Anesthesia for adult bronchoscopy

INTRODUCTION — Bronchoscopy is a common diagnostic and therapeutic procedure performed by thoracic surgeons or interventional pulmonologists to diagnose and/or treat a variety of pulmonary conditions. Flexible bronchoscopy can be used for most diagnostic and therapeutic procedures (figure 1 and figure 2). Rigid bronchoscopy may be necessary for selected procedures (eg, removal of airway foreign bodies, treatment of tracheal stenosis, placement of silicon airway stents) (picture 1 and picture 2).

Anesthetic considerations differ markedly for flexible versus rigid bronchoscopy. This topic reviews anesthetic management of adult patients during flexible or rigid bronchoscopy procedures.

For flexible bronchoscopy, indications, equipment, specific procedures, and complications are discussed in other topics:

●(See "Flexible bronchoscopy in adults: Overview".)

●(See "Flexible bronchoscopy in adults: Preparation, procedural technique, and complications".)

●(See "Flexible bronchoscopy in adults: Indications and contraindications".)

For rigid bronchoscopy, intubation techniques, instrumentation details, and complications are addressed separately:

●(See "Rigid bronchoscopy: Intubation techniques".)

●(See "Rigid bronchoscopy: Instrumentation".)

ANESTHETIC TECHNIQUES FOR FLEXIBLE BRONCHOSCOPY

Equipment, patient preparation, and monitoring — Considerations regarding patient and equipment preparation for flexible bronchoscopy procedures are similar to those for flexible scope intubation and described elsewhere:

●(See "Flexible scope intubation for anesthesia".)

●(See "Flexible bronchoscopy in adults: Preparation, procedural technique, and complications", section on 'Preprocedural preparation'.)

Monitoring always includes standard American Society of Anesthesiologists (ASA) monitors (table 1) [1,2], which are applied prior to administration of topical anesthesia, sedatives, or anesthetic induction agents. (See "Basic patient monitoring during anesthesia", section on 'Standards for monitoring during anesthesia'.)

The patient is preoxygenated in the supine position and any oropharyngeal secretions are suctioned before beginning the procedure.

Choice of technique — Selection of the anesthetic technique for flexible bronchoscopy depends on the specific planned procedure, which may be a basic diagnostic, advanced diagnostic, or therapeutic procedure [3]. Other factors include the severity of the patient's lung disease, comorbid conditions, and preferences of the bronchoscopist, anesthesiologist, and patient.

Topical anesthesia of the airway with supplemental light or moderate sedation is typically employed for basic diagnostic procedures, such as dynamic flexible bronchoscopy or endobronchial biopsy, particularly if the following factors are present [3]:

●Cooperative patient

●Brief anticipated procedure duration

●Stable respiratory status

●Planned rapid discharge to home or hospital room

●Relative contraindications to blind airway instrumentation (eg, recent tracheal surgery)

General anesthesia may be preferred for procedure-specific or patient-specific considerations such as [3]:

●Patient inability to tolerate bronchoscopy with light or moderate levels of sedation due to anxiety, severe lung disease, or a person with obesity.

●Requirement for paralysis to prevent patient movement.

●Longer or more complex procedures that are not limited to a quick inspection of the airway. Examples include:

•Endobronchial ultrasound (EBUS), which allows visualization and biopsy of structures adjacent to the airway using an ultrasound probe embedded in the tip of the bronchoscope. (See "Flexible bronchoscopy in adults: Overview", section on 'Endobronchial ultrasound'.)

•Electromagnetic navigation bronchoscopy (NB), which allows sampling of lesions in distal lung regions [4,5]. (See "Flexible bronchoscopy in adults: Overview", section on 'Navigation bronchoscopy'.)

