【Guidelines Consensus】(Bronchioscopy) Expert Consensus on Sedation/Anesthesia (2020 Edition)

(bronch) Expert consensus on tracheoscopy for sedation/anesthesia

(2020 Edition)

Deng Xiaoming (Person in charge), Wang Yuelan, Feng Yi, Liu Jingchen, Liu Youtan, Mi Weidong, Yang Yuguang, Yang Jinfeng, Zhu Tao, Zhang Wei, Zhang Jianqiang, Zhang Liangcheng, Guo Qulian, Xu Guohai, Han Jiange, Lu Kaizhi, Bo Lulong (Author)

(bronchial) tracheoscopy is an important means of clinical diagnosis and treatment of respiratory diseases, and its clinical application is becoming increasingly popular
.
(bronchial) tracheoscopy diagnosis and treatment is a kind of operation
with high stimulation intensity, high incidence of hypoxemia, and strong discomfort of patients.
Sedation/anesthesia techniques improve the comfort and tolerance of patients receiving (bronchoscopy) and provide better conditions for the operator; However, sedation/anesthesia itself can clearly affect the patient's respiratory circulation, and how to share the airway with the (bronchioscope) operator and ensure patient safety is a major challenge
for anesthesiologists.

The medical treatment of (bronchiol) tracheoscopy under sedation / anesthesia has gradually increased, and the sedation/anesthesia regimen and ventilation mode vary greatly
due to the different complexity of the operation of (bronchiol) tracheoscopy.
With reference to relevant guidelines and research at home and abroad, the Anesthesiology Branch of the Chinese Medical Association first formulated the "Expert Consensus on Sedation/Anesthesia in the Diagnosis and Treatment of (Bronchal) Tracheoscopy (2014)"
for the first time in 2014.
The update of this expert consensus aims to further standardize the indications, contraindications, operation procedures, preoperative preparation, intraoperative monitoring, postoperative recovery and complications of sedation/anesthesia in the diagnosis and treatment of (bronchial) tracheoscopy in China, so as to facilitate the popularization and promotion of comfortable (bronchial) tracheoscopy diagnosis and treatment in China, and reduce the risks and complications
related to sedation/anesthesia 。 Coronavirus disease 2019 (COVID-19) poses new challenges to the safe and orderly development of (bronchal) tracheoscopy diagnosis and treatment, and this expert consensus also emphasizes
the key points of sedation/anesthesia in (bronchial) tracheoscopy diagnosis and treatment under the COVID-19 epidemic.
This expert consensus does not address sedation/anesthesia
for (bronchioscopic treatment) in intensive care monitoring units.

(Bronch) tracheoscopy diagnosis and treatment of sedation / anesthesia refers to an anesthesia technique
in which anesthesiologists closely monitor the patient's respiratory and circulatory state, and through the application of appropriate sedatives and/or narcotic analgesics and other drugs and maintenance of breathing and other techniques, so that patients can achieve a certain state of sedation or anesthesia.

The vast majority of patients have nervousness, anxiety and fear of (bronchioscope) diagnosis and treatment operations, and the examination process is prone to nausea and vomiting, severe cough, laryngeal spasm and bronchospasm, pneumothorax, hypoxemia and other respiratory system abnormalities, as well as circulatory system abnormalities such as increased blood pressure and arrhythmias, and even induce circulatory complications
such as angina, myocardial infarction, stroke, respiratory failure or cardiac arrest.
A small number of patients cannot tolerate or cooperate, so that (bronchioscope) operation can not accurately diagnose and treat related diseases, resulting in missed or misdiagnosis, and even aggravated patient injury
.
The purpose of tracheoscopy sedation/anesthesia is to eliminate or alleviate the patient's anxiety and discomfort, thereby enhancing the patient's tolerance, satisfaction and compliance with the endoscopic operation, and minimizing the risk of injury and accident during the (bronchiol) tracheoscopy operation, providing the best conditions
for (bronchiol) operation.

(1) (bronch) tracheoscopy for sedation/anesthesia site and equipment requirements

In addition to meeting the basic configuration requirements of a routine (bronchioscope) treatment room, the following conditions should be met for sedation/anesthesia for (bronchal) tracheoscopy treatment:

1.
The area of each diagnosis and treatment unit should be greater than 20 m2, and if the space is limited, the minimum should not be less than 15^m2
.

2.
Each diagnosis and treatment unit should meet the basic configuration requirements of surgical anesthesia, that is, it must be equipped with anesthesia machines and conventional monitors (including electrocardiogram, respiratory rate, pulse oximetry saturation and non-invasive blood pressure), oxygen and oxygen supply devices, as well as negative pressure suction devices for anesthesia, intravenous infusion devices, conventional airway management equipment (simple breathing sac, ordinary metal laryngoscopy or video laryngoscope, commonly used tracheal and bronchial catheters and other intubation appliances, etc.
), commonly used anesthetic drugs (such as propofol, etomidate, midazolam, opioids, muscle relaxation drugs, etc.
) and commonly used cardiovascular drugs (such as atropine, ephedrine, phenylephrine, etc.

