Spontaneous Pneumomediastinum in Connective Tissue Diseases

Abstract

SESSION TITLE: Systemic Disease and Pulmonary Manifestations SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: Spontaneous pneumomediastinum (SP) is an uncommon manifestation of connective tissue diseases (CTD) but has been associated with the diagnosis of dermatomyositis/polymyositis (DM/PM). We aimed to explore this relationship by identifying consecutive adult patients with CTD and SP and analyzing the presenting features and clinical course associated with this complication. METHODS: Using a computer-assisted search, we retrospectively identified and reviewed the medical records of all CTD patients diagnosed with SP between January 1997 and December 2016. We extracted data regarding demographics, clinical manifestations and treatment of the underlying CTD. We also gathered information regarding clinical-radiological presentation and treatment of SP, and its outcome. Chest CT studies were reviewed to investigate the presence and describe the pattern of the underlying interstitial lung disease (ILD). RESULTS: We identified 27 patients affected by CTD who developed SP (8 cases of DM/PM, 6 rheumatoid arthritis, 6 systemic sclerosis, 4 overlap syndromes, 2 systemic lupus erythematosus and 1 unclassifiable CTD). Median age at SP presentation was 53 (range 18-82) years and 59% were women. Sixty-two per cent of patients were never smokers, 27% were former smokers and 11% were current smokers. SP occurred before the diagnosis of CTD in 3 patients while SP led to the diagnosis of CTD in 5 additional patients; remaining 19 patients (70%) had a known CTD including associated ILD in all but one patient. SP-related symptoms were present in 58% of patients and included dyspnea (46%), followed by chest pain (27%) and cough (12%); 42% were asymptomatic. The precipitating factors included pulmonary function testing in 31% of patients, severe coughing due to exacerbation or respiratory infection in 15%, vomiting in 8%, air travel in 8%; in 46% no potential precipitating factors were identified. Seventy-eight per cent of patients were on immunosuppressant therapy at the time of SP onset. The initial diagnosis of SP was achieved by chest radiography in 20% of cases, chest CT in 64% and CT pulmonary angiography in 16%. Concomitant pneumothorax was present in 4 cases (17%). Only 2 cases (8%) of SP occurred in the absence of CTD-associated interstitial lung disease (ILD). The most common ILD pattern on chest CT was NSIP in 45%, followed by BOOP superimposed on NSIP in 18%, unclassifiable ILD in 23%, and possible UIP in 5%. SP was treated with observation alone in 23 cases (88%). Eleven patients (42%) were hospitalized. Chest tube drainage was instituted in one of 4 patients with pneumothorax. The median hospital stay was 11 (range 1-20) days. There were no deaths attributable to SP nor were there any relapses of SP in a median follow up of 14 (range 0-183) months. The cumulative survival at 1 and 2 years was 56% and 44% respectively. CONCLUSIONS: SP is an uncommon manifestation of CTD related ILD but sometimes it can lead to the diagnosis of CTD. SP is associated with a relatively benign course in patients with CTD. CLINICAL IMPLICATIONS: SP is an uncommon manifestation seen in patients with CTD and can usually be managed conservatively with observation alone. DISCLOSURE: The following authors have nothing to disclose: Federica De Giacomi, Misbah Baqir, Christian W. Cox, Jay Ryu No Product/Research Disclosure Information