Pediatric emergency medicine trisk 4656 4656

prophylactic antibiotics Infections generally occur within months of shunt placement, with a higher incidence of infections in children younger than years Other risk factors include insertion of the shunt into a premature infant and insertion after a previous infection The common organisms cultured from infected CSF shunts are gram-positive bacteria ( Table 135.3 ) Staphylococci adhere well to Silastic tubing, and these infections are often difficult to eradicate without removal of the catheter Infections with S epidermidis , S aureus , and P acnes are common within the first few weeks after surgery Infections that occur more than months after shunt placement are more likely due to gram-negative infections caused by H influenzae infection, bowel erosion, or pressure necrosis from the shunt apparatus Fungi are rare pathogens occasionally seen in premature infants External infection of skin and subcutaneous tissue overlying the shunt hardware can occur; however, these superficial infections may not lead to shunt infection if treated promptly Necrosis of the area around the reservoir can occur as a result of the constant pressure in infants or nonambulatory patients Skin breakdown leading to visualization of the shunt mechanism is, by definition, a shunt infection and must be treated accordingly TABLE 135.3 COMMON ORGANISMS INVOLVED IN CEREBROSPINAL FLUID SHUNT INFECTIONS Gram positive Gram negative Coagulase-negative Escherichia coli staphylococci (Staphylococcus epidermidis ) Staphylococcus aureus Enterococcus species Streptococcus species Haemophilus influenzae