American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Oct 1996
Microcirculatory changes in rat skeletal muscle in sepsis.
The aim of this study was to confirm that microvascular perfusion was abnormal during the early phases of normotensive sepsis and to determine whether these changes were due to the development of tissue edema. Skeletal muscle red blood cell (RBC) flow was studied in rats made septic by cecal ligation and perforation (CLP). After anesthesia with halothane, arterial and venous cannulae were inserted and, in the treatment group, a CLP performed. ⋯ This study shows that sepsis was associated with increased RBC flow heterogeneity. These changes, which occur within 24 h of the septic insult, are a persistent feature of the evolving septic process in the absence of tissue edema. These observations support the view that extrinsic compression of the microcirculation by tissue edema is not the primary cause of alterations in microcirculatory flow in sepsis.
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Am. J. Respir. Crit. Care Med. · Oct 1996
Chest wall compliance in infants and children with neuromuscular disease.
Respiratory muscle weakness is the primary cause of respiratory dysfunction in neuromuscular disease (NMD), but structural abnormalities of the chest wall also play a role. In adults with NMD, restrictive lung disease is in part caused by reduced chest wall compliance (C(W)), believed to reflect stiffening of connective tissue resulting from chronically reduced chest wall motion in the presence of respiratory muscle weakness. We hypothesized that chronic limitation of chest wall motion in young children with NMD leads to structural underdevelopment of the chest wall, and results in increased, rather than decreased, C(W). ⋯ C(W)/kg was higher in subjects with NMD than in controls, at 5.2 +/- 2.8 (mean +/- SD) versus 2.4 +/- 0.8 ml/cm H2O (p < 0.001). In subjects who had normal lung compliance values during spontaneous breathing (C(Lspont)), C(W)/C(Lspont) was significantly greater in subjects with NMD (5.5 +/- 3.2) than in controls (1.9 +/- 1.0) (p < 0.001). By predisposing to rib cage deformation and reduced end-expiratory lung volume, abnormally high C(W) in infants and young children with NMD may contribute to respiratory dysfunction.
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Am. J. Respir. Crit. Care Med. · Sep 1996
Multicenter Study Comparative StudyBacteremia and severe sepsis in adults: a multicenter prospective survey in ICUs and wards of 24 hospitals. French Bacteremia-Sepsis Study Group.
To examine the relationships between bacteremia and severe sepsis and assess the influence of characteristics of infection on the risk of severe sepsis and outcome of bacteremia, we analyzed all clinically significant episodes of bacteremia occurring during a 2-mo prospective survey of 85,750 admissions to adult wards and intensive care units (ICUs) of 24 hospitals in France. Incidence rates of bacteremia and of bacteremic severe sepsis were 9.8 (95% CI: 9.2 to 10.5) and 2.6 (95% CI: 2.2 to 2.9), respectively, per 1,000 adult admissions; these rates were eight and 32 times higher in ICUs than in wards, respectively. Independent risk factors for severe sepsis during bacteremia included age (p < 0.001) and an intraabdominal (p < 0.001), pulmonary (p < 0.001), neuromeningeal (p = 0.004), or multiple (p < 0.001) source of bacteremia, but not categories of organisms involved. ⋯ The risk of death after bacteremia increased with age (p < 0.001), a rapidly or ultimately fatal underlying disease (p < 0.001), and the presence of severe sepsis (p < 0.001), shock (p = 0.03), and infection caused by gram-positive organisms other than coagulase-negative staphylococci, relative to other organisms (p < 0.001). A primary urinary tract source of infection was associated with a better prognosis (p = 0.03). We conclude that whereas sources of infection influence both the risk of severe sepsis and the outcome of bacteremia, the microbiologic characteristics of infection influence only the outcome, with gram-negative organisms and coagulase-negative staphylococci posing a lesser risk than other organisms.
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Am. J. Respir. Crit. Care Med. · Sep 1996
ReviewEthical considerations of ensuring an informed and autonomous consent in research involving critically ill patients.
Despite several codes of research ethics, the issuance of comprehensive rules regarding informed consent by governmental agencies, and numerous writings on the subject of informed consent, many commentators still question the quality of the informed consent process in clinical research. A major concern is that investigators emphasize only the information-giving aspect of "informed" consent, whereas moral philosophy stresses a more robust concept of informed consent that incorporates the additional requirements of subject competence and voluntariness of the consent, thus ensuring that a consent is not only informed, but autonomous as well. This article aims to examine the issues involved with disclosure, competence, and voluntariness, especially those related to research involving critically ill patients. Suggestions concerning methods that can promote an informed consent process that is more respectful of autonomous decision making will also be discussed.