Air emphysema is a pathological condition in which air is forced into soft tissues where it is not physiologically present. Mediastinal emphysema (pneumomediastinum) is the presence of free air within the connective tissue of the mediastinum. It is often accompanied by subcutaneous emphysema, characterised by palpable crepitations within the skin. In the case of mediastinal emphysema as a result of trauma to the posterior pharyngeal wall, the air in the retropharyngeal space passes into the parapharyngeal space and from there along the least resistance route along the neck fascia into the mediastinum. From there, it can pass further into the pleural cavity or even the pericardial cavity, thus posing an immediate threat to life. Mediastinal emphysema usually occurs in young patients with loose and flaccid mediastinal tissues compared to older patients with fibrotic tissues in this space, impeding air migration (1). The patient’s symptoms, general condition and possible complications may correlate with the extent of emphysema and the prevailing mediastinal pressure. The following is a case of a patient admitted to the Department of Pediatric Otolaryngology with mediastinal emphysema due to throat trauma

A 5-year-old boy with trisomy 21 was admitted to the Department of Pediatric Otolaryngology, Medical University of Warsaw, from a children’s hospital of a lower referral level because of posttraumatic mediastinal emphysema and subcutaneous emphysema of the neck and supraclavicular region found on CT examination. On the day of admission to the first hospital, the boy sustained injury to the posterior pharyngeal wall with a toothbrush held in the mouth during a fall. The injury caused throat bleeding, and the boy reported throat pain and difficulty swallowing saliva. Fiberoptic examination on admission did not show damage to the pharyngeal mucosa or active bleeding, only a protrusion/swelling of the posterior pharyngeal wall was visible. A CT scan of the neck and chest performed described: “Examination with administration of 15 ml contrast medium. Presence of increased subcutaneous emphysema of the neck and upper chest. Presence of air in pharyngeal space, perivascular space, upper mediastinum and vestigially subpleural. At the level of the lower pharynx, on the right side, a small tissue element of 5 mm in the pharyngeal space is visible, which may correspond to a fragment of pharyngeal tissue entered into the pharyngeal space. The larynx is undamaged, pear-shaped lobules and epiglottis are unchanged. The cervical venous and arterial vessels were properly patched, without lesions” (Fig. 1a-c). No pathological fluid reservoirs or haematomas or shadowing foreign bodies were found within the neck organs. The bony elements within the scope of the examination were not damaged.

On the next day of hospitalization, due to the severity of emphysema and the possibility of its further development as well as the risk of nasopharyngeal flora infection, the patient was transferred by medical transport to the Children Clinical Hospital of the Medical University of Warsaw.

Until the nasopharyngeal swab for COVID-19 collected during the stay in the previous hospital was negative (test result – negative), the patient was isolated in the patient room and all nursing activities and medical examination were performed in personal protective equipment.

On admission to the Pediatric Otolaryngology Department of the Medical University of Warsaw, the boy was in good general condition, with efficient respiratory and circulatory systems. No respiratory disturbances in the form of stridor or dyspnoea were found. The boy’s voice was sonorous. No significant abnormalities were found in vital signs: saturation 96%, pulse 103/minute, blood pressure 110/79 mmHg, body temperature 36.9 degrees Celsius. The boy reported complaints of throat and neck pain.

On physical examination, swelling of the soft tissues in the anterior part of the neck and in the supraclavicular region was found; palpation showed marked crepitations in the swollen areas. Neck mobility was preserved in all directions. Auscultation was normal with alveolar respiratory murmur, numerous crackles were heard in the upper part of the chest from the front, and normal murmur from the back.

ENT examination of the posterior wall of the middle pharynx, in its lower part on the right side, revealed a small wound without the presence of active bleeding; the wound area with mucosal oedema was present. No other post-traumatic lesions were found within the oral cavity, palatal arches, palatine uvula and tonsils. There were also no features of upper respiratory tract infection. Due to the lack of laryngeal symptoms and examination performed the day before, repeat fibroscopy was not performed. The laboratory blood tests showed elevated CRP and slight leucocytosis; gasometry was normal. Due to short time since injury, the patient was fasted and started i.v. hydration. Constant monitoring of vital signs (saturation, HR, RR) and restriction of exercise were ordered. The treatment included analgesics and broad-spectrum intravenous antibiotic therapy (second-generation cephalosporin and clindamycin). On the 1^st day of treatment, an i.v. corticosteroid was also continued.

On the next day of observation, the patient reported slight throat and neck pain, no fever, no respiratory disturbances or cough, saturation maintained at 96-97%, heart rate 92-117/min. Crepitations of the neck region were still palpable. Oral rehydration was started, followed by feeding with pureed diet, which the boy accepted reluctantly due to sore throat. In the following days, the patient’s vital signs were monitored, which remained within normal limits, and the decrease of neck tissue oedema was observed. The boy reported no more pain, his appetite improved, no respiratory disturbances were observed. On post-injury day 4, the chest X-ray was performed, which revealed slight mediastinal emphysema and air in the soft tissues of the neck and in the scapular projection (Fig. 2). Otherwise, the chest and neck organs were normal. There were no abnormalities on ECG.