Ventilator-Associated Pneumonia: Update on Etiology, Prevention, and Management
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Ventilator-associated pneumonia (VAP) remains one of the most important nosocomial infections in the intensive care unit and has been the focus of much recent research. New evidence on VAP preventive measures includes evidence for the efficacy of changes in endotracheal tube cuff design and materials, drainage of subglottic secretions, saline instillation prior to tracheal suctioning, patient positioning, oral decontamination, aerosolized antibiotics, and probiotic use. In the absence of a clinical reference standard, the diagnosis of VAP remains problematic. Although extensive research on invasive sampling techniques for microbiological confirmation has been conducted, current evidence suggests that endotracheal aspirates are equivalent. Promising new diagnostic methods include non–culture-based microbiological techniques and biomarkers. The treatment of VAP continues to evolve. Shorter antibiotic treatment duration is effective. As well, novel methods of antimicrobial delivery to maximize antibiotic effectiveness and the use of inflammatory biomarkers to guide duration of antibiotic therapy show promise.
KeywordsVentilator-associated pneumonia Nosocomial infections Etiology Prevention Diagnosis Management Intensive care unit
Conflicts of interest: O. Rewa—none; J. Muscedere—unrestricted research grant for investigator-initiated trial, Covidien.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 7.Holzapfel L, Chastang C, Demingeon G, et al. A randomized study assessing the systematic search for maxillary sinusitis in nasotracheally mechanically ventilated patients. Influence of nosocomial maxillary sinusitis on the occurrence of ventilator-associated pneumonia. Am J Respir Crit Care Med. 1999;159:695–701.PubMedGoogle Scholar
- 8.• Kollef M, Afessa B, Anzueto A et al.: Silver-Coated Endotracheal Tubes and Incidence of Ventilator-Associated Pneumonia: The NASCENT Randomized Trial, JAMA 2008, 300: 805–813. This article describes the first RCT examining the role of silver-coated endotracheal tubes and their role in the prevention of VAP.PubMedCrossRefGoogle Scholar
- 9.• Shorr AF, Zilberberg MD, Kollef M: Coast-effectiveness analysis of silver-coated endotracheal tubes to reduce the incidence of ventilator-associated pneumonia, Infect Control Hosp Epidemiol 2009, 30:759–763. An analysis of the cost effectiveness of the use of silver-coated endotracheal tubes in the prevention of VAP with the aid of a theoretical model.PubMedCrossRefGoogle Scholar
- 12.TaperGuard™ Endotracheal Tube FDA 510(k) Premarket Notification. Available at http://www.accessdata.fda.gov/cdrh_docs/pdf9/K090352.pdf. Accessed October 2010.
- 13.• Dave MH, Frotzler A, Spielmann N, Madjdpour C, Weiss M: Effect of tracheal tube cuff shape on fluid leakage across the cuff: an in vitro study, Brit J Anaes 2010, 105: 538–43. This recent paper demonstrates that in an in vitro study, polyurethane cuffs showed less leakage than PVC cuffs. The investigators also demonstrated that tapered cuffs were not inferior to cylindrical cuffs, and may in fact be superior to cylindrical cuffs in decreasing fluid leakage past the cuffs.CrossRefGoogle Scholar
- 18.• Caruso P, Denari S, Ruiz SAL, Demarzo SE, Deheinzelin, D: Saline instillation before tracheal suctioning decreases the incidence of ventilator-associated pneumonia, Crit Care Med 2009, 37: 32–38. This article examines the effect of saline instillation before suction on VAP. The investigators determined that with saline instillation, incidence of VAP was decreased.PubMedCrossRefGoogle Scholar
- 19.• Manzano F, Fernandez-Mondejar E, Colmenero M, et al.: Positive-end expiratory pressure reduces incidence of ventilator-associated pneumonia in non hypoxemic patients, Crit Care Med 2008, 36: 2225–2231. This paper examined the effects of PEEP versus no PEEP on VAP, and determined that minimal amounts of PEEP—regardless of the oxygenation of intubated patients—decreased the incidence of VAP.PubMedCrossRefGoogle Scholar
