Current guidelines discourage the use of broad-spectrum prophylactic antibiotics to prevent fever and neutropenia becauseof lack of efficacy and concerns about development of antibioticresistance. Administration of trimethoprim-sulfamethoxazole to prevent P. jiroveci infection is routine for patients undergoing intensive chemotherapy or immunosuppression for transplantation. Prophylaxis generally is begun with initiation ofanticancer therapy and continued until 6 months after chemotherapy has been completed. In select populations, such aspatients undergoing hematopoietic stem cell transplantation,prophylactic antifungals such as fluconazole are beneficial.
Immunocompromised susceptible persons exposed to chickenpox within 2 days before the onset of rash until 5 days after the onset of rash in the index case should receive varicella zoster immune globulin (VZIG). Modified infection after VZIG may not result in protective immunity, and persons who receive VZIG prophylaxis should be considered still at risk with any subsequent exposures.
Infections are a common and important complication of medical devices and are a major part of health care–associated infections (formerly known as nosocomial infections).
Vascular catheters are inserted in most inpatients and used in many outpatients. The use of catheters for long-term access to the bloodstream has been an important advance for the care of persons who require parenteral nutrition, chemotherapy, or extended parenteral antibiotic therapy. The major complication of catheters is infection.
Short, peripheral intravenous (IV) catheters used for short-term access in stable patients are associated with a low rate of infection, especially in children. Peripherally inserted central catheters are commonly used for short-term venous access. Central catheters are commonly placed for extended venous access, such as for chemotherapy, using tunneled silicone elastomer catheters (Broviac or Hickman catheters) that are surgically inserted into a central vein, passed through a
Gram-positive Coagulase-negative Diphtheroids, organisms staphylococci, Bacillus, Staphylococcus Micrococcus aureus, Enterococcus
Gram-negative Escherichia Acinetobacter, organisms coli, Klebsiella, Enterobacter, Pseudomonas Neisseria aeruginosa
Fungi Candida albicans Malassezia furfur, Candida parapsilosis, Candida glabrata, Candida tropicalis subcutaneous tunnel before exiting the skin, and anchored by a subcutaneous cuff. Contamination of the catheter hub or any connection of the IV tubing is common and is a major predisposition to catheter-associated infection. Totally implanted venous access systems (Port-a-Cath, Infuse-a-Port) have a silicone elastomer catheter tunneled beneath the skin to a reservoir implanted in a subcutaneous pocket. Implanted catheters or ports decrease, but do not eliminate, the opportunity for microbial entry at the skin site.
Catheter-related thrombosis and catheter-related infection can develop separately or together. Ultrasound or radiographscan identify thrombi, but infection can be identified by culture only. Thrombophlebitis is inflammation with thrombosis. Septic thrombophlebitis is thrombosis with organisms embedded in the clot. Catheter-related bloodstream infection implies isolation of the same organism from a catheterand from peripheral blood of a patient with clinical symptomsof bacteremia and no other apparent source of infection. Confirmation requires quantitative colony counts of both samples,which is not routinely performed. Possible sources of the bacteremia include the infusate, contamination via tubing and catheter connections, or established infection, which may or maynot be clinically apparent. Infection may appear as an exit site infection limited to the insertion site or may extend along thecatheter tunnel of buried catheters to cause a tunnel infection.