Critical care medicine
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Critical care medicine · Nov 1991
Is neonatal inspired gas humidity accurately controlled by humidifier temperature?
To investigate: a) the relationship between humidifier temperature and inspired gas humidity and b) the effect of insulating the inspiratory tube on "rainout" (condensate). ⋯ Inspired gas humidity cannot be predicted reliably from humidifier temperature. Accurate control will require a new generation of humidifiers that measure inspired gas humidity.
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Although it is useful in certain clinical situations for manual resuscitator units to be used with spontaneously ventilating patients, there are few data regarding their performance in these settings. We measured the percent-delivered oxygen from 13 adult manual resuscitator units during simulated spontaneous ventilation in the range of respiratory frequency, tidal volume, and oxygen supply in which manual resuscitator units might be used with patients. We also measured the resistive pressure developed during simulated ventilation and at constant inspiratory flow of 50 L/min. ⋯ Reliable administration of high percent-delivered oxygen to spontaneously ventilating patients, while retaining the capability to manually ventilate them, is best achieved by a manual resuscitator unit with a valve of low resistance, incorporating a disc to prevent air entrainment. We recommend that manufacturers indicate on the product information sheet the degree (and confidence limits) to which their manual resuscitator unit presents resistance and delivers oxygen to a spontaneously ventilating subject.
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Critical care medicine · Nov 1991
Experience with phenylephrine as a component of the pharmacologic support of septic shock.
To evaluate the use of the selective alpha 1-adrenergic receptor agonist phenylephrine in the hemodynamic support of patients with septic shock. ⋯ Treatment with phenylephrine was associated with beneficial hemodynamic effects when used to maintain perfusion, while increasing DO2 and VO2 in patients with septic shock.
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Critical care medicine · Nov 1991
Perfusion of the interventricular septum during ventilation with positive end-expiratory pressure.
To determine whether regional hypoperfusion of the interventricular septum occurs during ventilation with positive end-expiratory pressure. ⋯ The decrease in cardiac output during positive end-expiratory pressure is not caused by impaired interventricular septum blood supply. The preferential perfusion of the right ventricular interventricular septum indicates increased local right ventricular interventricular septum oxygen-demand and suggests that during positive end-expiratory pressure, this part of the interventricular septum functionally dissociates from the left ventricular interventricular septum and the left ventricular free wall to support the stressed right ventricle.