A 67-year-old female with a 50 pack-year of smoking history, COPD, hypertension, and type II diabetes is admitted to the ICU following a right middle lobectomy for resection of non–small-cell adenocarcinoma. The patient has required positive pressure ventilation since her operation because of persistent hypoxemia and inadequate ventilation on pressure support. On postoperative day 5, she develops a new persistent air leak through her right-sided chest tube. Bronchoscopy confirms the presence of a bronchopleural fistula (BPF) on the right side. The ventilator repeatedly alarms for low minute ventilation (less than 0.8 L/min) despite increasing tidal volumes and RR. The latest ABG shows the following:
Blood pressure and heart rate have remained stable.
Which of the following ventilation strategies is most appropriate until surgical repair of BPF can take place?
A. Pressure control ventilationCorrect Answer: B
BPF occurs when air from a lobar or segmental bronchus leaks into the pleural space. This is most commonly encountered after lung resection surgery with a frequency ranging from 4.5% to 20% after pneumonectomy and 0.5% to 1% after lobectomy.
In most cases BPF is present in the early postoperative period (<2 weeks) following lung resection. BPF should be suspected in the postoperative lung resection patient who presents with sudden onset of dyspnea, chest pain, subcutaneous emphysema, and hemodynamic instability (ie symptoms of tension pneumothorax). Symptoms may be less abrupt, however, in patients whose chest tube is still in place. In such patients, presence of persistent or new air leak may be the only presenting sign. Bronchoscopy is often used to confirm the diagnosis.
BPFs are associated with significant morbidity and a mortality that ranges from 16% to 72%. BPFs do not typically resolve spontaneously and almost always require surgical or bronchoscopic intervention. Supportive measures should be taken to maintain hemodynamic and ventilatory stability. The first intervention is insertion of a chest tube (if not already in place) on the ipsilateral side, to drain air and fluid from the pleural space. Positive pressure and PEEP should be minimized as higher airway pressures worsen air leak and may result in impairment in ventilation and gas exchange. If adequate ventilation is not achieved using minimal positive pressure and low PEEP, isolated ventilation of the contralateral lung is indicated to maintain adequate gas exchange until definitive correction of BPF can take place.
References: