Critical care medicine
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Critical care medicine · Aug 1983
Case ReportsClinical aspects of resuscitation with and without an algorithm: relative importance of various decisions.
Clinical description was made of a series of hypotensive patients resuscitated with and without an algorithm. Of 603 hypotensive patients, there were 114 (19%) deaths and 169 (28%) patients with complications; the average low MAP was 53 +/- 25 mm Hg. Of 169 patients with complications, 48 (28%) had shock-related (SR) complications; 25 (52%) of these patients died. ⋯ The importance of various decision nodes of the algorithm were evaluated. The present algorithm, designed for these hypotensive emergency patients, provides a framework for fluid management that expedites resuscitation and reduces complications related to shock. We conclude that: (a) delays in resuscitation can be clearly related to an increased incidence of SR complications; (b) when the algorithm was satisfactorily followed, there was faster resuscitation and less SR complications; and (c) when the algorithm was satisfactorily followed in patients with severe associated illnesses, there was also shorter ICU stay, shorter hospitalization and decreased mortality.
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The clinical course of 33 patients with acute respiratory distress syndrome (ARDS) was monitored by noninvasive oxygen derived variables and compared to data obtained by invasive monitoring. A total of 350 data points were used to compare the physiologic shunt fraction (Qsp/Qt) with the ratio of arterial oxygen to inspired oxygen concentration (PaO2/FIO2), the alveolar-arterial oxygen pressure difference [P(A-a)O2], the respiratory index (RI)-[P(A-a)O2/PaO2], and the ratio of arterial oxygen to alveolar oxygen (a/A). The PaO2/FIO2 ratio, the RI and the aA ratio correlated well with Qsp/Qt (r = 0.87 to 0.94). ⋯ Changes in the cardiac index (CI) and the arteriovenous oxygen content difference C(a-v)O2 had only a minimal effect on the correlation of the oxygen derived variables with Qsp/Qt, although a higher correlation resulted when these extrapulmonary factors were within normal range. We conclude that a number of oxygen derived variables may accurately reflect the degree of Qsp/Qt. The PaO2/FIO2 ratio is the easiest of these variables to calculate, yet accurately predicts the degree of Qsp/Qt throughout a course of acute respiratory failure.
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Critical care medicine · Aug 1983
Comparative StudyIntermittent positive pressure ventilation and high frequency ventilation in dogs with experimental bronchopleural fistulae.
This study evaluated respiratory and cardiovascular responses of canines in whom bilateral bronchopleural fistulae were created surgically, and in whom ventilation was varied between intermittent positive pressure ventilation (IPPV) and high frequency ventilation (HFV). An Emerson prototype ventilator was used for HFV at rates of 300-1400/min at driving pressures of 2.5, 5.0, and 10 psi. ⋯ Ventilation during IPPV with the fistula open resulted in a statistically significant increase in PaCO2 and a decrease in PaO2 when compared to both HFV modes. Variations in cardiac function in these open-chested animals were insignificant for all variables tested except pulmonary artery pressures which rose significantly in the IPPV group.
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Critical care medicine · Aug 1983
Case ReportsDiagram for easy volume setting of an infant ventilator.
A pressure-volume diagram with isocompliance lines allows quick, accurate volume setting of the piston-driven infant ventilator Bourns LS. A line parallel with the machine compliance line and an intercept on the ordinate equal to the tidal volume, serves as a guideline for initial volume setting and subsequent adaptation according to the patient's lung compliance. This diagram is particularly useful when the lung compliance is low; changes consistently during controlled ventilation.