Chest
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Pulse oximetry is widely used in the critical care setting, but few studies have examined its usefulness in clinical decision making. One area where pulse oximetry might be useful is in the titration of fractional inspired O2 concentration (FIO2) in ventilator-dependent patients. Unfortunately, documented guidelines for this use do not exist, and in a survey of directors of intensive care units, we found that they employed a wide range of target O2 saturation (SpO2) values. ⋯ However, in black patients, such a SpO2 reading was commonly associated with significant hypoxemia (PaO2 as low as 49 mm Hg), and a higher SpO2 target, 95 percent, was required. In addition, inaccurate oximetry readings (ie, greater than 4 percent difference between SpO2 and direct SaO2 measurements) were more common in black (27 percent) than in white patients (11 percent, p less than 0.05). In conclusion, a SpO2 target of 92 percent was reliable when titrating supplemental O2 in white patients receiving mechanical ventilation; however, in black patients, such a SpO2 reading was commonly associated with significant hypoxemia, and a higher SpO2 target, 95 percent, was required to ensure a satisfactory level of oxygenation.
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Case Reports
A new device that allows synchronous intermittent inspiratory chest tube occlusion with any mechanical ventilator.
Controlling a massively leaking bronchopleural fistula (BPF) can prove difficult. In combination with acute respiratory failure (ARF), BPF results in a mortality of 81 percent. ⋯ The effectiveness of the device and associated technique in controlling BPF leaks is clearly demonstrated and may have played a role in the eventual recovery of a patient with BPF. Further study of the technique is warranted.
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Bronchoalveolar lavage (BAL) was performed in 51 adult immunocompromised patients (30 acquired immunodeficiency syndrome [AIDS] and 21 non-AIDS) as part of an extensive diagnostic evaluation for diffuse pulmonary infiltrates. Because multiple episodes occurred in several patients, a total of 60 BALs were performed. A diagnosis of fungal pneumonia was eventually made in 12 patients (24 percent). ⋯ In addition, BALs detected six episodes of bacterial pneumonia and three of five cases of radiation pneumonitis. Overall, the diagnostic sensitivity of BAL was 52 of 60 or 87 percent. While examination of induced sputum for the presence of Pneumocystis may eliminate the need for bronchoscopy in some AIDS patients, BAL remains an excellent diagnostic procedure in the immunocompromised patient without AIDS.
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Norepinephrine, an alpha 1,2-beta 1,2-adrenergic agonist, seems to be an alternative to epinephrine, an alpha 1,2-beta 1,2-agonist, for restoration of spontaneous circulation in VF. We therefore studied the effect of epinephrine and norepinephrine on MDO2 and MVO2 using OCCM after five minutes of cardiopulmonary arrest in 21 pigs. After OCCM of three minutes, seven animals each received placebo (controls) or epinephrine (45 micrograms/kg) or norepinephrine (45 micrograms/kg). ⋯ The oxygen requirements of the fibrillating heart seemed to be increased via beta 2-adrenergic stimulation. In both the control and epinephrine-treated groups, only three of the seven animals could be successfully resuscitated, whereas all of the animals in the group with norepinephrine survived the 15-minute period of observation. In this model, norepinephrine, in contrast to epinephrine, improves the balance between MDO2 and MVO2 and eases restoration of spontaneous circulation.