Chest
-
We administered a questionnaire and observed usage of a placebo metered dose inhaler (MDI) among 35 physicians, 14 nurses, and 12 respiratory therapists. Ninety-two percent of the respiratory therapists performed at least four of seven steps correctly, compared with 65 percent of house staff physicians, 57 percent of nurses, and 50 percent of nonpulmonary faculty. Most participants followed package insert instructions, while only 18 percent followed recent recommendations for proper MDI use. We conclude that (1) medical personnel should have additional instruction in proper MDI usage and (2) respiratory therapists and nurses can play a prominent role in instructing patients in their proper use.
-
Randomized Controlled Trial Clinical Trial
Calcium inhibits the cardiac stimulating properties of dobutamine but not of amrinone.
To contrast the effect of increasing blood calcium concentrations on the cardiovascular actions of intravenous beta-adrenergic agonists and phosphodiesterase inhibitors, 46 patients recovering from aortocoronary bypass surgery received either dobutamine or amrinone both in the presence and absence of a calcium infusion. Cardiac output, systemic arterial pressure, pulmonary arterial pressure, central venous pressure, pulmonary artery occlusion pressure, heart rate, and blood ionized calcium concentration were measured before and during infusions of dobutamine (2.5 and 5.0 micrograms/kg/min) and amrinone (0.75 mg/kg bolus + 10 micrograms/kg/min or 2.25 mg/kg bolus + 20 micrograms/kg/min). After the initial dobutamine infusion period, patients were randomly and blindly assigned to receive either a calcium or placebo infusion, and the dobutamine infusions were repeated. ⋯ Calcium infusion increased arterial pressure (8 to 13 percent) but had no significant effects on any other hemodynamic parameters. Calcium reduced the increase in cardiac output produced by dobutamine by 30 percent, but it did not alter the cardiotonic actions of amrinone. Thus, calcium inhibits the cardiotonic actions of certain beta-adrenergic agonists, most likely by interfering with signal transduction through the beta-adrenergic receptor complex.
-
The spectrum of pathogens and the microbiologic investigations used to obtain a diagnosis in 178 patients with severe pneumonia (88 percent requiring intermittent positive-pressure ventilation) are reviewed. Ninety-five patients had primary pneumonia, 31 had nosocomial pneumonia, 24 were immunocompromised patients, and 28 had aspiration pneumonia. ⋯ Serologic studies were valuable in patients in whom no positive microbiologic diagnosis was evident; however, fiberoptic bronchoscopy contributed minimally to the microbiologic diagnosis in this group of patients. The cause of severe primary pneumonia differs from less severe disease, and this should be recognized when selecting empiric antibiotic therapy.