Critical care medicine
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Critical care medicine · Aug 1993
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialAccurate placement of central venous catheters: a prospective, randomized, multicenter trial.
a) To define the frequency of dangerous (intracardiac) central venous catheter placement in a multicenter study of large community hospital intensive care units (ICUs) and to evaluate physician responses to this finding. b) To validate right atrial electrocardiography as a technique to assure adherence with recent Food and Drug Administration (FDA) guidelines regarding the location of central venous catheter tips. c) To conduct a literature review of vascular cannulation and its associated potentially lethal complications. ⋯ a) The FDA guidelines regarding catheter tip location (catheter tip should not be in the right atrium) have not been widely publicized. b) The average safe insertion depth for a central venous catheter from the left or right internal jugular vein or subclavian vein is 16.5 cm for the majority of adult patients; a central venous catheter should not be routinely inserted to a depth of > 20 cm. Catheters longer than this size are rarely needed, and potentially dangerous. Catheter tip location is important to document following central venous catheter insertion. Thirty-centimeter central venous catheters should not be used when accessing the central circulation via internal jugular or subclavian veins. c) Right atrial electrocardiography is a technique that assures initial tip position outside the heart in accordance with FDA guidelines. This technique would virtually eliminate the major risk of death (i.e., cardiac perforation) associated with this procedure. d) Recently available, 15- and 16-cm central venous catheters have significant potential to minimize intracardiac placement of central venous catheters by either the internal jugular or subclavian vein route and may become the standard of care.
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Critical care medicine · Aug 1993
Comparative StudyA new ventilation inhomogeneity index from multiple breath indicator gas washout tests in mechanically ventilated patients.
a) To determine the validity of a new method to analyze indicator gas washout tests on mechanically ventilated patients. This method takes into account the difference between the end-expiratory gas fraction and the mean gas fraction in the lung and provides the end-expiratory lung volume and a new index of ventilation inhomogeneity called volumes regression index. b) To determine the validity of this index as a predictor of chronic obstructive pulmonary disease. c) To compare this index with the moment ratio index and Becklake index. ⋯ The proposed technique provides a means for accurate measurement of the end-expiratory lung volume and the amount of ventilation inhomogeneity in mechanically ventilated intensive care unit patients.
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Critical care medicine · Aug 1993
Changes in myocardial blood flow rates during hyperdynamic sepsis with induced changes in arterial perfusing pressures and metabolic need.
To determine whether hyperdynamic sepsis is associated with dysregulation in the control of myocardial blood flow rates unrelated to hypotension or the use of anesthetic agents. ⋯ In this model of hyperdynamic sepsis, increases in blood flow to both the left and right ventricles were positively coupled to changes in respective ventricular work. From the interventional PGE1 and zymosan-activated plasma infusion studies, we found no evidence to support previous suggestions that the regulation of myocardial blood flow rates according to changes in perfusing pressure and/or metabolic oxygen need is significantly altered during hyperdynamic sepsis.
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Critical care medicine · Aug 1993
Editorial Comment Comparative StudyThoracic electrical bioimpedance measurement of cardiac output--not ready for prime time.
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Critical care medicine · Aug 1993
Combined continuous monitoring of systemic and cerebral oxygenation in acute brain injury: preliminary observations.
To continuously evaluate the relationship between global systemic and cerebral oxygenation during temporary profound hypocapnia, which was attempted for prompt management of posttraumatic intracranial hypertension. ⋯ In young adults with severe acute brain trauma who require prompt management of intracranial hypertension, transient profound hypocapnia is effective in lowering the intracranial pressure, as well as in offsetting the cerebral luxury perfusion, while improving or maintaining adequate systemic oxygenation. The systemic-cerebral oxygenation index and the systemic-cerebral ventilatory index are potentially useful, physiologically monitorable variables for the combined assessment of global systemic and cerebral oxygenation in a variety of areas involving physiologic and/or therapeutic approaches.