an infectious insult. The hierarchical continuum of inflammatory response leads, in absence of counterregulatory forces, to organ damage and death. We have learned first the response to treatment and afterwards the pathophysiology behind it. This lesson has, of course, not always been followed by a reduction of mortality. The definition, natural history, risk factors, diagnoses, and treatment based on emerging evidence will help to improve patient outcomes and mortality. Standardized care seems to improve survival, and validation and further evaluation of this care is necessary to maximize resources and outcomes.

Ligustrazine attenuates acute lung injury after burn trauma

Acute lung injury is a common complication in patients with extensive burns in which the burned area exceeds 30% of the total body surface area (TBSA). This study was undertaken to evaluate the effect of Ligustrazine on burn-induced lung injury as well as the release of interleukin-8 (IL-8) in rats to characterize the role of Ligustrazine and IL-8 in lung injury after burn trauma. Sprague-dawley rats were divided into three groups: (1) sham group, rats who underwent sham burn; (2) control group, rats given third-degree burns over 30% TBSA and lactated Ringer solution for resuscitation; and (3) Ligustrazine group, rats given burn injury and lactated Ringer's solution with Ligustrazine inside for resuscitation. Pulmonary injury was assessed at 24 h by pulmonary capillary permeability determined with fluorescein isothiocyanate-labeled albumin and lung histologic analysis, and lung myeloperoxidase (MPO) activity as well as lung wet/dry weight ratio. The IL-8 levels were measured in serum by enzyme-linked immunosorbent assay. These studies showed that burn trauma results in increased pulmonary leakage permeability and lung wet/dry ratio, elevated serum IL-8 levels and MPO activity, and worsened histologic condition. Ligustrazine inhibited these changes, prevented burn-mediated lung injury, and the production of IL-8. This will likely provide further evidence for ligustrazine as a therapeutic strategy in burn-induced lung injury.

Cytokine upregulation of surface antigens correlates to the priming of the neutrophil oxidative burst response

BACKGROUND

Neutrophil activation is strongly related to organ dysfunction that occurs during systemic inflammatory responses. The aim of our study was to analyze the oxidative burst response in correlation to the up- and downregulation of N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) receptors and the surface antigens CD11b, CD62L, and CD66b as potential surrogate markers of the degree of neutrophil priming for an increased oxidative burst response induced by proinflammatory cytokines.

METHODS

Blood was taken from healthy donors. Neutrophils were pretreated with cytokines (interleukin [IL]-1beta, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNFalpha]; 0.01-10 ng/ml) and stimulated with fMLP (100 nM) in vitro. Functional and phenotypical parameters were quantified flow cytometrically.

RESULTS

The oxidative burst response increased after priming with 0.1 ng/ml TNFalpha, 1 ng/ml GM-CSF, or 10 ng/ml IL-8. Upregulation of fMLP receptors, CD11b, and CD66b and downregulation of CD62L showed a close correlation to the oxidative burst response. Altered expression of these parameters partly reached significance at lower cytokine concentrations in comparison with the oxidative burst. IL-1beta and IL-6 had no effect.

CONCLUSIONS

Our results showed that the expression of phenotypical parameters closely correlates with functional parameters in human neutrophils. Thus an up- or downregulation of antigens such as CD11b or CD62L reflects cytokine-induced functional changes.

Colloidal gold particles as a new in vivo marker of early acute lung injury

Permeability of the endothelial barrier to large molecules plays a pivotal role in the manifestation of early acute lung injury. We present a novel and sensitive technique that brings microanatomical visualization and quantification of microvascular permeability in line. White New Zealand rabbits were anesthetized and ventilated mechanically. Rabbit serum albumin (RSA) was labeled with colloidal gold particles. We quantified macromolecular leakage of gold-labeled RSA and thickening of the gas exchange distance by electron microscopy, taking into account morphology of microvessels. The control group receiving a saline solution represented a normal gas exchange barrier without extravasation of gold-labeled albumin. Infusion of lipopolysaccharide (LPS) resulted in a significant displacement of gold-labeled albumin into pulmonary cells, the lung interstitium, and even the alveolar space. Correspondingly, intravital fluorescence microscopy and digital image analysis indicated thickening of width of alveolar septa. The findings were accompanied by a deterioration of alveolo-arterial oxygen difference, whereas wet/dry ratio and albumin concentration in the bronchoalveolar lavage fluid failed to detect that early stage of pulmonary edema. Inhibition of the nuclear enzyme poly(ADP-ribose) synthetase by 3-aminobenzamide prevented LPS-induced microvascular injury. To summarize: colloidal gold particles visualized by standard electron microscopy are a new and very sensitive in vivo marker of microvascular permeability in early acute lung injury. This technique enabling detailed microanatomical and quantitative pathophysiological characterization of edema formation can form the basis for evaluating novel treatment strategies against acute lung injury.

