Effect of empiric antibiotic treatment on plasma endotoxin activity in septic patients.

OBJECTIVES: Efficient empiric antibiotic therapy remains the cornerstone of sepsis treatment. However, antibiotics could be responsible for the transient clinical deterioration provoked by the release of bacterial cell-wall constituents, such as endotoxin, into the blood stream. The aim of this study was to evaluate if a transient elevation of endotoxin level occurred in septic patients following antibiotic administration. METHODS: Thirty-three septic intensive care unit (ICU) patients were enrolled in this prospective trial. Four blood samples were collected from each of these patients during a 24-h period, and endotoxin activity was measured in these samples by the chemiluminescence technique. Fifteen ICU non-septic patients and 15 healthy volunteers were also observed for possible daily fluctuations in endotoxin activity. RESULTS: There was no significant increase in endotoxin levels following the initiation of empiric antibiotic therapy in septic patients. A clinical deterioration in the 4 h following antibiotic administration was observed in 14 septic patients (42 %). These patients had significantly higher endotoxin levels than stable septic patients. CONCLUSIONS: Although endotoxin levels failed to increase after the administration of antibiotic(s) to critically ill patients, they were higher in the septic patients presenting a transient deterioration than in the other patients. This observation suggests that a possible release of endotoxin due to bacteria lysis by antibiotics could be responsible for the observed clinical deterioration.

Time course of iron metabolism in critically ill patients.

BACKGROUND: Altered iron metabolism plays a central role in the development of anaemia in critically ill patients but the time course of iron status in septic and non-septic critically ill patients has not been well defined. METHODS: Prospective study in a 34-bed medico-surgical ICU. The complete blood count, iron, ferritin, transferrin, and transferrin receptor concentrations, transferrin saturation and C-reactive protein (CRP) concentrations were measured on days 1, 3 and 5 of the ICU stay in 95 consecutive ICU patients (33 with sepsis and 62 without). RESULTS: Despite an identical complete blood count on day 1, septic patients had significantly lower iron concentrations (21 [13-34] vs 50[28-75] microg/dL, p<0.001), transferrin concentrations (169[121-215] vs 214[173-247] mg/dL; p=0.003), and transferrin saturation (11[7-15] vs 19[11-25]%; p= 0.004), and higher ferritin concentrations (432[184-773] vs 204[78-354] ng/mL; p=0.002) than non-septic patients. These alterations were associated with a lower reticulocyte count (42[29-61] vs 58[48-77] x 10(3)/mm3; p=0.028). On day 1, CRP concentrations, which were higher in septic than in non-septic patients (20.0[13.5-27.5] vs 2.3[0.7-5.9] mg/dL; p<0.001), were directly correlated with ferritin concentrations (rho=0.55, p<0.001) and inversely correlated with transferrin concentrations (rho=-0.49, p=0.0001) and transferrin saturation (rho=-0.49, p=0.0001). After 3 days, iron and transferrin concentrations were identical in septic and non-septic patients. Iron metabolism remained altered in both populations until the 5th day. CONCLUSIONS: Iron status is rapidly altered in critically ill patients, especially in septic patients. These alterations persist during the course of the disease and are associated with decreased erythropoiesis.

A 'shock room' for early management of the acutely ill.

Our 850-bed, academic, tertiary care hospital uses a four-bed dedicated 'shock room' situated between the Departments of Emergency Medicine and Intensive Care to stabilise all acutely ill patients from outside or inside the hospital before transfer to the intensive care unit or other department. Admitted patients stay a maximum of four hours in the shock room. In this article we describe our experiences using this shock room by detailing the demographic data, including time and source of admission, diagnosis and outcome, for the 2514 patients admitted to the shock room in 2006. The most common reasons for admission were cardiac (33%) and neurological (21%) diagnoses. After diagnosis and initial treatment, 54% of patients were transferred to an intensive care unit or a coronary care unit; 2.5% of patients died in the shock room. The shock room provides a useful area of collaboration between emergency department and intensive care unit staff and enables acutely ill patients to be assessed and treated rapidly to optimise outcomes.

