Articles: ventilators.
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In an effort to characterize the performance of self-inflating resuscitators, three examples of three models were subjected to laboratory testing: the Ohio Hope II resuscitator (Ohio Medical Products, Madison, WI), the PMR-2 resuscitator (Puritan Medical Products, Lenexa, KS), and the Laerdal resuscitator (AS Laerdal, Stavanger, Norway). The devices were connected to a test lung and compressed at frequencies of from 10 to 60 and at greater than 60 breaths per minute at 5, 10, and 15 L/min of flow. ⋯ The pop-off valves for each device were activated throughout a wide range of pressures, the Laerdal 41 to 72 cm H2O, PMR-2 51 to 97 cm H2O, and the Ohio Hope II 38 to 106 cm H2O, well in excess of the manufacturer's specifications. Only the Laerdal with reservoir was able to deliver an Fio2 of greater than 0.9 when compressed at more than the pop-off valve pressure at rates of up to 30 breaths per minute using flows of 10 L/min, and it was the only device to produce Fio2 values of greater than 0.9 at all rates to 60 breaths per minute when compressed at less than the pop-off valve pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Postgraduate medicine · Jan 1986
Mechanical ventilation. Physiology, equipment design, and management.
The major goals of mechanical ventilation are the prevention of significant respiratory acidosis and the correction of arterial hypoxemia. Ventilators are categorized as negative- or positive-pressure types, depending on their effect on airway pressure. Positive-pressure ventilators, which are used in the treatment of acute respiratory failure, may be subclassified as pressure-, volume-, or time-cycled. ⋯ Ventilation may be provided in a number of modes. No clear-cut advantage of intermittent mandatory ventilation over assisted mechanical ventilation has been demonstrated. By following simple guidelines, the clinician can initiate mechanical ventilation that provides an ideal ventilatory pattern.
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Ann Fr Anesth Reanim · Jan 1986
Case Reports[Expiratory blockage of a Monnal S respirator caused by rupture of the capsule of a pneumatic Bennett valve].
In the recovery room, a ventilated patient suddenly developed bradycardia and severe cardiovascular collapse due to increased airway pressure. The cause of this life-threatening complication was continuous occlusion of the expiratory valve by a ruptured diaphragm in a Bennett's valve. ⋯ On expiration, the expiratory gas under pressure penetrates the ruptured capsule, maintaining the valve occluded. A small part of the expired gas escapes through the small-bore connecting tube of the diaphragm.