Objective: To study the risk factors and the clinical characteristics of non-tuberculous mycobacterial (NTM) pulmonary diseases in patients with mechanical ventilation.
Methods: Retrospective survey was carried out in the patients with mechanical ventilation who combined with NTM pulmonary disease admitted to intensive care unit (ICU) of the First Affiliated Hospital of Guangzhou Medical University from May 2016 to May 2019. The general information, basic diseases, symptoms, signs, biochemical examinations, acid-fast stain test, mycobacterium culture and strain identification results, and chest CT data were collected to summarize the clinical characteristics of patients with mechanical ventilation combined with NTM pulmonary disease.
Results: There were 12 patients with mechanical ventilation combined with NTM pulmonary disease, 6 males and 6 females, 37-82 years old, with an average age of 65 years. In these 12 cases, patients with cancer (lung cancer were 4 cases, mediastinal tumor was 1 case) and after lung transplantation (use of anti-rejection drugs at the same time) were 5 and 2 respectively. Patients with at least 3 underlying diseases [included hypertension, diabetes, coronary heart disease, chronic obstructive pulmonary disease (COPD), bronchiectasis, chronic renal insufficiency] were 5. Clinical symptoms of the 12 cases were non-specific. The CT findings were not characteristic, including nodules, patchy infiltrations and fibrous streak. Pleural effusion was common among these subjects but nodular bronchiectatic patterns were absence. Routine laboratory indicators of bacterial infection were non-specific. But the number of lymphocytes of all cases decreased. Mycobacteria cultures were positive with the rapid growth of mycobacteria in these 12 cases. Mycobacterium avium (4 cases), Mycobacterium chelonae (4 cases), Mycobacterium chelonae-abscessus complex (2 cases) and Mycobacterium intracellulare (2 cases) were isolated. Anti-NTM therapy was given to the patients when the acid-fast staining test of their airway secretion was positive and the TB-DNA test was negative, including oral levofloxacin and clarithromycin. Finally, all patients were successfully weaned and discharged from ICU.
Conclusions: The clinical symptoms of NTM patients with pulmonary disease are non-specific, and the imaging features of chest CT are varied. Patients with mechanical ventilation in ICU, who have the risk of immune dysfunction or underlying structural lung diseases, and who have difficult controlled lung infection, accompanied by pleural effusion and with decreased lymphocytes, should be aware that pneumonia may be caused by non-tuberculous mycobacteria.