Introduction
The ability of the flexible bronchoscope to provide either diagnostic data or a therapeutic intervention is changing with technology. Improvements in digital imaging and materials along with newer interfaces utilizing global positioning technology and diagnostic imaging are enhancing the capabilities of flexible bronchoscopy. Thus the role of flexible bronchoscopy in practice is changing and will depend on the facilities available at a particular center. This review covers the broad indications and the relatively few contraindications for flexible bronchoscopy based on the current state of the art. The considerations for obtaining informed consent as it pertains to flexible bronchoscopy will also be reviewed.
Indications for Flexible Bronchoscopy
Indications for flexible bronchoscopy are often thought of in terms of diagnosis and therapy. For diagnostic bronchoscopy we can divide areas broadly into endobronchial signs and symptoms, findings from diagnostic studies such as chest radiography, and those based on specific injuries that may impact the airways. Symptoms and signs of endobronchial disease are the most common indications for flexible bronchoscopy and include chronic cough, hemoptysis, focal unexplained atelectasis with or without a fever, or a post obstructive pneumonia. In the setting of suspected complicated infection, flexible bronchoscopy combined with lavage, washings, and protected specimen brushings can be used to obtain specific cultures and cells for microbiologic analysis. Because of the directional control that flexible bronchoscopy provides cultures can be obtained from specific segments of the lung based on radiographic guidance.
Findings on exam can also be indications for flexible bronchoscopy including a localized wheeze, which could be the result of something partially blocking an airway. Patients with what sounds like refractory “asthma” or focal findings of wheezing on examination, or altered breath sounds associated with a radiographic finding may be appropriate indications (Figure 8.1). Patients who have abnormal flow volume curves may have obstructing lesions in the large airways that can easily be assessed using a flexible bronchoscope. While stridorus breath sounds may be considered a tempting indication for taking a look, any patient with stridor needs to be approached with great caution and with a well-planned approach to the difficult airway. Findings that can cause changes in examination of the chest or respiratory symptoms might include an endobronchial neoplasm, broncholithiasis, stricture or stenosis of large airways, foreign body aspiration, extrinsic compression of an airway by a parenchymal or mediastinal tumor or lymph node, a bronchopleural fistula, paradoxical vocal cord dysfunction, or the carcinoid syndrome. Very often an abnormal chest radiograph will result in a referral for flexible bronchoscopy. Findings that raise concern and are indications for flexible bronchoscopy include an obvious mass lesion, or a recurring pulmonary infiltrate in the same anatomical region that may signal an obstructive lesion (Figure 8.2). Persistent atelectasis could signal a compressive lesion or endobronchial obstruction due to a tumor or foreign body. Mediastinal abnormalities such as enlarged lymph nodes that are abutting the trachea and accessible by transtracheal or transbronchial needle biopsy may be seen on chest radiograph or computed tomography of the chest. Likewise diffuse parenchymal disease such as sarcoidosis may be approached with the bronchoscope for a diagnosis (Figure 8.3). In other cases of interstitial lung disease, flexible bronchoscopic sampling may not provide enough tissue for a definitive diagnosis and thoracoscopic or open lung biopsy may still be required.
Figure 8.3 Diffuse lung disease that on transbronchial biopsy was consistent with sarcoidosis.
One of the most important indications for bronchoscopy is in the diagnosis of lung cancer. The bronchoscope can be used to make a tissue diagnosis via endobronchial, transbroncial, or needle biopsy; for staging of lung cancer with transtracheal lymph node biopsy; or early diagnosis in the setting of chronic cough or abnormal chest radiograph in the appropriate patient.
Patients who suffer traumatic injuries may require bronchoscopy in order to assess the extent of injury. This might include patients who have suffered extensive burn or thermal injury and are suspected of having injuries to the lower airways. Because these patients may have significant debris or tissue damage, diagnostic bronchoscopy may be combined with therapeutic bronchoscopy for purposes of rinsing out debris or necrotic tissue. Likewise patients who have suffered blunt or penetrating thoracic trauma may require bronchoscopy to assess for bronchial disruption or fracture. Finally, in the intensive care unit in patients who are intubated, bronchoscopy can be utilized for assessment of endotracheal tube position.
Therapeutic bronchoscopy covers a number of areas. One of the more important and often difficult indications for flexible bronchoscopy is in the removal of a foreign body. In general, foreign body removal is best done with a rigid bronchoscope under general anesthesia. Flexible bronchoscopy can be used as an initial screening procedure for suspected cases of aspiration. Patients with known or suspected foreign bodies should undergo rigid bronchoscopy. If the evidence for aspiration is equivocal, patients should undergo diagnostic flexible bronchoscopy. If a foreign body is found, a rigid bronchoscopy can follow. In certain cases, a foreign body extraction can be done using a flexible bronchoscope, but this is often a rare case.
When a patient presents with lung abscess flexible bronchoscopy can be performed to rule out endobronchial obstruction as a result of foreign body or a mass lesion. In certain cases the bronchoscope can be used for drainage of the abscess cavity. Other indications may include tracheal stenosis requiring dilation and possible stenting, or refractory atelectasis that may benefit from a balloon dilatation.
Occasionally, flexible bronchoscopy will be indicated for respiratory toilette. As a general rule, postural drainage, cough, and suction of secretions are sufficient. If for some reason these cannot be done, then bronchoscopy can be done for respiratory toilette. Prospective studies have shown that good intensive respiratory toilette can accomplish good results in the control of atelectasis. However, there are many clinical circumstances when respiratory toilette cannot ideally be accomplished. These include immobilized patients, patients with spine or spinal cord injury, patients with thoracic trauma such as flail chest or postoperative patients where pain is a significant issue, or patients supported with an aortic balloon pump. Some bronchoscopists advocate treating left lower lobe atelectasis with the flexible bronchoscope and lavage. In general blind passage of a mini BAL catheter or blind suctioning in the intubated patient with in line catheters are hard to direct to specific regions such as the left lower lobe. In cases where it is important to verify where a sample is obtained, flexible bronchoscopy provides obvious benefit.
Flexible bronchoscopy may serve as a prelude to other procedures or interventions. In patients with pneumonia or diffuse lung disease, bronchoscopy can be done to obtain respiratory secretions for establishing the diagnosis of an infection. The choice of brushing, protected brush specimen, or broncho-alveolar lavage is dependent on the clinical situation and can be done following airway inspection.
If you experience difficulty in performing an intubation, or anticipate a difficult intubation a flexible bronchoscope can be used. The endotracheal tube is placed over the flexible bronchoscope and once the bronchoscope is advanced through the vocal cords and is in a good position, the endotracheal tube is passed over the bronchoscope and, under direct vision, can be introduced into the trachea and it’s position verified.
There are a number of conditions in which flexible bronchoscopy may not be helpful. This is dependent on the state of available technology and the experience of the bronchoscopist. An important example is the peripheral solitary pulmonary nodule beyond the reach of the bronchoscope (Figure 8.4). Further, there is no role for bronchoscopy in the setting of an isolated pleural effusion, or a chronic cough in a patient who is younger than 55, with a clear chest radiograph, and no smoking history or risk factors for lung cancer. Acute stridor in children is a medical emergency and an absolute contraindication for bronchoscopy. In cases of uncomplicated pneumonia, either community acquired or hospital acquired pneumonia, bronchoscopy often adds little information and has no impact on medical decision-making. Lastly, in cases of massive hemoptysis, the flexible bronchoscope is often too small and ineffective in clearing blood fast enough to prevent occlusion of the airway or to find and treat a source of bleeding. Rigid bronchoscopy is the preferred approach to massive hemoptysis.