Simultaneous onset of acute inflammatory response, sepsis-like symptoms and intestinal mucosal injury after cancer chemotherapy

Chemotherapy is 1 method for the treatment of cancer, but serious side effects can sometimes limit the dosage given. Mild fever and diarrhea are common side effects of cancer chemotherapy. Gastrointestinal injury induced by chemotherapeutic agents may result in bacterial/endotoxin translocation from the gut into the systemic circulation. An experimental study was therefore conducted to clarify the effect of systemic chemotherapeutic agents on gastrointestinal barrier function. Male Wistar rats were divided into a 5-fluorouracil (5-FU) group (100 mg/kg/day for 4 days; n = 27) and a control group (n = 5). All rats were fasted and central venous catheterization was performed for total parenteral nutrition and blood sampling. Intestinal tissue was also sampled for pathological examination. Plasma levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha) were determined by ELISA, bacterial translocation was quantified by lymph node culture and plasma endotoxin content of portal blood was measured by the Limulus-amebocyte-lysate test. In the 5-FU group on day 4, a proportion of rats exhibited severe watery diarrhea (73.9%) and occasional vomiting (86.2%). The levels of plasma TNFalpha and IL-6 were seen to increase, peaking at day 6 (IL-6, 350.0 +/- 67.8 pg/ml; TNFalpha, 26.1 +/- 3.2 pg/ml). The pathological findings also changed on day 4. On day 6, 90% of the rats in the 5-FU group showed dramatic sepsis-like manifestations, whereas the control group did not. Within the 5-FU group, only at day 6 was bacterial translocation in the rat mesenteric lymph nodes or significantly elevated levels of endotoxin evident. These results suggest that bacterial/endotoxin translocation might cause sepsis-like manifestations after systemic chemotherapy.

Penetration of fosfomycin into inflammatory lesions in patients with cellulitis or diabetic foot syndrome

We investigated the distribution of the broad-spectrum antibiotic fosfomycin in infected soft tissue of patients with uncomplicated cellulitis of the lower extremities or diabetic foot infection using in vivo microdialysis. Our findings suggest that fosfomycin exhibits good and similar penetration into the fluid in the interstitial space in inflamed and noninflamed soft tissue in patients.

Response of in vivo protein synthesis in T lymphocytes and leucocytes to an endotoxin challenge in healthy volunteers

In vivo determination of protein synthesis in immune cells reflects metabolic activity and immunological activation. An intravenous injection of endotoxin to healthy volunteers was used as a human sepsis model, and in vivo protein synthesis of T lymphocytes and leucocytes was measured. The results were related to plasma concentrations of selected cytokines, peripheral cell counts and subpopulations of immune cells. The subjects (n = 8 + 8) were randomized to an endotoxin (4 ng/kg) or a saline group. In vivo protein synthesis was determined twice: before and 1-2.5 h after the endotoxin/saline injection. Protein synthesis decreased in isolated T lymphocytes, but increased in leucocytes. Plasma levels of TNF-alpha, IL-8, IL-6, IL-1 ra and IL-10 were elevated, whereas IL-2 and IFN-gamma, produced predominantly by T lymphocytes, did not change in response to endotoxin. Neutrophils increased, whereas lymphocytes and monocytes decreased 2.5 h after the endotoxin injection. Flow cytometry revealed a drop in total CD3+ T lymphocytes and CD56+ natural killer cells, accompanied by an increase in CD15+ granulocytes. In summary, in vivo protein synthesis decreased in T lymphocytes, while the total leucocyte population showed a concomitant increase immediately after the endotoxin challenge. The changes in protein synthesis were accompanied by alterations in immune cell subpopulations and in plasma cytokine levels.

Adult respiratory distress syndrome in the tropics

Today ARDS is more frequently recognized and managed in tropical countries, although published data from most locations is meager. The spectrum of disorders causing ARDS in tropical countries includes virtually all conditions encountered in the West. Additionally, tropical infections and other disorders are seen far more commonly. In particular, malaria and TB are important infections that predispose patients to ARDS in the tropics. Both of these illnesses give lead to severe forms of disease, such as falciparum malaria, acute miliary TB or TB bronchopneumonia, and may cause ARDS. Awareness of the complications helps in early recognition and differential diagnosis from several similar manifestations. Although earlier reports painted a gloomy picture of the outcome of these patients in general--mainly due to financial and logistic constraints--the scenario is improving quickly with better and wider availability of newer diagnostic and management tools.

Ascorbic acid and N-acetylcysteine improve in vitro the function of lymphocytes from mice with endotoxin-induced oxidative stress

Oxidative stress associated with reactive oxygen species (ROS) and cytokines produced by immune cells, which is involved in septic shock caused by endotoxin, can be controlled to a certain degree by antioxidants with free radical scavenging action. N-acetylcysteine (NAC) and ascorbic acid (AA) are ROS scavengers that improve the immune response, and modulate macrophage function in mice with endotoxin-caused oxidative stress. Therefore, we have investigated the in vitro effects of these antioxidants on the functions of lymphocytes from BALB/c mice with lethal endotoxic shock caused by intraperitoneal injection of E. coli lipopolysaccharide (LPS) (100 mg/kg). Adherence to tissues and chemotaxis (the earliest two functions of lymphocytes in the immune response), as well as ROS levels and TNF alpha production were determined in the presence or absence of NAC or AA (0.001, 0.01, 0.1, 1 and 2.5 mM) in lymphocytes from peritoneum, axillary nodes, spleen and thymus obtained at several times (2, 4, 12 and 24 hours) after LPS injection. Endotoxic shock decreases the chemotaxis of lymphocytes from all the above localizations and increases their adherence, TNF alpha and ROS production. These changes in lymphocyte function were counteracted by NAC and AA, bringing these functions to values near those of control animals. Our data suggest that lymphocytes are important targets of endotoxins contributing to oxidative stress by septic shock, and that antioxidants can preserve the function of lymphocytes, preventing the homeostatic disturbances caused by endotoxin.

