1 What is flexible bronchoscopy?

Bronchoscopy literally means “to see the airways.” This procedure allows visualization of the upper airways, trachea, and bronchi. Flexible bronchoscopy uses a small-caliber fiberoptic scope, which is passed through the nose or mouth or through a tracheostomy or endotracheal tube (Fig. 17-1). The bronchoscope is then directed down the trachea to the main carina (Fig. 17-2) and beyond to the regions of interest. In most patients, the airways can be visualized at least to the segmental bronchi.

Figure 17-1 Flexible bronchoscopy

Figure 17-2 Bronchoscopic view of the distal trachea, main carina, and right and left main stem bronchi.

2 How is flexible bronchoscopy performed?

Flexible bronchoscopy can be performed at the bedside or in a specialized suite with the assistance of a nurse and a respiratory therapist. Preparation includes the following steps:

3 How is rigid bronchoscopy different from flexible bronchoscopy?

Rigid bronchoscopy is performed while the patient is receiving mechanical ventilation under general anesthesia, with use of a rigid hollow tube that provides a large working channel and direct illumination. This technique is preferable to flexible bronchoscopy when more suction is required (as in the work-up of hemoptysis), during removal of some foreign bodies, during surgical or laser removal of endobronchial lesions, or in the placement of endobronchial stents. Rigid bronchoscopy requires a stable cervical spine and the ability to manipulate the mandible.

4 When should intubation be considered before bronchoscopy?

A spontaneously breathing patient scheduled to undergo flexible bronchoscopy without an artificial airway or mechanical ventilation should be cooperative, without violent coughing, and without risk for upper airway obstruction or hypoxic or hypercarbic respiratory failure. Patients who do not fit these criteria, but in whom bronchoscopy is considered a necessary procedure, may require intubation before the procedure. In all cases, equipment for endotracheal intubation should be easily accessible.

5 How is bronchoscopy different for patients receiving mechanical ventilation?

Fiberoptic bronchoscopy can be performed through an endotracheal tube at least 7.0 mm in diameter. Topical anesthesia is achieved with 1 to 2 mL of 2% lidocaine through the endotracheal tube, followed by additional boluses as needed during the procedure. A silicone-based lubricant is applied to the bronchoscope to facilitate passage through the endotracheal tube. The bronchoscope will partially obstruct the tube, causing increased airway pressure and potentially increased air trapping. The respiratory therapist should set the ventilator on a volume mode with increased peak airway pressure limits to ensure that the patient receives adequate minute ventilation. The fractional concentration of oxygen in inspired gas (FiO₂) should be increased (usually to 1.0) because bronchoscopy and lavage may cause transient hypoxia.

6 What are the indications for bronchoscopy in the intensive care unit (ICU)?

Bronchoscopy allows inspection of the airways, collection of samples from the lower airways, and performance of various interventions (Table 17-1). In the ICU, it is most commonly used to diagnose infection via bronchoalveolar lavage (BAL) or protected specimen brush. In BAL, the tip of the bronchoscope is wedged into a subsegmental bronchus while aliquots of saline solution (typically 30 mL each) are injected and aspirated into sterile traps. Alveolar contents are collected while the bronchoscope position prevents flooding of other regions of the lung. The protected specimen brush is a sterile brush with a gelatin cap that is inserted into a potentially infected area, agitated, then withdrawn and sent for culture.

^{Table 17-1} Indications for bronchoscopy

7 What other kinds of samples can be collected by bronchoscopy?