Chest
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Comparative Study
Elevated pulmonary artery systolic storage volume associated with improved ventilation-to-perfusion ratios in acute respiratory failure.
The possibility that an elevated pulmonary artery systolic storage volume (PASSV) correlates with improved overall ratios of ventilation-to-perfusion and hence benefits gas exchange in acute respiratory failure was examined. We examined this by assessing the correlation between PASSV and both the physiologic dead space to tidal volume ratio (VD/VT) and intrapulmonary shunt fraction (Qsp/Qt). The VD/VT and Qsp/Qt were used as an index of distribution of ventilation-to-perfusion as well as efficiency of pulmonary gas exchange. ⋯ Comparison of the two groups revealed that VD/VT and Qsp/Qt were lower (p less than 0.0001, and p = 0.018, respectively), PA time constant was higher (p less than 0.001), and right ventricular stroke-work index was higher (p = 0.005) in the group with a high PASSV/SVI. There were no differences in other hemodynamic data between the two groups. These data suggest that an elevated PASSV may indeed benefit gas exchange in acute respiratory failure.
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To examine the relationship among clinical dyspnea ratings, physiologic pulmonary function, and general health status in symptomatic patients with chronic obstructive pulmonary disease (COPD). ⋯ Dyspnea ratings influence and predict general health status to a greater extent than do physiologic measurements in symptomatic patients with COPD. A shift in focus from the pathophysiology of disease to assessment and relief of symptoms may provide more meaningful benefits for the individual patient in terms of quality of life. This consideration requires that health-care providers use available measuring tools in clinical practice to quantify symptoms, as well as overall health status.
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We conducted a population-based case-control study to determine the magnitude of the excess risk of tuberculosis in those infected with the human immunodeficiency virus (HIV) in Seattle-King County, Washington. Patients were 39 of the 54 cases of tuberculosis in white and in black (including Hispanic) men aged 20 through 49 reported to the Seattle-King County Department of Public Health between January 1986 and June 1988. ⋯ Eleven (28 percent) of the 39 patients with tuberculosis and 2 (6 percent) of the 34 controls tested positive for antibody to HIV (odds ratio adjusted for age and race = 6.2; 95 percent confidence interval 1.2 to 31.9). Calculation of the etiologic fashion indicated that 24 percent of the tuberculosis cases in this population of young black and white men were attributable to concurrent HIV infection.
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There are several bronchiolar diseases with different pathologic and clinical findings. Idiopathic BOOP is a distinct entity consisting of a flu-like illness, late inspiratory crackles, patchy infiltrates roentgenographically, and physiologically decreased vital capacity and diffusing capacity. Response to corticosteroid therapy is good and relapse does not occur if sufficient therapy is given. ⋯ Furthermore, the entity can be described to clinicians and pathologists throughout the world in such a fashion that patient care and research can be standardized. Researchers from different centers studying the cause or utilizing treatment protocols are able to discuss a single BOOP entity rather than comparing results of a heterogeneous group of many different types of interstitial lung disorders. This will lead to breakthroughs in discovery of etiologic causes and new effective therapeutic regimens.
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Randomized Controlled Trial Clinical Trial
Role of oxygen debt in the development of organ failure sepsis, and death in high-risk surgical patients.
In a series of 253 high-risk surgical patients, we measured the oxygen consumption (VO2) at frequent intervals before, during, and immediately after surgical operations and calculated the rate of VO2 deficit from the measured VO2 minus the VO2 need estimated from the patient's own resting preoperative control values corrected for both temperature and anesthesia. The calculated oxygen deficit was related to multiple organ failure, complications, and outcome. The 64 patients who died all had organ failure; their cumulative VO2 deficit averaged 33.2 +/- 4.0 L/m2 (+/- SEM) at its maximum, which occurred 17.8 +/- 2.2 h after surgery. ⋯ In a prospective randomized clinical trial, a protocol group maintained at supranormal hemodynamic and oxygen transport values had significantly reduced oxygen debt (7.6 +/- 3.4 L/m2 vs 17.3 +/- 6.8 L/m2; p less than 0.05), fewer organ failures, and lower mortality (4 percent vs 33 percent; p less than 0.05) compared with a control group maintained at normal hemodynamic values. The data demonstrate a strong relationship between the magnitude and duration of the VO2 deficit in the intraoperative and early postoperative period and the subsequent appearance of organ failure and death. The latter may be reduced when oxygen debts were prevented or minimized by augmenting naturally occurring compensations that increased oxygen delivery.