EPO levels can be inappropriately low in critically ill patients, so that EPO deficiency may contribute to the development of anaemia in these patients. This phenomenon is observed not only in the presence of acute renal failure, but also in the presence of sepsis.

The evaluation and management of acute renal failure in the ICU patient remains a formidable task because of the complexity of this condition. Clinical and physiologic assessment and complementing laboratory and imaging tests are currently insufficient to differ between true renal parenchymal damage (acute tubular necrosis; it is important to realize that this term does not necessarily imply widespread injury, because whole organ dysfunction in humans has often been associated with very limited parenchymal cellular necrosis) and prerenal azotemia (decreased renal blood flow with altered glomerular hemodynamics and subsequently diminished glomerular filtration, without significant epithelial cell injury). Moreover, tubular damage and altered glomerular hemodynamics may coexist or lead to each other, and their relative contribution to the evolving renal dysfunction has not been unequivocally established. The limited data regarding the renal pathology of such patients and the scant information about human morphologic and functional correlates further undermine our knowledge about diagnostic and therapeutic approaches to these patients. Advanced techniques are critically needed to establish noninvasively the dynamic status of renal parenchymal microcirculation and the distribution of intrarenal oxygenation and to identify evolving cellular energy depletion and tubular cell damage. A few technologies are potentially promising, such as blood oxygen level dependent magnetic resonance imaging, positron emission tomography, and kidney injury molecule-1 detection in patients' urine. Because of the difficulties in analyzing the pathophysiology in humans, clinicians continue to rely largely on animal models to guide understanding and rationale for the identification of therapeutic targets. Data from such animal studies are complemented by studies in isolated perfused kidneys, isolated tubules, and tubular epithelial cell cultures. In this report, we summarize some concepts of acute tubular necrosis that have evolved as a result of these studies, evaluate available animal models, and underscore controversies regarding experimental acute tubular necrosis.

Introduction Community-acquired pneumonia remains a common condition worldwide. It is associated with significant morbidity and mortality. The aim of this study was to evaluate conditions that could predict a poor outcome. Design Retrospective analyse of 69 patients admitted to the ICU from 1996 to 2003. Demographic data included age, sex and medical history. Etiologic agents, multiorgan dysfunction, nosocomial infections, SAPS II and PORT scores were recorded for each patient. For statistical analysis we used a t test, chi-square test and Mann-Whitney U test on SPSS ® . A value of P less than 0.05 was considered significant. Results Forty-seven patients were male and 22 patients were female. Mean age was 52 years. Sixty-seven percent had serious pre-morbid conditions including pulmonary disease (34.8%), cardiac problems (36.2%), diabetes (13%) and chronic liver disease (5.8%); 40.6% were smokers, drug abusers or alcohol dependents. Sixtyeight patients required invasive mechanical ventilation. The average length of ventilation was 13.5 days, median 8 days. The mean SAPS II score was 40.14 and the mean PORT score was 141. The mortality rate was 27.5% (SAPS II estimated mortality, 35%). Complications reported were ARDS (40.6%), septic shock (34.8%), acute renal failure (2.9%), cardiac arrest (8.7%) and nosocomial infeccions (46.4%). Mortality rates were higher for previous hepatic (75%) and metabolic (33%) diseases. We found a close association between crude mortality and SAPS II score (P = 0.003) and development of complications (P = 0.0028). Respiratory dysfunction (P = 0.006) and septic shock (P = 0.022) were most significantly related to mortality. No significant differences were founded regarding age, comorbidities, PORT score, etiologic agents, nosocomial infections and length of invasive mechanical ventilation. Conclusions Previous hepatic chronic disease was strictly related to higher mortality as well as isolation of MRSA. ARDS and septic shock predicted a poor outcome. SAPS II score was the best severity indicator of mortality. Objective It is known that the closed tracheal suction system (CTSS) produces less hemodynamic and gasometric deterioration than an open tracheal suction system (OTSS). Use is limited because no decrease in the incidence of ventilator-associated pneumonia (VAP) was found and also because it is more expensive. But, is daily periodic change of the CTSS necessary? The aim of this study was to analyze the incidence of VAP using a CTSS without periodic change versus an OTSS. Methods It is a prospective study of ICU patients from 1 January 2004 to 31 October 2004. Patients who required mechanical ventilation (MV) were randomized into two groups: one group was suctioned with CTSS without periodic change and another group with OTSS. An aspirate tracheal swab and a throat swab on admission and afterwards twice weekly were taken. VAP was classified based on throat flora in endogenous and exogenous samples. The statistical analysis was performed by chi-square test and Student's t test, and w...

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Low and moderate doses of methylene blue can significantly increase arterial blood pressure but not cardiac index during endotoxic shock. Methylene blue infusion may selectively increase mesenteric blood flow. High doses of methylene blue can worsen systemic hypotension, myocardial depression, and pulmonary hypertension after endotoxemia.