).
It is recommended that those with conditions be equipped with monitoring equipment
such as end-expiratory carbon dioxide, arterial blood gas, and/or invasive arterial pressure.
The unit performing endotracheal electrocautery or laser ablation surgery should be equipped with a compressed air device or ventilator
.
For units that carry out hard tracheoscopy, it is recommended to be equipped with a high-frequency jet ventilator
.

3.
With independent anesthesia recovery room, according to the number of patients under examination and the nature of sedation / anesthesia, reasonable setting area and number of beds, it is recommended that the ratio of anesthesia recovery room to (bronchial) tracheoscopy operation room bed ratio is about 1:1
.
Its equipment should meet the basic requirements of the anesthesia recovery room, that is, it should be equipped with conventional monitors, anesthesia machines and/or ventilators, infusion devices, oxygen inhalation devices, negative pressure suction devices, and first-aid equipment and drugs
.

4.
(Bronch) tracheoscopy diagnosis and treatment area must be equipped with difficult airway treatment equipment (such as throat mask, video laryngoscope, etc.
) and rescue equipment (such as cardiac defibrillator, percutaneous or tracheostomy equipment), as well as commonly used emergency drugs (such as epinephrine, isoprenaline, lidocaine, etc.
) and antagonists (such as flumasinide, naloxone, sulgin sodium) and so on
.

(2) Staffing and responsibilities

Mild and moderate sedation in tracheoscopy can be handled by a physician trained in sedation
.
The deep sedation/anesthesia of tracheoscopy should be carried out by an anesthesiologist with the qualifications of the attending physician (including) or above
.
The number of anesthesiologists should be reasonably equipped according to the number of patients treated by (bronchioscopes), the mode of diagnosis and treatment, and the nature of sedation/anesthesia
.
It is recommended that each diagnosis and treatment unit that performs deep sedation/anesthesia be equipped with at least 1 senior resident physician in anesthesia, and it is recommended that every 1 to 2 diagnosis and treatment units be equipped with 1 to 2 anesthesia nurses, of which the nurse is responsible for pre-anesthesia preparation and sedation/anesthesia records to assist in sedation/anesthesia management; Every 2 to 3 diagnosis and treatment units are equipped with an anesthesiologist with the qualification of the attending physician (including) or above, who is responsible for the sedation/anesthesia and anesthesia recovery
of the patients in the unit.
The number of anesthesia nurses in the anesthesia recovery room should be equipped with 1:2 to 4 beds, which are responsible for monitoring and recording the patient's anesthesia recovery
.
Anesthesiologists and anesthesiology nurses should be relatively fixed to ensure the safety
of patients during sedation/anesthesia and anesthesia recovery process.

(1) Indications

1.
All patients who
are required for (bronchiol) tracheoscopy and are willing to undergo sedation / anesthesia.

2.
Patients who
have concerns or fears about (bronchioscopy), are highly sensitive and cannot tolerate local anesthesia procedures.

3.
Generally in good condition, ASA grade I or II patients
.

4.
ASA grade III or IV.
patients in a stable state should be implemented
under close monitoring.

(2) Contraindications

1.
There are contraindications to routine (bronchiol) tracheoscopy operation, severe liver and kidney function and hemostasis dysfunction and gastric or gastrointestinal obstruction accompanied by gastric contents retention
.

2.
Potentially life-threatening circulatory and respiratory diseases that are not properly controlled, such as acute coronary syndrome, severe uncontrolled hypertension, severe arrhythmias, severe heart failure, recent acute myocardial infarction and asthma attacks
.

3.
ASAV grade patients
.

4.
No escort or guardian
.

5.
Those who have sedation/anesthetic drug allergy and other anesthesia risks are
extremely high.

(3) Relative contraindications

Sedation/anesthesia under anesthesiologist is required in the following cases, and sedation under non-anesthesiologist is contraindicated:

1.
Patients with clear difficulty in airways, such as mouth distension, limited movement of the cervical and chin and jaw, ankylosing spondylitis, temporomandibular arthritis, tracheal partial stenosis, etc.
, Mallampati grade IV
.

2.
Severe neurological diseases, such as stroke, hemiplegia, convulsions, epilepsy, etc
.

3.
Patients
with a history of drug abuse, being too old or too young, morbidly obese, and confirmed obstructive sleep apnea.

4.
Multiple pulmonary bullae, severe superior vena cava obstruction syndrome, active macrohaemoptysis, etc
.

5.
Emergency airway patients with severe airway stenosis, active bleeding, foreign body obstruction and other emergency airway patients should be treated in accordance with the principle of emergency surgical anesthesia, and under the premise of strict performance of informed consent, first aid should be implemented for life rescue
.

