Critical care : the official journal of the Critical Care Forum
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Comparative Study
Recombinant human activated protein C attenuates endotoxin-induced lung injury in awake sheep.
Acute lung injury often complicates severe sepsis. In gram-negative sepsis, bacterial endotoxin activates both coagulation and inflammation. Enhanced lung vascular pressures and permeability, increased extravascular lung water content and deteriorated gas exchange characterize ovine endotoxin-induced lung injury, a frequently used model of acute lung injury. Recombinant human activated protein C (rhAPC), with its anticoagulant, anti-inflammatory, fibrinolytic and antiapoptotic effects, reportedly reduces the respirator-dependent days and the mortality of patients with severe sepsis. We speculate whether rhAPC antagonizes endotoxin-induced lung injury in sheep. ⋯ In awake sheep, rhAPC alleviates endotoxin-induced lung injury--as characterized by improvements of oxygenation, coagulation and inflammation, as well as by reversal of pulmonary hemodynamic and volumetric changes.
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In this issue of Critical Care, Dutch investigators report that, in a cohort of patients with sepsis/septic shock admitted to three different intensive care units (ICUs), low central venous oxygen saturation (ScvO2) was uncommon at the time of ICU admission, and hospital mortality was <30%. Their findings, taken together with those of recent reports from Australia and New Zealand (ANZ), raise serious concerns about the utility of early goal directed therapy (EGDT) outside the context of the original trial. Despite inclusion of EGDT into the Surviving Sepsis Guidelines, in response to growing uncertainty, ANZ and US investigators will soon begin randomization of patients into two large multicentre trials comparing EGDT to standard therapy. Until such studies are completed, basing international treatment guidelines on a single centre study performed in what may turn out to be a highly atypical environment would seem premature.
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Comparative Study
The influence of body composition on therapeutic hypothermia: a prospective observational study of patients after cardiac arrest.
Patients after out-of-hospital cardiac arrest (OHCA) benefit from therapeutic hypothermia for 24 hours. The time needed to reach hypothermia (target temperature of 32 degrees C to 34 degrees C) varies widely. In this study, we explore the relation between measures of body composition and the time needed to reach target temperature with hypothermia. ⋯ The body composition measures from single-frequency impedance and anthropometrics appear to be very concordant. Only TBF percentage (anthropometrics) showed a significant but clinically irrelevant influence on time needed to achieve target temperature with hypothermia. We conclude that there are no indications to adjust current cooling practice toward the body composition of patients.
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Constipation is the most common gastrointestinal complication associated with opioid therapy in chronic pain patients, and also frequently occurs in sedated intensive care unit patients. Conventional therapy may not provide sufficient relief from constipation, which can be severe enough to limit opioid use or the dose. In a recent study on terminally ill patients suffering from laxative-resistant opioid-induced constipation, Thomas and colleagues demonstrated subcutaneous methylnaltrexone to rapidly induce defecation. This appealing result might also have favourable prospects for intensive care patients, as their outcome is often codetermined by recovery of bowel functioning.
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Comparative Study
Norepinephrine to increase blood pressure in endotoxaemic pigs is associated with improved hepatic mitochondrial respiration.
Low blood pressure, inadequate tissue oxygen delivery and mitochondrial dysfunction have all been implicated in the development of sepsis-induced organ failure. This study evaluated the effect on liver mitochondrial function of using norepinephrine to increase blood pressure in experimental sepsis. ⋯ Norepinephrine treatment during endotoxaemia does not increase hepatosplanchnic flow, oxygen delivery or consumption, and does not improve the hepatic lactate extraction ratio. However, norepinephrine increases the liver mitochondria complex I-dependent and II-dependent respiratory control ratios. This effect was probably mediated by a direct effect of norepinephrine on liver cells.