Exocrine pancreatic dysfunction in sepsis

Effects of hindgut acidosis on production, metabolism, and inflammatory biomarkers in previously immune-activated lactating dairy cows

Previous stressors and systemic inflammation may increase the intestine's susceptibility to hindgut acidosis (HGA). Therefore, our experimental objectives were to evaluate the effects of isolated HGA on metabolism, production, and inflammation in simultaneously immune-activated lactating cows. Twelve rumen-cannulated Holstein cows (118 ± 41 d in milk; 1.7 ± 0.8 parity) were enrolled in a study with 3 experimental periods (P). Baseline data were collected during P1 (5 d). On d 1 of P2 (2 d), all cows received an i.v. lipopolysaccharide (LPS) bolus (0.2 µg/kg of body weight; BW). During P3 (4 d), cows were randomly assigned to 1 of 2 abomasal infusion treatments: (1) control (LPS-CON; 6 L of H₂O/d; n = 6) or (2) starch infused (LPS-ST; 4 kg of corn starch + 6 L of H₂O/d; n = 6). Treatments were allocated into 4 equal doses (1.5 L of H₂O or 1 kg of starch and 1.5 L of H₂O, respectively) and administered at 0000, 0600, 1200, and 1800 h daily. Additionally, both treatments received i.v. LPS on d 1 and 3 of P3 (0.8 and 1.6 µg/kg of BW, respectively) to maintain an inflamed state. Effects of treatment, time, and their interaction were assessed. Repeated LPS administration initiated and maintained an immune-activated state, as indicated by increased circulating white blood cells (WBC), serum amyloid A (SAA), and LPS-binding protein (LBP) during P2 and P3 (29%, 3-fold, and 50% relative to P1, respectively) for both abomasal infusion treatments. Regardless of abomasal treatment, milk yield and dry matter intake were decreased throughout P2 and P3 but with lesser severity following each LPS challenge (54, 44, and 37%, and 49, 42, and 40% relative to baseline on d 1 of P2, d 1 and d 3 of P3, respectively). As expected, starch infusions markedly decreased fecal pH (5.56 at nadir vs. 6.57 during P1) and increased P3 fecal starch relative to LPS-CON (23.7 vs. 2.4% of dry matter). Neither LPS nor starch infusions altered circulating glucose, insulin, nonesterified fatty acids, or β-hydroxybutyrate, although LPS-ST cows had decreased blood urea nitrogen throughout P3 (16% relative to LPS-CON). Despite the striking reduction in fecal pH, HGA had no additional effect on circulating WBC, SAA, or LBP. Thus, in previously immune-activated dairy cows, HGA did not augment the inflammatory state, as indicated by a lack of perturbations in production, metabolism, and inflammatory biomarkers.

Nutritional support in sepsis: when less may be more

Despite sound basis to suspect that aggressive and early administration of nutritional support may hold therapeutic benefits during sepsis, recommendations for nutritional support have been somewhat underwhelming. Current guidelines (ESPEN and ASPEN) recognise a lack of clear evidence demonstrating the beneficial effect of nutritional support during sepsis, raising the question: why, given the perceived low efficacy of nutritionals support, are there no high-quality clinical trials on the efficacy of permissive underfeeding in sepsis? Here, we review clinically relevant beneficial effects of permissive underfeeding, motivating the urgent need to investigate the clinical benefits of delaying nutritional support during sepsis.

Protective effects of carbon monoxide releasing molecule‑2 on pancreatic function in septic mice

