Risk factors of nosocomial bacteremia associated with pulmonary artery catheters in a critical care unit.

An epidemiologic investigation at a community teaching hospital identified 17 cases of endemic primary nosocomial bacteremias associated with the use of pulmonary artery catheters (PACs). A matched-case control study was undertaken to identify risk factors associated with these bacteremias. Factors significantly associated with bacteremia were length of hospitalization; length of stay in the critical care unit; length of time the PAC introducer was left in place and used as an intravenous (IV) access device after PAC withdrawal; respiratory compromise; PAC site infection; prior infections at other sites; concomitant hyperalimentation; and number of IV piggyback administrations per day prior to onset of bacteremia. Pathogens isolated included coagulase-negative Staphylococcus species (55.6%), Staphylococcus aureus (22.2%), Candida albicans (14.8%), and enterococci (7.4%). These pathogens were generally resistant to antibiotics given before the development of bacteremia. Bacteremia was associated with significant mortality, a prolonged hospital stay, and increased hospital charges. This study identifies important risk factors to consider in formulating guidelines to prevent and control PAC-associated nosocomial infections.

Indium-111-labeled human polymorphonuclear leukocytes: viability, random migration, chemotaxis, bacterial capacity, and ultrastructure.

Human polymorphonuclear leukocytes (PMNs) were labeled with indium-111 oxine in ethanol, and the effects of the labeling procedure, radioactivity, and concentrations of oxine and ethanol on PMN function and structure were studied in vitro. The standard labeling procedure did not alter the viability, random migration, chemotaxis, bactericidal capacity, or the ultrastructure of PMNs. Exposure to higher doses of radioactivity, or to higher concentrations of ethanol, had no appreciable effects on random migration and chemotaxis of PMNs. A dose-dependent reduction in their random migration and chemotaxis was observed when higher concentrations of oxine were used. These results indicate that In-111-labeled PMNs are structurally intact and have normal in vitro locomotion and bactericidal activity. Indium-111-labeled PMNs should be suitable for studying the kinetics and distribution of these cells in health and disease.

Granulocyte function during lithium therapy.

Random migration, chemotaxis, phagocytosis, and bactericidal ability of neutrophils from 5 patients receiving lithium carbonate were compared with those of neutrophils from healthy donors. These cells functioned normally in all respects. Neither sera from patients receiving lithium carbonate nor the addition of lithium chloride to control cells in vitro significantly altered their functional capacity. These findings suggest that neutrophil function in patients receiving lithium therapy is preserved, and they support the potential utility of this drug as a leukopoietic agent in neutropenic states.

Neutrophil function and host resistance.

The part played by the phagocytic cells against invading pathogens has been known since the work of Metchnikoff nearly a century ago. This review deals primarily with the role of the neutrophilic polymorphonuclear leukocyte in host defense against microbial infections. The overall function of these cells in protection from infection is dependent on a number of steps. First, an adequate number of functionally mature neutrophils have to be produced and released into the circulation by the bone marrow. Cells must circulate normally and be capable of adhering to capillary and venule walls overlying inflammatory sites. The next step involves the exit of phagocytes from the blood stream through the capillary wall and emigration into the tissues to establish contact with the invading pathogens. This process is accomplished by the locomotive characteristics of these cells and chemotaxis. Most organisms must then be phagocytized to be killed. Two discrete phases are involved in phagocytosis; the "recognition" and attachment phase followed by the ingestion phase. After phagocytosis a series of coordinated morphologic and biochemical events are set into motion which leads to eventual death and lysis of the ingested microbes. A variety of antimicrobial mechanisms are involved in this final step and indicate that these cells have an appreciable reserve capacity if one mechanism is impaired. Recent evidence which clarifies mechanisms involved in all these stages is discussed.

Unusually high occurrence of drug reactions with nafcillin.

Five patients seen during a two-month period who developed untoward systemic reactions following high dose intravenous administration of nafcillin are described. Recovery was complete upon discontinuation of the drug. The clustering of these cases and the high incidence (5 of 5) of side effects are highly unusual, and suggest that the frequency of nafcillin reactions might be higher than previously suspected.

Trichosporon cutaneum endocarditis.

A 61-year-old man with Trichosporon cutaneum (T. cutaneum) prosthetic valve endocarditis is reported. He had had an aortic valve replacement for rheumatic heart disease 3 years earlier. Onset of the valve infection was subacute. A systolic murmur was noted on admission. Subsequently, he developed conjunctival hemorrhages, hematuria and transient episodes of confusion, aphasia and cranial nerve palsies. Three of 17 blood cultures taken over 3 weeks were positive for T. cutaneum. He was given amphotericin B (AmB) and 5-fluorocytosine (5FC); T. cutaneum infection of prosthetic aortic valve was identified. The aortic valve was replaced. Postoperatively he developed refractory ventricular fibrillation and died. Striking synergy to AmB-5FC and AmB-rifampin combinations was demonstrated in vitro.