Cytokine Responses in Low-Risk Coronary Artery Bypass Surgery

Inflammatory cytokines have been implicated in myocardial function, severe congestive heart failure and sepsis. The present study tested the hypothesis that cytokine levels are elevated after low-risk coronary artery bypass surgery (CABG), and that they may be associated with postoperative cardiac dysfunction. Twenty male patients undergoing elective CABG in cardiopulmonary bypass (CPB) were studied. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, IL-8, and IL-10 were measured before anesthesia induction, 5 minutes after, and 1, 4, and 20 hours after reperfusion to the myocardium. Levels of the MB isoenzyme of creatine kinase (CK-MB) were measured postoperatively. Hemodynamic data were also recorded. Myocardial ischemia was followed by an increase in the plasma levels of IL-6, IL-8, and IL-10. The duration of IL-6 response lasted throughout the postoperative period studied. Plasma cytokine levels at 1 hour after reperfusion correlated with the maximum CK-MB value (IL-6, r = 0.587, p < 0.01; IL-8, r = 0.460, p < 0.05; IL-10, r = 0.570, p < 0.05). Higher plasma IL-6 and IL-8 levels after reperfusion tended to be linked with lower cardiac index. The present results confirm that the levels of inflammatory cytokines IL-6, IL-8, and IL-10 are elevated after CABG. Increased systemic pro-inflammatory cytokine levels were partially associated with postoperative myocardial dysfunction. </hea

Surgery and intensive care procedures affect the target site distribution of piperacillin

OBJECTIVE

Therapeutic failure of antibiotic therapy has been ascribed to pharmacokinetic alterations in compromised patient populations. The present study, therefore, aimed at examining the influences of cardiac surgery and intensive care procedures on the postoperative target site distribution of piperacillin. For this purpose, the penetration of piperacillin to the interstitial space fluid, the relevant target site for most bacterial infections, was compared between patients after aortic valve replacement and healthy volunteers.

DESIGN

Comparative study in two study populations.

SETTING

The intensive care unit and research ward of a university hospital.

PATIENTS

The study population included six otherwise healthy patients scheduled to undergo aortic valve replacement and a control group of six healthy male volunteers.

INTERVENTIONS

After the administration of a single i.v. infusion of 4.0 g piperacillin, free piperacillin concentrations were measured in the interstitium of skeletal muscle and subcutaneous tissue by in vivo microdialysis and in venous serum. Piperacillin concentrations were assayed with reversed phase high-performance liquid chromatography.

MEASUREMENTS AND MAIN RESULTS

Interstitial piperacillin concentrations in muscle and subcutaneous adipose tissue were significantly lower in patients compared with volunteers with the area under the curve for the interstitium/area under the curve for serum concentration ratios ranging from 0.25 to 0.27 and from 0.43 to 1.22 in patients and volunteers, respectively (p < .05 between groups). The terminal elimination half-life was markedly prolonged in patients, leading to a concomitant increase in t > minimal inhibitory concentration (MIC) values, the relevant surrogate for therapeutic success of therapy with beta-lactam antibiotics, for strains with MIC50 <4 microg/mL. For strains with MIC50 >20 microl/mL, however, inadequate target site concentrations were attained in the patient population.

CONCLUSIONS

During the postoperative and intensive care periods, target site concentrations of piperacillin are markedly altered and decreased. This may also be true for other antibiotic agents and may have clinical implications in that current dosing guidelines may result in inadequate target site concentrations for high-MIC strains. Conceivably, this could lead to therapeutic failure in some patients.

Serum albumin as a predictor of survival in HIV-infected women in the Women's Interagency HIV study

BACKGROUND

The level of serum albumin is associated with mortality in a wide variety of chronic diseases. However, few studies have examined the relationship between serum albumin and survival in HIV-1 infection.

OBJECTIVES

To determine whether the serum albumin level is associated with survival in HIV-1 infected women.

DESIGN

Prospective cohort study. Patients were interviewed and examined at 6 month intervals.

SETTING

A North American multi-institutional cohort of HIV-infected women from five geographical areas.

PARTICIPANTS

A total of 2056 HIV-infected women at various stages of disease.

MEASUREMENTS

Mortality during the first 3 years of follow-up. The relative risk of death by serum albumin level was estimated using a proportional hazards ratio adjusted for CD4 cell count, HIV-1-RNA level and other relevant covariates.

RESULT

Three year mortality for women in the lowest serum albumin category (< 35 g/l) was 48% compared with 11% in the highest category (> or = 42 g/l; P < 0.001). The adjusted relative hazard (RH) of death was 3.1 times greater for those in the lowest albumin category (P < 0.01). The excess risk associated with lower serum albumin levels remained when subjects with moderate to severe immunosuppression and abnormal kidney and liver function were excluded (P < 0.01).

CONCLUSION

The baseline serum albumin level is an independent predictor of mortality in HIV-1-infected women. The serum albumin level may be a useful additional marker of HIV-1 disease progression, particularly among asymptomatic women with little or no evidence of immunosuppression.

Endogenous mediators in emergency department patients with presumed sepsis: are levels associated with progression to severe sepsis and death?

STUDY OBJECTIVE

We sought to determine whether levels of the endogenous mediators tumor necrosis factor (TNF)-alpha, interleukin (IL) 6, and nitric oxide (NO) measured in patients with presumed sepsis (systemic inflammatory response syndrome [SIRS] and infection) are different than levels in patients with presumed noninfectious SIRS, whether levels are associated with septic complications, and whether there are potential relationships between mediators.

