Critical care medicine
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Critical care medicine · Mar 1993
Cardiovascular effects of dopamine and dobutamine in conscious pigs with chronic heart failure.
To test the hypothesis that the cardiovascular responses of dopamine and dobutamine might be affected by the cardiovascular conditions. ⋯ Both dopamine and dobutamine increased cardiac output in conscious pigs with chronic heart failure. Unlike the response in normal conscious pigs, in which only heart rate increased, in animals with heart failure, these agents enhanced both stroke volume and heart rate.
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Critical care medicine · Mar 1993
Use of vitamin B12 in the treatment and prevention of nitroprusside-induced cyanide toxicity.
To review the mechanism of action, safety, and efficacy of hydroxocobalamin in the treatment and prevention of nitroprusside-induced cyanide toxicity. ⋯ Hydroxocobalamin is a safe and effective agent in the prevention and treatment of nitroprusside-induced cyanide toxicity. Prolonged or high-dose infusions of nitroprusside should be minimized in critically ill patients, especially if hepatic and/or renal dysfunction is present.
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Critical care medicine · Feb 1993
Randomized Controlled Trial Multicenter Study Clinical TrialDetrimental effects of high-dose methylprednisolone sodium succinate on serum concentrations of hepatic and renal function indicators in severe sepsis and septic shock. The Methylprednisolone Severe Sepsis Study Group.
To evaluate the effects of high-dose methylprednisolone sodium succinate on biochemical markers of hepatic and renal function in patients with severe sepsis and septic shock. ⋯ The frequency of acutely increased blood urea nitrogen and bilirubin concentrations in severe sepsis was increased significantly with high-dose methylprednisolone therapy. Similar frequencies of circulatory shock in the study groups excluded differences in global perfusion as a cause of this phenomenon. Possible adverse effects of pharmacologic concentrations of methylprednisolone in critically ill patients should be considered in planning treatment.
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Critical care medicine · Feb 1993
Comparative StudyImposed work of breathing and methods of triggering a demand-flow, continuous positive airway pressure system.
To compare the inspiratory imposed work of breathing during spontaneous ventilation with continuous positive airway pressure using three methods of triggering "ON" the demand-flow system of a ventilator: a) conventional pressure triggering with the pressure measuring/triggering site inside the ventilator on the exhalation limb of the breathing circuit; b) tracheal pressure triggering from the tracheal or carinal end of the endotracheal tube; and c) flow-by (flow triggered) triggering. ⋯ An endotracheal tube is a resistor in the breathing apparatus over which a pressure decrease must be developed by the patient in order to inhale spontaneously. An endotracheal tube, therefore, imposes substantial resistance and work. The results indicate that the pressure measuring/triggering site for a ventilator's demand-flow system should be at the tracheal or carinal end of an endotracheal tube so as to effectively decrease the resistance of the endotracheal tube, thus, decreasing the patient's work of breathing.