title: Prolonged application of closed in-line suction catheters increases microbial colonization of the lower respiratory tract and bacterial growth on catheter surface.
abstract: BACKGROUND
  Microorganisms become attracted to polymer surfaces for a number of reasons including positive charge of biomaterial or concentration of nutrients on the biomaterial surface. Many bacteria additionally possess specific receptors for the interaction with extracellular host protein components that adhere on the biomaterial surface. Several authors suggest that application of closed in-line polypropylene suction catheters (CISC) in intubated patients for more than 24 h is safe and can reduce the costs associated with mechanical ventilation. Therefore, we evaluated the possible role of prolonged application of CISC to cause enhanced colonization of both the biomaterial and the lower respiratory tract.
  
  
  METHODS
  The prospective, randomized study included 23 mechanically ventilated patients. The CISC tips, adjacent segments and tracheobronchial aspirates of each patient were examined for microbial growth.
  
  
  RESULTS
  Application for 72 h significantly enhanced the microbial growth on the CISC tips and on the adjacent catheter segment. Usage for 3 days led to a significant increase in colonization in the lower respiratory tract.
  
  
  CONCLUSIONS
  Normal saline instillation in conjunction with endotracheal suctioning may lead to a dispersion of microorganisms into the lower respiratory tract. More effective self-cleaning mechanisms are necessary to decontaminate the CISC surface after suctioning.
authors.affiliation: Institute of Medical Microbiology, Otto-von-Guericke University, Leipzigerstr 44, D-39120 Magdeburg, Germany. ccfreytag@t-online.de
authors.forename: C C
authors.initials: CC
authors.lastname: Freytag
authors.forename: F L
authors.initials: FL
authors.lastname: Thies
authors.forename: W
authors.initials: W
authors.lastname: König
authors.forename: T
authors.initials: T
authors.lastname: Welte
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D002408:Catheters, Indwelling / Q000382:microbiology*; D003428:Cross Infection / Q000209:etiology* / Q000382:microbiology / Q000517:prevention & control; D004866:Equipment Contamination; D005260:Female; D006801:Humans; D008297:Male; D018410:Pneumonia, Bacterial / Q000209:etiology* / Q000382:microbiology / Q000517:prevention & control; D012137:Respiratory System / Q000382:microbiology*; D013396:Suction / Q000295:instrumentation