The use of sedative/anesthetic drugs during tracheoscopy procedures can reduce or disappear
the patient's level of consciousness.
Depending on the degree to which the patient's level of consciousness is suppressed, the depth of sedation/anesthesia can be divided into four levels: mild sedation, moderate sedation, deep sedation, and general anesthesia (Table 1
).
Different patients tolerate (bronchioscope) the depth of sedation/anesthesia required
.
The depth of sedation/anesthesia required for tracheoscopy is affected
by many factors.
Due to differences in individual patient response, operation site, intensity of operation stimulation, etc.
, the same dose of sedative/anesthetic drugs can produce different sedation depths or anesthesia
.

Table 1 The depth of sedation/anesthesia for bronchoscopy and its assessment points

*Deep sedation and general anesthesia must be performed
by an anesthesiologist.

Any (bronchiol) tracheoscopy operation is invasive operation, and it is necessary to follow the principle of preparation for invasive operation before surgery, optimize the diagnosis and treatment of various comorbidities, and do a good job in visit assessment and sedation/anesthesia preparation to ensure the smooth and safe implementation
of sedation/anesthesia.

(1) Sedation/pre-anesthesia visits and assessments

Before performing (bronchioscope) sedation/anesthesia, anesthesiologists should do a good job of pre-anesthesia visits and evaluations, which can be performed in
anesthesia clinics or preoperative evaluation centers.
This includes the following:

1.
Pre-anesthesia assessment The assessment content should be the same as the preoperative assessment of patients receiving sedation / anesthesia in the operating room, but the focus should be on individual risk assessment
related to (bronchiol) tracheoscopy diagnosis and treatment.
Patient clinical signs and symptoms, as well as (bronchial) tracheoscopic protocols, are important
for the choice of anesthesia/sedation regimen and ventilation maintenance.

There are three main areas: history, physical examination, and laboratory tests
.
Focus on judging whether the patient has a difficult airway; The presence of conditions such as acute coronary syndrome, uncontrolled hypertension, severe arrhythmias, and significant heart failure that may lead to severe perioperative cardiovascular events, and it is recommended that the risk of cardiac events be assessed based on the revised cardiac risk index (RCRI); Whether there are severe airway strictures, acute respiratory infections, obesity, asthma, smoking, etc.
that may lead to severe perioperative respiratory events; Whether there are conditions
such as unfasting, gastrointestinal retention, reflux, or obstruction that may lead to reflux aspiration.

Each patient should routinely take a positive lateral chest and/or chest CT (with enhanced or thin-slice CT if necessary) to determine the location, extent, and severity of the lesion to help the anesthesiologist assess the airway and lungs
.
Patients with severe airway stenosis should be evaluated more comprehensively, with a detailed understanding of the extent of dyspnea in the natural sleep state, the effect of postural changes on dyspnea, and the nature of tracheal stenosis (endogenous or external pressure), chest CT examination and previous (bronchiol) tracheoscopy results are helpful in the assessment of the condition, and the evaluation of patients with external pressure airway stenosis should be more cautious
.
It is important to note that no preoperative imaging of the patient is fully representative of the patient's current airway status
.

In laboratory tests, patients should undergo routine blood routine and blood biochemical tests (liver and kidney function and electrolytes); If there is no obvious risk of bleeding, routine coagulation tests are not recommended, and intra-institutional routines
are recommended.
For patients who are to be biopsied, the patient's preoperative drug history should be fully evaluated, it is recommended to discontinue clopidogrel in advance (5 to 7) days, to discontinue ticagrelor in advance (3 to 5) days, and whether to continue or stop aspirin should consult with relevant specialists to weigh the advantages and disadvantages
of the use of the drug.
Patients who require early warfarin discontinuation should consult with a specialist to assess the risk of thrombosis during discontinuation and the need for bridging therapy
.
If there is or is a high suspicion of a specific comorbidity (e.
g.
, endocrine disorders such as hyperthyroidism), tests (e.
g.
, hormone level testing)
should be performed.

2.
Informed consent of the patient The patient and (or) his or her entrusted agent should be informed of the sedation / anesthesia operation plan, and explain the purpose and risks of sedation / anesthesia to the patient and (or) its entrusted agent, obtain the consent of the patient and/or its entrusted agent, and sign the anesthesia informed consent form
.

(ii) (bronchal) tracheoscopy for sedation/preparation for anesthesia

1.
The general preparation before sedation/anesthesia for the diagnosis and treatment of (bronchioscope) is basically the same as that before the
preparation of ordinary (bronchiol) tracheoscopy.

2.
Generally, patients should fast for at least 6 hours before surgery and at least 2 hours
before surgery.
If the patient has gastric emptying dysfunction or gastric retention, fasting and water abstinence should be appropriately extended
.
If necessary, ultrasound evaluates gastric contents and gastric emptying, and endotracheal intubation may be used to protect the airway
.