[Acute renal failure in the intensive care unit: which technique of renal replacement therapy?]. / Insuffisance rénale aiguë en soins intensifs: quelle technique d'epuration extra-rénale?

Acute renal failure is still associated with a high mortality rate among intensive care patients, despite improvements in renal replacement therapies. The available intermittent and continuous renal replacement therapy techniques all have their own advantages and disadvantages. The best time to start renal replacement therapy and various other practical aspects of these techniques still need to be clarified. For these reasons, daily consultation between intensivists and nephrologists is necessary to select the best technique for the ICU patient with acute renal failure, based on the hemodynamic status, biological variables (uremia, coagulation, acid-base balance, electrolytes) and effects on other organ systems (cognitive state, pericarditis, myopathy). In the future, new markers of renal dysfunction may facilitate treatment choices.

Assessment of erythrocyte shape by flow cytometry techniques.

BACKGROUND: Red blood cell (RBC) rheology is altered in different diseases, including acute conditions such as patients in intensive care units (ICU) with sepsis or with an inflammatory reaction due to postoperative states or intracerebral haemorrhage, or chronic conditions such as diabetes mellitus or terminal renal failure. Several techniques are available to assess alterations in RBC rheology, especially deformability, but they are too cumbersome to be used on a large number of cells. OBJECTIVE: To develop a new, rapid flow cytometry technique for easy assessment of RBC shape in patients. METHODS: In flow cytometry, healthy human RBC shape shows a bimodal distribution related to the biconcave form. On this histogram, the second Pearson coefficient of dissymmetry (PCD) representing the asymmetry of this histogram and the spherical index (M2:M1) were calculated, both representing the spherical shape. This technique was used in healthy volunteers (n=17) and in diseases characterised by abnormalities in RBC rheology, including terminal renal failure requiring haemodialysis (n=28), diabetes mellitus (n=18), sepsis (n=19) and acute inflammatory states (postoperative, intracerebral haemorrhage, chronic obstructive pulmonary disease, epilepsy or severe drug intoxication; n=21). Multivariate analysis was performed to determine the factors influencing RBC shape. RESULTS: Measurement of RBC shape was highly reproducible. A good correlation was observed between the PCD and the spherical index, except in the critically ill patients without sepsis. RBCs were more spherical in patients with terminal renal failure (PCD -0.56 (0.14), p<0.05), diabetes mellitus (PCD -0.59 (0.23), p<0.05), sepsis (PCD -0.58 (0.22), p<0.05) or an acute inflammatory state (PCD -0.65 (0.29), p<0.05) than in healthy volunteers (PCD -0.89 (0.12)). The spherical index was also increased in all populations compared with healthy volunteers (terminal renal failure 2.30 (0.20); diabetes mellitus 2.27 (0.38); sepsis 2.28 (0.37); acute inflammatory state 2.35 (0.42) vs healthy volunteers 2.72 (0.47); all p<0.05). Multivariate analysis demonstrated that the underlying pathology (sepsis, acute inflammatory state, diabetes mellitus, terminal renal failure) was the principal cause of these RBC shape abnormalities. CONCLUSION: RBCs are characterised by an increased spherical shape in many disease states. The measure of the second PCD in flow cytometry is a new, easy method to investigate RBC shape in various diseases. This technique could facilitate the investigation of abnormalities of RBC rheology.

Effects of sample temperature on red blood cell shape in septic patients.

Several recent in vitro studies have observed that alterations in red blood cell (RBC) rheology depend on sample temperature. This possibility could limit the in vivo validity of the assessment of RBC shape. We investigated the effects of sample temperature on RBC shape estimated by flow cytometry in septic patients compared with those of volunteers. 0.5 ml of blood was placed at 4 degrees C, room temperature (20 degrees C) or at 37 degrees C. RBCs were analyzed at 30 minutes (T30) by flow cytometry and results compared to baseline measures. With the flow cytometry technique, the RBC shape of healthy volunteers shows a bimodal distribution related to the biconcave form. On this histogram, we calculated the second Pearson coefficient of dissymmetry--PCD--representing the asymmetry of this histogram. At baseline, RBC PCD was increased in septic patients representing a more spherical shape compared to volunteers (-0.73+/-0.18 versus -0.95+/-0.05; p=0.007). For both groups, RBC shape estimated by the flow cytometry technique was not modified by the temperature of the sample. We conclude that estimation of RBC shape by flow cytometry is not influenced by the temperature of the sample. The present study validates the flow cytometry technique to assess RBC shape in vitro.