The present study aimed to investigate the effect of carbon monoxide (CO)‑releasing molecule‑2 (CORM‑2) on pancreatic function in sepsis‑model mice. To perform the present investigation, mice were rendered septic by cecal ligation and puncture (CLP). Then, mice were either treated with or without CORM‑2 (8 mg/kg, intravenous) for different durations (6, 12 and 24 h) immediately following CLP. The levels of serum amylase and lipase, tumor necrosis factor α, interleukin‑1β and interleukin‑6 in addition to myeloperoxidase (MPO) activity in pancreatic tissues were determined at 6, 12 and 24 h post‑CLP. Histological scores and the expression of intercellular adhesion molecule 1 (ICAM‑1), vascular cell adhesion molecule 1 (VCAM‑1), nuclear factor‑κB (NF‑κB) and phosphorylated inhibitor of κB (p‑IκB‑α) in the pancreas were also evaluated at 24 h post‑CLP. The results of the present study revealed that compared with CLP‑alone group, CORM‑2 treatment significantly (P<0.05) reduced the levels of serum amylase, lipase and pro‑inflammatory cytokines. In parallel, the severity of pancreatic histology, MPO activity and the expression levels of ICAM‑1 and VCAM‑1 in the pancreas of CORM‑2 treated CLP mice were substantially decreased compared with the untreated group. Furthermore, CORM‑2 treatment inhibited the expression levels of NF‑κB and P‑IκB‑α in the pancreas of mice following CLP compared with the untreated group. CORM‑2‑liberated CO exerted protective effects on the pancreatic function of septic mice, and the beneficial effects may be due to the suppression of NF‑κB activation and subsequent regulation of NF‑κB‑dependent expression of cytokines.

Prognostic value of the biomarkers serum amyloid A and nitric oxide in patients with sepsis

OBJECTIVE

Sepsis is a major cause of mortality among critically ill patients in the intensive care unit (ICU). Alterations in serum amyloid A (SAA) and nitric oxide (NO) levels have been associated with mortality in critically ill patients. In the present study, we investigated the predictive value of SAA and/or NO compared to traditional predictive markers such as C-reactive protein (CRP) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score.

METHODS

100 adult patients with sepsis and 25 without sepsis were enrolled in a prospective, randomized study in our ICU. The APACHE II score was calculated, and their peripheral venous blood SAA, NO and CRP levels were evaluated on days 1, 3, and 7 after sepsis was diagnosed. The patients were sorted based on incidence of septic shock into septic shock (A) and non-septic shock (B) groups. Comparative analyses of altered levels of these indicators between the two groups were performed, and correlations between SAA, NO, and the more traditional APACHE II score were probed. Patients were sorted based on survival status into death (D) and survival (S) groups based on death endpoint within 28 days after admission.

RESULTS

We observed that the difference in APACHE II score, SAA and CRP levels were statistically significantly (p < 0.05) between groups A and B on days 1, 3 and 7 post-diagnosis, while inter-group NO level significantly differed (p < 0.05) on days 1 and 3 post-diagnosis, no apparent difference was observed on day 7 post-diagnosis. For groups D and S, SAA, CRP and NO levels significantly differed (p < 0.05) on days 3 and 7 post-diagnosis, with no apparent difference on day 1. APACHE II score was significantly different on day 7 (p < 0.05), however the difference on days 1 and 3 were non-significant. We also demonstrated a positive correlation between APACHE II scores, SAA levels on days 1, 3, and 7, as well as NO levels on days 1 and 3. In addition, for the D and S groups, SAA at all time points, NO on day 3 and CRP on day 7 positively correlated with increased death events.

CONCLUSION

The dynamic monitoring of SAA and NO serum levels with APACHE II scores better reflect the severity of sepsis than traditional indicators like CRP and may serve as independent prognosticators of sepsis in critically ill patients, shorten time to diagnosis confirmation and improve therapeutic decision-making.

Stimulation of the endogenous incretin glucose-dependent insulinotropic peptide by enteral dextrose improves glucose homeostasis and inflammation in murine endotoxemia