●Bronchial thermoplasty procedures involving application of controlled radiofrequency energy within large- and medium-sized airways to reduce airway smooth muscle mass [6,7]. Such procedures are performed to relieve symptoms in patients with severe asthma refractory to traditional pharmacotherapy. General anesthesia or deep sedation is employed for bronchial thermoplasty, and a laryngeal mask airway (LMA) is typically selected rather than an endotracheal tube (ETT) [7]. Thus, risk of intraoperative bronchospasm is minimized while airway patency is maintained. (See 'Laryngeal mask airway' below and 'Endotracheal tube' below.)

●Procedures requiring rigid bronchoscopy

Since anesthetic requirements or procedural conditions may change after a bronchoscopy has begun, conversion to general anesthesia may become necessary for some sedated patients.

Topical airway anesthesia with sedation

Topical anesthesia — We typically choose lidocaine for topical airway anesthesia because of its relatively rapid onset and the availability of different preparations [3]. Since topical anesthesia of the airway for bronchoscopy always includes the vocal cords, airway protective reflexes are depressed or absent after completion of the procedure. (See 'Emergence and postoperative care' below.)

Patients initially gargle 4% lidocaine to produce topical anesthesia of the mouth and base of the tongue. This is followed by direct application of atomized 1 or 2% lidocaine by spraying structures in the oropharynx and laryngopharynx. Then the flexible bronchoscope is introduced. Additional 2% lidocaine is sprayed via the bronchoscope port onto the cords (picture 3), down into the trachea (picture 4), and finally onto the carina (picture 5). If necessary, the lower airways may be anesthetized by injecting local anesthetic through the distal channel of the bronchoscope (figure 1 and figure 2). Total dose of lidocaine should not exceed 5 mg/kg. However, total dose calculation is challenging since much of the initial 4% lidocaine gargle is expectorated, and swallowed lidocaine is subject to the first-pass effect in the gastrointestinal tract. Typically, we use 50 mL of 4% lidocaine for gargling followed by 10 to 20 mL of 1 or 2% atomized lidocaine for delivery via the bronchoscope. Although this total volume greatly exceeds 5 mg/kg, nearly all the 4% lidocaine is expectorated, and much of the atomized lidocaine is swallowed.

Prilocaine is avoided for topical airway anesthesia. Although it has excellent penetration of the respiratory mucosa, it may cause methemoglobinemia, which is particularly undesirable in patients with respiratory disease [8]. (See "Methemoglobinemia", section on 'Topical anesthetics'.)

Regional anesthesia — Some clinicians perform a superior laryngeal nerve block to decrease severity of coughing, incidence of hypoxemia, and duration of time to complete the procedure [9].

Sedation — Topical anesthesia is usually supplemented with one or more sedative agents to provide light or moderate sedation under monitored anesthesia care (MAC) [3]. Agent selection depends on the planned procedure and patient-specific factors and preferences. In general, medications with rapid onset and short duration of action are preferred to allow rapid titration of sedation and analgesia during the procedure, as well as a quick recovery. (See "Monitored anesthesia care in adults".)

Agents used alone or in combination for sedation include [10]:

●A combination of midazolam (1 to 2 mg) and fentanyl (50 to 100 mcg) is typically administered to achieve anxiolysis, sedation, tolerance of the procedure, and partial or total amnesia. Additional titrated boluses of midazolam (0.5 to 1 mg) and/or fentanyl (25 to 50 mcg) may be administered if necessary. (See "Monitored anesthesia care in adults", section on 'Midazolam' and "Monitored anesthesia care in adults", section on 'Opioids'.)

●Remifentanil is an ultrashort-acting opioid that has excellent pharmacokinetics for short-duration sedation due to its very rapid onset and offset [11]. It is particularly useful for suppressing airway reflexes if administered by infusion. Paradoxically, bolus dosing of remifentanil may stimulate a strong urge to cough or in extreme cases, bronchospasm, and bolus dosing is also more likely to cause apnea compared with infusion. (See "Monitored anesthesia care in adults", section on 'Opioids'.)

