A Case of Massive Subcutaneous Emphysema and Pneumomediastinum Due to Dehiscence of Stoma After Emergent Tracheostomy

Abstract

Tracheostomy is commonly performed on patients who require long-term ventilator support. As with all other airway managements, tracheostomy comes with risks: tracheal scarring, tracheal rupture, pneumothorax, and tracheoesophageal fistula. Although rare, free air leakage into the surrounding tissues of the tracheostomy site and consequent pneumomediastinum can also occur due to various reasons, such as tracheal rupture and mispositioning of the tracheal tube. Such conditions may require treatments including high flow oxygen, ventilator management, and occasionally surgical intervention. In our case of a 61-year-old female, emergent tracheostomy was performed and subsequent complications of massive pneumomediastinum and subcutaneous emphysema were treated with negative pressure wound therapy. The follow-up radiograph after negative pressure wound therapy showed resolution of pneumomediastinum and subcutaneous emphysema, and there were no additional complications. Negative pressure wound therapy is an effective treatment option for massive pneumomediastinum and subcutaneous emphysema after tracheostomy.

Introduction

Tracheostomy is performed in emergency when intubation is not feasible in patients with acute respiratory distress syndrome (ARDS) due to airway obstruction conditions such as acute epiglottitis or a laryngeal mass. Otherwise, elective tracheostomy is performed to replace the long-term intubation state in comatose patients with cerebrovascular disease or with chronic respiratory failure. ¹ Compared to elective tracheostomy, emergent tracheostomy is known to have high incidences of death and severe complications after the procedure. General complications of tracheostomy include intraoperative and postoperative bleeding and infection at the tracheostomy site, while subcutaneous emphysema, pneumothorax, misposition of the cannula, and stricture of the trachea stricture have been reported less commonly.^2,3

Postoperative subcutaneous emphysema occurs primarily when air permeates the surrounding soft tissue through a displaced cannula. In this situation, replacing the cannula in adequate position and further conservative treatment are required. ⁴ There are only a few reports that address of extensive cervical subcutaneous emphysema and pneumomediastinum after tracheostomy and the treatment protocol of such conditions has not been clearly established. Our objective is to report a case of massive subcutaneous emphysema and pneumomediastinum after an emergent tracheostomy with a review of the literature.

Case report

A 61-year-old woman presented in the emergency room with a 2-day history of sore throat and dyspnea and was referred to our department after neck contrast-enhanced computed tomography. The computed tomography findings showed that inflammation that began as a form of right peritonsillar abscess spread to the ipsilateral hypopharynx and sublingual area. The laryngoscopy exam was performed, and we planned to hospitalize the patient in the intensive care unit (ICU) after intubation in the emergency room to secure the airway (Figure 1). Intubation was tried in the emergency room but failed due to severe swelling of the pharynx, larynx, and epiglottis, and consequently, emergent tracheostomy was performed to secure the airway. After tracheostomy, the patient received intravenous analgesics and antibiotics in general ward and no specific findings were observed postoperatively. On the postoperative day (POD) 2, the blood test showed a rapid decrease of white blood cells (WBCs) and C-reactive protein (CRP), and the decrease of laryngeal swelling was observed in the laryngoscopy exam. The cuffed double lumen tracheostomy was replaced with an uncuffed double lumen tracheostomy tube, and voice practice and oral intake were encouraged. On the night of POD 3 and the early morning of POD 4, the patient complained of dyspnea and stuffiness accompanied by severe coughing, but these symptoms were improved shortly without a decrease in oxygen saturation. The neck CT scan obtained on POD 4 showed multiple air shadows in the peri-tracheostomy site, the danger space and within the mediastinum (Figures 2A, B).

Figure 1.

Image of a severely swollen, U-shaped epiglottis, swollen arytenoid, and hypopharyngeal bulging at first visit to the ER.

Figure 2.

Image of diffuse subcutaneous emphysema refers to trapped air from tracheostomy dehiscence site along the fascia. (A, axial view; B, coronal view) Obstructed tip of T-tube (*) was found on CT image both axial (A) and coronal view (B). Coronal image (B) shows extrapleural extension (white arrow) surrounding aorta arch.

