The effects of dexmedetomidine/remifentanil and midazolam/remifentanil on auditory-evoked potentials and electroencephalogram at light-to-moderate sedation levels in healthy subjects.

Avoidance of excessively deep sedation levels is problematic in intensive care patients. Electrophysiologic monitoring may offer an approach to solving this problem. Since electroencephalogram (EEG) responses to different sedation regimens vary, we assessed electrophysiologic responses to two sedative drug regimens in 10 healthy volunteers.

Membrane microdialysis: Evaluation of a new method to assess splanchnic tissue metabolism.

Objective: Measuring peritoneal lactate concentrations could be useful for detecting splanchnic hypoperfusion. The aims of this study were to evaluate the properties of a new membrane-based microdialyzer in vitro and to assess the ability of the dialyzer to detect a clinically relevant decrease in splanchnic blood flow in vivo.

Design: A membrane-based microdialyzer was first validated in vitro.

Effects of prolonged endotoxemia on liver, skeletal muscle and kidney mitochondrial function.

Introduction: Sepsis may impair mitochondrial utilization of oxygen. Since hepatic dysfunction is a hallmark of sepsis, we hypothesized that the liver is more susceptible to mitochondrial dysfunction than the peripheral tissues, such as the skeletal muscle. We studied the effect of prolonged endotoxin infusion on liver, muscle and kidney mitochondrial respiration and on hepatosplanchnic oxygen transport and microcirculation in pigs.

Decreasing gut wall glucose as an early marker of impaired intestinal perfusion.

Objective: The aim of this study was to assess the microcirculatory and metabolic consequences of reduced mesenteric blood flow.

Design: Prospective, controlled animal study.

Setting: The surgical research unit of a university hospital.

Effects of low abdominal blood flow and dobutamine on blood flow distribution and on the hepatic arterial buffer response in anaesthetized pigs.

Low cardiac output impairs the hepatic arterial buffer response (HABR). Whether this is due to low abdominal blood flow per se is not known. Dobutamine is commonly used to increase cardiac output, and it may further modify hepatosplanchnic and renal vasoregulation.

Reversible encephalopathy complicating post-streptococcal glomerulonephritis.

We describe a 15-year-old boy with acute transient encephalopathy complicating poststreptococcal glomerulonephritis. Based on advanced magnetic resonance imaging, cerebral alterations were related to cerebrovascular autoregulatory dysfunction (ie, a vasogenic edema) and vasculitis was excluded. These insights into the pathophysiology improve patient management and argue against the therapeutic immunosuppression postulated by some authors.

Does fluid loading influence measurements of intestinal permeability?

Introduction: Urinary recovery of enterally administered probes is used as a clinical test of intestinal mucosal permeability. Recently, evidence has been provided that the recovery of some but not all sugar probes is dependent on the amount of diuresis and renal function. The aim of this study was to assess the effect of fluid loading on the urinary recovery of sugar probes in healthy volunteers.

Preconditioning with monophosphoryl lipid A improves survival of critically ischemic tissue.

In this study we sought to assess the effects of preconditioning with monophosphoryl lipid A on critically ischemic wound margins and on systemic and local hemodynamics and oxygenation during prolonged anesthesia with volatile anesthetics and narcotics. Twenty large white pigs were randomly assigned to receive either monophosphoryl lipid A 35 mug/kg IV or saline 24 h before dissection of a buttock flap. The animals were anesthetized with isoflurane (end-tidal concentration approximately 1.

Comparison of continuous and intermittent renal replacement therapy for acute renal failure.

Background: Mortality rates of critically ill patients with acute renal failure (ARF) requiring renal replacement therapy (RRT) are high. Intermittent and continuous RRT are available for these patients on the intensive care units (ICUs). It is unknown which technique is superior with respect to patient outcome.

Severe acute pancreatitis: case-oriented discussion of interdisciplinary management.

The clinical course of an episode of acute pancreatitis varies from a mild, transitory illness to a severe often necrotizing form with distant organ failure and a mortality rate of 20-40%. Patients with severe pancreatitis, representing about 15-20% of all patients with acute pancreatitis, need to be identified as early as possible after onset of symptoms allowing starting intensive care treatment early in the disease process. An episode of severe acute pancreatitis progresses in two phases.

Siglec-9 transduces apoptotic and nonapoptotic death signals into neutrophils depending on the proinflammatory cytokine environment.

We report about new apoptotic and non-apoptotic death pathways in neutrophils that are initiated via the surface molecule sialic acid-binding immunoglobulin-like lectin (Siglec)-9. In normal neutrophils, Siglec-9 ligation induced apoptosis. Inflammatory neutrophils obtained from patients with acute septic shock or rheumatoid arthritis demonstrated increased Siglec-9, but normal Fas receptor-mediated cytotoxic responses when compared with normal blood neutrophils.

Hepatosplanchnic blood flow control and oxygen extraction are modified by the underlying mechanism of impaired perfusion.

Objective: To assess the effects of low hepatosplanchnic blood flow on regional blood flow control and oxygenation.

Design: Three randomized, controlled animal experiments.

Setting: Two university experimental research laboratories.

Estimation of central venous pressure by ultrasound.