3.
If the patient has a moving denture, it should be removed
before the examination.

4.
The physician in charge of sedation/anesthesia on the same day shall confirm the sedation/anesthesia pre-evaluation and preparation records, and check the patient and the operation to be performed again, and fully communicate
with the (bronchioscope) operator.

5.
Routine use of anticholinergic drugs (such as atropine etc.
)
is not recommended before surgery.

6.
Preoperative preparation for special patients

(1) Patients with suspected chronic obstructive pulmonary disease should be tested for pulmonary function
.
If pulmonary function is severely degraded, such as FEV₁<40% estimate or_SpO2<93%, arterial blood gases should be measured
.

(2) Asthma patients should use bronchodilators prophylactically before (bronchioscopy), and patients with chronic obstructive pulmonary disease should decide whether to use bronchodilators
prophylactically according to the situation.

(3) Patients at risk of bleeding should routinely test platelet count and/or prothrombin time
before surgery.
In patients who are going to undergo (bronchioscope) biopsy, if oral anticoagulants are being taken before surgery, they should be discontinued at least 3 days before the test
.
If the patient must use an anticoagulant, it should be replaced with unfractionated heparin and the International Normalized Ratio (INR) ≤ 1.
5
.
For patients who are to be biopsied, dabigatran ester and rivaroxaban need to be discontinued 24 to 36 hours in advance, and low molecular weight heparin replacement
is not required.

(3) (bronchal) tracheoscopy diagnosis and treatment of sedation/anesthesia implementation and respiratory management

Intravenous access should be established first, with the patient in a lying position or as needed, a monitoring device attached, vital signs recorded, and continued oxygen
inhalation.
Depending on the purpose of the (bronchal) tracheoscopy practitioner, the appropriate sedation/anesthesia regimen may be selected, and the following different sedation or anesthesia methods
may be used.

1.
Surface anesthesia Good surface anesthesia can significantly reduce the patient's pain, maintain a relatively stable hemodynamic and respiratory function, provide good operating conditions for the surgeon, and reduce the occurrence
of intraoperative complications.
Surface anesthesia alone is only indicated for patient tolerance and simple (bronchioscopy
).

Lidocaine is recommended as a commonly used surface anesthetic
.
At present, the use of lidocaine is mainly the following methods: spray method or atomization inhalation method, tracheal drip method, gargle-containing method, cyclothyroid puncture method
.
Lidocaine aerosol has the characteristics of convenient surface anesthesia, good effect, accurate quantification, and small side effects, and has become the main method of (bronchial) tracheoscopic surface anesthesia in recent years, but there are still a small number of patients who cannot tolerate
it because of chest tightness or asthma.
A 2% lidocaine gel
is recommended for nasal anesthesia.
For throat anesthesia, a 1% lidocaine spray is recommended, and bronchoscopy should be sprayed with a local surface spray through the front of the
phonoscope.
Lidocaine-related complications are mainly local anesthetic toxicities
.
Total lidocaine should be less than 8.
2 mg/kg
.

2.
Mild and moderate sedation Although surface anesthesia can reduce the stress response of (bronchopscopy), some patients still have suffocation and dyspnea due to nervousness and fear, so it is advisable to give sedation and appropriate analgesic drugs on the basis of surface anesthesia, so that patients are at the level of mild and moderate sedation, and retain spontaneous breathing
.
At present, midazolam or combined fentanyl or sufentanil is most commonly selected clinically, which is suitable for patients with good tolerance and simple operation (bronchoscopy
).

Midazolam can be administered by titration, the initial dose of adult patients under 60 years of age is (0.
03 ~ 0.
05) mg / kg (should not exceed 3 mg), administered before the start of the operation (5 ~ 10) min, intravenous injection 2 minutes after the start of action, gradually reach the degree of moderate sedation, in the operation (30 ~ 40) min generally do not need to add
again.
Intravenous administration of midazolam should be slow, about 1 mg / 30s; If the operation time is prolonged, 1mg can be added if necessary, but the total amount of use should not exceed 5mg
.
In patients over 60 years of age, debilitating and comorbid with multiple chronic diseases, the dosage of midazolam should be reduced
.
Adult patients given fentanyl (1 to 2) μg/kg or sulfentanil (0.
1 to 0.
2) μg/kg in batches can significantly improve patient tolerance
.
The new intravenous anesthetic remazoram, which has a rapid onset of action and failure and has a mild effect on respiratory and cardiovascular system inhibition, can also be tried for sedation
for (bronchaloscopy).
Adults can first slowly inject fentanyl (50 to 75) μg or sulfentanil (5 to 7.
5) μg, and then intravenously inject ramazolam (5.
0 to 7.
5) mg, when moderate sedation can be achieved, the operation can be started, if necessary, rimazoram 2.
5 mg, but the number of additions should not exceed 5 times
.

