Visualization of the airways for diagnosis or treatment can involve the use of either flexible or rigid bronchoscopes. Flexible bronchoscopes generally are used for evaluation and biopsy, whereas rigid bronchoscopes are uniquely capable of establishing and maintaining airway control in a life-threatening situation, such as acute upper airway obstruction or massive hemoptysis. Although these procedures often can be used interchangeably, the rigid bronchoscope is uniquely suitable for applications that require precise airway measurement (e.g., tracheal stricture) or a large working port (e.g., endobronchial tumor).

The trachea extends from the cricoid cartilage at the level of C6 to the origin of the left and right mainstem bronchi at the carina (approximately at the level of T6). In normal adults, the trachea is 12 cm long (range: 9–15 cm). The normal trachea is approximately 16 mm in lateral diameter and 14 mm in anteroposterior diameter. The anterior wall of the trachea is composed of cartilaginous horseshoe-shaped rings, and the posterior wall is a continuous membranous wall (Fig. 61-1).

The left mainstem bronchus, approximately 4 to 4.5 cm in length, is oriented at 45 degrees to the axis of the trachea. The right mainstem bronchus gives rise to the right upper lobe bronchus near the carina. The right upper lobe has three segments corresponding to the apical (B1), posterior (B2), and anterior (B3) segments. The airway distal to the right upper lobe orifice is the bronchus intermedius. The bronchus intermedius extends 2 cm from the right upper lobe to the middle lobe bronchus. The middle lobe bronchus is 1.2 to 1.5 cm in length and has a diameter of 8 mm. The middle lobe has a medial (B4) and a lateral (B5) segment. The superior segment (B6) of the lower lobe arises at the level of the middle lobe bronchus. The orientation of the basilar segment orifices (B7–10) is variable, and these generally are considered collectively (i.e., composite basilar segmentectomy).

The origin of the left upper lobe bronchus is caudal to that of the right upper lobe bronchus. The left upper lobe orifice branches into upper and lower divisions. The upper division is approximately 1 cm long and gives rise to three segments, two of which are often combined (e.g., B1 + B2 and B3). The lower division is composed of the superior (B4) and inferior (B5) divisions of the lingula. The lower lobe superior segment (B6) has a similar course to the right side. There are only three basilar segments (B8–10; the B7 segment is absent) in the left lower lobe compared with five in the right lower lobe. Similar to the right side, the basilar segments are vertical in orientation and generally considered as a composite structure.

The principal advantages of flexible versus rigid bronchoscopy are detailed in Table 61-1. The diagnostic and therapeutic indications are summarized in Table 61-2.

Patients undergoing bronchoscopy should have a normal platelet count, prothrombin time, and partial thromboplastin time and no evidence of uremia to minimize the risk of bleeding. Relevant past medical history includes a recent myocardial infarction or documented arrhythmias. Asthma frequently is exacerbated by bronchoscopy and may require pretreatment with bronchodilators.

The label high-risk bronchoscopy usually is reserved for patients with a labile PO₂ or evidence of CO₂ retention. Bronchoscopy will decrease arterial PO₂ by 10 to 20 mm Hg under optimal conditions—more if the patient’s ventilatory mechanics are impaired.^1,2 It is important to recognize CO₂ retention before the procedure is performed to avoid sedative-related hypercarbic effects. High-risk bronchoscopy should be performed through an endotracheal tube to facilitate positive-pressure ventilation and oxygen delivery if necessary.

The specific preprocedure evaluation for patients undergoing rigid bronchoscopy includes an examination for concomitant neck injury or cervical disease. In addition, the ventilatory inefficiencies during rigid bronchoscopy make patients with poor lung compliance a particularly high-risk group.

Patients undergoing flexible bronchoscopy benefit from sedation. Although a number of medications have been used, the most common combination used today is an IV narcotic and a benzodiazepine. The most popular benzodiazepine is midazolam (Versed). Midazolam is a short-acting benzodiazepine that decreases anxiety and impairs memory retention. Midazolam is also associated with respiratory depression and hypotension. A typical starting dose is 2 mg IV (1 mg IV in an elderly person).

Fentanyl is the most popular narcotic. A short-acting potent narcotic, fentanyl contributes a sedative effect as well as cough suppression. It is associated with respiratory depression and hypotension as well. A typical starting dose is 50 μg IV (25 μg IV in an elderly person).

All endoscopic procedures carry the risk of cardiac arrhythmia. Although elective outpatient bronchoscopy is rarely associated with arrhythmias, perioperative therapeutic bronchoscopies can be associated with atrial arrhythmias and bradycardias. All patients must have continuous electrocardiographic monitoring for the duration of the procedure. Patients receiving midazolam or fentanyl sedation should have blood pressure monitoring during and after bronchoscopy, and all patients should receive supplemental oxygen and have continuous oxygen saturation monitoring.

Anesthesia