●Propofol administration by bolus dosing or infusion offers deeper sedation than remifentanil infusion, but the risk of apnea is significant. Thus, propofol is avoided in patients with a challenging airway. Another disadvantage is that propofol may cause disinhibition and loss of patient cooperation during the procedure. (See "Monitored anesthesia care in adults", section on 'Propofol'.)

●Dexmedetomidine may be particularly useful for patients at high risk of respiratory depression with sedation (eg, those with obesity or obstructive sleep apnea), and for longer procedures in which avoidance of respiratory depression is desirable. In one study of 65 patients undergoing endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration with MAC sedation, use of dexmedetomidine resulted in no respiratory events such as bradypnea, apnea, or hypoxia, but a slightly longer time until discharge from the post-anesthesia care unit (3 to 38 minutes) compared with remifentanil (three to five minutes) [12]. (See "Monitored anesthesia care in adults", section on 'Dexmedetomidine'.)

●Ketamine may be employed to achieve sedation without respiratory depression. Disadvantages include increased oral secretions and potential for disturbing postoperative hallucinations. (See "Monitored anesthesia care in adults", section on 'Ketamine'.)

Oxygen delivery — During sedation for bronchoscopy, standard methods for oxygen delivery include insertion of an oxygen cannula into the bite block through which the bronchoscope is inserted (eg, at a flow rate of 10 L/minute), or via a nasal cannula (eg, at a flow rate of 2 to 5 L/minute). An alternative technique is administration of high-flow nasal oxygen (eg, at a flow rate of 30 to 70 L/minute), which may result in less frequent peripheral arterial oxygen desaturation to <90 percent compared with standard management [13]. Use of noninvasive ventilation via a mask designed to allow for insertion of a bronchoscope has also been reported [14].

General anesthesia

Anesthetic techniques — General anesthesia is usually induced with intravenous anesthetic agents. (See "Induction of general anesthesia: Overview" and "General anesthesia: Intravenous induction agents".)

Either a volatile inhaled anesthetic or total intravenous anesthesia (TIVA) may be selected for anesthetic maintenance during flexible bronchoscopy. A neuromuscular blocking agent (NMBA) may be administered with either technique, if desired.

Inhalation anesthesia — We typically employ a potent volatile inhalation anesthetic (eg, sevoflurane or isoflurane) to maintain general anesthesia. Advantages of these agents include bronchodilatory and anti-inflammatory effects, as well as rapid elimination during emergence [15]. (See "Maintenance of general anesthesia: Overview", section on 'Inhalation anesthetic agents and techniques'.)

Disadvantages of an inhalation technique include difficulty with control of anesthetic depth due to necessary interruptions in ventilation for technical reasons during flexible bronchoscopy. Other disadvantages include room pollution due to frequent removal of the bronchoscope, as well as high consumption of the selected volatile agent because of frequent suctioning and the high fresh gas flows necessary to compensate for leaks around the bronchoscope.

Total intravenous anesthesia — Advantages of a TIVA technique during flexible bronchoscopy include the ability to administer anesthetic agents independent of ventilation, without waste of anesthetic agents or operating room pollution. Similar to TIVA use for other procedures, disadvantages include inability to monitor blood concentrations of intravenous anesthetic agents, greater risk of awareness, and higher cost. (See "Maintenance of general anesthesia: Overview", section on 'Total intravenous anesthesia'.)

The sedative-hypnotic component of a TIVA technique for bronchoscopy is typically propofol. Dose is titrated to the minimum required to prevent awareness (see "Maintenance of general anesthesia: Overview", section on 'Sedative-hypnotic agent: Propofol'). Ideally, neuromonitoring of the processed or unprocessed electroencephalogram (EEG) is employed during TIVA, with alarms set to detect high EEG indices that indicate possible awareness, particularly if an NMBA is administered. (See "Accidental awareness during general anesthesia", section on 'Brain monitoring'.)