3.
Deep sedation or intravenous anesthesia Deep sedation or intravenous anesthesia on the basis of surface anesthesia is suitable for routine (bronchioscope) diagnosis and treatment operations, especially in patients with
poor tolerance.

Dexmedetomidine in combination with anesthetic analgesics is indicated for (bronchaloscopy
).
On the basis of adequate surface anesthesia, dexmedetomidine (0.
2 to 1) μg/kg can be injected intravenously at (10 to 15) min, and then maintained
at (0.
2 to 0.
8) μg·kg-1·h-1.
Appropriate amount of fentanyl, sufentanil or refentanil should be used in combination to significantly inhibit the stimulation
of airway operation.

Midazolam or propofol may also be used for deep sedation or intravenous anesthesia in (bronchioscopy), and a combination of anesthetic analgesics (e.
g.
, fentanyl, sufentanil, refentanil, or oxycodone) is recommended to improve patient tolerance
.
In adult patients, the dosage of midazolam is mostly (1 to 3) mg, or intravenous injection of propofol (1 to 1.
5) mg/kg within (1 to 5) min, and the maintenance dose is (1.
5 to 4.
5) mg·kg-1·^h-1 ； The usual dose of intravenous injection of fentanyl is (1 to 2) μg/kg, and its onset of action is rapid and can be maintained (30 to 60) min; The usual dose of sufentanil for intravenous injection is (0.
1 ~ 0.
2) μg / kg, which has a faster onset of action and a long time of action; Refentanil can be injected intravenously (0.
5 to 1.
0) μg/kg in adults with 5 minutes after 5 min, or continuous infusion (0.
05 to 0.
1) μg·kg-1·^min-1 after a single injection, followed by gradual dose adjustment to 0.
025 μg·kg-1·^min-1
.
Opioids should be given slowly to avoid respiratory depression and chest wall rigidity
.
Oxycodone hydrochloride can be given a single dose (0.
05 to 0.
1) mg/kg, which can be maintained for a long time and generally does not need to be added
again.

It is also possible to inject fentanyl (1 to 2 μg/kg) or sulfentanil (0.
1 to 0.
2 μg/kg) with propofol for targeted infusion (effector concentration: 3 to 5 μg/ml); Dual targeted infusion of propofol (effector concentration: 3 to 5 μg/ml) and refentanil (effector concentration: 1.
5 to 3 ng/ml) can also be selected, generally requiring a higher initial concentration of targeted infusion and then a gradual decrease
.
After the patient's eyelash reflex has disappeared and breathing is stable, tracheoscopy can be started and the sedation or anesthesia depth
adjusted appropriately according to the patient's response.
If the patient has physical movement or coughing, propofol (0.
3 to 0.
5) mg/kg
can be added.

Dexmedetomidine in combination with anesthetic analgesics may cause severe bradycardia or even cardiac arrest, especially when placed (bronchiol) tracheoscopy, should be closely monitored and promptly managed
.
Midazolam or propofol combined with anesthetic analgesics may cause significant respiratory depression, so the dose and speed of medication should be adjusted appropriately according to the patient's age, condition, and the nature of (bronchaloscopy) operation, and vital signs
such as breathing should be closely monitored.

Etomidate has little effect on the respiratory and circulatory system, has a rapid and short-lived effect after intravenous injection, and is also suitable for sedation/anesthesia
in (bronchaloscopy).
Etomidate (0.
2 to 0.
3 mg/kg) should be given after the application of midazolam and/or fentanyl or sulfentanil (1.
5 to 2) min to prevent muscle tremor
.
In recent years, the application of etomidate and propofol mixture, etomidate and propofol combined infusion in various endoscopic diagnosis and treatment has increased, and it can also be used for sedation/anesthesia of (bronch) tracheoscopy diagnosis and treatment, which can avoid adverse reactions such as hypotension and respiratory depression caused by propofol, and can also reduce adverse reactions
such as muscle tremor caused by etomidate ester 。 After intravenous administration of fentanyl or sufentanil (1.
5 to 2) min, a volume ratio of 1:2 mixture (etomidate 20 mg/10 ml with propofol 200 mg/20 ml) is used, and the first dose is (0.
15 to 0.
2) ml/kg of slow intravenous injection, and a single administration (1-2) ml is added
according to the patient's sedation depth.

The new intravenous anesthetic cyclopofol is a GABA_A agonist whose efficacy is comparable to propofol, but the incidence of injection pain, respiratory and circulatory adverse events is reduced, and it is also suitable for sedation/anesthesia
in (bronchaloscopy).
The first dose of cyclopofol (0.
3 to 0.
4) mg/kg should be given after the application of fentanyl or sufentanil (2 to 3) min
.
In the course of diagnosis and treatment, according to clinical observation, cyclopofol can be added, < 65-year-old patients can add 0.
15 mg/kg each time, ≥ 65-year-old patients can add 0.
12 mg/kg each time, if necessary, an appropriate amount of fentanyl or sufentanil<b13> can be added.

