Diagnostic yield of quantitative endotracheal aspirates in patients with severe nursing home-acquired pneumonia.
BACKGROUND
Diagnostic strategies based on tracheal aspirates in patients with severe nursing home-acquired pneumonia have not previously been evaluated. The objectives of the study were to investigate, in patients with severe nursing home-acquired pneumonia, the diagnostic value of quantitative endotracheal aspirate (QEA) cultures using increasing interpretative cutoff points, as compared with bronchoalveolar lavage (BAL) and protected specimen brush (PSB) quantitative cultures.


METHODS
Seventy-five nursing home patients requiring mechanical ventilation for suspected pneumonia were studied. Endotracheal aspirate, PSB, and BAL samples were obtained consecutively. The diagnostic yield of QEA at thresholds raging from 10(3) to 10(7) colony-forming units (cfu)/ml was assessed by calculating sensitivities, specificities, and accuracy rates. A receiver operator characteristic curve for the series of cutoff points was constructed.


RESULTS
Forty-nine patients were diagnosed with pneumonia either by BAL (<or= 10(4) cfu/ml) or PSB (<or= 10(3) cfu/ml). Diagnostic accuracy of QEA was most favorable at 10(4) cfu/ml. At this threshold, endotracheal aspirates coincided with both BAL and PSB in 30 cases, whereas partial agreement was observed in 14 cases. This resulted in sensitivity and specificity of 90% (95% confidence interval 78% to 97%) and 77% (95% confidence interval 56% to 91%), respectively. QEA findings correlated significantly with both PSB and BAL quantitative cultures (r = 0.71 [P < 0.001] and r = 0.77 [P < 0.001], respectively).


CONCLUSIONS
QEA may be used as a diagnostic tool to determine the presence of pneumonia in ventilated patients admitted from nursing homes when bronchoscopic procedures are not feasible or available.
El Solh
Ali A
AA
Western New York Respiratory Research Center, Department of Medicine, State University of New York, Buffalo School of Medicine and Biomedical Sciences, Grider Street Buffalo, New York 14215, USA. solh@buffalo.edu
Akinnusi
Morohunfolu E
ME
Pineda
Lilibeth A
LA
Mankowski
Corey R
CR
D000368:Aged; D018893:Bronchoalveolar Lavage; D003428:Cross Infection / Q000175:diagnosis* / Q000382:microbiology; D004926:Escherichia coli / Q000302:isolation & purification; D005260:Female; D006707:Homes for the Aged; D006801:Humans; D008297:Male; D009735:Nursing Homes; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000382:microbiology; D012372:ROC Curve; D012121:Respiration, Artificial; D013048:Specimen Handling / Q000379:methods*; D013211:Staphylococcus aureus / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D014132:Trachea / Q000382:microbiology*