A MEDIASTINAL mass causing compression of the tracheobronchial tree poses a difficult challenge for the anesthesiologist. Obstruction of the airway extending into the bronchi may require bronchial intubation or stenting. We describe the modification of a single-lumen endobronchial tube for airway management in a patient with bilateral bronchial compression due to Hodgkin's lymphoma.
A 19-yr-old man presented to another hospital with a 3-week history of flu-like illness, nonproductive cough, increasing dyspnea, and pleuritic left-sided chest pain. There was no history of hemoptysis, night sweats, or fevers, and his medical history was otherwise unremarkable. Physical examination showed that he was cyanotic, tachypneic, and dyspneic at rest with prolonged expiration and accessory muscle use. Auscultation showed that chest breath sounds were absent on the left but normal on the right.
Blood chemistry and hematology were both within normal limits except for hypoxemia and mild respiratory alkalosis (partial pressure of oxygen [Po2]= 53 mmHg, arterial oxygen saturation [Sao2]= 86%, partial pressure of carbon dioxide [Pco2]= 30 mmHg, and pH = 7.48; fraction of inspired oxygen [Fio2]= 1). A chest radiograph showed a large left pleural effusion with a large mass in the anterior and middle mediastinum abutting the heart and hilar structures. Subsequent computed tomographic examination showed a mass in the anterior mediastinum measuring 12.3 × 5.6 × 11 cm, compressing the tracheobronchial tree posteriorly, with near complete occlusion of the left mainstem bronchus (fig. 1). In addition, there was severe compression of the right pulmonary artery.
Drainage of 1.8 l pleural fluid from the left pleural cavity provided little symptomatic relief. The patient was transferred to our institution for further treatment. At the time of arrival, the patient was immediately brought to the operating room for emergent intubation for management of severe respiratory failure and anterior mediastinoscopy for histologic diagnosis.
Anesthesia was induced with use of sevoflurane inhalation, with the patient sitting at a 45° angle. Assisted respiration was provided, and tracheal intubation was achieved with an 8.5-mm endotracheal tube positioned above the lesion, without use of neuromuscular blockade. Fiberoptic bronchoscopy revealed severe (> 70%) compression of the lumen of the lower third of the trachea and right mainstem bronchus with near-complete occlusion of the left mainstem bronchus. Based on the bronchoscopic appearance of left bronchial obstruction and computed tomographic appearance of severe right pulmonary artery compression, a decision was made to intubate the left mainstem bronchus.
A size 8.0 left single -lumen endobronchial tube (EBT) with bronchial and tracheal cuffs (model No. 115900; R 252 üsch Inc., Duluth, GA), was modified by cutting a 5 × 8-mm oval fenestration in the tube approximately 11 mm below the tracheal cuff (fig. 2A). The modified EBT was inserted over an 8-mm fiberoptic bronchoscope positioned past the obstruction in the left mainstem bronchus until the bronchial cuff lay completely inside the left mainstem bronchus and allowed clear ventilation of the distal, normal-appearing left upper and lower lobes. In this position, the newly cut hole lay at the opening of the right mainstem bronchus (fig. 2B), and the endobronchial portion stented the obstructed proximal left endobronchus. This allowed ventilation of the both lungs and subsequent bronchoscopic examination and toilet of both the right mainstem bronchus and the distal left mainstem bronchus. Uncomplicated left anterior mediastinoscopy and biopsy revealed a high-grade Hodgkin lymphoma.
The patient was kept intubated and was transferred to the intensive care unit. He was sedated, but not paralyzed, and was maintained on pressure-support ventilation. Inadvertent displacement of the modified tube on the first postoperative night during patient positioning resulted in acute desaturation and required urgent repositioning of the tube under bronchoscopic guidance. Combination chemotherapy and radiotherapy was commenced on the first postoperative day. Subsequently, the patient underwent fiberoptic bronchoscopy daily to observe the extent of left mainstem bronchial compression. Tumor shrinkage was noted over the next 3 days, and the patient underwent extubation on the fourth postoperative day.
Complete or partial airway obstruction during anesthesia due to a mediastinal mass is a significant cause of morbidity and mortality. 1–3Tracheal intubation is sometimes required to maintain a patent airway in the presence of worsening airway obstruction or during delivery of general anesthesia for surgical biopsy. 4If bilateral bronchial obstruction is present, placement of a double-lumen tube or stent may be required to maintain airway patency. 5
The hardware options for stenting bronchial obstruction include double-lumen tubes, inverted-Y stents, 6covered stents, 7and single-lumen endobronchial tubes. Use of standard double-lumen tubes is a common practice for maintenance of bronchial patency in this clinical scenario. 8However, intubation can be prolonged, and because of the small caliber of double-lumen tubes, regular suctioning and bronchoscopic examination of the airway is difficult; a 39-French double-lumen tube has a narrowest internal dimension of 5 mm. Stents are often unsuitable because inverted-Y stents have a large thickness-to-lumen ratio and covered stents are difficult to remove, particularly when temporary stenting only is required. Rarely, bilateral bronchial obstruction is treated by endobronchial placement of a conventional single-lumen tube, thereby necessarily sacrificing ventilation to the other lung with resultant shunt.
Despite high concentrations of inspired oxygen and adequate ventilation of his right lung, the patient had significant hypoxemia due to severe ventilation/perfusion mismatch. Computed tomographic examination showed severe compression of the right pulmonary artery. Therefore, we considered ventilation of both lungs to be necessary because continued isolated ventilation of the right lung may have proven fatal.
We chose to modify a newly available Rüsch left-sided, single-lumen EBT to maximize internal diameter (8 mm) and provide left endobronchial intubation, while ventilating the right lung. These tubes differ from normal single-lumen tubes in that they are longer, have a curved end to facilitate endobronchial intubation, and have both a bronchial and a tracheal cuff. A fenestration was cut in the EBT, adjacent to the orifice of the right mainstem bronchus, thus allowing ventilation of the right lung. In doing this, the tube connecting the pilot balloon to the bronchial cuff was cut, rendering it unable to be inflated. This did not change our management because this cuff was not used (cutting a similar hole in a right-sided EBT does not result in bronchial cuff deflation).
Currently, single-lumen EBTs are rarely used, occasionally providing lung isolation during one-lung anesthesia, such as for carinal pneumonectomy or bronchopleural fistula. Furthermore, EBTs are usually constructed from single-lumen endotracheal tubes by individual anesthesiologists. The Rüsch tube and modification provides a new tool in our armamentarium for management of tracheobronchial airway obstruction.