4.
General anesthesia for the treatment of rigid tracheoscopy, laryngeal hood or flexible bronchoscopy under endotracheal intubation

Flexible bronchoscopy under general anesthesia, such as (bronchial) endotracheoscopy with flexible tracheoscopy, stent placement or removal, and tumor removal
.

The implementation of general anesthesia and the maintenance of ventilation should be based on the nature and requirements of the (bronchal) tracheoscopy diagnosis and treatment operation, the configuration of anesthesia equipment in the tracheoscopy room, and the experience and level of the anesthesiologist, select the appropriate anesthesia method, airway management tools such as throat hood (should choose classic, flexible and dual-cavity types), anti-laser tracheal catheterization, etc.
, and appropriate ventilation
。 Because the anesthesiologist shares the airway with the endoscopist, and the bronchoscope enters the airway causing partial lumen obstruction, causing increased airway resistance and a decrease in alveolar ventilation, both parties should work closely together to adopt appropriate and effective ventilation strategies, such as ventilation through the laryngeal hood or the Y-interface at the end of the endotracheal catheter or high-frequency jet ventilation under hard tracheoscopy to successfully complete the operation
under the premise of ensuring effective oxygenation of the patient.

When performing general anesthesia, consider using an appropriate amount of muscle relaxant to assist with rigid tracheoscopy, supraglottic airway management tools (laryngeal masks), or tracheal catheter placement, especially when performing operations with a high risk of
injury or requiring fine positioning (e.
g.
, laser therapy, transbronchoscopic ultrasonography needle aspiration biopsy, electromagnetic navigation bronchoscopy, etc.
), requiring the patient to remain motionless to avoid complications such as airway perforation 。 The anesthesia method can be selected according to the patient's condition, the nature of the (bronchial) tracheoscopy operation, and the experience and level of the anesthesiologist, depending on intravenous anesthesia, inhalation anesthesia or intravenous compound anesthesia, but it should be noted that there may be severe air leakage during ventilation
.
The selection of airway management tools should be based on the type of diagnosis and treatment, the experience of the operator, etc.
, endotracheal intubation anesthesia is suitable for long-term diagnosis and treatment of the distal trachea and bronchi, and laryngeal mask anesthesia is suitable for subglottic diagnosis and treatment operations
, including trachea and main bronchi.

5.
Respiratory management

In (bronchioscope) tracheoscopy, sedatives and/or narcotic analgesics may inhibit breathing and increase the difficulty
of respiratory management because the operating physician shares the airway with the anesthesiologist, increasing the difficulty of ventilation.
Therefore, it is essential
to maintain effective respiratory function.
The commonly used respiratory management methods in clinical practice are as follows:

(1) Denitrogen oxygenation: All patients receiving (bronchioscopic sedation / anesthesia should fully denitrogen oxygen
under spontaneous breathing before sedation / anesthesia.

(2) Nasal catheter oxygenation: Oxygen ventilation through nasal catheter is the most commonly used oxygen administration method for surface anesthesia and mild to moderate sedation, and the patient is happy to accept, but it cannot guarantee the maintenance of sufficient oxygenation of the patient, and it is only suitable for patients with good lung function under surface anesthesia or mild to moderate sedation and receiving simple operation and short time (bronchal) tracheoscopy diagnosis and treatment
.

(3) Mask ventilation: Effective mask ventilation (especially endoscopic masks) is conducive to maintaining adequate oxygenation of patients, and can also significantly improve patient ventilation, which is a recommended ventilation method
.
When_SpO2 < 90%, a mask should be used to assist breathing or control breathing, and should be used in patients with
significant decline in oxygenation and/or ventilation under deep sedation or intravenous anesthesia.
The Y-shaped interface on the mask is also used for ventilation, which can maintain effective respiratory function while performing simple diagnosis and treatment in the (bronchial) duct for a short time
.

(4) High-frequency ventilation: High-frequency ventilation modes commonly used include high-frequency jet and high-frequency oscillatory ventilation
.
High-frequency ventilation is delivered directly through the nose or mouth to the patient's pharynx, or it can be provided by a jet catheter or connected to a rigid tracheoscopy, which provides oxygen to reduce the incidence of
hypoxemia.
Appropriate ventilation parameters, including frequency of ventilation, ventilation pressure, and suction ratio, should be selected to prevent possible complications (e.
g.
, barotrauma, carbon dioxide accumulation, etc.

).
High-frequency ventilation is indicated for (bronchioscope) under deep sedation or intravenous anesthesia, especially for rigid tracheoscopy
.

(5) Laryngeal mask ventilation: when implementing (bronchal) tracheoscopy diagnosis and treatment under general anesthesia, laryngeal mask ventilation using Y-type interface is a more commonly used ventilation method, and its advantage is that it is convenient for (bronchioscopy) surgery physicians to observe glottis and endotracheal lesions; Easy to use quickly, the airway is easy to maintain; The laryngeal mask is less difficult to place, has a high success rate, and can be used for autonomous ventilation and controlled ventilation, and to avoid damage to the mucosa in the trachea; Patients can also tolerate it under lighter anesthesia, and the incidence of cough during convalescent anesthesia is low
.
Laryngeal mask ventilation is also suitable for more complex and long-term (bronchial) intratracheal diagnosis and treatment under
general anesthesia.

(6) (bronchial) tracheal catheter ventilation: the effect of trans-(bronchial) duct ventilation using Y-type interface under general anesthesia is accurate and reliable, and it is suitable for the more complex and long tracheal distal and intrabronchial diagnosis and treatment operations under general anesthesia, especially suitable for tracheal stenosis caused by severe tracheal stenosis
obstruction or external compression.
Transtracheal foreign body removal or tumor removal through tracheal catheter may present with difficulties in removing the foreign body or tumor, and there is a risk of
withdrawal from the tracheal catheter.
Care should be taken to prevent hypoxemia during single lung ventilation through bronchial catheters
.

(7) When an electric knife, condenser or laser is required for airway operation, it is advisable to use all-vein anesthesia and select an appropriate endotracheal catheter (such as an anti-laser catheter).

During the operation, the inhalation and exhaled oxygen concentration are closely monitored, and the oxygen concentration should be controlled below 40% throughout the process to ensure that the patient is not hypoxic, so as to avoid fire
in the airway.

(4) Guardianship during sedation/anesthesia and during convalescence

Monitoring of vital signs in sedative/anesthesia and convalescent patients is an important part
of the diagnosis and treatment of sedation/anesthesia with bronchoscopy.
Routine monitoring should include: electrocardiogram, respiration, blood pressure and pulse oximetry, and those with conditions should monitor the partial pressure of end-expiratory carbon dioxide; Endotracheal intubation (including laryngeal mask) for general anesthesia should routinely monitor end-expiratory carbon dioxide partial pressure
.

1.
ECG monitoring Closely monitor the changes and abnormalities of heart rate and heart rhythm, and deal
with them in a timely manner if necessary.
About 90% of cardiac arrests precede bradycardia, and it is difficult to detect
them in time without continuous dynamic ECG monitoring.
Therefore, the ECG
must be closely monitored during sedation/anesthesia.

2.
Respiratory monitoring The patient's respiratory rate and amplitude should be closely monitored, especially for laryngeal spasms or airway obstruction
.
Slowing and shallow breathing suggests sedation / deep anesthesia; Faster and deeper breathing indicates sedation/shallow
anesthesia.
Abnormal breathing often suggests airway obstruction, and common causes include laryngospasm, posterior tongue fall, and bronchospasm
.
Supporting the lower jaw often relieves airway obstruction caused by posterior tongue fall during anesthesia recovery, and oropharyngeal or nasopharyngeal ventilation tubes
can be placed if necessary.
Arterial blood gases
should be monitored for special surgery and high-frequency ventilation.

3.
Blood pressure monitoring In general, patients can monitor non-invasive arterial blood pressure (3-5 minutes apart), but special patients (with cardiovascular disease, expected diagnosis and treatment time) should undergo invasive arterial pressure monitoring
.
In general, patients with blood pressure levels that change by more than 30% of the basic level and ± 20% of the blood pressure level in high-risk patients that change by ±more than the basic level, that is, vasoactive drug intervention should be given and the depth of
sedation/anesthesia should be adjusted in time.

4.
Pulse oximetry monitoring The patient's oxygen saturation should be monitored before sedation/anesthesia is performed and continued until fully awake
.
It is worth noting that pulse oximetry mainly represents the ventilation function of the lungs, and is not a sensitive indicator reflecting early hypoventilation; A decrease in pulse oximetry indicates a significant decrease in ventilation function, so close observation of the patient's respiratory status
is required.

5.
End-expiratory carbon dioxide partial pressure monitoring Continuous monitoring of end-expiratory carbon dioxide partial pressure is recommended when possible, which can detect hypoventilation before
the patient's pulse oxygen saturation decreases.
Ventral carbon dioxide partial pressure can be monitored with nasal masks, nasal canals, translaryngeal masks, or tracheal catheters and show dynamic changes in
their patterns.
Due to the influence of (bronch) tracheoscopy and ventilation mode, the end-expiratory carbon dioxide tracography may be irregular
.
Studies have shown that patients with alveolar hypoventilation through carbon dioxide mapping are more sensitive than visual observation, and should be considered in patients with deep sedation or general anesthesia
.

(5) Recovery after anesthesia

1.
The anesthesia recovery room is an important place
to continue to observe the condition after the end of sedation/anesthesia, prevent and treat recent complications after sedation/anesthesia, and ensure patient safety.
Patients who are not awake (including drowsiness) after the end of sedation/anesthesia, or who are awake but are not satisfied with the recovery of muscle tone, should enter the anesthesia recovery room for observation
.