The opioid component of a TIVA technique for bronchoscopy is typically remifentanil, administered as a loading dose of 1 mcg/kg, followed by a continuous infusion at 0.1 to 0.2 mcg/kg/minute. Dose is reduced in older patients and those with severe comorbidities. In young, healthy patients, an initial remifentanil infusion of 0.2 mcg/kg/minute is typical, with titration to a higher infusion dose as needed. Although bronchoscopy can be an intensely stimulating procedure, there is little discomfort following the procedure. Thus, titration of remifentanil is ideal for ablation of airway and hemodynamic responses to noxious stimuli, followed by a desirable rapid emergence at the end of the procedure. (See "Perioperative uses of intravenous opioids: Specific agents", section on 'Remifentanil'.)

Airway control — During general anesthesia, the airway is usually secured with placement of either a LMA or an ETT [3]. Placement of an airway device has the advantage of expediting the procedure because the bronchoscopist can access the airway quickly via a bronchoscope adapter attached to the LMA or ETT, without needing to navigate from the mouth to the vocal cords. Adequate continuous ventilation is usually achieved by ventilating around the scope after its passage through the adapter, although frequent suctioning can cause a large leak.

Factors favoring selection of an LMA include:

●Desire to avoid muscle relaxation

●Need for inspection or biopsy of the glottis, upper airway, or adjacent structures

●Brief anticipated duration of procedure

●Low anticipated ventilator pressures

Factors that favor the selection of an ETT include:

●High risk of aspiration

●Long anticipated duration of procedure

●High anticipated ventilator pressures

●Need to avoid atelectasis. In a randomized trial conducted in 66 patients undergoing peripheral bronchoscopy, a ventilatory strategy to prevent atelectasis (VESPA) that included insertion of an ETT followed by a recruitment maneuver, titration of the fraction of inspired oxygen (FiO₂) <100 percent, and use of positive end-expiratory pressure (PEEP) of 8 to 10 cm H₂O was compared with standard ventilation via a LMA with 100% FiO₂ and zero PEEP [16]. Chest computed tomography (CT) imaging included analysis for atelectasis, which was observed 20 to 30 minutes after insertion of the airway device in 7.9 percent in the VESPA group versus 72.6 percent in the standard ventilation group [16].

Laryngeal mask airway — Passage of a flexible bronchoscope via an LMA requires neuromuscular blockade, or selective paralysis of the vocal cords with topical application of local anesthetic to avoid laryngospasm. Local anesthetic is typically administered via the working channel of the bronchoscope. Advantages of this approach include avoidance of muscle relaxation (ie, paralysis) and the ability to perform a complete inspection of the glottis and proximal trachea.

Endotracheal tube — When an ETT is used, the size (ie, internal diameter [ID]) of the tube must be sufficiently large to accommodate the bronchoscope and allow effective ventilation. Although an 8.0 mm ID tube is selected for many flexible bronchoscopy cases, a larger ETT is occasionally necessary. For example, the Olympus endobronchial ultrasound (EBUS) bronchoscope has an external diameter of 6.9 mm. When an 8.0 mm ID ETT is used, the remaining cross-sectional area after insertion of the EBUS scope is equivalent to that of a 4.0 mm ID ETT, which is too narrow to allow effective ventilation in an adult patient. Thus, an 8.5 or 9.0 mm ID ETT is selected if EBUS is planned.

If a small ETT is necessary (eg, a patient with glottic or tracheal stenosis), the anesthesiologist must ensure that the planned bronchoscope will fit through the selected ETT before induction of general anesthesia and endotracheal intubation. Other options include using a smaller bronchoscope or using an LMA. (See "Flexible bronchoscopy in adults: Preparation, procedural technique, and complications", section on 'Route of entry'.)

Emergence and postoperative care — Extensive suctioning may be required during emergence from general anesthesia after flexible bronchoscopy in order to clear copious secretions and/or blood. During recovery from anesthesia, aspiration precautions are necessary since residual vocal cord paralysis may last two to four hours after topical anesthesia with lidocaine. Thus, postoperative patients should remain “nil per os” (ie, NPO) until paralysis has resolved.

