Chest
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Ischemic tracheal complications due to the ETT cuff occur in approximately 10 percent of mechanically ventilated critically ill patients despite the use of high-volume, low-pressure ETT cuffs. Using a laboratory model, we studied the effects of airway pressure on three different ETT cuff designs, including two "low pressure" designs. ⋯ Increases in airway pressure caused by decreased lung compliance resulted in higher cuff inflation pressures in all three groups, with the smallest increase occurring in the design that had the longest tracheal contact length. We conclude that the current high-volume, low-pressure ETT cuff design currently used does not guarantee low cuff pressure when high airway pressures occur, and an alternative design should be developed.
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Weaning of patients from mechanical ventilation is a time-consuming, labor-intensive process. Because most weaning decisions are based on objective data, we tested a computer-directed weaning system on postoperative patients. We developed an automatic, computer-controlled ventilator weaning system which interfaces a laptop computer to a ventilator and a pulse oximeter. ⋯ We successfully weaned nine patients using the system. Additional studies are underway to determine if this system can be used in medical patients. We believe this computer-controlled ventilator weaning system can be used successfully in patients requiring mechanical ventilation and may decrease the time and cost associated with the care of these patients.
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A case of positionally symptomatic right-to-left shunting across a patent foramen ovale with both platypnea and orthodeoxia despite normal pulmonary arterial pressures and normal right ventricular function is documented. When the patient was in a supine position, the calculated right-to-left shunt was 12.8 percent, and when seated 25 percent. ⋯ It is recommended that those at risk of thromboembolism be screened for patency by contrast ultrasound or color flow techniques. If present, surgical closure needs to be considered to prevent paradoximal embolism and stroke.