METHODS

A prospective, observational tricenter study of a convenience sample of adults presenting to the emergency department meeting Bone's criteria for SIRS (any combination of fever or hypothermia, tachycardia, tachypnea, or WBC count aberration) was performed. Mediator levels were determined and associated with deterioration to severe sepsis (hypotension, hypoperfusion, or organ dysfunction) and death in subjects admitted to the hospital with presumed sepsis.

RESULTS

One hundred eighty subjects with SIRS were enrolled and classified into 3 groups: group 1 (SIRS, presumed infection, admitted; n=108), group 2 (SIRS, presumed infection, discharged; n=27), and group 3 (SIRS, presumed noninfectious, admitted; n=45). Group 1 TNF-alpha and IL-6 levels were significantly higher than those found in the other groups. NO levels for groups 1 and 2 were significantly lower than those for group 3. TNF-alpha and IL-6 levels were higher in the group 1 subjects who had bacteremia or progressed to severe sepsis or death. NO levels were not associated with these outcomes.

CONCLUSION

ED patients admitted with presumed sepsis have elevated cytokine levels compared with patients with sepsis who are discharged and with those patients with presumed noninfectious SIRS. An association appears to exist between cytokines and subsequent septic complications in these patients. The importance of these measures as clinical predictors for the presence of infection and subsequent septic complications needs to be evaluated.

Inducible expression of the kinin B1 receptor in the endotoxemic heart: mechanisms of des-Arg9bradykinin-induced coronary vasodilation

1 We have investigated the role of kinin B1 receptor induction in the endotoxemic rat heart and elucidated the mechanisms underlying B1 receptor-mediated coronary vasodilation. We also investigated the role of these receptors in endotoxin-induced hypotension. 2 Endotoxin treatment induced cardiac B1 receptor mRNA expression and promoted a coronary vasodilation response to des-Arg9bradykinin (DABK; ED50 = 149.4 pmol, n = 9) ex vivo peaking at 6 h. The B1 receptor antagonist des-Arg9-[Leu8]-BK (DALBK, 30 nM) significantly (P<0.05) inhibited the DABK-induced response (pA2 = 8.4, n = 5) whilst HOE140 (B2 receptor antagonist, 10 nM) was inactive (n = 4). 3 Removal of the endothelium or infusion with indomethacin (5 microM), but not L-NAME (300 microM) or ODQ (1 microM), inhibited (>85%, P<0.05, n = 5) the DABK-induced response. DABK caused a dose-dependent release of the prostacyclin metabolite, 6-keto-PGF1a (Emax = 0.3 ng ml-1, n = 6). 4 In vitro perfusion of hearts with endotoxin (1 microg ml-1, n = 6) or interleukin-1beta (5 ng ml-1, n = 6) induced B1 receptor mRNA expression and promoted a time-dependent vasodilation response to DABK. 5 Endotoxin treatment (6 h) in vivo promoted a hypotensive response to DABK (ED50 = 29.7 nmol kg-1, n = 10) which was antagonised by DALBK (3-6 nmol kg-1 min-1, P<0.05, n = 7). DALBK (3 nmol kg-1 min-1) and des-Arg10HOE140 (B1 receptor antagonist, 30 nmol kg-1 min-1) produced a 5.3% (n = 6, P<0.05) and 8.8% (n = 5, P<0.05) reversal, respectively, of endotoxin-induced hypotension. 6 In summary, we have shown that in endotoxemia activation of B1 receptors causes coronary vasodilation via endothelial prostacyclin release. Additionally, B1 receptor antagonists partially reversed endotoxin-induced hypotension. Therefore activation of B1 receptors may have a role to play in the vascular changes associated with endotoxemia.

Inflammatory response after myocardial revascularization with or without cardiopulmonary bypass

BACKGROUND

Tumor necrosis factor-alpha has been implicated in complications seen after cardiac operations with cardiopulmonary bypass. The release of tumor necrosis factor-alpha and its possible effects were studied in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass.

METHODS

Twenty patients were studied, 10 with (group 1) and 10 without cardiopulmonary bypass (group 2). Serial blood samples were obtained before, during, and up to 48 hours after operation. Circulating tumor necrosis factor-alpha levels, leukocyte counts, and erythrocyte sedimentation rates were measured. Hemodynamic variables (blood pressure and heart rate), temperature, orotracheal intubation time, postoperative bleeding, and inotropic drug requirements were compared.

RESULTS

Serum levels of tumor necrosis factor-alpha were detected in 6 patients (60%) in group 1 and none in group 2. The patients in group 1 had more hypotension than those in group 2 (7.4 +/- 1.0 mm Hg versus 8.5 +/- 0.7 mm Hg), required more inotropic drugs (8 patients versus 1 patient), and had a higher heart rate (114 +/- 8 beats per minute versus 98 +/- 10 beats per minute), a higher temperature (37.1 degrees +/- 0.5 degrees C versus 36.6 degrees +/- 0.3 degrees C), increased postoperative bleeding (820 +/- 120 mL versus 360 +/- 84 mL), a longer orotracheal intubation time (13.6 +/- 2.2 hours versus 9.3 +/- 1.4 hours), and a more pronounced leukocytosis.

CONCLUSIONS

Cardiopulmonary bypass induces the whole-body inflammatory response through the release of tumor necrosis factor alpha, resulting in adverse systemic effects.