GENERAL ANESTHESIA FOR RIGID BRONCHOSCOPY

Equipment, patient preparation, and monitoring — A rigid bronchoscope is a large straight metal tube with a beveled distal end that is inserted into the trachea through the mouth (or tracheostomy stoma) to visualize the larynx, trachea, and, in some cases, the mainstem bronchi. The bronchoscopist (eg, thoracic surgeon, interventional pulmonologist, otolaryngologist) uses instruments to perform diagnostic and therapeutic procedures through the scope (picture 1 and picture 2) [17]. (See "Rigid bronchoscopy: Instrumentation".)

Similar to preparations for flexible bronchoscopy, standard American Society of Anesthesiologists (ASA) monitors are placed (table 1), preoxygenation is employed, and oropharyngeal secretions are suctioned prior to beginning the procedure. (See "Rigid bronchoscopy: Intubation techniques", section on 'Patient preparation'.)

Choice of technique — Patients require deep general anesthesia to tolerate rigid bronchoscopy because the procedure involves noxious airway stimulation and extreme discomfort (picture 6) [3]. The anesthesiologist consults with the bronchoscopist to determine the best anesthetic plan. Decisions include:

●Whether to induce general anesthesia with intravenous agents or perform an inhalation induction.

●Whether to administer a neuromuscular blocking agent (NMBA) or maintain spontaneous ventilation prior to initially securing the airway.

●Whether to employ intermittent positive pressure ventilation (PPV) or jet ventilation (JV) during the procedure.

Total intravenous anesthesia — We typically employ a total intravenous anesthesia (TIVA) technique to maintain general anesthesia since ventilation is frequently interrupted during rigid bronchoscopy, which leads to fluctuations in anesthetic depth when an inhalation technique is used. TIVA is the only anesthetic choice if JV is to be used because inhalation anesthetics cannot be administered via a JV system (see 'Jet ventilation' below). We typically administer an NMBA to induce complete muscle relaxation. This prevents patient movement and facilitates exposure of the glottis for the bronchoscopist.

Similar to a TIVA technique for flexible bronchoscopy, we typically administer a combination of propofol and remifentanil (see 'Total intravenous anesthesia' above), although alternative or additional agents may be selected, as described separately. (See "Maintenance of general anesthesia: Overview", section on 'Total intravenous anesthesia'.)

Inhalation anesthesia — If the bronchoscopist's ability to secure the airway with the rigid bronchoscope is uncertain (eg, tracheal stenosis, presence of a foreign body), we select an inhalation anesthetic induction technique, typically with sevoflurane, in order to maintain spontaneous ventilation (see "Inhalation anesthetic agents: Clinical effects and uses", section on 'Induction of general anesthesia' and "Induction of general anesthesia: Overview", section on 'Inhalation anesthetic induction'). No NMBA is administered during spontaneous ventilation. Also, opioid administration is minimized during induction to avoid hypoventilation and apnea. This “don’t burn your bridges” approach affords a margin of safety if the bronchoscopist is unable to rapidly secure the airway.

After induction of general anesthesia, before attempts at securing the airway, we usually switch to isoflurane as the volatile anesthetic agent, rather than continuing sevoflurane administration. Isoflurane is the most soluble potent volatile agent available in North America (or halothane may be used, if available). Thus, changes in anesthetic depth are less rapid when inhalation anesthetic administration is briefly interrupted (eg, when the rigid bronchoscope must be removed to perform airway interventions or during temporary periods of apnea). Anesthetic depth is more stable because a spontaneously breathing patient will not have apnea, and an apneic patient will not immediately awaken from general anesthesia produced with isoflurane or halothane. (See "Maintenance of general anesthesia: Overview", section on 'Isoflurane' and "Inhalation anesthetic agents: Properties and delivery".)