Although the tracheostomy tube was confirmed to be in the trachea without displacement on the neck CT scan, the lumen was found to be obstructed (Figures 2A, B). The fiberoptic laryngoscopy revealed that the opening of the uncuffed double lumen tracheostomy tube was not obstructed, but the end portion was blocked with sputum. The tracheostomy tube was immediately removed. On the stoma site, a dehiscence was found between the skin, soft tissue, and trachea, resulting from tearing of a staying suture. On the physical examination, swelling and crepitus were present in the cervical and both supraclavicular areas. On the CT scan, air shadows were detected in both sides of the sublingual space, the masticator space, the hypopharynx, pharynx, the danger space, mediastinum, and the superior diaphragm (Figures 2A, B). The defect in the stoma site was assumed to be caused by severe coughing due to the obstruction of the lumen of the tracheostomy tube, resulting in massive subcutaneous emphysema and pneumomediastinum. Surgery was performed to repair the tissue defect around the tracheostomy site. The defect was identified at the tracheal incision site from the 12 to 4 o’clock position, and the defect closure with suture was performed. Additionally, subcutaneous emphysema was treated with negative pressure wound therapy (NPWT) by approaching the bilateral cervical areas (Figure 3). The apron flap incision was made, and the neck dissection of cervical levels II, III, IV, and V was performed. By placing negative pressure sponge in the aforementioned areas and maintaining the negative pressure of 100 mmHg in the NPWT device, we hoped to achieve effective elimination of extensive subcutaneous emphysema. The NPWT dressing was changed aseptically 2–3 times a week in the operating room. The progression of emphysema was monitored daily by physical examination and chest and neck radiographs (Figure 4).

Figure 3.

Image of a wound vacuum-assisted closure device (https://www.medicalexpo.com/prod/kinetic-concepts/product-89921-571103.html).

Figure 4.

Plain neck a-p X-ray showing free air along the retropharyngeal space (arrow).

On POD 18 of tracheostomy, most of the anterior neck crepitus disappeared, and the negative pressure wound therapy was terminated. To remove remaining small amounts of emphysema, a negative pressure JP drain was inserted into the bilateral cervical areas (Figure 5). No defect was found in the tracheostomy site, and therefore, the sutures on the defect site were removed. On POD 22, the negative pressure drain was removed and the patient was discharged (Figure 6). In outpatient follow-up on POD 25, cervical subcutaneous emphysema was not detected on the X-ray image, and there were no additional complications.

Figure 5.

Image of a Jackson-Pratt (JP) surgical drain.

Figure 6.

Plain neck a-p X-ray showing no evidence of free air in the retropharyngeal space before discharge.

Discussion

Common complications after tracheostomy include intraoperative and postoperative bleeding, and infection. Subcutaneous emphysema, pneumothorax, pneumomediastinum, misposition of the cannula, and trachea stricture can occur rarely.^2,3 Subcutaneous emphysema chiefly results from the misposition of the cannula and is extremely rare for other reasons. ⁵

Symptoms of emphysema in the head and neck area and mediastinum include swelling of the neck, neck and chest pain, dysphonia, sore throat and dysphagia, and crepitus can be felt within the range of emphysema. ⁶ A diagnosis can be easily rendered by simple chest and neck radiographs, and the CT scan can be considered for more accurate evaluation.

The treatment for emphysema is determined based on the presence of complications. Without accompanying complications, conservative treatments such as pain control, stabilization, and avoiding activities that increase intrapleural pressure are sufficient. However, if there are any other organic conditions that are suspicious of the cause of emphysema, the corresponding treatment should be performed simultaneously.^6,7

In this case, it appeared that there was a high pressure applied to the subcutaneous layer at the tracheal incision site due to severe coughing incidence, leading to massive subcutaneous emphysema and pneumomediastinum. Simple subcutaneous emphysema can be treated with conservative management alone. However, if it is accompanied by massive subcutaneous pneumomediastinum, the condition can be life-threatening with increasing acute symptoms, therefore requiring more rapid and effective treatment.^2,3 To control massive subcutaneous emphysema and pneumomediastinum, we tried to approach externally through bilateral cervical areas by applying continuous negative pressure wound therapy, which had been used in the head and neck region and suturing the defect site, which is requisite for effective negative pressure wound therapy, was performed together. Since there have been no definitive guidelines for the use of antibiotics in the treatment of emphysema, its utility is currently controversial. ⁶ In multiple case reports, prophylactic antibiotics have been used to prevent secondary infection and other complications.^8-10

Massive subcutaneous emphysema and pneumomediastinum can occur as complications after tracheostomy. In worsening conditions, life-threatening fatal problems could be presented, which require rapid and effective treatments. The differential diagnosis of causes is important, and in cases of accompanying massive subcutaneous emphysema as shown in this case, consistent negative pressure wound therapy as well as management of the direct causes is considered as effective treatments. ¹ Although the cases of post-tracheostomy subcutaneous emphysema have been commonly reported in the previous literature, we report this case of massive subcutaneous emphysema and pneumomediastinum because such great extent of emphysema was rarely reported but the proper management was still possible for the successful recovery of the patient.