A comparison of two antimicrobial-impregnated central venous catheters. Catheter Study Group.

BACKGROUND: The use of central venous catheters impregnated with either minocycline and rifampin or chlorhexidine and silver sulfadiazine reduces the rates of catheter colonization and catheter-related bloodstream infection as compared with the use of unimpregnated catheters. We compared the rates of catheter colonization and catheter-related bloodstream infection associated with these two kinds of antiinfective catheters. METHODS: We conducted a prospective, randomized clinical trial in 12 university-affiliated hospitals. High-risk adult patients in whom central venous catheters were expected to remain in place for three or more days were randomly assigned to undergo insertion of polyurethane, triple-lumen catheters impregnated with either minocycline and rifampin (on both the luminal and external surfaces) or chlorhexidine and silver sulfadiazine (on only the external surface). After their removal, the tips and subcutaneous segments of the catheters were cultured by both the roll-plate and the sonication methods. Peripheral-blood cultures were obtained if clinically indicated. RESULTS: Of 865 catheters inserted, 738 (85 percent) produced culture results that could be evaluated. The clinical characteristics of the patients and the risk factors for infection were similar in the two groups. Catheters impregnated with minocycline and rifampin were 1/3 as likely to be colonized as catheters impregnated with chlorhexidine and silver sulfadiazine (28 of 356 catheters [7.9 percent] vs. 87 of 382 [22.8 percent], P<0.001), and catheter-related bloodstream infection was 1/12 as likely in catheters impregnated with minocycline and rifampin (1 of 356 [0.3 percent], vs. 13 of 382 [3.4 percent] for those impregnated with chlorhexidine and silver sulfadiazine; P<0.002). CONCLUSIONS: The use of central venous catheters impregnated with minocycline and rifampin is associated with a lower rate of infection than the use of catheters impregnated with chlorhexidine and silver sulfadiazine.

Malignant airway obstruction: recognition and management.

Malignant airway obstruction affects up to 80,000 patients annually, many of whom will present acutely to the emergency department (ED). This clinical entity should be sought in any patient presenting to the ED with increasing shortness of breath, recurrent chest infections, hemoptysis, and an inability to lie flat. Interventions suggested in malignant airway obstruction include: maintenance of spontaneous ventilation by avoiding respiratory depressing sedation, muscle relaxants or narcotics; changes in patient's position; avoidance of general anesthesia and positive pressure ventilation, if possible; placement of endotracheal tube beyond the level of obstruction; radiotherapy; corticosteroids; availability of helium-oxygen mixtures, cardiopulmonary bypass, or extracorporeal membrane oxygenation. If time allows, further diagnostic studies will be of assistance in assessing the best therapy before definitive intervention.

Acute thoracic aortic dissection: the basics.

With an increasing incidence, aortic dissection is the most common acute illness of the aorta. In the setting of chronic hypertension, with or without other risk factors for aortic dissection, this diagnosis should be considered a diagnostic possibility in patients presenting to the emergency department with acute chest or back pain. Left untreated, about 75% of patients with dissections involving the ascending aorta die within 2 weeks of an acute episode. But with successful initial therapy, the 5-year survival rate increases to 75%. Hence, timely recognition of this disease entity coupled with urgent and appropriate management is the key to a successful outcome in a majority of the patients. This article reviews acute thoracic aortic dissection, including ED diagnosis and management.