- 20.•• Terragni P, Antonelli M, Fumagalli R, et al.: Early vs Late Tracheotomy for Prevention of Pneumonia in Mechanically Ventilated Adult ICU Patients A Randomized Controlled Trial, JAMA 2010; 303: 1483–1489. This article describes a 600-patient, multicenter, Italian, RCT that examined the role of early tracheostomy for the prevention of VAP. Investigators determined that early tracheostomy versus late tracheostomy did not prevent the development of VAP.PubMedCrossRefGoogle Scholar
- 22.• Tiruvoipati R, Bangash M, Manktelow B, Peek GJ: Efficacy of prone ventilation in adult patients with acute respiratory failure: a meta-analysis, J Crit Care 2008, 23: 101–110. A meta-analysis of five studies examining the effect of prone ventilation in patients. The authors did not find any reduction in mortality, pneumonia, or length of ICU stay with prone ventilation, but did find improved oxygenation.PubMedCrossRefGoogle Scholar
- 23.• Staudinger T, Bojic A, Holzinger U, et al.: Continuous lateral rotation therapy to prevent ventilator-associated pneumonia, Crit Care Med 2010, 38: 486–490. The authors of this prospective randomized trial examined the effect of continuous lateral rotation to prevent VAP. They found that it did reduce VAP, but was also technically difficult and at times not tolerated by patients.PubMedCrossRefGoogle Scholar
- 24.•• de Smet AM, Kluytmans JA, Cooper BS et al.: Decontamination of the digestive tract and oropharynx in ICU patients. N Engl J Med 2009, 360:20–31. The authors of this clinical trial examined the role of decontamination of the digestive tract and oropharynx in ICU patients. They found a 3.5% reduction in mortality in patients with selective decontamination of the digestive tract, and a 2.9% reduction in mortality in patients with selective oral decontamination at 28 days.PubMedCrossRefGoogle Scholar
- 26.• Tantipong H, Morkchareonpong C, Jaiyindee S, Thamlikitkul, V: Randomized Controlled Trial and Meta-analysis of Oral Decontamination with 2% Chlorhexidine Solution for the Prevention of Ventilator-Associated Pneumonia, Inf Cont Hosp Epidemiol 2008, 29: 131–136. The authors of this study determined that oral decontamination with 2% chlorhexidine is associated with a decreased incidence of VAP.CrossRefGoogle Scholar
- 29.• Siempos, II, Ntaidou, TK, Falagas, ME: Impact of the administration of probiotics on the incidence of ventilator-associated pneumonia: A meta-analysis of randomized controlled trials, Crit Care Med 2010, 38: 954–962. This recent meta-analysis depicts how probiotics may be associated with decreased incidence of VAP.PubMedCrossRefGoogle Scholar
- 30.Institute for Healthcare Improvement Ventilator Bundle available at: http://www.ihi.org/IHI/Topics/CriticalCare/IntensiveCare/Changes/ImplementtheVentilatorBundle.htm. Accessed November 2010. Safer Health Care Now Ventilator Associated Pneumonia Prevention Bundle available at: http://www.saferhealthcarenow.ca/EN/Interventions/VAP/Pages/gsk.aspx. Accessed November 2010.
- 31.•• Tejerina E, Esteban A, Fernandez-Segoviano P. et al.: Accuracy of clinical definitions of ventilator-associated pneumonia: Comparison of autopsy findings, J Crit Care 2010, 25: 62–68. This recent paper compared the accuracy of clinical and microbiological diagnostic criteria with the autopsy diagnosis of VAP. Clinical criteria were found to have poor sensitivities and specificities for the diagnosis of VAP, but did improve with microbiological confirmation.PubMedCrossRefGoogle Scholar
- 33.• Bouza E, Torres M, Radice C et al.: Direct E-Test (AB Biodisk) of Respiratory Samples Improves Antimicrobial Use in Ventilator-Associated Pneumonia, Clin Inf Dis 2007, 44:3 82–7. This study examined the effect of E-test for the treatment of VAP. E-test was shown to improve antibiotic use in the treatment of VAP.Google Scholar
- 34.• Ramirez P, Garcia MA, Ferrer M et al.: Sequential measurements of procalcitonin levels in diagnosing ventilator-associated pneumonia, Eur Respir J 2008, 31: 356–362. This is an important article about examining CRP and PCT levels in making the diagnosis of VAP. The authors arrive at a clinical decision-making tool involving PCT for the diagnosis of VAP.PubMedCrossRefGoogle Scholar