Loss of glucose homeostasis during sepsis is associated with increased organ dysfunction and higher mortality. Novel therapeutic strategies to promote euglycemia in sepsis are needed. We have previously shown that early low-level intravenous (IV) dextrose suppresses pancreatic insulin secretion and induces insulin resistance in septic mice, resulting in profound hyperglycemia and worsened systemic inflammation. In this study, we hypothesized that administration of low-level dextrose via the enteral route would stimulate intestinal incretin hormone production, potentiate insulin secretion in a glucose-dependent manner, and thereby improve glycemic control in the acute phase of sepsis. We administered IV or enteral dextrose to 10-week-old male C57BL/6J mice exposed to bacterial endotoxin and measured incretin hormone release, glucose disposal, and proinflammatory cytokine production. Compared with IV administration, enteral dextrose increased circulating levels of the incretin hormone glucose-dependent insulinotropic peptide (GIP) associated with increased insulin release and insulin sensitivity, improved mean arterial pressure, and decreased proinflammatory cytokines in endotoxemic mice. Exogenous GIP rescued glucose metabolism, improved blood pressure, and increased insulin release in endotoxemic mice receiving IV dextrose, whereas pharmacologic inhibition of GIP signaling abrogated the beneficial effects of enteral dextrose. Thus, stimulation of endogenous GIP secretion by early enteral dextrose maintains glucose homeostasis and attenuates the systemic inflammatory response in endotoxemic mice and may provide a therapeutic target for improving glycemic control and clinical outcomes in patients with sepsis.

Pancreatic injury in patients with septic shock: A literature review

Sepsis and septic shock are life threatening condition associated with high mortality rate in critically-ill patients. This high mortality is mainly related to the inadequacy between oxygen delivery and cellular demand leading to the onset of multiorgan dysfunction. Whether this multiorgan failure affect the pancreas is not fully investigated. In fact, pancreatic injury may occur because of ischemia, overwhelming inflammatory response, oxidative stress, cellular apoptosis and/or metabolic derangement. Increased serum amylase and/or lipase levels are common in patients with septic shock. However, imaging test rarely reveal significant pancreatic damage. Whether pancreatic dysfunction does affect the prognosis of patients with septic shock or not is still a matter of debate. In fact, only few studies with limited sample size assessed the clinical relevance of the pancreatic injury in this group of patients. In this review, we aimed to describe the epidemiology and the physiopathology of pancreatic injury in septic shock patients, to clarify whether it requires specific management and to assess its prognostic value. Our main finding is that pancreatic injury does not significantly affect the outcome in septic shock patients. Hence, increased serum pancreatic enzymes without clinical features of acute pancreatitis do not require further imaging investigations and specific therapeutic intervention.

PANCREATITIS OR NOT?--Elevated lipase and amylase in ICU patients

Elevation in serum levels of pancreatic enzymes (Hyperamylasemia and/or Hyperlipasemia) can occur in any Intensive Care Unit (ICU) patient either as a result of true acute pancreatitis (AP) or as a reflection of a non-pancreatic disease. Although most patients may not have clinical pancreatitis, identifying true acute pancreatitis in the ICU setting may be critical in the presence of associated co-morbid conditions of the disease for which the patient is being managed. With neither amylase nor lipase being specific for pancreatitis, it is important for the clinician to be aware of different causes of hyperamylasemia and hyperlipasemia, especially when clinical diagnosis of pancreatitis is unclear. This review will focus on understanding different non-pancreatic conditions where there is elevation of pancreatitis enzymes and to identify true acute pancreatitis in critically ill patients without typical symptoms.

Specificity of infant digestive conditions: some clues for developing relevant in vitro models

Digestion of nutrients is an essential function of the newborn infant gut to allow growth and development and understanding infant digestive function is essential to optimize nutrition and oral drug delivery. Ethical considerations prohibit invasive in vivo trials and as a consequence in vitro assays are often conducted. However, the choice of in vitro model parameters are not supported by an exhaustive analysis of the literature and do not mimic precisely the digestive conditions of the infant. This review contains a compilation of the studies which characterized the gastroduodenal conditions in full-term or preterm infants of variable postnatal age from birth up to six months. Important data about healthy full-term infants are reported. The enzymatic (type of enzymes and level of activity) and nonenzymatic (milk-based diet, frequency of feeding, bile salt concentrations) conditions of digestion in infants are shown to differ significantly from those in adults. In addition, the interindividual and developmental variability of the digestive conditions in infants is also highlighted.

