Reduced burden of bacterial airway colonization with a novel silver-coated endotracheal tube in a randomized multiple-center feasibility study

Crit Care Med. 2006 Nov;34(11):2766-72. doi: 10.1097/01.CCM.0000242154.49632.B0.


Objective: To assess the feasibility and safety of the respiratory infection control (RIC) device, a silver-coated endotracheal tube, and its effect on bacterial burden in the airways.

Design: Prospective, randomized, single-blind, multiple-center study.

Setting: Three hospitals in Spain and one in the United States.

Patients: Patients were eligible adults who required mechanical ventilation for > or =24 hrs and did not have respiratory infections. One hundred forty-nine patients were intubated and analyzed for safety; 121 were intubated > or =24 hrs and analyzed for tube colonization; 67 had negative baseline quantitative endotracheal aspirates and were analyzed for quantitative endotracheal aspirates colonization.

Interventions: Intubation with the RIC device or a control endotracheal tube.

Measurements and main results: The RIC device was associated with delayed colonization on the tube compared with the control device at the threshold of ++, +++, or > or =10(4) colony-forming units/mL (p = .02, log-rank test; p = .10, Wilcoxon's test) and in quantitative endotracheal aspirates at > or =10(6) colony-forming units/mL (p = .08, log-rank test; p = .05, Wilcoxon's test). The RIC device was associated with reduced colonization rate by days on the tube (p = .04, Wilcoxon's test) and in quantitative endotracheal aspirates (p = .05, Wilcoxon's test) at the same thresholds. The RIC device was associated with lower maximal bacterial burden in tracheal aspirates for 7 days (mean log-transformed burden, 4.2 +/- 2.3 vs. 5.5 +/- 1.7 log colony-forming units/mL; p = .02, Wilcoxon's test). Other between-group differences favored the RIC device but were not significant. Five adverse events were considered device related, including three events in the RIC group and two events in the control group.

Conclusions: In this prospectively planned, preliminary analysis, the RIC device was feasible and well tolerated. Larger studies are needed to determine whether delayed colonization, reduced colonization rate, and decreased bacterial burden will decrease the incidence of ventilator-associated pneumonia.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Coated Materials, Biocompatible*
  • Colony Count, Microbial
  • Cross Infection / etiology
  • Cross Infection / prevention & control*
  • Equipment Contamination / prevention & control
  • Feasibility Studies
  • Female
  • Humans
  • Intubation, Intratracheal / adverse effects
  • Intubation, Intratracheal / instrumentation*
  • Male
  • Middle Aged
  • Pneumonia, Aspiration / etiology
  • Pneumonia, Aspiration / prevention & control*
  • Respiration, Artificial / adverse effects
  • Respiration, Artificial / methods*
  • Silver*
  • Single-Blind Method
  • Spain
  • United States


  • Coated Materials, Biocompatible
  • Silver