Critical care medicine
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Critical care medicine · Feb 1990
Editorial CommentHypertonic saline for resuscitation: a word of caution.
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Critical care medicine · Jan 1990
ReviewTherapy of shock based on pathophysiology, monitoring, and outcome prediction.
High-risk patients who survived general (noncardiac) surgery were observed to have cardiac index (CI) values averaging 4.5 L/min.m2, oxygen delivery (DO2) greater than 600 ml/min.m2, and oxygen consumption (VO2) 170 ml/min.m2 during the first 2 or three days postoperatively. Patients who subsequently died maintained relatively normal CI, DO2, and VO2 values in this period. Values of other variables in survivors and nonsurvivors were not appreciably different. ⋯ Optimal goals were more easily attained with colloids, red cells, and an inotropic agent, dobutamine. Dobutamine was used because, in a prospective crossover clinical trial with dopamine at various doses, dobutamine produced greater increases in flow and flow-related variables. More importantly, it improved tissue perfusion as reflected by greater increases in VO2 and greater reductions in pulmonary and systemic vascular resistance.
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Management of shock is generally guided by hemodynamic data, but the true aim of therapy should be optimizing oxygen delivery (DO2) and consumption (VO2). Available data do not support the hypothesis that there is a single critical threshold of DO2 below which tissue hypoxia occurs; thus, DO2 and VO2 should be addressed for each patient. Interventions that raise BP, such as infused catecholamines, may actually decrease DO2, as can mechanical ventilation with PEEP. Therefore, the clinician should avoid responding solely to hemodynamic data and should direct interventions toward delivering the optimum amount of oxygen to the patient's tissues.
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Critical care medicine · Jan 1990
Comparative StudyAutomated sulfur hexafluoride washout functional residual capacity measurement system for any mode of mechanical ventilation as well as spontaneous respiration.
A new sulfur hexafluoride (SF6) washout functional residual capacity (FRC) measurement system has been developed which will work with any mode of mechanical ventilation, as well as with spontaneous respiration. This system was evaluated in three different human studies. In the first two studies, the accuracy of the system was compared with He dilution and body plethysmography in 12 spontaneously breathing normal volunteers and in 12 spontaneously breathing chronic obstructive pulmonary disease (COPD) patients. ⋯ The "stable" periods were 14 +/- 2 h long and ranged from 60 min to 63.5 h. The reproducibility for all 12 patients was 188 +/- 17 ml or 11.7 +/- 0.7%. This automated SF6 washout system should make routine FRC measurements in patients who are being mechanically ventilated simple and easy to do.(ABSTRACT TRUNCATED AT 250 WORDS)