Critical care medicine
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Critical care medicine · Jun 1984
Relation of inspired oxygen fraction to hypoxemia in mechanically ventilated adults.
To evaluate the recommendation that all adult patients started on mechanical ventilation (MV) should have an initial fraction of inspired oxygen (FIO2) of 1.0, 207 consecutive adult patients started on MV in the critical care units were studied. The initial FIO2, the resultant PaO2, and the level of training of the physician ordering the initial ventilator settings were recorded for each patient. ⋯ Staff-level physicians tended to employ an initial FIO2 less than 1.0 more often than did physicians-in-training, and the latter had a 19% incidence of PaO2 less than 60 torr, while staff-level physicians had no PaO2 values less than 60 torr when using an initial FIO2 less than 1.0. It is concluded that all adult patients started on MV should receive an initial FIO2 of 1.0, especially when the physician ordering the initial FIO2 is a physician-in-training.
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Critical care medicine · Jun 1984
Continuous S-vO2 measurement and oxygen transport patterns in cardiac surgery patients.
Twenty adult cardiac surgery patients with impaired ventricular function by contrast ventriculography at cardiac catheterization were monitored from before anesthesia until the time of extubation up to 12 h postoperatively. A thermodilution pulmonary artery catheter with fiberoptic channels for continuous measurement of mixed-venous oxygen saturation (S-vO2) by reflection oximetry was substituted for the usual catheter. The S-vO2 was recorded continuously along with blood pressure, cardiac filling pressures, and heart rate. ⋯ Thus, S-vO2 reflects oxygen extraction and continuous S-vO2 provides continuous quantification of global oxygen extraction. None of the other oxygen transport variables including cardiac index showed significant correlation with S-vO2. The oximetry system provides a continuous and reliable indication of mixed-venous blood oxygenation which is a continuous reflection of oxygen extraction.
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Critical care medicine · Jun 1984
Pulmonary interstitial emphysema in the premature baboon with hyaline membrane disease.
During experiments designed to develop an appropriate ventilatory strategy for high-frequency ventilation (HFV) in the premature baboon with hyaline membrane disease (HMD), we observed the development of pulmonary interstitial emphysema (PIE). Four study groups of 5 animals each received positive-pressure ventilation and positive end-expiratory pressure (PPV/PEEP) or HFV and 1 of 3 sighing techniques. ⋯ This was evident from the location of striking dilation of the distal airways and pseudocysts in areas of atelectasis. Thus, early in the course of HMD when saccular aeration is minimal, the pathogenesis of PIE is related to airway rather than alveolar rupture.
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Critical care medicine · Jun 1984
Comparative StudyPharmacokinetic assessment of immunosuppressive activity of antibiotics in human plasma by a modification of the mixed lymphocyte reaction.
Antibiotics may impair the development and expression of specific or nonspecific immune responses. Prophylactic administration of antibacterial antibiotics is widely used in ICUs. We studied the immunosuppressive activities of cefotaxime, chloramphenicol, gentamicin, metronidazole, and rifamycin as a function of time after the administration of these drugs to ICU patients, finding that the last 4 drugs had an immunosuppressive activity detectable up to 8 h by a mixed lymphocyte reaction. When these antimicrobial agents were added to normal pooled plasma in concentrations similar to those obtained in vivo, a similar degree of inhibition was observed.