Noninvasive positive pressure ventilation (NPPV) provides ventilatory support without the need for intubation and for earlier removal of the endotracheal tube to reduce complications related to prolonged intubation. Burns and coworkers, in a recent Cochrane review, reported significant benefits: decreased mortality (risk ratio [RR], 0.41; 95% confidence interval [CI], 0.22 to 0.76), lower rates of VAP (RR 0.28; 95% CI, 0.0.90 to 0.85); decreased length of ICU and shorter hospital stays; and lower duration of mechanical support. The impact of NPPV is greater in patients with COPD exacerbations or congestive heart failure than for patients with VAP. Recent data also indicate that NPPV may not be a good strategy to avoid reintubation after initial extubation, and is recommended for hospitals with staff who are experienced in this technique.
The endotracheal tube lumen is also a nidus for the growth of bacteria-encased in biofilm. Rates of bacterial biofilm formation increase over time, are protected from host humoral and cellular defenses, and antibiotics, and may contain high concentrations of bacteria. Biofilm-encased bacteria also are less susceptible to killing by host defenses. Suction-ing of patients or passage of a bronchoscope may dislodge biofilm-encased bacteria that may increase the risk of late-onset VAP.
Prevention of bacterial biofilm formation on urinary catheters has been reduced by the use of a silver coating. The use of a silver-coated endotracheal tubes, which was effective in preventing VAP in a dog model, is currently being evaluated in a large, multicenter, randomized clinical trial of patients receiving mechanical ventilation.
Moller and coworkers, using a retrospective study design, examined the potential benefit of early tracheostomy ET (< 7 days) vs late tracheostomy in severely injured surgical SICU patients. Patients with late tracheostomy had significantly higher rates of VAP (42.3% vs 27.2%, p < 0.05), duration of mechanical ventilation, and length of ICU stay. The authors suggest that if patients will require prolonged ventilation (> 7 days), that tracheostomy be performed between day 3 and 7. In a trial of 60 trauma patients randomized to early tracheostomy by Barquist and coworkers, the study was terminated as the intervention had no effect on mortality, rates of VAP, ICU stay, or other outcomes. A systematic review and metaanalysis by Griffiths and coworkers from 406 patients in five studies also reported no reduction in pneumonia, mortality, ventilator days, or length of ICU stay.