Inflammatory mediators in bronchoalveolar lavage fluid and plasma in leukocytopenic patients with septic shock-induced acute respiratory distress syndrome

OBJECTIVES

The acute respiratory distress syndrome (ARDS) is a frequent complication of severe sepsis and a major cause of death in patients with hematologic malignancy during chemotherapy-induced leukocytopenia. Inflammatory mediators are important modulators of host response to injury and have been found to be increased in the bronchoalveolar lavage (BAL) fluid of nonleukocytopenic patients with ARDS. Since inflammatory cytokines in plasma of nonleukocytopenic patients seem to be efficient predictors of the course of ARDS, we examined this hypothesis in leukocytopenic patients with septic shock-induced ARDS.

DESIGN

Prospective, observational study.

SETTING

Intensive care unit (ICU) of a university hospital.

PATIENTS

Nineteen patients with leukocytopenia (white blood cell count of <1/nL) following cytoreductive chemotherapy for malignant disorders and severe sepsis with shock-induced ARDS (Murray score of >2.5).

INTERVENTIONS

BAL and plasma sampling and ICU management.

MEASUREMENTS AND MAIN RESULTS

The proinflammatory cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8 were measured in the BAL aspirates and in plasma samples, both obtained within 18 hrs after onset of ARDS. Hemodynamic and oxygen metabolism data were measured immediately before plasma samples were taken and BAL was performed. Of the 19 patients studied, nine patients responded to ICU treatment (e.g., mechanical ventilation as indicated by PaO2/FIO2, FIO2, shunt volume, and course of pulmonary infiltrates), whereas ten patients did not respond. BAL cytokine concentrations were significantly increased in nonresponders in comparison with responding patients (TNF-alpha, p = .021; IL-6, p = .008; IL-8, p = .019). In contrast, we did not observe any differences between the groups in terms of plasma cytokine concentrations.

CONCLUSION

Determination of cytokine concentrations in BAL samples may be useful for evaluation of severity and course of ARDS in leukocytopenic patients, whereas measurement of plasma cytokines is not helpful.

The significance of endotoxin release in experimental and clinical sepsis in surgical patients--evidence for antibiotic-induced endotoxin release?

Sepsis and peritonitis remain a serious challenge for surgical patients, despite improvement in surgical therapy and intensive care and the introduction of new powerful antibiotics. Recent in vitro studies revealed the potential of certain antibiotics, e.g. penicillin-binding protein (PBP) 3-specific antibiotics, to cause antibiotic-induced endotoxin release. Other types of antibiotics, e.g., PBP 2-specific antibiotics, were associated with no or less endotoxin release. Further in vitro experiments and investigations in animals support the hypothesis of antibiotic-induced endotoxin release, but there is little clinical evidence. The clinical significance of endotoxin is subject of open dispute with many pro's and contra's. Endotoxin, although an important trigger, may not be the only factor to induce cytokine release, e.g., peptidoglycans were able to stimulate cells to release cytokines. Gram-positive pathogens have gained more importance in clinical sepsis and may not be sufficiently reflected in current clinical studies. The hypothesis that neutralization of endotoxin and pro-inflammatory cytokines is beneficial in sepsis was seriously challenged by the results of recent clinical and experimental studies. The better understanding of mechanisms in endotoxin-induced cell activation and cell, cell-receptor and soluble receptor interactions led to new treatment options. Recent reports on the complex pathogenesis of peritonitis and the detection of pathogen-related factors with intraperitoneal immune response may have implications on clinical studies investigating the potential of new compounds and the effect of antibiotics on endotoxin release. However, only few reports are available on the clinical significance of antibiotic-induced endotoxin release, and association of endotoxin release with pathogens, mortality or alteration of physiological parameters were not observed. With regard to the particulars of these studies, e.g., a small study population or low mortality rate, mortality may not be an ideal outcome parameter for these studies. There is clinical evidence for antibiotic-induced endotoxin release. However, the need for well-designed and performed studies using newly developed monitoring devices in intensive care therapy is obvious.

Inflammatory mediators in BAL fluid as markers of evolving pneumonia in leukocytopenic patients

STUDY OBJECTIVES

Pneumonia during chemotherapy-induced leukocytopenia is a major cause of overall treatment failure in patients with hematologic malignancies. To improve outcome in these high-risk patients, early diagnosis of pulmonary infiltrates and institution of adequate antimicrobial treatment are mandatory. To identify patients with evolving pneumonia, we have prospectively studied the prognostic value of cytokine and complement measurements in early BAL samples from febrile leukocytopenic patients.

DESIGN

Prospective, comparative study.

SETTING

Hematology/oncology section of a university hospital.

PATIENTS

Twenty-one patients with leukocytopenia (WBC count < 1.000/microL) following cytoreductive chemotherapy for malignant disorders.

INTERVENTION

Early BAL sampling primarily for microbiologic diagnostic purposes.

MEASUREMENTS AND RESULTS

Proinflammatory cytokines and activated complement components were measured in the BAL aspirates and the results were related to the prevalence or subsequent evolution of overt pneumonia. Of the 21 patients studied, 10 patients presented with overt pneumonia at BAL sampling (group A), 5 patients developed objective signs of pneumonia 3 to 5 days after BAL (group B), and 6 patients remained free of pneumonia during follow-up (group C). In comparison with group C, patients in groups A and B both had distinctly elevated bronchoalveolar levels of tumor necrosis factor-alpha, interleukin-6, granulocyte colony-stimulating factor, C3a, and C5a.