Clinical and pathologic characteristics of pancreatic necrosis in critically ill children

BACKGROUND

Pancreatic damage in critically ill patients is associated with the progressive failure of multiple organs, but little is known about its clinical characteristics. At present, no guidelines are available for the diagnosis and management of pancreatic damage. This study was undertaken to analyze the clinical and pathologic characteristics of pancreatic necrosis in critically ill children, and to find some biological markers of pancreatic damage or pancreatic necrosis.

METHODS

We retrospectively reviewed the clinical data, laboratory results, and autopsy findings of 25 children, who were admitted to Hunan Children's Hospital, China from 2003 to 2009, and died of multiple organ failure. The autopsy revealed pancreatic necrosis in 5 children, in whom sectional or gross autopsy was performed.

RESULTS

The 5 children had acute onset and a fever. Two children had abdominal pain and 2 had abdominal bulging, flatulence and gastrointestinal bleeding. Four children had abnormal liver function, characterized by decreased albumin and 3 children had elevated level of C-reactive protein (CRP). B-ultrasonography revealed abnormal acoustic image of the pancreas in all children, and autopsy confirmed pancreatic necrosis, which may be associated with the damage of the adrenal gland, liver, lung, heart, spleen, kidney, intestine, thymus, mediastinal and mesenteric lymph nodes and other organs. Children 1 and 2 died of acute hemorrhagic necrotizing pancreatitis (AHNP); children 3-5 died of multiple organ dysfunction syndrome (MODS) due to pancreatic necrosis.

CONCLUSION

Pancreatic damage or pancreatic necrosis in critically ill children is characterized by acute onset, severity, short course, multiple organ damage or failure. It may be asymptomatic in early stage, and easy to be ignored.

Novel RNA interference-based therapies for sepsis

INTRODUCTION

Sepsis is an extremely fast-paced disease, initiated by an infection that can progress to multiple organ dysfunction and death. The complexity associated with sepsis makes the therapies difficult to develop. Moreover, the 'one-fits-all' kind of therapy is far from being realistic.

AREAS COVERED

This review provides a conspectus of the current results of sepsis therapies and their benefits, focusing on the development of small interfering RNA (siRNA) therapeutics for targeting immune cells and sepsis pathways.

EXPERT OPINION

The question, 'When will an effective therapy for sepsis be available for patients?' remains unanswered. New RNA interference-mediated therapies are emerging as novel approaches for the treatment of sepsis by downregulating key inflammatory cytokine expression. Strategies that exploit multimodal gene silencing using siRNA and targeted delivery systems are discussed in this review. Some of these strategies have shown positive results in preclinical model of sepsis.

Screening and risk factors of exocrine pancreatic insufficiency in critically ill adult patients receiving enteral nutrition

Introduction

Malnutrition is a frequent problem associated with detrimental clinical outcomes in critically ill patients. To avoid malnutrition, most studies focus on the prevention of inadequate nutrition delivery, whereas little attention is paid to the potential role of exocrine pancreatic insufficiency (EPI). In this trial, we aim to evaluate the prevalence of EPI and identify its potential risk factors in critically ill adult patients without preexisting pancreatic diseases.

Methods

In this prospective cross-sectional study, we recruited 563 adult patients with critical illnesses. All details of the patients were documented, stool samples were collected three to five days following the initiation of enteral nutrition, and faecal elastase 1 (FE-1) concentrations were assayed using an enzyme-linked immunosorbent assay kit. Blood samples were also taken to determine serum amylase and lipase activity.

Results

The percentages of recruited patients with EPI (FE-1 concentration <200 μg/g) and severe EPI (FE-1 concentration <100 μg/g) were 52.2% and 18.3%, respectively. The incidences of steatorrhea were significantly different (P < 0.05) among the patients without EPI, with moderate EPI (FE-1 concentration = 100 to 200 μg/g) and severe EPI (FE-1 concentration < 100 μg/g). Both multivariate logistic regression analysis and z-tests indicated that the occurrence of EPI was closely associated with shock, sepsis, diabetes, cardiac arrest, hyperlactacidemia, invasive mechanical ventilation and haemodialysis.

