Journal of critical care
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Journal of critical care · Sep 1996
Ventilatory factors affecting inhaled nitric oxide concentrations during continuous-flow administration.
Inhaled nitric oxide has been reported to be useful in acute respiratory distress syndrome and other lung diseases characterized by pulmonary hypertension and hypoxemia. The best site to inject the NO is still controversial, as is whether it can be affected by changes in ventilatory settings. The objective of this study was to examine the impact of various ventilator settings (tidal volume [Vt], inspiratory-to-expiratory [I:E] ratio, added dead space) in the final NO concentrations reached when NO is administered as a continuous flow near the endotracheal tube. ⋯ According to our lung model, continuous-flow administration of NO near the endotracheal tube is influenced strongly by changes in ventilatory settings.
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Journal of critical care · Sep 1996
Comparative Study Clinical Trial Controlled Clinical TrialHypercalcitoninemia and inappropriate calciuria in the acute trauma patient.
This study was undertaken to determine the role of calcium-regulatory hormones (calcitonin [CT], parathyroid hormone [PTH], and vitamin D analogs) during the first 48 hours after acute trauma. ⋯ Acute trauma patients have ionized hypocalcemia associated with inappropriate urinary calcium loss, increased CT levels, and normal PTH and vitamin D analog values. We believe the degree of calciuria we observed was inappropriate in the context of ionized hypocalcemia. The cause of these increased CT levels is unclear. Our results suggest that Ca(2+)-regulatory mechanisms may be disrupted in the acute trauma patient.
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Journal of critical care · Sep 1996
Relationship between ventilator-associated pneumonia and intramucosal gastric pHi: a case-control study.
Prior investigations have suggested a clear relationship between nosocomial pneumonia and intramucosal gastric pH (pHi), a probable marker of bacterial translocation. ⋯ Most patients with nosocomial pneumonia had no associated intramucosal gastric acidosis. However, low pHi was associated with increased mortality.
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Journal of critical care · Sep 1996
Poor in vivo reproducibility of gastric intramucosal pH determined by saline-filled balloon tonometry.
The reproducibility of gastric intramucosal pH (pHi) determinations by saline-filled balloon tonometry has not been assessed adequately. We examined the agreement of pHi obtained using pairs of tonometry catheters under various conditions in a canine model of global hypoxia. ⋯ Clinically important disagreement was observed in simultaneous pHi determinations obtained using separate gastric balloon tonometry catheters exposed to identical in vivo conditions. Poor reproducibility of individual pHi determinations may limit the accuracy of pHi obtained by gastric balloon tonometry in the clinical setting.
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Journal of critical care · Sep 1996
Comparative Study Clinical Trial Controlled Clinical TrialComparison of transesophageal echocardiographic, fick, and thermodilution cardiac output in critically ill patients.
Recent observations have highlighted errors in the thermodilution technique of measuring cardiac output. Thus, cardiac output measurements using transesophageal echocardiography and the Fick method were compared with simultaneous thermodilution measurements. ⋯ There are substantial differences in cardiac output as measured by these three methods, best demonstrated using the method of Bland and Altman. The variability of cardiac output and its derivatives (eg, oxygen delivery) should be borne in mind when making clinical decisions on individual patients.