CONCLUSIONS

Cytokine and complement determinations in early BAL samples may aid in the identification of febrile leukocytopenic patients with evolving pneumonia 3 to 5 days prior to the manifestation of diagnostic clinical and radiographic signs.

Association of serum albumin and mortality risk

Reduced levels of serum albumin concentration, a routine blood test, within the "normal" range have been reported to be associated with mortality risk. The literature is reviewed, with a focus on cohort studies meeting specified criteria, and findings are summarized. In studies of many populations, comprising healthy subjects and patients with acute or chronic illness, serum albumin concentration is inversely related to mortality risk in a graded manner over its entire range; the estimated increase in the odds of death ranges from 24% to 56% for each 2.5 g/l decrement in serum albumin concentration. The association predicts overall and cause-specific mortality including cardiovascular mortality. It is likely that albumin concentration is a highly sensitive indicator of preclinical disease and disease severity. A direct protective effect of the albumin molecule is suggested by the persistence of the association after adjustment for other known risk factors and preexisting illness, and after exclusion of early mortality. Although biologically plausible, there is no direct evidence for this hypothesis. Serum albumin concentration is an independent predictor of mortality risk and could be useful in the quantification of risk in a broad range of clinical and research settings.

Should continuous renal replacement therapy be used for 'non-renal' indications in critically ill patients with shock?

Accumulating experience with the use of continuous renal replacement therapy (CRRT) in critically ill patients with acute renal failure suggests that these treatment modalities have distinct advantages relative to conventional dialysis in terms of solute clearances, fluid removal and hemodynamics, which may translate in improved renal and patient outcome. Recent data point to a possible beneficial effect of CRRT on the clinical course, independent from an impact on fluid balance, in critically ill patients with shock which is attributed to the continuous elimination of inflammatory mediators from the circulation. This has raised the question as to whether CRRT might be used for 'non-renal' indications such as the systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). In some animal models of experimental septic and non-septic shock, (short-term) hemodialysis and hemofiltration were found to improve hemodynamics and/or gas exchange. However, data were inconsistent and the clinical relevance questionable. Observations from both uncontrolled and controlled clinical studies (comprising only a small number of patients) support the hypothesis that CRRT may exert beneficial effects on the clinical course in critically ill patients with SIRS and MODS, independent from volume removal. Although several mediators known to play a role in the development of SIRS/MODS may pass hemofiltration membranes, quantitative data on the extent of its extracorporeal clearance relative to the production rate and endogenous clearance is often lacking. In addition, this aspecific elimination with CRRT may also effect levels of anti-mediators, which may be harmful. Ultrafiltrate properties include depression of cardiac performance, induction of proteolysis and immunosuppressive activity suggesting that water-soluble factors responsible for these deleterious effects are removed from the circulation by convection. However, no significant survival advantage has yet been shown for critically ill patients with SIRS/MODS when treated with CRRT as an adjunct to conventional therapy. Only prospective controlled studies of appropriate sample size, which requires a multicenter approach, might answer the question whether use of CRRT may alter the clinical course and outcome in critically ill patients with SIRS and MODS. Until such studies are performed, the rationale for the use of CRRT in the absence of conventional indications for dialytic support remains unproven.

Effect of hemocarboperfusion on organ blood flow and survival in porcine endotoxic shock

OBJECTIVE

To evaluate the effects of hemocarboperfusion on hemodynamics, organ blood flow, and survival in endotoxin shock.

DESIGN

Prospective, placebo-controlled, animal trial.

SETTING

Research laboratory in a major university teaching hospital.

SUBJECTS

Pentobarbital-anesthetized pigs.

INTERVENTIONS

Twenty-eight pentobarbital-anesthetized pigs (18.5 to 22.3 kg) received 100 micrograms/kg of Escherichia coli endotoxin (lipopolysaccharide 0127) over 30 mins. Group 1 animals (n = 14) were controls and had blood diverted through an extracorporeal circuit without activated charcoal for 60 mins after lipopolysaccharide infusion. Group 2 animals (n = 14) underwent nonpulsatile hemocarboperfusion (activated charcoal SCN-1K).

MEASUREMENTS AND MAIN RESULTS

Mean arterial pressure, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure, pulmonary vascular resistance, oxygen delivery, and regional blood flow (radiolabeled microsphere technique) were determined at baseline and every 30 mins for 150 mins. Results are presented as mean +/- SD. Parameters in the two groups were compared by two-way analysis of variance. A p < .05 was considered significant. The survival rate was ten (71%) of 14 animals in group 1 compared with 14 (100%) of 14 animals in group 2 (p < .05, Fisher's exact test). The mean cardiac output at the end of hemocarboperfusion was 1.6 +/- 0.6 L/min in group 1 compared with 3.0 +/- 0.9 L/min in group 2, and remained lower in group 1 animals throughout the experiment. Pulmonary arterial pressure and pulmonary vascular resistance were lower in the hemocarboperfusion-treated animals during and after hemocarboperfusion. Systemic vascular resistance increased by 70% after lipopolysaccharide infusion and returned to baseline values in the hemocarboperfusion group but remained increased in controls. Oxygen delivery was lower in group 1 at 90 and 150 mins (287 +/- 34 vs. 478 +/- 48 mL/min and 251 +/- 24 vs. 356 +/- 21 mL/min, respectively). Blood flow rates to the brain (38.5 +/- 7.5 vs. 27.1 +/- 5.4 mL/min/100 g), large intestine (26.6 +/- 1.1 vs. 17.7 +/- 2.5 mL/ min/100 g), and adrenal cortex (200 +/- 45 vs. 139 +/- 41 mL/min/100 g) were higher in the hemocarboperfusion group at the completion of carboperfusion but not at later time points.

