Bronchopleural fistula

Published on 07/02/2015 by admin

Filed under Anesthesiology

Last modified 22/04/2025

Print this page

This article have been viewed 2070 times

Bronchopleural fistula

Glenn E. Woodworth, MD

A bronchopleural fistula is a connection between the bronchi or lung parenchyma and the pleural space. If the fistula communicates with the surface of the chest, it is a bronchopleural cutaneous fistula. Communication between the airways and the pleural space substantially increases the risk of infection and can make ventilation difficult, accounting for the high morbidity associated with this condition. Anesthesia providers may encounter patients with bronchopleural fistulas when these patients present for surgical repair of the fistula or in the intensive care unit when the patients require ventilator management of the condition. In rare cases, a patient may present to the operating room for surgery in which the fistula is an incidental condition.

Etiology

Common causes of bronchopleural fistula include trauma and infection; fistulas may also occur as a postoperative complication of lung surgery. The mechanism is usually rupture or erosion of a lung abscess, bronchus, bulla, cyst, suture line, or parenchymal tissue into the pleural space; however, by far the most common cause is a complication of thoracic surgery. The incidence of postoperative formation of a bronchopleural fistula has been reported to be 2% to 40% after pulmonary resection. Persistent air leak, sepsis, empyema, purulent sputum, and respiratory distress characterize such fistulas. Predisposing factors include perioperative radiation or chemotherapy, residual neoplasm, age greater than 60 years, infection at the resection site, and an avascular bronchial stump.

Treatment

Treatment of bronchopleural fistulas is highly dependent on the cause and nature of the fistula. In general, attempts are made to reduce the pleural space and seal the fistula by either placing a chest tube or performing pleurodesis. In those patients who are intubated, ventilator management is critical to give the fistula the best chance of healing. If the fistula is large (e.g., disruption of a postpneumonectomy bronchial stump), conservative management is often not effective, and surgical intervention will be necessary.

Anesthetic considerations

The primary clinical concern when caring for patients undergoing surgical repair of bronchopleural fistulas relates to providing adequate alveolar gas exchange during positive-pressure ventilation. The following must be considered.

• Tidal volume is preferentially delivered into the pleural space through the low-resistance fistula.

• Air leak into the pleural space can produce a tension pneumothorax.

• Healthy lung tissue should be protected from contamination by the infected lung.

• Differences in compliance and gas exchange between healthy lung and diseased lung or diseased lung and the fistula can exacerbate the difficulty in delivering an adequate tidal volume through the fistula.

Tension pneumothorax is prevented or treated by placement of a chest tube. If an empyema or lung abscess is present, drainage under local anesthesia or bronchoscopy should be considered. Because the use of positive-pressure ventilation may exacerbate difficulties in providing adequate gas exchange, alternative anesthetic techniques—including maintenance of spontaneous ventilation and the use of regional anesthesia (e.g., thoracic epidural anesthesia)—have been used. Unfortunately, most procedures to repair or treat bronchopulmonary fistulas will require general anesthesia and the use of positive-pressure ventilation.

Mechanical ventilation

In general, the goal of positive-pressure ventilation in patients with bronchopleural fistulas is to minimize tidal volume loss to the pleura or atmosphere by isolating the fistula, e.g., by using double-lumen tracheal tubes or bronchial blockers. If this is not possible, the goal is to keep airway pressures and tidal volumes to a minimum. In addition, the differing physiology and mechanics of varying regions of diseased and nondiseased lung may require different ventilation strategies for different portions of the lung (Table 159-1). In patients with bronchopleural fistulas, delivering adequate ventilation with conventional mechanical ventilators and single-lumen tracheal tubes may be difficult unless the fistula is small.

Table 159-1

Approaches to Positive-Pressure Ventilation for Reducing Trans-Fistula Gas Flow

Technique	Pro	Con
Single-lumen tracheal tube Pressure- or volume-controlled ventilation with increased respiratory rate, low tidal volumes, increased inspiratory time, and minimal, if any, PEEP	Simple to perform	Effective only with very small air leak Difficult to keep airway pressures low enough
Timed occlusion of chest tubes during inspiration	Increases pleural pressure during inspiration to decrease trans-fistula pressure gradient Can be added to other techniques	Requires specialized equipment
Single-lumen tracheal tube with intubation of contralateral lung	Simple to perform Protects contralateral lung from infection	Underlying pulmonary disease may make one-lung ventilation difficult
Double-lumen tracheal tube	Relatively simple to perform Protects contralateral lung from infection Can be positioned with bronchoscope Allows for addition of CPAP with 100% O2 to nonventilated lung	Underlying pulmonary disease may make one-lung ventilation difficult even with the addition of CPAP with 100% O₂
Double-lumen tracheal tube with different ventilation of each lung	Protects contralateral lung from infection Can be positioned with bronchoscope Allows for use of optimal ventilatory mode for each lung Can be combined with a bronchial blocker or HFO technique	Complex to perform Still may be difficult to ventilate diseased lung while minimizing tidal volume loss
Bronchial blockers	Can provide for highly selective isolation (level of the individual bronchus) of the leak, thereby maximizing amount of lung that can be ventilated Can be combined with other techniques	Requires skillful placement with a bronchoscope Blockers can become dislodged during surgery
HFO ventilation	Can be combined with other techniques Airway pressures are decreased Allows for humidification and warming of gases Gas trapping on expiration is decreased Can be used for prolonged ventilation in the ICU	Requires specialized equipment and knowledge
High-frequency jet ventilation	Can be combined with other techniques	Requires specialized equipment and knowledge Control of tidal volume and agent delivery may be difficult Warming and humidification may be difficult Ventilation may be complicated by gas trapping

CPAP, Continuous positive airway pressure; HFO, high-frequency oscillation; ICU, intensive care unit; PEEP, positive end-expiratory pressure.

Related

Fausts Anesthesiology Review Expert Consult 4e