Abstract: We found three eligible randomized controlled trials, with a total of 2081 participants. One of the three included studies did not mention the amount of participants and presented no outcome data. The 'Risk of bias' assessment indicated that there was a high risk of detection bias owing to lack of blinding of outcomes assessors, but we assessed all other domains to be at low risk of bias. Trial design and conduct were generally adequate, with the most common areas of weakness in blinding. The majority of participants were included in centres across North America. The mean age of participants ranged from 61 to 64 years, and the mean duration of intubation was between 3.2 and 7.7 days. One trial comparing silver-coated ETTs versus non-coated ETTs showed a statistically significant decrease in VAP in favour of the silver-coated ETT (1 RCT, 1509 participants; 4.8% versus 7.5%, risk ratio (RR) 0.64, 95% confidence interval (CI) 0.43 to 0.96; number needed to treat for an additional beneficial outcome (NNTB) = 37; low-quality evidence). The risk of VAP within 10 days of intubation was significantly lower with the silver-coated ETTs compared with non-coated ETTs (1 RCT, 1509 participants; 3.5% versus 6.7%, RR 0.51, 95% CI 0.31 to 0.82; NNTB = 32; low-quality evidence). Silver-coated ETT was associated with delayed time to VAP occurrence compared with non-coated ETT (1 RCT, 1509 participants; hazard ratio 0.55, 95% CI 0.37 to 0.84). The confidence intervals for the results of the following outcomes did not exclude potentially important differences with either treatment. There were no statistically significant differences between groups in hospital mortality (1 RCT, 1509 participants; 30.4% versus 26.6%, RR 1.09, 95% CI 0.93 to 1.29; low-quality evidence); device-related adverse events (2 RCTs, 2081 participants; RR 0.65, 95% CI 0.37 to 1.16; low-quality evidence); duration of intubation; and length of hospital and ICU stay. We found no clinical studies evaluating the cost-effectiveness of silver-coated ETTs. This review provides limited evidence that silver-coated ETT reduces the risk of VAP, especially during the first 10 days of mechanical ventilation.

Plain-language summary: We found three randomized controlled trials involving 2081 participants. No outcome data were available for one included study. The design of the other two RCTs was generally good, although there were some weaknesses. The majority of participants were included in centres around North America. The evidence is current to October 2014. Both RCTs were funded but stated that the sponsors contributed only to the study design and did not participate in the conduct of the study. We found that silver-coated ETT reduced the risk for developing VAP from 6.7% to 3.5% within 10 days of intubation compared with non-coated ETT in people who required mechanical ventilation for 24 hours of longer, although the quality of evidence for this outcome was low. One study showed that an initial VAP occurrence appeared much later in time in people who had a silver-coated ETT compared with a non-coated ETT, although again the evidence was low quality. We could not draw conclusions about hospital mortality, device-related complications, duration of intubation, and length of hospital and intensive care unit stay owing to uncertainty of the effects. We found no clinical studies evaluating the cost-effectiveness of silver-coated ETTs. The overall quality of evidence was low for all interested outcomes mentioned. Limited evidence suggests that silver-coated ETT seems to be an effective device in reducing the risk of VAP, although data for our other key outcome of hospital mortality were inconclusive. Larger studies with more participants who are at risk for VAP and who require mechanical ventilation for a longer period of time are needed.