Microscopic examination of intracellular organisms in protected bronchoalveolar mini-lavage fluid for the diagnosis of XXXX .

@entity1 @entity2489 @entity8307
STUDY OBJECTIVES: To assess the cutoff percentage of cells containing intracellular organisms (ICOs) in the microscopic examination of mini-lavage fluid for the diagnosis of @entity2489 ( @entity2489 ), and to study the accuracy of this diagnostic procedure on @entity1 who have received previous @entity8307 ( @entity8307 ). DESIGN: Prospective clinical investigation. SETTING: The medico-surgical ICU of a university hospital. @entity1 : Eighty-two @entity1 who fulfilled the clinical criteria of first episode of @entity2489 . INTERVENTIONS: Lower airway secretion samples were obtained by a nonbronchoscopic protected bronchoalveolar mini-lavage (mini-PBAL). MEASUREMENTS AND RESULTS: A total of 82 mini-PBALs were performed. The fluid obtained was divided into two samples. The first sample underwent direct microscopic examination using centrifugal cytology and Giemsa stain in order to determine the percentage of cells containing ICOs. The second sample was processed for Gram stain and quantitative cultures. @entity2489 was the final diagnosis in 65 @entity1 based on the mini-PBAL results obtained in the quantitative cultures. At least one bacterial species grew in a significant concentration (> or = 10(3) cfu/mL). The mini-PBAL was performed on 42 @entity1 during @entity8307 (> or = 24 h of effective @entity8307 at the time of diagnostic procedure) and on another 40 @entity1 with no @entity8307 (No @entity8307 ). The results of the quantitative cultures were compared with the percentage of cells containing ICOs using a receiver operator characteristic (ROC) curve. The cutoff point of > or = 2% of cells containing ICOs had the highest sensitivity (80%) and specificity (82%) in the studied population (area under the ROC curve [AUC], 0.83; 95% confidence interval [CI], 0.70 to 0.90). In @entity1 receiving @entity8307 , the sensitivity was 70% and specificity was 75% (AUC, 0.73; 95% CI, 0.58 to 0.90); and in No @entity8307 -group @entity1 sensitivity was 88% and specificity was 100% (AUC, 0.92; 95% CI, 0.84 to 1.0). The comparative analysis of both ROC curves was statistically significant (p = 0.04). CONCLUSIONS: The cutoff point of > or = 2% of cells containing ICOs has the highest sensitivity and specificity in the microscopic examination of mini-lavage fluid for the diagnosis of @entity2489 . However, sensitivity is too low to be clinically useful. The direct examination of mini-PBAL fluid is less accurate when previous @entity8307 has been administered.