- 37.• Anand NJ, Zuick S, Klesney-Tait J, Kollef MH: Diagnostic implications of soluble triggering receptor expressed on myeloid-1 cells in BAL fluid in patients with pulmonary infiltrates in the ICU, Chest 2009; 135: 641–647. This prospective cohort study found that sTREM-1 may have minimal diagnostic value for VAP.PubMedCrossRefGoogle Scholar
- 38.• Horonenko G, Hoyt JC, Robbins RA et al.: Soluble triggering receptor expressed on myeloid-1 cells is increased with patients with ventilator associated pneumonia: A preliminary report, Chest 2007, 132: 58–63. This article describes a prospective study that found that sTREM-1 may be useful in diagnosing VAP.PubMedCrossRefGoogle Scholar
- 39.• Oudhuis GJ, Beuving J, Bergmans D et al.: Soluble Triggering Receptor Expressed on Myeloid cells-1 in bronchoalveolar lavage fluid is not predictive for ventilator-associated pneumonia, Intensive Care Med, 2009, 35: 1265–1270. This observational study found that sTREM-1 in BAL is not useful in the diagnosis of VAP.PubMedCrossRefGoogle Scholar
- 40.Kuti EL, Patel AA, Coleman CI. Impact of inappropriate antibiotic therapy on mortality in patients with ventilator-associated pneumonia and blood stream infections: a meta-analysis. J Crit Care. 2008;23:91–100. Inappropriate initial antibiotic therapy is associated with increased mortality in VAP.PubMedCrossRefGoogle Scholar
- 41.• Joffe AR, Muscedere J, Marschall JC, Su Y, Heyland DK: The safety of targeted antibiotic therapy for ventilator-associated pneumonia: A multicenter observational study, J Crit Care, 2008; 23: 82–90. This observational study found that targeted antibiotic therapy for VAP was associated with less antibiotic use and was not associated with any increased harm.PubMedCrossRefGoogle Scholar
- 42.• Heyland DK, Dodek P, Muscedere J: Randomized trial of combination versus monotherapy for the empiric treatment of suspected ventilator-associated pneumonia, Crit Care Med 2008, 36: 737–744. Monotherapy is not inferior to combination therapy for the treatment of VAP. There is a trend for patients with late-onset VAP to do better with combination therapy versus monotherapy.PubMedCrossRefGoogle Scholar
- 43.• Craven DE, Chroneou A, Zias N, Hjalmarson KI: Ventilator-associated tracheobronchitis: The impact of targeted antibiotic therapy on patient outcomes, CHEST 2009, 135: 521–528. The authors report that VAT may be an important risk factor for the development of VAP, and treatment of VAT may result in a lower incidence of VAP.PubMedCrossRefGoogle Scholar
- 44.• Nseir S, Favory R, Josefowicz J, et al.: Antimicrobial treatment for ventilator-associated tracheobronchitis: a randomized, controlled, multicenter study, Critical Care 2008, 12:R62 doi:10.1186/cc6890. Available online at http://ccforum.com/content/12/3/R62. Accessed October 2010. In patients with VAT, antimicrobial treatment is associated with lower rates of VAP and ICU mortality.
- 45.•• Palmer LB, Smaldone GC, Chen JJ, et al.: Aerosolized antibiotics and ventilator-associated tracheobronchitis in the intensive care unit, Crit Care Med 2008, 36: 2008 –2013. This article describes a double-blind RCT examining the role of aerosolized antibiotics and VAT in the ICU. The authors found that with aerosolized antibiotics, there was a significant reduction in VAP, which facilitated weaning and decreased administration of systemic antibiotics. PubMedCrossRefGoogle Scholar
- 49.• Stolz D, Smyrnios N, Eggimann P et al.: Procalcitonin for reduced antibiotic exposure in ventilator-associated pneumonia: a randomised study, Eur Respir J 2009, 34: 1364–1375. This article describes a multicenter RCT that found following PCT levels reduces patient exposure to antibiotics in the treatment of VAP.PubMedCrossRefGoogle Scholar
- 50.•• Bouadama L, Luyt CE, Tubach F et al.: Use of procalcitonin to reduce patients’ exposure to antibiotics in intensive care units (PRORATA trial): a multicentre randomized controlled trial, Lancet 2010, 375: 463–74. This article describes a large, multicenter, randomized trial examining the role of PCT in guiding continued antimicrobial therapy for VAP. The authors found that by using PCT with specific cut-off criteria, the duration of antimicrobial therapy could be shortened with no adverse effects.CrossRefGoogle Scholar