Conclusions

More than 50% of critically ill adult patients without primary pancreatic diseases had EPI, and nearly one-fifth of them had severe EPI. The risk factors for EPI included shock, sepsis, diabetes, cardiac arrest, hyperlactacidemia, invasive mechanical ventilation and haemodialysis.

Trial registration

NCT01753024

[Nutrition and gastrointestinal intolerance]. Med Klin Intensivmed Notfmed. 2013;108:396-400. [PMID: 23740106 DOI: 10.1007/s00063-012-0203-1]

The functional integrity of the gastrointestinal tract is an essential prerequisite in intensive care patients for the sufficient administration of enteral nutrition. Up to 65% of patients in intensive care units develop symptoms of gastrointestinal dysfunction with high residual gastric volume, vomiting and abdominal distension. The pathophysiological alterations of gastrointestinal intolerance and the subsequent effect on the tolerance of enteral nutrition can affect the whole gastrointestinal tract. Gastroduodenal motility disorders in particular, with increased gastroesophageal reflux lead to intolerance. In more than 90% of intensive care patients with gastrointestinal motility disorders an adequate postpyloric enteral nutrition can be carried out using a jejunal tube. In addition to improved tolerance of enteral nutrition this leads to a reduction of gastroesophageal reflux and the incidence of ventilation-associated pneumonia. Apart from the possibility of endoscopic application of the jejunal tube, alternative techniques were developed which allow a faster positioning of the jejunal tube with less complications. Furthermore, there are therapeutic options for improvement of gastrointestinal motility disorders and apart from general measures, also medicinal options for treatment of gastrointestinal intolerance which allow a sufficient enteral nutrition for intensive care patients.

[Nutritional therapy in acute pancreatitis]. Med Klin Intensivmed Notfmed. 2013;108:401-407. [PMID: 23681278 DOI: 10.1007/s00063-012-0202-2]

Acute pancreatitis is a frequent clinical entity in the West. About 80% of patients with acute pancreatitis develop edematous pancreatitis, while 20% develop necrotizing pancreatitis: The latter is a potentially life-threatening disease. In this case, early enteral nutrition has been shown to improve the course of the disease. Usually, gastric enteral nutrition with a polymeric formula via a nasogastric tube is possible; only in a minority of patients is jejunal feeding necessary owing to the high gastric residual volume. An elemental formula is useful for patients with significant intestinal maldigestion. If enteral feeding is not feasible within 5-7 days, (additional) parenteral nutrition has to be considered. Individualized--primary enteral--nutritional support is an essential part of a multimodal therapy in severe acute pancreatitis and it improves clinical outcome.

Is the pancreas affected in patients with septic shock?--a prospective study

BACKGROUND

Hyperamylasemia can be observed anecdotally during the course of severe sepsis or septic shock. This study aimed to investigate the possibility of pancreatic involvement in patients with septic shock using serum pancreatic enzyme determinations and imaging techniques in 21 consecutive patients with septic shock and 21 healthy subjects as controls.

METHODS

The serum activity of pancreatic amylase and lipase was assayed initially in all subjects and 24 and 48 hours after the initial observation in the 21 patients with septic shock. All patients also underwent radiological examination to detect pancreatic abnormalities.

RESULTS

The serum activity of pancreatic amylase was significantly higher in the 21 patients with septic shock than in the 21 control subjects during the study period, while the serum activity of lipase was similar to that of the control subjects. Amylase and lipase serum activity did not significantly changed throughout the study period in the 21 patients with septic shock. None of the patients with pancreatic hyperenzymemia had clinical signs or morphological alterations compatible with acute pancreatitis.

CONCLUSION

The presence of pancreatic hyperenzymemia in septic shock patients is not a biochemical manifestation of acute pancreatic damage, and the management of these patients should be dependent on the clinical situation and not merely the biochemical results.

Exocrine pancreatic involvement in critically ill patients

PURPOSE OF REVIEW

To learn about the prevalence, pathophysiology, and treatment of exocrine pancreatic involvement in critically ill patients.