CONCLUSION

These data suggest that hemocarboperfusion may be of value in the treatment of septic shock.

Lipid deposition in Kupffer cells after parenteral fat nutrition in rats: a biochemical and ultrastructural study

OBJECTIVE

To study fat metabolism and evaluate lipid deposition in hepatocytes and Kupffer cells during parenteral nutrition (PN) with or without fat.

DESIGN

20 male Sprague-Dawley rats, divided into four groups, were investigated. Rats fed orally were used as a reference group and compared to three groups of rats receiving PN either without fat or with 33% of non-protein energy as fat or with 66% of non-protein energy as fat. The PN regimens were equicaloric and administered continuously via a jugular catheter for 7 days.

INTERVENTIONS

After suffocation, blood was collected for determination of serum lipids. Epididymal fat and heart were collected for analysis of lipoprotein lipase activities, and pieces of liver were saved for analyses of liver triglyceride concentration and hepatic lipase activity. Light and electron microscopy were used for examination of lipid deposition in Kupffer cells.

RESULTS

Directly after termination of parenteral feeding, the serum levels of triglycerides were similar in all PN groups, while the levels of non-high-density lipoprotein (HDL) cholesterol and non-HDL phospholipids were significantly increased in parallel with increased doses of fat. Lipid-free PN resulted in significantly less liver steatosis than high-fat PN. Lipid PN also resulted in downregulated hepatic lipase activity, signs of lipid accumulation in Kupffer cells and hepatocytes and an increased number of phagosomes in Kupffer cells.

CONCLUSIONS

Fat vacuoles were found in Kupffer cells after lipid PN, although serum levels of triglycerides were not elevated and lipoprotein lipase activity were not depressed. The cells were distended by fat vacuoles after administration of PN solutions with a high fat concentration. Morphological signs of increased Kupffer cell activity were also found, suggesting that intravenous fat emulsions may activate macrophages.

Influence of pentoxifylline on cytokine levels and inflammatory parameters in septic shock

OBJECTIVE

To evaluate the influence of pentoxifylline (PTX), a phosphodiesterase inhibitor, on cytokines and inflammatory proteins in patients suffering from septic shock.

DESIGN

Prospective study comparing a therapy group to a matched control group.

SETTING

Medical intensive care unit at a university hospital.

PATIENTS

Twenty four patients fulfilling the criteria of septic shock were included in this study. Twelve patients received PTX (therapy group) and 12 patients matched for diagnosis, age and gender served as the control group.

INTERVENTIONS

Pentoxifylline at 1 mg/kg per hour over 24 h in the therapy group.

MEASUREMENTS AND RESULTS

Cytokine levels [tumor necrosis factor-alpha (TNF)], soluble TNF receptor [TNF-R], and interleukin-6 [IL-6] and inflammatory proteins [C-reactive protein, alpha-1-antitrypsin (AAT), fibronectin, and haptoglobin], as well as hemodynamic parameters and the APACHE III score were evaluated before initiation of therapy and 24 h-later. After 24 h, TNF levels were significantly lower in the therapy group (p = 0.013), while IL-6 levels were significantly higher in the therapy group (p = 0.030). Within the 24 h TNF declined significantly in the therapy group (p = 0.006), while IL-6 showed a significant increase (p = 0.043). AAT and the APACHE III score tended to differ significantly after 24 h between the groups [AAT levels higher in the therapy group (p = 0.05), APACHE III score lower (p = 0.05)]. In the therapy group, the systemic vascular resistance index was significantly higher after 24 h (p = 0.0026) whereas the cardiac index declined (p = 0.035).

CONCLUSIONS

PTX does influence TNF levels in septic shock patients. Nevertheless, inhibiting a single mediator in severe septic shock cannot stop the inflammatory overreaction.

Octreotide treatment in patients with necrotizing pancreatitis and pulmonary failure

OBJECTIVE

To determine the efficiency of intravenous infusion of octreotide in the treatment of patients with severe pancreatitis and pulmonary failure.

DESIGN

Prospective, case-control study.

SETTING

Intensive care unit of a university hospital.

PATIENTS

Treatment group: 39 patients with necrotizing pancreatitis were selected for the study. In all, pulmonary failure developed under conservative treatment and surgical intervention had been necessary because of local (abscess, necrosis) or systemic (systemic inflammatory response syndrome) complications. The outcome was prospectively followed up until death or discharge from the hospital.

CONTROL GROUP

54 case-control matched patients with acute necrotizing pancreatitis and pulmonary failure, who had not been treated with octreotide.

INTERVENTION

Each patient in the treatment group received 100 micrograms intravenous octreotide three times daily for 10 days, in addition to the standard intensive care therapy.

RESULTS

The groups (octreotide group, control group) were highly comparable with regard to age (mean age: 54, 51 years), sex, severity of illness (Acute Physiology and Chronic Health Evaluation II score: 27, 27), etiology of pancreatitis, and pretreatment at the time of admission to the intensive care unit. There was no difference in the development of renal, hepatic, gastrointestinal, hemostatic, neurologic, or local complications. But the frequency of the adult respiratory distress syndrome (18 vs 40%; p < 0.05) and circulatory shock (51 vs 87%; p < 0.05) was significantly lower in the treatment group. Furthermore, mortality was 26% (10 of 39 patients) in the octreotide group and 61% (33 of 54 patients) in the control group (p < 0.01).

