Critical care : the official journal of the Critical Care Forum
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Pleth Variability Index (PVI) is a new algorithm that allows continuous and automatic estimation of respiratory variations in the pulse oximeter waveform amplitude. Our aim was to test its ability to detect changes in preload induced by passive leg raising (PLR) in spontaneously breathing volunteers. ⋯ PVI can detect haemodynamic changes induced by PLR in spontaneously breathing volunteers. However, we found that PVI was a weak predictor of fluid responsiveness in this setting.
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Comparative Study
The 'cardiac-lung mass' artifact: an echocardiographic sign of lung atelectasis and/or pleural effusion.
We conducted an ultrasound study to investigate echocardiographic artifacts in mechanically ventilated patients with lung pathology. ⋯ Lung atelectasis and/or pleural effusion may create a mirror image, intracardiac artifact in mechanically ventilated patients. The latter was named the 'cardiac-lung mass' artifact to underline the important diagnostic role of both echocardiography and lung echography in these patients.
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Comparative Study
Risk factors for the development of nosocomial pneumonia and mortality on intensive care units: application of competing risks models.
Pneumonia is a very common nosocomial infection in intensive care units (ICUs). Many studies have investigated risk factors for the development of infection and its consequences. However, the evaluation in most of theses studies disregards the fact that there are additional competing events, such as discharge or death. ⋯ More studies using competing risk models, which provide more accurate data compared to naive survival curves or logistic models, should be carried out to verify the impact of risk factors and patient characteristics for the acquisition of nosocomial infections and infection-associated mortality.
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Lung fibrosis, reduced lung compliance, and severe hypoxemia found in patients with acute lung injury often result in a need for the support of mechanical ventilation. High-tidal-volume mechanical ventilation can increase lung damage and fibrogeneic activity but the mechanisms regulating the interaction between high tidal volume and lung fibrosis are unclear. We hypothesized that high-tidal-volume ventilation increased pulmonary fibrosis in acute lung injury via the serine/threonine kinase-protein kinase B (Akt) and mitogen-activated protein kinase pathways. ⋯ We conclude that high-tidal-volume ventilation-induced microvascular permeability, lung fibrosis, and chemokine production were dependent, in part, on activation of the Akt and ERK1/2 pathways.
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Acute lung injury (ALI) is a major cause of acute respiratory failure with high mortality despite lung-protective ventilation. Prior work has shown disordered inflammation and coagulation in ALI, with strong correlations between biomarker abnormalities and worse clinical outcomes. We measured plasma markers of inflammation, coagulation and fibrinolysis simultaneously to assess whether these markers remain predictive in the era of lung-protective ventilation. ⋯ Despite lung-protective ventilation, abnormalities in plasma levels of markers of inflammation, coagulation and fibrinolysis predict mortality in ALI patients, indicating more severe activation of these biologic pathways in nonsurvivors.