Validation of the 2005 American Thoracic Society/Infectious Diseases Society of America guidelines for ventilator-associated pneumonia: a Japanese multicenter observational study

Introduction

To select the empirical antimicrobial treatment for patients with ventilator-associated pneumonia (VAP), the 2005 American Thoracic Society/Infectious Disease of America (ATS/IDSA) guidelines classify patients according to time of onset and risk factors for potential multidrug-resistant pathogens (MDRPs). This study aimed to evaluate the effectiveness of microbial prediction and validate the adequacy of these guidelines for antibiotic strategy in VAP patients.

Methods

We retrospectively analyzed 296 patients who received empiric antimicrobial treatment for VAP between January 2006 and December 2010 in 10 ICUs of Japanese tertiary hospitals. VAP was diagnosed according to CDC criteria. After assigning patients to the ATS/IDSA risk group (n = 250; late onset or risk factors for MDRPs) or non-risk group (n = 46; early onset without risk factors for MDRPs), we determined the accuracy of the guidelines for predicting pathogens and the impact of guideline adherence on patient outcome.

Results

Median age and SOFA scores on ICU admission were 66 (interquartile range: 50 to 77) years and 6 (4 to 8) years, respectively. Primary diagnosis on ICU admission was coma including post-cardiac arrest syndrome (31%), trauma (29.4%), and sepsis (9.8%). Prediction of MDRPs was significantly higher in the risk group than in the nonrisk group (36.8% vs. 15.2%, P = 0.004). Guideline adherence was lower in the risk group (45.6% vs. 65.2%, P = 0.016). Treatment adequacy was greater with guideline adherence than with nonadherence (75.7% vs. 55.9%, P < 0.01). Hospital mortality was not affected by guideline adherence (P = 0.70). Multivariate analysis revealed that the independent factors related to hospital mortality were adequate antimicrobial treatment (odds ratio: 0.53, 95% CI: 0.29 to 0.95; P = 0.034), age (1.02, 1.00 to 1. 04; P = 0.004), history of malignancy (8.59, 1.48 to 49.6; P = 0.016), trauma (0.41, 0.2 to 0.87; P = 0.02), acute kidney injury (5.54, 2.69 to 11. 4: P < 0.001), and severe sepsis at VAP onset (2.7, 1.4 to 5.1; P = 0.002).

Conclusion

The prediction of MDRPs using the 2005 ATS/IDSA guidelines was acceptable. To ensure adequate antimicrobial treatment, strict guideline adherence is required in the Japanese setting.