Critical care medicine
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Critical care medicine · Jan 1989
Pressure-augmented fluid administration: modified system and general results.
Rapid fluid infusion is generally augmented by compression devices (pumps) that take advantage of compressibility of modern plastic fluid containers. The most commonly used pumps are not the most effective pressure sources for driving pressure. This paper describes the experience at a Level I trauma hospital with a relatively new device that serves as a more efficient source of pressure for rapid fluid administration. This device, commercially manufactured but locally modified, increases capability with minimal expense and additional training.
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Critical care medicine · Jan 1989
Blood histamine concentrations are not elevated in humans with septic shock.
Histamine has been suggested as an important mediator of the cardiovascular abnormalities during septic shock. To determine if blood histamine levels were increased during human sepsis and septic shock, plasma histamine was measured using a very sensitive radioenzyme assay employing histamine N-methyltransferase (HNMT) in the following patient groups: normal controls (n = 76), nonseptic critically ill (n = 12), nonseptic shock (n = 2), sepsis without shock (n = 28), and septic shock (n = 41). Using this enzyme binding assay, all these groups had similar, normal plasma histamine concentrations, except those patients with septic shock whose mean histamine measurements were significantly reduced (p less than .002). ⋯ After removal of this inhibitor from plasma, septic shock plasma histamine levels were normal. Thus, septic shock patients may have a circulating inhibitor of the HNMT enzyme, but plasma histamine concentrations are normal. Histaminemia is unlikely to play an important role in the pathogenesis of septic shock in humans.
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Critical care medicine · Jan 1989
Sequential physiologic interactions in pediatric cardiogenic and septic shock.
We report that the pediatric cardiogenic shock and septic shock populations show similar hemodynamic and oxygen utilization physiologic relationships during aggressive intensive care therapy. We examined the mathematical relationships between vascular tone and flow, and oxygen utilization and oxygen delivery (DO2) in the early and middle stages of cardiogenic and septic shock. ⋯ In addition, it appears that the major determinant of VO2 in these populations is DO2, not oxygen extraction. We suggest that patients with cardiogenic or septic shock can be treated according to similar physiologic principles.
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Critical care medicine · Jan 1989
Comparative StudyNoninvasive assessment of cardiac output by impedance cardiography in the newborn canine.
Currently, critical care monitoring of cardiac function in the newborn human consists mainly of measuring heart rate and BP. A noninvasive technique for assessing cardiac output routinely in the critically ill neonate would facilitate clinical management. Impedance cardiography (IC) is a noninvasive technique which measures stroke volume on a beat-by-beat basis. ⋯ There were no significant differences between the two methods for either the absolute value of cardiac output (r = .96) or the percent change in cardiac output (r = .97). Coefficients of variation were 3.0% for TD and 3.6% for IC. These results indicate that IC can be used to assess serially cardiac function in the newborn.