Zinc chloride (smoke bomb) inhalation lung injury: Clinical presentations, high-resolution CT findings, and pulmonary function test results

Study objectives: Zinc chloride smoke inhalation injury (ZCSII) is uncommon and has been rarely described in previous studies. We hypothesized that structural changes of the lung might correlate with pulmonary function. To answer this question, we correlated findings from high-resolution CT (HRCT) scan and the results of pulmonary function tests (PFTs) in patients with ZCSII. Design: Retrospective cohort study. Setting: University hospital. Patients: Twenty patients who had been hospitalized with ZCSII-related conditions. Measurements: The study included HRCT scan scores (0 to 100), static and dynamic lung volumes, and diffusing capacity of the lung for carbon monoxide (DLCO). Results: HRCT scans and PFTs were performed initially after injury (range, 3 to 21 days) in all patients and during the follow-up period (range, 27 to 66 days) in 10 patients. The predominant CT scan findings were patchy or diffuse ground-glass opacities with or without consolidation. The majority of patients showed a significant reduction of FVC, FEV₁, total lung capacity, and DLCO, but normal FEV₁/FVC ratio values. Changes of functional parameters correlated well with HRCT scan scores. Substantial improvements in CT scan abnormalities and pulmonary function were observed at follow-up. Conclusions: The majority of our patients with ZCSII presented with a predominant parenchymal injury of the lung that was consistent with a restrictive type of functional impairment and a reduction in DLCO rather than with obstructive disease. Our results suggest that HRCT scanning and pulmonary function testing may reliably predict the severity of ZCSII.