CONCLUSION

The results of our case-control study showed a beneficial effect of octreotide in patients with severe necrotizing pancreatitis and pulmonary failure. Based on these data, a prospective, double-blind, placebo-controlled study should be performed to evaluate these results.

Efficacy of treatment with the iron (III) complex of diethylenetriamine pentaacetic acid in mice and primates inoculated with live lethal dose 100 Escherichia coli

The iron (III) complex of diethylenetriamine pentaacetic acid (DTPA iron [III]) protected mice and baboons from the lethal effects of an infusion with live LD100 Escherichia coli. In mice, optimal results were obtained when DTPA iron (III) was administered two or more hours after infection. Prevention of death occurred in spite of the fact that the adverse effects of TNF-alpha were well underway in the mouse model. The half-life of DTPA iron (III) was 51 +/- 9 min in normal baboons; primary clearance was consistent with glomerular filtration. In septic baboons, survival was observed after administration of two doses of DTPA iron (III) at 2.125 mg/kg, the first one given before, or as late as 2 h after, severe hypotension. Administration of DTPA iron (III) did not alter mean systemic arterial pressure, but did protect baboons in the presence of high levels of TNF-alpha and free radical overproduction. Furthermore, exaggerated production of nitric oxide was attenuated. The mechanism of protection with DTPA iron (III) is not obvious. Because of its ability to interact in vitro with free radicals, its poor cell permeability, and its short half-life, we postulate that DTPA iron (III) and/or its reduced form may have protected the mice and baboons by sequestration and subsequent elimination of free radicals (including nitric oxide) from their systems.

Pathophysiology of the burn wound and pharmacological treatment. The Rudi Hermans Lecture, 1995

The body's reaction to thermal injury is much more than an initial, local inflammatory response. The burn wound is a continuous, severe threat against the rest of the body due to invasion of infectious agents, antigen challenge and repeated additional trauma caused by wound cleaning and excision. The inflammatory mediators which control blood supply and microvascular permeability in the wound have been extensively studied and are largely understood. Attempts to suppress the inflammatory reaction by different drugs, have, however, been less successful. Extensive thermal injury and sepsis also results in immunosuppression. The defects causing immunosuppression are still very much under consideration. An understanding of these defects is essential for the development of therapies. The increasing interest in the control of the inflammatory reactions by cytokines may, in the near future, be of great importance.

Predictors of mortality in severe malaria: a two year experience in a non-endemic area

Management of severe malaria is an increasing problem worldwide. This paper reviews the pathophysiology and management documenting two years' experience of admissions of severe malaria to an ICU in a non-endemic area. Clinical and laboratory features of severe malaria were analysed for predictors of mortality Twenty-eight patients had clinical or laboratory features compatible with the WHO criteria for severe malaria and, despite treatment with intravenous quinine and supportive ICU care, mortality was 28.5% (8/28). The three pregnant patients died with 100% foetal mortality and the four paediatric patients survived. Of the non-survivors, 8/8 developed ARDS (defined by worst ALI score > 2.5), 7/8 developed shock requiring inotropic support and 7/8 developed acute renal failure requiring CVVHD. Admission haemoglobin, platelet count, parasite count, and lowest Glasgow Coma Score in the first 24 hours were shown not to be predictors of mortality.

Effects of heparin and low molecular weight heparin on lipid transport during parenteral feeding in the rat

BACKGROUND

Treatment with heparin has been reported to interfere with lipid metabolism by release of Lipoprotein Lipase (LPL) into the circulation. The purpose of the present study was to determine the effects on LPL activity by anticoagulants in combination with total parenteral nutrition (TPN) in the rat. In an earlier investigation we could show that TPN, per se, caused a three-fold increase of triglyceride content in liver tissue, retention of lipids in the circulation and disturbed cholesterol metabolism with accumulation of cholesterol in the non High Density Lipoprotein (HDL) fraction of lipoproteins. The activity of Hepatic Lipase (HL) was decreased, while the activities of LPL in adipose tissue and heart were up-regulated.

METHODS

Effects on lipid metabolism by TPN for seven days with or without simultaneous administration of heparin or Low Molecular Weight Heparin (LMWH) were studied in 52 healthy male Sprague-Dawley rats. Combinations of Heparin or LMWH and discontinuous or continuous administration of TPN solutions (including approximately 8 g triglycerides/kg body weight daily) were investigated.

RESULTS

Addition of LMWH, but not heparin, to treatment with TPN resulted in significant up-regulation of LPL activity in the heart. Combination of heparin and continuous administration of TPN solutions was followed by modest, but significant, increases of S-Triglycerides and HDL-Triglycerides. No differences between the TPN groups were observed concerning liver steatosis, cholesterol metabolism, phospholipid metabolism or HL activity.

CONCLUSION

Treatment with LMWH during TPN resulted in up-regulated LPL activity in the heart, which might represent a compensatory mechanism for enzyme release from the capillary walls induced by anticoagulants. Administration of heparin, a more effective lipase-releasing agent, was not associated with increased LPL activity. Heparin treatment in combination with continuous TPN administration was followed by increased levels of triglycerides in blood and HDL particles, suggesting that treatment with heparin might have impaired the capacity for LPL up-regulation, resulting in the development of hyperlipidemia. Further investigations are necessary for evaluation of the mechanisms. Depletion of LPL activity could not be demonstrated by this study in healthy rats.