RECENT FINDINGS

Elevations in the levels of pancreatic enzymes are observed in up to 80% of intensive care patients. Most of these patients do not develop clinically relevant pancreatitis. However, elevations in enzyme levels do represent pancreatic damage with a risk of complications. Different factors have been discussed, which may contribute to pancreatic damage in critically ill patients. These include splanchnic hypoperfusion during shock or major surgery, bacterial translocation, elevated triglyceride levels, development of biliary sluge, and biliary pancreatitis, as well as several drugs. Imaging procedures and inflammatory markers help to identify relevant disease. Several therapeutic options have been discussed recently with a focus on early enteral nutrition.

SUMMARY

Pancreatic damage is frequently observed in critically ill patients. Although in most of these patients, this is without major clinical consequences, some patients develop relevant pancreatitis, which contributes to morbidity and mortality. Risk factors have been identified and therapeutic strategies have been changed.

Sepsis in 2003: are we still in the middle of nowhere?

PURPOSE OF REVIEW

Although enthusiasm of intensivists has been raised during the last 2-3 years due to several successful clinical trials, severe sepsis and septic shock still have an increasing incidence with more or less unchanged mortality. Within the last 12 months, the progress in sepsis research covering definitions, epidemiology, pathophysiology, diagnosis, standard and adjunctive therapy, as well as experimental approaches is encouraging. In this review, state-of-the-art publications of 2003 are presented to elucidate the possible impact on clinical routine.

RECENT FINDINGS

The rationale for using a new definition based on the PIRO system has been widely acknowledged, although it is not yet applicable in clinical practice. This includes genomic information for stratifying subgroups of patients, and a broader field of laboratory diagnostics due to clinical studies and basic research on the cellular mechanisms of inflammation and organ dysfunction. Early diagnosis is important for a fast implementation of specific therapies, and it has been confirmed that the time until the start of therapy has an impact on patient outcome. Thorough data analysis of successful trials with activated protein C has revealed encouraging details on long-term outcome and subgroup effects. Together with new findings on low-dose hydrocortisone, this stresses the relevance of adjunctive therapy in severe sepsis and septic shock.

SUMMARY

Scientific progress in areas of sepsis has been continuing throughout 2003, although the challenges are still enormous. The identification of more specific markers and new therapeutic approaches will hopefully improve the diagnosis, monitoring of therapy, and outcome in the septic patient.

Pharmacokinetic changes in critical illness

Physiologic alterations in critically ill patients can significantly affect the pharmacokinetics of drugs used in the critically ill patient population. Understanding these pharmacokinetic changes is essential relative to optimizing drug therapy. This article outlines the major differences seen in the absorption, distribution, metabolism, and excretion of drugs in critically ill patients. Important strategies for drug therapy dosing and monitoring in these patients are also addressed.

Increased heat shock protein 70 expression in the pancreas of rats with endotoxic shock

AIM: To investigate the ultra-structural changes and heat shock protein 70 (HSP70) expression in the pancreas of rats with endotoxic shock and to detect their possible relationship.

METHODS: A total of 33 Wistar rats were randomly divided into three groups: control group (given normal saline), small dose lipopolysaccharide (LPS) group (given LPS 5 mg/kg) and large dose LPS group (given LPS 10 mg/kg). Pancreas was explanted to detect the ultra-structural changes by TEM and the HSP70 expression by immunohistochemistry and Western blot.

RESULTS: Rats given small doses of LPS showed swelling and loss of mitochondrial cristae of acinar cells and increased number of autophagic vacuoles in the cytoplasm of acinar cells. Rats given large doses of LPS showed swelling, vacuolization, and obvious myeloid changes of mitochondrial cristae of acinar cells, increased number of autophagic vacuoles in the cytoplasm of acinar cells. HSP70 expression was increased compared to the control group (P<0.05).

CONCLUSION: Small doses of LPS may induce stronger expression of HSP70, promote autophagocytosis and ameliorate ultra-structural injuries.