Once the airway has been secured by the bronchoscopist’s interventions (eg, removal of a foreign body or treatment of tracheal stenosis), we typically discontinue the volatile anesthetic and switch to a TIVA technique; an NMBA is usually administered as part of the TIVA technique.

Disadvantages of an inhalation technique include difficulty in providing adequate anesthetic depth that prevents coughing and movement during bronchoscopic instrumentation. Typically, a 1.5 to 2.0 minimum alveolar concentration (MAC) is necessary (with MAC defined as the concentration of an inhaled agent in the alveoli that is required to prevent movement in response to a surgical stimulus in 50 percent of patients). However, accurate measurements of the end-tidal anesthetic agent cannot be obtained because anesthetic gases leak around the bronchoscope. Another disadvantage of an inhalation technique is the pollution of the operating room with anesthetic gases that occurs with such leakage.

Ventilation techniques — Controlled ventilation during rigid bronchoscopy in the anesthetized patient may be accomplished with standard PPV or a JV system [3].

Positive pressure ventilation — PPV is accomplished by connecting an anesthesia circuit to the side connector of the rigid bronchoscope (picture 6). Ventilation is typically controlled by hand in order to accommodate the bronchoscopist’s need for periods of apnea. (See "Mechanical ventilation during anesthesia in adults".)

A disadvantage for this technique is the need for the bronchoscopist to completely cover the proximal end of the bronchoscope that is outside the body each time the anesthesiologist generates positive pressure with hand ventilation. This impairs the bronchoscopist's ability to work and necessitates frequent interruption of ventilation (ie, periods of apnea). Also, as noted above, there is significant leakage of gases around the bronchoscope. Although the bronchoscopist can place a throat pack in the oropharynx to ameliorate this, hypoventilation often occurs and measurements of end-tidal gases (eg, oxygen, carbon dioxide, inhalation anesthetic agents) may be inaccurate.

Jet ventilation — JV is an alternative ventilation technique during rigid bronchoscopy suitable for patients having a patent airway with a diameter large enough to allow an adequate pathway for egress of ventilation gases. Use of a jet ventilator requires TIVA because inhaled anesthetics cannot be administered via a JV system. An NMBA is often administered to induce complete muscle relaxation. (See 'Total intravenous anesthesia' above.)

Typical settings for JV during rigid bronchoscopy are:

●Respiratory rate: 20 to 30 breaths per minute (bpm). "High frequency" JV >60 bpm is not usually required. Respiratory rate is limited by expiratory time to avoid "stacking breaths."

●Driving pressure: 15 to 30 pounds/square inch (psi). The minimum driving pressure to achieve appropriate chest rise and adequate oxygenation varies; a large patient with a heavy chest wall will require higher driving pressure than a smaller patient.

●Inspiratory time: 30 to 50 percent. Increasing the inspiratory time can be helpful in the absence of positive end-expiratory pressure (PEEP), as the breath-stacking effect seems to improve oxygenation, likely by reducing atelectasis.

●Fraction of inspired oxygen concentration (FiO₂): Variable (as low as 0.3 when a surgical laser is used, and up to 1.0 if hypoxemia is present).

Many rigid bronchoscopes have a purpose-built port with a Luer-Lok connection for JV tubing (picture 1). This is desirable since it provides a secure location for attaching the jet ventilator tubing, preventing too much slippage in or out. However, it is possible to accomplish JV via a catheter inserted directly into a rigid bronchoscope (eg, an airway exchange catheter).

We use the only electronic JV system that is commercially available in the United States (the Monsoon III jet ventilator manufactured by Acutronic Medical Systems AG). This ventilator has sampling catheters that measure airway pressures within the JV catheter before the administration of each breath, as well as during inspiration (via a second sampling catheter). If either pressure exceeds the maximal setting, ventilation is immediately suspended by the device. Thus, build-up of high pressures that may cause a pneumothorax is prevented.

