Articles: critical-illness.
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J Intensive Care Med · Jan 1995
ReviewGastric tonometry: a new monitoring modality in the intensive care unit.
In many critically ill patients, systemic measures of hemodynamic and O2 transport variables may not be sufficiently sensitive to portray the complex interaction between energy requirements and energy supply in all tissues. Gastric or intestinal tonometry has been proposed as a relative noninvasive index of the adequacy of aerobic metabolism in the gut mucosa, a tissue that is particularly vulnerable to alterations in perfusion and oxygenation. The gut mucosa lacks some of the microvascular control mechanisms that allow other tissues, such as the heart, skeletal muscle, and the brain, to increase tissue perfusion during times of stress, and, just like the canary, it will display metabolic changes indicative of dysoxia earlier than those more "vital" tissues. ⋯ Increases in mucosal PCO2, or conversely, decreases in mucosal pH (pHi), are associated with the development of intestinal mucosa ischemia. The clinical utility of pHi to detect intestinal mucosal ischemia has been demonstrated in patients undergoing abdominal aortic surgery. Further, a low gastric mucosal pHi on admission to the ICU appears to be predictive of mortality and pHi-guided resuscitation may improve outcome in a subpopulation of patients admitted to the ICU with normal pHi, perhaps by preventing splanchnic ischemia and the development of a systemic oxygen deficit.
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Acta Anaesthesiol Scand Suppl · Jan 1995
ReviewQuantifying pulmonary oxygen transfer deficits in critically ill patients.
The clinical picture describing oxygen transfer deficits in literature is complicated by inconsistent terminology, and a weak perception of the influence total errors of measured and estimated values have on clinical decision-making. Clinical and analytical terminology: Terms like hypoxia, hypoxaemia and tissue hypoxia in clinical literature are often used synonymously. In present terminology, arterial hypoxia (pO2(a)) is considered to be based on measurements of oxygen tension in arterial blood. ⋯ A calculated shunt of 20-29% may be life threatening in a patient with limited cardiovascular function. A calculated shunt greater than 30% usually requires significant cardiopulmonary support. The necessity of sampling mixed-venous blood seems to be the most limiting factor for a widespread clinical use of shunt calculations.
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Critical care medicine · Dec 1994
Variability in dobutamine pharmacokinetics in unstable critically ill surgical patients.
To delineate the variability in the pharmacokinetics of dobutamine over time in an unstable critically ill adult surgical patient population concurrently receiving therapeutic interventions to optimize oxygen delivery and consumption variables. ⋯ Dobutamine pharmacokinetics in adult critically ill patients is best described by a first-order model. Pathophysiologic factors may have an effect on the pharmacokinetics of dobutamine which appears to change over time. Both inter- and intrapatient variability in infusion rate administered and resultant serum concentrations were wide, suggesting that infusion rate should be guided by clinical end points rather than by predetermined values.