Pseudomonas pneumonia-mediated sepsis induces expression of pancreatitis-associated protein-I in rat pancreas

Severe impairment of exocrine pancreatic secretion has recently been demonstrated in a clinical study in sepsis and septic shock patients. The purpose of this study was to further evaluate involvement of the pancreas in the acute phase reaction in sepsis. Using a normotensive rat model of Pseudomonas pneumonia-induced sepsis, we assessed the expression of PAP-I, amylase and trypsinogen mRNA, PAPI protein levels, and cytokine expression in the pancreas by Northern and Western blot analysis and RT-M PCR, respectively. Presence of several well-established features of pancreatitis in sepsis-induced animals were examined by biochemical and histopathological methods as well as by a determination of both water and myeloperoxidase content. Sepsis resulted in an up-regulation of PAP-I gene expression and increase in its protein level in pancreas while the mRNA levels of amylase and trypsinogen were down-regulated. Differences in the pancreatic cytokine expression, serum amylase and serum lipase levels, the occurrence of pancreatic edema as well as the severity of inflammatory infiltration and necrosis were not significantly different between sham and pneumonia groups. Acinar cells showed increased vacuolization in pneumonia animals 24 hours after the treatment. These findings demonstrate that the pancreas is actively involved in the acute phase reaction in sepsis of remote origin. This involvement occurs without concomitant biochemical and histopathologic alterations observed in pancreatitis. Taken all together, these features are indicative of a sepsis-specific dysfunction of the pancreas.

Ethyl pyruvate decreases sepsis-induced acute renal failure and multiple organ damage in aged mice

BACKGROUND

Sepsis is a common cause of acute renal failure (ARF). The incidence of sepsis increases dramatically after 50 years of age; however, most ARF studies are performed in young mice.

METHODS

We performed two common sepsis models, lipopolysaccharide (LPS) administration and cecal ligation puncture (CLP) in aged mice. We developed a fully treated CLP model in aged mice by treating mice with fluid resuscitation and antibiotics.

RESULTS

LPS induced renal injury in aged but not young mice. However, volume resuscitation starting within 6 hours decreased renal injury. We then used this fluid resuscitation scheme, along with antibiotics, to develop a fully treated CLP model in aged mice. Mice subjected to CLP developed functional and histologic ARF and multiple organ damage. Treatment with ethyl pyruvate, even when started 12 hours after surgery, decreased serum creatinine, tubular damage, and multiple organ injury at 24 hours. Ethyl pyruvate decreased plasma tumor necrosis factor-alpha (TNF-alpha), and kidney mRNA for TNF alpha, tissue factor, and plasminogen activator inhibitor-1 (PAI-1), and increased mRNA for urokinase-like plasminogen activator.

CONCLUSION

CLP in aged mice causes functional and histologic changes consistent with human ARF. A single dose of ethyl pyruvate inhibits renal and multiple organ damage, and is still effective when given 12 hours after surgery.

Effect of nitric oxide on capillary hemodynamics and cell injury in the pancreas during Pseudomonas pneumonia-induced sepsis

Sepsis-induced nitric oxide (NO) overproduction has been implicated in a redistribution of flow from the pancreas making it vulnerable to ischemic injury in septic shock. To test this hypothesis in a remote injury model of normotensive sepsis, we induced Pseudomonas pneumonia in the rat and used intravital video microscopy (IVVM) of the pancreas to measure functional capillary density, capillary hemodynamics [red blood cell (RBC) velocity, lineal density, and supply rate], and lethal cellular damage (propidium iodine staining) at 6 and 24 h after the induction of pneumonia. With pneumonia, plasma nitrite/nitrate [NO2(-)/NO3(-)(NOx(-))] levels were doubled by 21 h (P < 0.05). To assess the effect of NO overproduction on microvascular perfusion, N6-(1-iminoethyl)-L-lysine (L-NIL) was administered to maintain NOx(-) levels at baseline. Pneumonia did cause a decrease in RBC velocity of 23% by 6 h, but by 24 h RBC velocity and supply rate had increased relative to sham by 22 and 38%, respectively (P < 0.05). L-NIL treatment demonstrated that this increase was due to NO overproduction. With pneumonia, there was no change in functional capillary density and only modest increases in cellular damage. We conclude that, in this normotensive pneumonia model of sepsis, NO overproduction was protective of microvascular perfusion in the pancreas.