Critical care medicine
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Critical care medicine · Mar 1983
Pressure-time relationships of pressure-limited neonatal ventilators.
A pressure-limited ventilator (Bourns BP-200, Anaheim, CA) and a simple, manually operated constant flow ventilator were studied using a commercially available infant lung simulator (Bourns LS-130, Anaheim, CA). The characteristics of inspiratory pressure-time relationships during ventilation with these ventilators were analyzed. ⋯ Qualitatively similar tracings were obtained with the BP-200 during normal ventilation, with simulated airway obstruction and thoracic restriction. These findings suggest that monitoring pressure-time relationships may be useful in the qualitative assessment of resistance and compliance during pressure-limited ventilation of neonates.
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Critical care medicine · Mar 1983
Optimum left heart filling pressure during fluid resuscitation of patients with hypovolemic and septic shock.
The effect of increasing filling pressures on cardiac performance was examined in 15 patients undergoing fluid resuscitation for hypovolemic and septic shock. The initial significant increase in pulmonary artery wedge pressure (WP) from 7.0 +/- 2.0 to 11.9 +/- 1.6 mm Hg was associated with an increase in stroke volume index (SVI) from 24.2 +/- 9.8 to 34.7 +/- 12.4 ml/M2 (p less than 0.01), left ventricular stroke work index (LVSWI) from 16.9 +/- 7.8 to 28.5 +/- 11.6 g x m/M2 (p less than 0.01) and cardiac index (CI) from 2.25 +/- 0.68 to 3.06 +/- 0.85 L/min x M2 (p less than 0.01). ⋯ The correlation between central venous pressure (CVP) and WP during fluid loading was only fair and the changes in CVP vs WP did not significantly correlate. We suggest that the optimum left heart filling pressure during fluid resuscitation of patients with hypovolemic and septic shock may not exceed a WP of 12 mm Hg.