Critical care medicine
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Critical care medicine · May 2002
Comparative StudyEffects of epinephrine and vasopressin in a piglet model of prolonged ventricular fibrillation and cardiopulmonary resuscitation.
We recently demonstrated that vasopressin alone resulted in a poorer outcome in a pediatric porcine model of asphyxial cardiac arrest when compared with epinephrine alone or with epinephrine plus vasopressin in combination. Accordingly, this study was designed to differentiate whether the inferior effects of vasopressin in pediatrics were caused by the type of cardiac arrest. ⋯ In this pediatric porcine model of ventricular fibrillation, the combination of epinephrine with vasopressin during cardiopulmonary resuscitation resulted in significantly higher levels of left ventricular myocardial blood flow than either vasopressin alone or epinephrine alone. Both vasopressin alone and the combination of epinephrine with vasopressin, but not epinephrine alone, improved total cerebral blood flow during cardiopulmonary resuscitation. In stark contrast to asphyxial cardiac arrest, vasopressin alone or in combination with epinephrine appears to be of benefit after ventricular fibrillation in the pediatric porcine model.
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Critical care medicine · May 2002
Lessons from everyday lives: a moral justification for acute care research.
Progress in emergency and critical care requires that clinical research be performed on patients who are incapable of granting consent for research participation. Analyses of the ethics of such research have left some questions incompletely answered. ⋯ By relying on a framework for assessing research risks, and by drawing on the example of pediatric research, this justification is founded in how institutional review boards, and society in general, analyze risk. Our justification for emergency research also suggests additional protections for emergency research participants, including a stringent threshold for research risk, that still permit important research to proceed.
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Critical care medicine · May 2002
Effect of perfluorocarbon (perfluorooctyl bromide) vapor on tidal volume measurement during partial liquid ventilation.
To compare measured tidal volumes with and without perfluorocarbon (perfluorooctyl bromide) vapor, by using tidal volumes in the range suitable for neonates ventilated with partial liquid ventilation. We also aimed to determine the correction factor needed to calculate tidal volumes measured in the presence of perfluorooctyl bromide vapor. ⋯ The presence of perfluorooctyl bromide vapor in the gas flowing through pneumotachometers gives falsely high tidal volume measurements. An estimate of the true tidal volume allowing for the presence of perfluorooctyl bromide vapor can be made from regression equations. Any calculation of lung mechanics must take into account the effect of perfluorooctyl bromide vapor on the measurement of tidal volume.
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Critical care medicine · May 2002
Repeat bedside percutaneous dilational tracheostomy is a safe procedure.
Previous tracheostomy has been considered a relative contraindication for percutaneous dilational tracheostomy. The objective of this study was to assess the safety of percutaneous dilational tracheostomy in critically ill patients with a history of previous tracheostomy. ⋯ Trained physicians can safely perform bedside percutaneous dilational tracheostomy after previous tracheostomy. Percutaneous dilational tracheostomy offers an alternative to surgical tracheostomy in this particular patient population and should not be considered contraindicated.
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Critical care medicine · May 2002
Tracheal pressure control provides automatic and variable inspiratory pressure assist to decrease the imposed resistive work of breathing.
To evaluate the operation of a continuous positive airway pressure system by using tracheal airway pressure (PT) as the control signal for system operation (i.e., tracheal pressure control). ⋯ Tracheal pressure control results in automatic and variable levels of pressure assist to decrease imposed resistive work of breathing under conditions of varying spontaneous inspiratory flow demands and endotracheal tube occlusion. Conventional systems are potentially flawed when PY is used as the control signal because they do not function in this manner and do not accurately assess pulmonary airway pressure.