Introduction: Increasing blood volume and cardiac output is one of the most commonly needed intervention in the primary care of traumatized and severely ill patients. Although cardiac filling pressures have severe limitations in assessing the preload, central venous pressure (CVP) is the invasive measure most frequently used in clinical practice for the assessment of volume status and cardiac preload. We combined ultrasound and tissue pressure measurement for non-invasive jugular and brachial venous pressure estimation.

Blood pressure and vessel recanalization in the first hours after ischemic stroke.

Background And Purpose: Transient elevation of arterial blood pressure (BP) is frequent in acute ischemic stroke and may help to increase perfusion of tissue jeopardized by ischemia. If this is true, recanalization may eliminate the need for this BP elevation.

Methods: We analyzed BP in 149 patients with acute ischemic stroke on admission to the hospital and 1 and 12 hours after intraarterial thrombolysis.

Midlatency auditory-evoked potentials in the assessment of sedation in cardiac surgery patients.

Objectives: Midlatency auditory-evoked potentials (MLAEPs) may provide an objective measure of depth of sedation. The aim of this study was to evaluate MLAEPs for measuring sedation in cardiac surgery patients.

Design: Prospective study.

N100 auditory potential and electroencephalogram discriminate propofol-induced sedation levels.

Objective: In the present study, we evaluated the electroencephalogram (EEG) and auditory N100 potential (N100) before and during propofol-induced sedation. The aim was to test whether using EEG and N100 the level of sedation may be evaluated.

Methods: Twenty-nine cardiac surgery patients were studied.

Measuring depth of sedation with auditory evoked potentials during controlled infusion of propofol and remifentanil in healthy volunteers.

Avoiding excessively deep levels of sedation is a major problem in intensive care patients. We studied whether clinically relevant levels of sedation can be objectively assessed using long latency auditory evoked potentials. We measured the auditory evoked potentials at 100 ms after the stimulus (N100) in 10 healthy volunteers during stepwise increasing, clinically relevant levels of sedation (Ramsay score [RS] 2-4).

Changes in splanchnic circulation during an alveolar recruitment maneuver in healthy porcine lungs.

Unlabelled: Recruitment maneuvers (RM) are advocated as a complement to mechanical ventilation during anesthesia and in acute lung injury. However, they produce high intrathoracic pressures and volumes that may compromise hemodynamics. Our aim was to analyze the effect of a RM on hemodynamics in 10 anesthetized pigs.

Diagnosis and management of electrolyte emergencies.

Electrolyte and fluid imbalances are disorders frequently observed in critical care patients. In many instances patients are asymptomatic, but they may also present with neurological alterations, severe muscle weakness, nausea and vomiting or cardiovascular emergencies. Therefore, a pathophysiological understanding of these disorders is necessary for initiating an appropriate therapy.

Changes in regional blood flow and pCO(2) gradients during isolated abdominal aortic blood flow reduction.

Objective: pCO(2) gradients are used for the assessment of splanchnic regional and local mucosal blood flow changes in experimental and clinical research. pCO(2) gradients may not parallel blood flow changes because of concomitant changes in metabolism, hemoglobin, temperature, and the Haldane effect.

Design And Setting: A randomized, controlled animal experiment in a university experimental research laboratory.

Apparent heterogeneity of regional blood flow and metabolic changes within splanchnic tissues during experimental endotoxin shock.

Unlabelled: We conducted a randomized, controlled experiment of prolonged lethal endotoxin shock in pigs aiming at 1) simultaneously measuring perfusion at different parts of the gut to study the potential heterogeneity of blood flow within the splanchnic region; 2) studying the association among regional blood flows, oxygen supply, and different metabolic markers of perfusion; and 3) analyzing the association between histological gut injury and markers of perfusion and metabolism. The primary response to endotoxin was a decrease in systemic and splanchnic blood flow followed by hyperdynamic systemic circulation. Redistribution of blood flows occurred within the splanchnic circulation: superior mesenteric artery blood flow was maintained, whereas celiac trunk blood flow was compromised.

Change in stroke volume in response to fluid challenge: assessment using esophageal Doppler.

Objective: To compare two methods of assessing a change in stroke volume in response to fluid challenge: esophageal Doppler and thermodilution with the pulmonary artery catheter.

Design: Prospective study.

Setting: Department of Intensive Care of a university medical center.

Splanchnic blood flow in low-flow states.

Insufficient splanchnic blood flow in critically ill patients is the result of a multitude of different diseases, treatment modalities and their interplay, and is associated with increased morbidity and mortality. A combination of diminished and heterogeneous mesenteric blood flow, impaired or exhausted regulatory mechanisms and adverse drug effects may coexist with normal systemic hemodynamics.

Clinical review: splanchnic ischaemia.

Inadequate splanchnic perfusion is associated with increased morbidity and mortality, particularly if liver dysfunction coexists. Heart failure, increased intra-abdominal pressure, haemodialysis and the presence of obstructive sleep apnoea are among the multiple clinical conditions that are associated with impaired splanchnic perfusion in critically ill patients. Total liver blood flow is believed to be relatively protected when gut blood flow decreases, because hepatic arterial flow increases when portal venous flow decreases (the hepatic arterial buffer response [HABR]).