[Value of blinded sampling methods in the pathogenic diagnosis of ventilator-associated pneumonia]

To evaluate the diagnostic value of blinded protected specimen brush and quantitative culture (BPSB-QC) in the pathogenic diagnosis of ventilator-associated pneumonia (VAP).

A prospective, self-controlled clinical trial was conducted during a 36-month period. QC of paired samples of BPSB and PSB via a fiberoptic bronchoscopy (FOB- PSB) in a total of 54 patients during 125 suspected episodes of VAP was compared. The sensitivity and accuracy, as well as the concordance between BPSB-QC and FOB-PSB-QC result in 48 patients with 106 episodes of VAP were assessed. Both BPSB-QC and FOB-PSB-QC greater than 103 cfu/ml (positive cutoff) was considered diagnostic of VAP.

Forty-eight patients with 106 episodes were considered to have VAP (84.8%). The accuracy of BPSB-QC and FOB-PSB-QC were 80.8% (101/125) and 83.2% (104/125), respectively. The rate of complete concordant results was high (75.2%) for BPSB-QC and FOB-PSB-QC. The pathogenic diagnostic agreement between the two techniques was 84.8% (106/125). There were no significant differences with regard to site of pneumonia and positive diagnostic rate between the two techniques.

BPSB-QC has similar accuracy and same feasibility compared with FOB-PSB-QC which was commonly primarily used in the pathogenic diagnosis of VAP, and that its use is substantially simpler, safe and cost saving, especially when FOB technique is not available.