Noninvasive respiratory care unit. A cost effective solution for the future.
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Cost-Benefit Analysis↗
Biomedical subjects
R A Balk
Publications and source records attributed to R A Balk.
A controlled clinical trial of high-dose methylprednisolone in the treatment of severe sepsis and septic shock.
The use of high-dose corticosteroids in the treatment of severe sepsis and septic shock remains controversial. Our study was designed as a prospective, randomized, double-blind, placebo-controlled trial of high-dose methylprednisolone sodium succinate for severe sepsis and septic shock. Diagnosis was based on the clinical suspicion of infection plus the presence of fever or hypothermia (rectal temperature greater than 38.3 degrees C [101 degrees F] or less than 35.6 degrees C [96 degrees F]), tachypnea (greater than 20 breaths per minute), tachycardia (greater than 90 beats per minute), and the presence of one of the following indications of organ dysfunction: a change in mental status, hypoxemia, elevated lactate levels, or oliguria. Three hundred eighty-two patients were enrolled. Treatment--either methylprednisolone sodium succinate (30 mg per kilogram of body weight) or placebo--was given in four infusions, starting within two hours of diagnosis. No significant differences were found in the prevention of shock, the reversal of shock, or overall mortality. In the subgroup of patients with elevated serum creatinine levels (greater than 2 mg per deciliter) at enrollment, mortality at 14 days was significantly increased among those receiving methylprednisolone (46 of 78 [59 percent] vs. 17 of 58 [29 percent] among those receiving placebo; P less than 0.01). Among patients treated with methylprednisolone, significantly more deaths were related to secondary infection. We conclude that the use of high-dose corticosteroids provides no benefit in the treatment of severe sepsis and septic shock.
Adult↗
Growth inhibition of Blastomyces dermatitidis in alveolar and peripheral macrophages from patients with blastomycosis.
Blastomyces dermatitidis evokes a pyogranulomatous disorder with organisms frequently found inside giant cells. Macrophages from bronchoalveolar lavage fluid and peripheral blood in monolayer cell cultures were challenged with live yeast organisms to examine phagocytosis and intracellular growth. A greater number of macrophages from patients recovering from blastomycosis had phagocytized Blastomyces compared with macrophages from healthy control donors. No differences were detected within the groups between alveolar and peripheral macrophages. Intracellular growth of the fungus was reduced in cultures of both cell types from patients compared with those from control subjects. Supernatants from specific Blastomyces antigen-stimulated lymphocyte cultures were collected, and treatment with the supernatant to control donors' macrophages resulted in increased phagocytosis and inhibition of intracellular growth. Antigen-induced lymphocyte stimulation as a correlate of cellular immunity is qualitatively related to alveolar or peripheral macrophage phagocytosis and growth inhibition of this fungus.
Blastomyces↗
Bacteremia during bronchoalveolar lavage.
We prospectively evaluated the incidence of bacteremia during fiberoptic bronchoalveolar lavage (BAL) and its relationship to postlavage symptoms in 12 volunteers. Qualitative and quantitative blood cultures were obtained before and during BAL. Three persons had qualitative blood cultures positive for organisms typical of normal skin flora. Quantitative blood cultures done simultaneously were negative. Approximately 42% of our subjects had postlavage symptoms, but no correlation was found between bacteremia and the occurrence of postlavage symptoms. Our results confirm the relative safety of BAL and the low incidence of BAL-associated bacteremia.
Adult↗
Alveolar macrophage function in a canine model of endotoxin-induced lung injury.
Humans with bacterial sepsis are predisposed to acute lung injury with respiratory failure and have an increased risk of pulmonary infection. Because the alveolar macrophage is the resident phagocyte in the lung and a defect in antimicrobial activity could predispose to infection, we assessed the functional integrity of these cells in vitro in a canine model of Escherichia coli endotoxin-induced lung injury with respiratory failure. Dogs were given 2 or 20 mg/kg of E. coli endotoxin 055:B5, and alveolar macrophages from pulmonary lavage were compared with those from control dogs. The physiologic criteria for the adult respiratory distress syndrome and pathologic confirmation of acute lung injury were produced in all endotoxin-treated animals. The production of acute lung injury with respiratory failure by E. coli endotoxin was associated with several alterations in alveolar macrophage function. Adherence was significantly reduced for cells from the endotoxin groups. The alveolar macrophages from endotoxin-treated animals differed from those from control animals, with significantly greater production of hydrogen peroxide, significantly greater peaks in chemiluminescence, significantly reduced phagocytosis of Staphylococcus aureus and E. coli at all times, and a diminished ability to kill cell-associated S. aureus and E. coli over time. These derangements could play a role in the therapeutic failures of pneumonia, an increased risk for nosocomial pneumonias, or the propagation of acute lung injury with respiratory failure.
Animals↗
Sleep apnea and the Arnold-Chiari malformation.
We present a polysomnogram-documented report of central sleep apnea (427 events) and moderately severe decreases in arterial oxygen saturation (to 81%) associated with the Arnold-Chiari malformation (ACM). Daytime hypersomnolence and other symptoms had significantly impaired our patient's work performance. After surgical correction of the ACM, there was marked improvement in symptomatology. A post-surgery polysomnogram revealed marked improvement in the number of central apneas (74 events) and only mild decreases in oxygen saturation (to 94%).
Arnold-Chiari Malformation↗
Lymphocyte subpopulations of blood and alveolar lavage in blastomycosis.
Patients with blastomycosis were found to have differing lymphocyte populations depending on the extent of disease manifestations and whether or not therapy had been started. Patients with recovering pulmonary blastomycosis who had been receiving antifungal treatment for at least four weeks had lymphocyte subpopulations no different from control donors. Patients with treated extrapulmonary blastomycosis had similar T helper (TH) to T suppressor (TS) ratios compared to recovering pulmonary patients and control subjects; this ratio gives a false impression because extrapulmonary blastomycosis patients had a reduced absolute number of lymphocytes with either marker. In bronchoalveolar lavage fluid, pulmonary blastomycosis patients who were clinically improved while receiving antifungal therapy had fewer TH cells and a greater number of lymphocytes with the TS marker than did control subjects. Patients with pulmonary blastomycosis prior to therapy had a smaller TH/S ratio than the other groups in peripheral blood primarily due to a reduction in the circulating TH fraction in both absolute numbers of cells and in the percentage of total T lymphocytes. Pulmonary blastomycosis patients re-evaluated after at least four weeks of antifungal therapy had TH/S ratios that were similar to normal persons. This increase in TH lymphocytes corresponded to clinical improvement and in a temporal correlation to that described for the development of specific immunity in this illness.
Adult↗
Radiographic patterns of pulmonary disease.
Pulmonary radiographs are essential adjuncts to the evaluation and diagnosis of suspected pulmonary disease. In the intensive care unit, radiographs are useful to confirm correct positioning of diagnostic and therapeutic devices. Patterns seen on the radiograph may be within broadly normal limits or may be interpreted as abnormal, especially when placed in the clinical context of a specific patient's problem. The description abnormal can be related to both nonspecific and specific radiographic patterns of disease. Nonspecific radiographic patterns of disease include location of disease, temporal course of disease, pleural abnormalities, hyperinflation, extra-alveolar air, atelectasis, bronchiectasis, and vascular disease. Specific radiographic patterns of disease are discrete anatomic structures seen on a radiograph, for example, cavitary and cystic disease. The interpretation of nonspecific and specific radiographic patterns is useful in diagnosis, selection of treatment, and monitoring of the course of disease and the patient's response to treatment.
Diagnosis, Differential↗