Inflammation and lung injury in an ovine model of fluid resuscitated endotoxemic shock.

BACKGROUND: Sepsis is a multi-system syndrome that remains the leading cause of mortality and critical illness worldwide, with hemodynamic support being one of the cornerstones of the acute management of sepsis. We used an ovine model of endotoxemic shock to determine if 0.9% saline resuscitation contributes to lung inflammation and injury in acute respiratory distress syndrome, which is a common complication of sepsis, and investigated the potential role of matrix metalloproteinases in this process. METHODS: Endotoxemic shock was induced in sheep by administration of an escalating dose of lipopolysaccharide, after which they subsequently received either no fluid bolus resuscitation or a 0.9% saline bolus. Lung tissue, bronchoalveolar fluid (BAL) and plasma were analysed by real-time PCR, ELISA, flow cytometry and immunohistochemical staining to assess inflammatory cells, cytokines, hyaluronan and matrix metalloproteinases. RESULTS: Endotoxemia was associated with decreased serum albumin and total protein levels, with activated neutrophils, while the glycocalyx glycosaminoglycan hyaluronan was significantly increased in BAL. Quantitative real-time PCR studies showed higher expression of IL-6 and IL-8 with saline resuscitation but no difference in matrix metalloproteinase expression. BAL and tissue homogenate levels of IL-6, IL-8 and IL-1ß were elevated. CONCLUSIONS: This data shows that the inflammatory response is enhanced when a host with endotoxemia is resuscitated with saline, with a comparatively higher release of inflammatory cytokines and endothelial/glycocalyx damage, but no change in matrix metalloproteinase levels.

Fluid resuscitation with 0.9% saline alters haemostasis in an ovine model of endotoxemic shock.

INTRODUCTION: Fluid resuscitation is a cornerstone of severe sepsis management, however there are many uncertainties surrounding the type and volume of fluid that is administered. The entire spectrum of coagulopathies can be seen in sepsis, from asymptomatic aberrations to fulminant disseminated intravascular coagulation (DIC). The aim of this study was to determine if fluid resuscitation with saline contributes to the haemostatic derangements in an ovine model of endotoxemic shock. MATERIALS AND METHODS: Twenty-one adult female sheep were randomly divided into no endotoxemia (n = 5) or endotoxemia groups (n = 16) with an escalating dose of lipopolysaccharide (LPS) up to 4 µg/kg/h administered to achieve a mean arterial pressure below 60 mmHg. Endotoxemia sheep received either no bolus fluid resuscitation (n = 8) or a 0.9% saline bolus (40 mL/kg over 60 min) (n = 8). No endotoxemia, saline only animals (n = 5) underwent fluid resuscitation with a 0.9% bolus of saline as detailed above. Hemodynamic support with vasopressors was initiated if needed, to maintain a mean arterial pressure (MAP) of 60-65 mm Hg in all the groups. RESULTS: Rotational thromboelastometry (ROTEM®) and conventional coagulation biomarker tests demonstrated sepsis induced derangements to secondary haemostasis. This effect was exacerbated by saline fluid resuscitation, with low pH (p = 0.036), delayed clot initiation and formation together with deficiencies in naturally occurring anti-coagulants antithrombin (p = 0.027) and Protein C (p = 0.001). CONCLUSIONS: Endotoxemia impairs secondary haemostasis and induces changes in the intrinsic, extrinsic and anti-coagulant pathways. These changes to haemostasis are exacerbated following resuscitation with 0.9% saline, a commonly used crystalloid in clinical settings.

Pre-clinical study protocol: Blood transfusion in endotoxaemic shock.

The Surviving Sepsis Campaign (SCC) and the American College of Critical Care Medicine (ACCM) guidelines recommend blood transfusion in sepsis when the haemoglobin concentration drops below 7.0 g/dL and 10.0 g/dL respectively, while the World Health Organisation (WHO) guideline recommends transfusion in septic shock 'if intravenous (IV) fluids do not maintain adequate circulation', as a supportive measure of last resort. Volume expansion using crystalloid and colloid fluid boluses for haemodynamic resuscitation in severe illness/sepsis, has been associated with adverse outcomes in recent literature. However, the volume expansion effect(s) following blood transfusion for haemodynamic circulatory support, in severe illness remain unclear with most previous studies having focused on evaluating effects of either different RBC storage durations (short versus long duration) or haemoglobin thresholds (low versus high threshold) pre-transfusion. •We describe the protocol for a pre-clinical randomised controlled trial designed to examine haemodynamic effect(s) of early volume expansion using packed RBCs (PRBCs) transfusion (before any crystalloids or colloids) in a validated ovine-model of hyperdynamic endotoxaemic shock.•Additional exploration of mechanisms underlying any physiological, haemodynamic, haematological, immunologic and tissue specific-effects of blood transfusion will be undertaken including comparison of effects of short (≤5 days) versus long (≥30 days) storage duration of PRBCs prior to transfusion.

Isolation of Leptospira kmetyi from residential areas of patients with leptospirosis in Kelantan, Malaysia.

BACKGROUND: Environmental sampling provides important information that enhances the understanding of the leptospiral human-environment-animal relationship. Several studies have described the distribution of Leptospira in the environment. However, more targeted sites, that is, areas surrounding leptospirosis patients' houses, remain under-explored. Therefore, this study aims to detect the presence of Leptospira spp. in the residential areas of patients with leptospirosis. METHODS: Soil and water samples near leptospirosis patients' residences were collected, processed and cultured into EMJH media. Partial 16S rRNA gene sequencing was performed to confirm the identity of Leptospira. RESULTS: EMJH culture and partial 16S rRNA gene sequencing revealed predominant growth of pathogenic Leptospira kmetyi (17%, n=7/42). All tested locations had at least one Leptospira sp., mostly from the soil samples. CONCLUSION: More than one species of Leptospira may be present in a sampling area. The most common environmental isolates were pathogenic L. kmetyi.

Molecular detection of leptospirosis and melioidosis co-infection: A case report.

Leptospirosis and melioidosis are important tropical infections caused by Leptospira and Burkholdheria pseudomallei, respectively. As both infections share similar clinical manifestations yet require different managements, complementary laboratory tests are crucial for the diagnosis. We describe a case of Leptospira and B. pseudomallei co-infection in a diabetic 40-year-old woman with history of visit to a freshwater camping site in northern Malaysia. To our knowledge, this is the first case of such double-infection, simultaneously demonstrated by molecular approach. This case highlights the possibility of leptospirosis and melioidosis co-infections and their underlying challenges in the rapid and accurate detection of the etiologic microorganism.