Critical care : the official journal of the Critical Care Forum
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Comparative Study
Regional distribution of acoustic-based lung vibration as a function of mechanical ventilation mode.
There are several ventilator modes that are used for maintenance mechanical ventilation but no conclusive evidence that one mode of ventilation is better than another. Vibration response imaging is a novel bedside imaging technique that displays vibration energy of lung sounds generated during the respiratory cycle as a real-time structural and functional image of the respiration process. In this study, we objectively evaluated the differences in regional lung vibration during different modes of mechanical ventilation by means of this new technology. ⋯ Pressure support and (to a lesser extent) pressure control modes cause a shift of vibration toward lower lung regions compared to volume control when tidal volumes are held constant. Better patient synchronization with the ventilator, greater downward movement of the diaphragm, and decelerating flow waveform are potential physiologic explanations for the redistribution of vibration energy to lower lung regions in pressure-targeted modes of mechanical ventilation.
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Comparative Study
Intracranial pressure monitoring in intensive care: clinical advantages of a computerized system over manual recording.
The presence of intracranial hypertension (HICP) after traumatic brain injury (TBI) affects patient outcome. Intracranial pressure (ICP) data from electronic monitoring equipment are usually calculated and recorded hourly in the clinical chart by trained nurses. Little is known, however, about how precisely this method reflects the real patterns of ICP after severe TBI. In this study, we compared hourly manual recording with a validated and continuous computerized reference standard. ⋯ Although manually recorded end-hour ICP accurately reflected the computerized end-hour and mean hour values, the important omission of a number of episodes of high ICP, some of long duration, results in a clinical picture that is not accurate or informative of the true pattern of unstable ICP in patients with TBI.
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Prediction of death and prolonged mechanical ventilation is important in terms of projecting resource utilization and in establishing protocols for clinical studies of acute lung injury (ALI). We aimed to identify risk factors for a combined end-point of death and/or prolonged ventilator dependence and developed an ALI-specific prediction model. ⋯ A model based on age and cardiopulmonary function three days after the intubation is able to predict, moderately well, a combined end-point of death and/or prolonged mechanical ventilation in patients with ALI.
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Little is known about the development of acute lung injury outside the intensive care unit. We set out to document the following: the association between predefined clinical conditions and the development of acute lung injury by using the American-European consensus definition; the frequency of lung injury development outside the intensive care unit; and the temporal relationship between antecedent clinical risk conditions, intensive care admission, and diagnosis of lung injury. ⋯ The time course from clinical insult to diagnosis of lung injury was rapid, but may be longer for extrapulmonary cases. Some patients with lung injury receive care and die outside the intensive care unit; this observation needs further study.
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Various cohort studies have shown that acute (short-term) mortality rates in unselected critically ill patients may have improved during the past 15 years. Whether these benefits also affect acute and long-term prognosis in chronically critically ill patients is unclear, as are determinants relevant to prognosis. ⋯ Acute and long-term prognosis in chronically critically ill surgical patients has remained unchanged throughout the past 12 years. After successful surgical intervention and intensive care, long-term outcome is reasonably good and is mainly determined by age and underlying disease.