Consistency Between Bronchoalveolar Lavage and Endotracheal Aspirate in the Diagnosis of Ventilator-Associated Pneumonia

Abstract

Background 
 Ventilator-associated pneumonia (VAP) is a common nosocomial lung infection. Quick and accurate identification of the causative pathogen is crucial to improve prognosis. To date, the literature is controversial regarding whether endotracheal aspirate (ETA) can be used as an alternative to bronchoalveolar lavage (BAL) in VAP diagnosis.
 Objectives 
 To evaluate the consistency between the results of BAL and ETA in the diagnosis of early- and late VAP and to determine the microbial profiles of the involved microorganisms and their antimicrobial susceptibility. 
 Patients and Methods
 This is a single-centre prospective study that included 50 VAP-suspected patients conducted at Shar Hospital, Sulaimani, Iraq, from July 2021 to February 2022. The patients were categorised into early VAP and late VAP. For each patient, both ETA and BAL techniques were used to obtain samples for microbiological analysis and antimicrobial susceptibility testing.
 Results
 Ten (20%) patients developed early VAP, and 40 (80%) developed late VAP. The culture results of samples obtained by BAL showed microbial growth in 45 (90%) of the cases. Meanwhile, ETA resulted in microbial growth in 40 (80%) patients. In 45 (90%) of the samples, both techniques yielded the same results regarding microbial growth in the cultures. Among the 45 samples with the same growth results, 35 (70%) showed the same type of microbes, and 5 (10%) showed no microbial growth, indicating substantial agreement. In both BAL and ETA, Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii were the most frequently isolated pathogens. Both early- and late-VAP were associated with a high frequency of multidrug-resistant microorganisms, 6 (75%) and 25 (56.8%), respectively. However, extensively drug-resistant/pan-drug-resistant isolates were much more common in late-VAP patients (12, 27.3%). 
 Conclusion
 ETA can be a reliable, non-invasive alternative to BAL in VAP diagnosis associated with rapid and relatively accurate results.