Red blood cell rheology in sepsis.

Changes in red blood cell (RBC) function can contribute to alterations in microcirculatory blood flow and cellular dysoxia in sepsis. Decreases in RBC and neutrophil deformability impair the passage of these cells through the microcirculation. While the role of leukocytes has been the focus of many studies in sepsis, the role of erythrocyte rheological alterations in this syndrome has only recently been investigated. RBC rheology can be influenced by many factors, including alterations in intracellular calcium and adenosine triphosphate (ATP) concentrations, the effects of nitric oxide, a decrease in some RBC membrane components such as sialic acid, and an increase in others such as 2,3 diphosphoglycerate. Other factors include interactions with white blood cells and their products (reactive oxygen species), or the effects of temperature variations. Understanding the mechanisms of altered RBC rheology in sepsis, and the effects on blood flow and oxygen transport, may lead to improved patient management and reductions in morbidity and mortality.

Disseminated aspergillosis in intensive care unit patients: an autopsy study.

Disseminated aspergillosis is an uncommon but frequently fatal disease in critically ill populations. With studies suggesting that the incidence of this disease is increasing, and with relatively few epidemiological data available in this population, we evaluated cases of disseminated aspergillosis identified at autopsy over a one-year period on a 31-bed mixed medico-surgical intensive care unit (ICU) of an academic university hospital. In 1999, there were 489 deaths out of 2984 ICU admissions, and 222 autopsies were performed. Post-mortem examination demonstrated disseminated aspergillosis involving non-contiguous organs in 6 (2.7%) autopsies and, of these, five patients (2.3% of total) had had chronic obstructive pulmonary disease (COPD) and had been treated with corticosteroids and mechanical ventilation for pulmonary infection. One patient also had granulocytopenia. In each patient, sputum and bronchoalveolar lavage (BAL) cultures had been positive for Aspergillus fumigatus after ICU admission but this was considered as colonization and the patients were given fluconazole for suspected candidal infection. In conclusion, COPD patients treated with corticosteroids and presenting with pulmonary infection should be considered at risk for disseminated aspergillosis. The rapidly fatal outcome after ICU admission suggests that colonization with Aspergillus can occur before ICU admission.

Outbreak of nosocomial multidrug-resistant Enterobacter aerogenes in a geriatric unit: failure of isolation contact, analysis of risk factors, and use of pulsed-field gel electrophoresis.

We describe herein an outbreak of Enterobacter aerogenes in a geriatric acute unit with failure of contact isolation that necessitated the temporary closure of the department. We emphasize the need for guidelines for the management of multiresistant bacteria.

Diagnosis and treatment of an unusual cause of metabolic acidosis: ethylene glycol poisoning.

Ethylene glycol intoxication is a rare but dangerous type of poisoning. It causes a severe acidosis with high anion and osmolal gaps. Clinical manifestations of the ethylene glycol intoxication can be divided in three phases: a neurologic stage, with hallucinations, stupor and coma; the second stage is cardiovascular with cardiac failure. Renal failure characterizes the third stage, due to acute tubular necrosis. After aggressive gastric emptying, the main treatment is ethanol or 4-methypyrazole, which can be given either orally or intravenous, with supportive measures for all symptoms or diseased organ.

A case of rapidly fatal systemic capillary leak syndrome in a kidney transplant recipient.

Idiopathic Systemic Capillary Leak Syndrome (SCLS) is a rare entity characterised by idiopathic increasing of capillary permeability associated with recurrent attacks of hypovolaemic shock. We report the case of a 39-year-old man with a SCLS fourteen years after a cadaveric renal transplantation. The clinical evolution was rapidly fatal despite treatment with corticoids, aminophylline and terbutaline which are the most efficient drugs known to prevent attacks.