Although manual JV is employed in some centers, this technique requires extreme caution due to a high risk for barotrauma. The anesthesiologist must ensure that there is no airway obstruction and that an adequate pathway exists for egress of gas from the chest. Since high pressures may be delivered to the patient’s lungs during manual JV, a pneumothorax or pneumomediastinum can develop rapidly, with resultant hemodynamic collapse and/or traumatic injury. Each one pound-force per square inch (psi) by jet ventilation is equivalent to 75 cm H₂O, compared with standard hospital wall outlets for oxygen that are calibrated to 50 psi (equivalent to >3500 cmH₂O).

Emergence and postoperative care — Airway management during emergence from general anesthesia after a rigid bronchoscopy procedure may be challenging. One option is to remove the rigid bronchoscope while the patient is still deeply anesthetized, with replacement with an endotracheal tube (ETT) or laryngeal mask airway (LMA) [3], or use of a facemask for continued delivery of controlled or assisted ventilation until spontaneous breathing has resumed.

An alternative strategy is to hold the rigid bronchoscope firmly in place so that it does not exert undue pressure on soft airway tissues or teeth, while continuing either PPV or low frequency JV through the bronchoscope as the patient awakens. Once the patient becomes responsive, the rigid scope is removed as quickly and smoothly as possible. An infusion of remifentanil ≥0.1 mcg/kg/min may be necessary to minimize struggling during bronchoscope removal that could result in airway injury. With this technique, extubation is decisively accomplished as soon as the patient can follow commands, typically prior to spontaneous respiratory efforts or recovery of airway reflexes.

Similar to emergence after flexible bronchoscopy, secretions and/or blood are frequently suctioned after rigid bronchoscopy (see 'Emergence and postoperative care' above).

Complications associated with rigid bronchoscopy include hypoxemia, laryngospasm, laryngeal edema, atelectasis, and pneumothorax, and such complications are more likely in patients with severe underlying disease [18,19].

BRONCHOSCOPY IN COVID-19 PATIENTS — Bronchoscopy may facilitate management of patients with novel coronavirus disease 2019 (COVID-19) who develop severe respiratory failure requiring prolonged mechanical ventilation. Bronchoscopy is an aerosol generating procedure, and therefore high-risk for infection of participating anesthesia, surgery, and other medical personnel due to aerosolization of oropharyngeal and tracheal secretions [20-22]. Proper personal protective equipment, such as an N95 mask, or respirator, and eye protection should be worn. Elective bronchoscopies may be postponed until the patient is no longer infectious. (See "COVID-19: Management of the intubated adult", section on 'Bronchoscopy'.)

SUMMARY AND RECOMMENDATIONS

●Flexible bronchoscopy – For patients undergoing flexible bronchoscopy (figure 1 and figure 2), either topical anesthesia of the airway combined with sedation or a general anesthetic may be acceptable. (See 'Choice of technique' above.)

•Topical anesthesia – Topical airway anesthesia involves gargling with 4% lidocaine to anesthetize the mouth and base of the tongue, direct spraying of atomized 1 or 2% lidocaine on structures in the oropharynx and laryngopharynx, spraying additional 1 to 2% lidocaine via the bronchoscope port onto the cords (picture 3), down into the trachea (picture 4), onto the carina (picture 5), and also into the lower airways if necessary. (See 'Topical anesthesia' above.)

•General anesthesia

-Airway control – The airway is secured with a laryngeal mask airway (LMA) or endotracheal tube (ETT). (See 'Airway control' above.)

Factors favoring selection of a LMA include desire to avoid muscle relaxation, need for inspection or biopsy of the glottis, upper airway, or adjacent structures, brief anticipated procedural duration, and low anticipated ventilator pressures. (See 'Laryngeal mask airway' above.)

