Critical care : the official journal of the Critical Care Forum
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The authors of a recent paper have described an updated simplified acute physiology score (SAPS) II mortality model developed on patient data from 1998 to 1999. Hospital mortality models have a limited range of applicability. SAPS II, Acute Physiology, Age, and Chronic Health Evaluation (APACHE) III, and mortality probability model (MPM)-II, which were developed in the early 1990s, have shown a decline in predictive accuracy as the models age. ⋯ In particular, mortality tends to get over predicted when older models are applied to more contemporary data, which in turn leads to 'grade inflation' when benchmarking intensive care unit (ICU) performance. Although the authors claim that their updated SAPS II can be used for benchmarking ICU performance, it seems likely that this model might already be out of calibration for patient data collected in 2005 and beyond. Thus, the updated SAPS II model may be interesting for historical purposes, but it is doubtful that it can be an accurate tool for benchmarking data from contemporary populations.
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Comparative Study Clinical Trial
Early hemoperfusion with an immobilized polymyxin B fiber column eliminates humoral mediators and improves pulmonary oxygenation.
The objective of this study was to clarify the efficacy and mechanism of action of direct hemoperfusion with an immobilized polymyxin B fiber column (DHP-PMX) in patients with acute lung injury or acute respiratory distress syndrome caused by sepsis. ⋯ The mechanism of action of DHP-PMX is still not fully understood, but we report the following findings. The mean blood levels of plasminogen activator inhibitor-1, NE, and IL-8 were significantly decreased from 48 hours after DHP-PMX treatment. The mean PaO2/FiO2 ratio was significantly improved from 96 hours after DHP-PMX treatment. Improvement in the PaO2/FiO2 ratio appeared to be related to the decreases in blood NE and IL-8 levels.
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This study was performed to determine whether surfactant application during extracorporeal membrane oxygenation (ECMO) improves lung volume, pulmonary mechanics, and chest radiographic findings in children with respiratory failure or after cardiac surgery. ⋯ Surfactant application may be of benefit in children with respiratory failure treated with ECMO, but these findings need confirmation from prospective studies.
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We conducted a prospective observational study from January 1995 to December 2004 to evaluate the impact on recovery of a major advance in renal replacement therapy, namely continuous veno-venous haemodiafiltration (CVVHDF), in patients with refractory septic shock. ⋯ Early CVVHDF may improve the prognosis of sepsis-related multiple organ failure. Failure to correct metabolic acidosis rapidly during the procedure was a strong predictor of mortality.
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Comment Comparative Study
Prediction of ventilation weaning outcome: children are not little adults.
Prediction of ventilation weaning outcome in children is important, as unsuccessful extubation increases both morbidity and mortality. Adult weaning criteria are poor predictors of weaning outcome in children for several possible reasons: the length of mechanical ventilation is generally much shorter, and the weaning failure rate is lower in children (thus larger patient numbers are required); integrated weaning indices, such as the rapid shallow breathing index, do not account for normal developmental changes in respiratory function; and the heterogeneity of mechanically ventilated children is greater than in adults. The challenge remains to find universal weaning outcome predictors in children.