Bronchoscopy

Bronchoalveolar lavage for pneumonia in immunocompromised patients

https://pubmed.ncbi.nlm.nih.gov/31541573/ In hematopoietic stem cell transplant recipients - discordant results occurred in 42 of 115 paired upper and lower respiratory viral multiplex samples. 17 of the 42 were positive in LRT but negative in URT.

Adenovirus, Human metapneumovirus, rhinovirus, and parainfluenza were discordant. RSV was concordant.

https://pubmed.ncbi.nlm.nih.gov/24977681/

"FOB with BAL can be completed in severely thrombocytopenic patients with a minimally increased risk of bleeding, and thrombocytopenia should not be considered a contraindication to performing this procedure [5]. There are no data to suggest that FOB with BAL has a higher risk of bleeding in coagulopathic patients or in those receiving anticoagulation, and these conditions should not preclude the procedure being performed [6].

The incidence of severe complications during bronchoscopy is 0.637%

A differential count with greater than 50% neutrophils may be indicative of acute lung injury or bacterial infection, whereas BAL lymphocytosis suggests granulomatous lung disease, viral infection, or interstitial lung disease [8].

Bacteria, including common pathogens causing community-acquired pneumonia and those causing healthcare-acquired pneumonia, if present in quantities greater than 104 colony forming units per milliliter on bacterial culture from BAL fluid, should be considered pathogenic and should be tested for antibiotic susceptibility.

Timing of BAL performance is also of significant consequence. Diagnostic yield of BAL is higher when the patient is not receiving antibiotics at the time of FOB [11], though it is not recommended to withhold antimicrobial therapy when awaiting the performance of diagnostic studies. One study retrospectively evaluated HSCT patients and the effect of BAL timing on diagnostic yield [48]. They found that diagnostic yield was significantly higher when BAL was performed earlier, specifically in the first 24 h after clinical presentation. This study showed an association between increased pulmonary-associatedmortality and antibiotic adjustments made later in the clinical course, implying that early FOB may favorably affect mortality.

Additionally, diagnostic yield is increased when the pulmonary infiltrates are predominantly alveolar in nature, with infiltrates that are consolidating, tree-in-bud opacities or ground-glass opacities, as opposed to nonalveolar infiltrates, which are predominantly nodular or reticular in nature [50].

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6739192/ BAL in AML or other high grade myeloid neoplasms: led to change in management in nearly half of cases.