Spontaneous pneumomediastinum complicating severe acute asthma exacerbation in adult patients.

: The real incidence of pneumomediastinum (PNM) in adult patients with severe acute asthma exacerbation continues to be unknown. The current study aims to investigate the occurrence of PNM in an adult population of patients presenting a severe asthma attack and to evaluate the risk factors associated to its development. : The 45 consecutive subjects who were admitted to our Division between January 1, 2015 and December 31, 2016 for severe acute asthma exacerbation underwent a diagnostic protocol including a standard chest X-ray and continuous monitoring of arterial oxygen saturation (SaO) during the first 24 hours following admission. The patients showing persistence or deterioration of oxyhemoglobin desaturation were prescribed a chest Computed Tomographic (CT) scan. : Five out of the 45 patients (11.1%) with severe acute asthma exacerbation were diagnosed with PNM, in one case on the basis of an X-ray image and in four on the basis of a chest CT scan. Data analysis showed that the PNM patients were younger [21 (17-21) vs 49.5 (20-73) yrs; < 0.001] and more likely to show sensitization to Alternaria (2/5 vs 0/40; = 0.0101) with respect to their non-PNM counterparts. The duration of hospital stay was similar in the two groups [8 (4-12) vs 7 (3-15) days; = 0.6939]. : PNM is a common clinical entity in young adults with severe acute asthma exacerbation, particularly in those with unsatisfactory response to initial medical therapy. Although generally benign, patients with suspected PNM should be closely monitored because of the risk of developing severe hypoxemia.