Discussion:
The incidence of pneumomediastinum secondary to NIV is low (1). This
pathology should be suspected in case of subcutaneous emphysema or
dyspneic sensation, mostly if there’s a concomitantly pneumothorax. The
risk increases, according to the cause for which mechanical ventilation
is required, in the patient exposed it was secondary to an ARDS
infection by COVID-19.
Due to the vital risk that pneumomediastinum can produce, especially
when accompanied by pneumothorax, it’s important to suspect it early and
confirm urgently using imaging techniques. Pneumomediastinum is
associated with increased morbidity and mortality, so avoiding it’s
decisive.
To prevent it is crucial to carry out protection strategies during
ventilation, such as maintaining pressure Plateau < 30cmH2O
(only possible in patients with invasive mechanical ventilation) or
maintaining reduced tidal volumes (between 6 to 8 mL/kg based on the
ideal body weight), or low support pressures (3).
In our patient, COVID-19 positive, even performing mechanical
ventilation with protection strategies, such as keeping volumes reduced,
and being in CPAP mode at 12 cmH2O, it was produced a
pneumomediastinum with its consequent worst outcome (6).
Therefore, in addition to the increased risk of pneumomediastinum due to
ARDS caused by the COVID-19 infection, we cannot rule out if this
infection may cause respiratory damage that may increase the risk of
barotrauma, and if those patients should be closely monitored.
There’re only two reported cases of spontaneous pneumomediastinum in a
positive COVID patient, who were not submitted to ventilation (4,5).
We still don’t have enough information available about all the
phisiopatology of the coronavirus infection and we will have to wait for
more publications and case series studies.