Critical care medicine
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Critical care medicine · May 1997
Randomized Controlled Trial Comparative Study Clinical TrialComparison of pressure- and flow-triggered pressure-support ventilation on weaning parameters in patients recovering from acute respiratory failure.
To compare the effects of pressure- and flow-triggered pressure-support ventilation on weaning parameters during recovery from acute respiratory failure. ⋯ The application of either a pressure- or flow-triggered system during pressure-support ventilation with the ventilator did not significantly affect short-term changes in gas exchange, respiratory mechanics, and inspiratory workload in patients recovering from acute respiratory failure of various etiologies without chronic obstructive pulmonary disease.
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Critical care medicine · May 1997
Comparative StudyNoninvasive determination of cardiac output in a model of acute lung injury.
To examine the utility of single breath CO2 analysis as a noninvasive measure of cardiac output in a model of acute lung injury. ⋯ Our results indicate that changes in cardiac output can be determined using components of the CO2 expirogram with a high degree of reliability in animals with induced acute lung injury. Specifically, the use of four parameters derived from a plot of expired CO2 concentration vs. expired volume predict changes in cardiac output in adult sheep with induced lung injury with an adjusted coefficient of determination of .80. Prospective application of this technology in the clinical setting with the rapidly changing physiology that is characteristic of the acutely ill patient will be essential in determining the clinical usefulness of single breath CO2 analysis as a noninvasive measure of cardiac output.
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Critical care medicine · May 1997
Randomized Controlled Trial Clinical TrialFunctional magnesium deficiency in critically ill patients identified using a magnesium-loading test.
To determine the feasibility of the magnesium-loading test in the critically ill and to validate serum ionized magnesium assay using the magnesium-loading test as a reference in this same patient population. ⋯ The magnesium-loading test is feasible and appears to be valid based on its performance during the 3-day evaluation. Using the magnesium-loading test as a reference, serum ionized magnesium appears to be an insensitive biochemical marker of functional hypomagnesemia. Larger cohort studies using the magnesium-loading test will help establish the true prevalence of magnesium deficiency and its associated risk factors in critically ill patients.
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Critical care medicine · May 1997
Comparative StudyWhole-body impedance cardiography in the measurement of cardiac output.
To evaluate the reliability of whole-body impedance cardiography with electrodes on wrists and ankles in the measurement of cardiac output compared with the thermodilution method. ⋯ There was close agreement between whole-body impedance cardiography and thermodilution in the measurement of cardiac output in patients with coronary artery disease without cardiac shunts and valvular lesions. The repeatability of the impedance method was significantly better than the repeatability of thermodilution. Whole-body impedance cardiography can be recommended for the assessment of cardiac output and its changes in the resting state. Whole-body impedance cardiography is a feasible and handy method for noninvasive and continuous measurement of cardiac output.
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Critical care medicine · May 1997
Comparative StudyRoutine portable chest radiographs in the medical intensive care unit: effects and costs.
To determine the effects and net costs of routine chest radiographs in a medical intensive care unit (ICU). ⋯ The policy of obtaining routine chest radiographs in the medical ICU is effective and results in net savings.