Factors favoring selection of an ETT include high risk of aspiration, long anticipated procedural duration, and high anticipated ventilator pressures. (See 'Endotracheal tube' above.)

-General anesthetic technique – Either a volatile inhalation or a total intravenous anesthesia (TIVA) technique may be employed. (See 'Anesthetic techniques' above.)

Advantages of volatile anesthetic agents include bronchodilatory and anti-inflammatory effects, as well as rapid elimination during emergence. Disadvantages include difficulty in controlling anesthetic depth due to interruptions in ventilation, operating room (OR) pollution due to frequent removal of the scope, and high consumption of volatile anesthetic agents due to frequent suctioning and high fresh gas flows. (See 'Inhalation anesthesia' above.)

Advantages of a TIVA technique include the ability to administer anesthetic agents independent of ventilation, without waste or OR pollution. Typically, propofol and remifentanil infusions are employed. (See 'Total intravenous anesthesia' above.)

•Postoperative considerations – After flexible bronchoscopy, extensive suctioning may be required during emergence to clear secretions and blood. During recovery, aspiration precautions are necessary since residual vocal cord paralysis may last two to four hours after topical anesthesia with lidocaine. (See 'Emergence and postoperative care' above.)

●Rigid bronchoscopy – Deep general anesthesia is typically required because of noxious airway stimulation and extreme discomfort during rigid bronchoscopy (picture 6 and picture 1 and picture 2).

•Induction of anesthesia – The anesthesiologist and bronchoscopist jointly decide whether to induce with intravenous agents or perform an inhalation induction technique with maintenance of spontaneous ventilation. (See 'Choice of technique' above.)

•Maintenance of anesthesia

-TIVA with a neuromuscular blocking agent (NMBA) – We prefer TIVA for most rigid bronchoscopy cases since ventilation is frequently interrupted, leading to fluctuations in anesthetic depth if an inhalation technique is employed. (If JV is to be used, TIVA is the only choice since inhaled anesthetic agents cannot be administered via a JV system.) A nondepolarizing NMBA is administered to prevent patient movement and facilitate exposure of the glottis. (See 'Total intravenous anesthesia' above.)

-Inhalation anesthesia with spontaneous ventilation – If the bronchoscopist’s ability to secure the airway with a rigid bronchoscope is uncertain, an inhalation anesthetic induction with sevoflurane is selected to maintain spontaneous ventilation; neuromuscular blockade is avoided. The volatile anesthetic agent is typically discontinued and a TIVA technique that includes administration of an NMBA is initiated once the airway has been secured. (See 'Inhalation anesthesia' above.)

•Ventilation technique (see 'Ventilation techniques' above):

-Positive pressure ventilation (PPV) – If PPV is selected for controlled ventilation, frequent interruption of ventilation is necessary, potentially resulting in hypoventilation, as well as inaccurate end-tidal gas measurements and significant leakage of inhaled gases around the bronchoscope. (See 'Positive pressure ventilation' above.)

-Jet ventilation (JV) – JV is an alternative ventilation technique suitable for patients with a patent airway and diameter large enough to allow egress of ventilation gases. Typical JV settings during rigid bronchoscopy include respiratory rate 20 to 30 breaths per minute, driving pressure 18 to 25 mmHg, inspiratory time 30 percent, with fraction of inspired oxygen concentration (FiO₂) as low as 0.3 during use of a surgical laser and up to 1.0 if hypoxemia is present. (See 'Jet ventilation' above.)

•Emergence – Removal of the rigid bronchoscope may be accomplished while the patient is still deeply anesthetized, with replacement with an ETT, LMA, or use of a facemask for continued ventilation until spontaneous breathing resumes. An alternative strategy is to hold the rigid bronchoscope firmly in place while continuing PPV or JV until the patient becomes responsive. An infusion of remifentanil ≥0.1 mcg/kg/min may be necessary to minimize struggling and facilitate extubation as soon as the patient can follow commands. (See 'Emergence and postoperative care' above.)