Evaluation of pulmonary infiltrates in patients with haematological malignancies using fibreoptic bronchoscopy and bronchoalveolar lavage

Abstract

Background : Chest infection is the major cause of morbidity and mortality among patients with haematological malignancies. Conventional diagnostic methods - chest x-ray , blood and sputum culture have limited yield . We used fibreoptic bronchoscopy and bronchoalveolar lavage to evaluate nature of pulmonary infiltrates on chest x-ray. Patients and Methods : 25 patients with haematological malignancies with fever and pulmonary infiltrates were studied. Patients median age was 32 years, ranging from 16 to 65 years. There were 21 males and 4 females. Initial evaluation included - detailed physical examination including chest to see for any focus of infection. In all patients , base line blood counts (total and differential), chest x-ray and cultures from blood and other body fluids were taken before starting broad spectrum antibiotics . Those not responding over next 48-72 hours received gram positive coverage followed by amphotericin-B therapy . Patients with persistent fever and pulmonary infiltrates were subjected to fibre-optic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) and samples were collected for bacterial, fungal, AFB and viral studies. The findings were correlated with Chest x-ray and CT scan. Results The median time for FOB and BAL was 16 days (range, 3 to 32 days) after the clinical diagnosis of chest infection.. BAL fluid examination/culture grew microbial isolates in 21 of 25 patients (84%). Of thesebacteria alone were present in 10, fungi alone in 1 and polymicrobial isolates were seen in 10 patients (40%). Later included- a combination of bacteria and fungi - in 2 patients, bacteria and AFB - 6 and a combination of bacteria, AFB and fungi were seen in 2 patients. BAL changed the radiological diagnosis in 14 patients (56% diagnostic utility). Therapy was modified according to BAL results in 6 patients (therapeutic utility of 24 %). Concordance between radiological and BAL findings were found only in 5 patients (20%). FOB procedure was tolerated well, with mild and reversible complications (throat pain, transient hypoxia, tachycardia) in some patients. Conclusions: Infections are the main cause of pulmonary infiltrates in patients with haematological malignancies. Bacterial , fungal and mycobacterium tubercular organisms are the main isolates. Isolation of ESBL positive organisms and polymicrobial isolates suggest inclusion of appropriate initial empirical antibiotics in these patients to prevent development of resistant organisms. Higher frequency of AFB isolates (32%) was the surprising finding and need to be confirmed in future studies.