2.
Observation indicators include blood pressure, heart rate, respiration, pulse oximetry and mental state, as well as whether there are complications
such as nausea and vomiting.
If there is a small amount of persistent bleeding from the respiratory tract, the observation time should be extended until the bleeding stops, pending joint evaluation by the (bronchioscopy) practitioner and anesthesiologist before leaving the hospital
.

3.
Strict monitoring to ensure that no bed crash occurs.

4.
Exit criteria: Outpatient patients receiving general (bronchiol) tracheoscopy for sedation/anesthesia can use a scoring system to evaluate whether patients can leave the hospital (Table 2
).
In general, if the score ≥ 9, the patient can be accompanied by a relative or friend
.
In the case of hospitalized patients, routine management
is resumed by anesthesia.

Table 2 Scale of sedation/post-anesthesia dismissal scores

5.
Inform the patient of precautions such as diet, activity, medication and follow-up time, and drink water and eat
after 2h after the end of local anesthesia or 6h after the end of general anesthesia.
Patients are instructed not to drive, sign legal documents or operate machinery and equipment on the same day, and to give written guidance and provide emergency contact numbers
.

Familiarity with the modalities and types of (bronchioscope) diagnosis and treatment is essential
for the successful completion of sedation/anesthesia in such patients.
Anesthesiologists should understand the special diagnosis and treatment of (bronchioscope) and the operation method, and be familiar with the key points
of operation.
It is of great significance
to ensure patient safety that anesthesiologists and operational physicians who perform (bronchioscope) diagnosis and treatment closely communicate before the patient's operation, and maintain communication on airway management and operation process in real time during operation.

(1) Tracheal and bronchial foreign body removal

See "Expert Consensus on Anesthesia for Airway Foreign Body Removal
.
"

(ii) (bronchial) tracheoscopy ultrasonography and/or biopsy

(bronchial) surface tissue biopsy can be performed
under direct view.
Subsurface (bronchial) tumors may require biopsy under ultrasonic localization, especially when the tumor is small, and may require pause for ventilation to minimize local tissue motility and avoid damage to blood vessels, thereby improving the accuracy of needle localization and biopsy positive rate
under ultrasound.
Adequate hemostasis
should be stopped after puncture biopsy.
Therefore, it is advisable to use a laryngeal hood with all intravenous anesthesia to ventilate and avoid coughing and physical reactions
.

(iii) (bronchial) intratracheal tumor ablation

Endotracheal and bronchial tumor ablation typically requires general anesthesia with rigid tracheoscopy, laryngeal hood, or endotracheal intubation, and is indicated for tumors with small tracheal or bronchial surfaces
.
Such tumor resection or peeling is more complex, long-lasting, and requires the use of electric knife, electrocoagulator or laser, etc.
, it is advisable to use all intravenous anesthesia and choose appropriate endotracheal catheters (such as anti-laser catheters).

During the operation, the anesthesiologist needs to closely monitor the inhalation and exhalation oxygen concentration, and control the oxygen concentration below 40% throughout the process to ensure that the patient is not hypoxic to avoid fire
in the airway.
If the patient's intraoperative oxygen saturation decreases and the inhaled oxygen concentration needs to be increased, communication and cooperation
should be maintained with the endoscopist.
Sufficient hemostasis should be stopped before the end of the operation, and severe cough or choking cough should be avoided as much as possible in patients convalescent from anesthesia
.

(4) Placement and removal of tracheal or main bronchial stents

Indications for (bronchial) stent placement mainly include: (1) reconstructions of the lumen of the central airway (including bronchi above the trachea and the bronchi) with organic stenosis; (2) Endotracheal and bronchosomalacia cartilage weakness support; (3) Closure
of trachea, bronchial fistula or fissure.
Tracheal stents may be subject to repeated proliferation of granulation (or tumor tissue) at both ends and in the spaces, or improvement in tracheal compression by tumor tissue after treatment, or successful remodeling of benign narrowed airways, and the stent
may be removed as appropriate.
Patients who need (bronchial) stenting or removal have different degrees of dyspnea and obstructive ventilation disorders, hypoxemia and even respiratory failure due to tracheal obstruction, so the risk and difficulty of sedation/anesthesia and stent insertion and removal are significantly increased
.

The patient's condition, especially ventilation, should be fully evaluated prior to sedation/anesthesia
.
Procedures can be performed under surface anesthesia combined with sedation, or by ventral anesthesia with a laryngeal mask ventilation or directly under rigid tracheoscopy
.
If an electrocauterizer is required for the treatment of (bronchiol) granules, the anesthesiologist should closely monitor the inhalation and exhalation oxygen concentrations, and control the oxygen concentration below 40% or suspend ventilation throughout the process to ensure that the patient is not hypoxiced; If the patient's intraoperative oxygen saturation decreases and the inhaled oxygen concentration needs to be increased, communication and cooperation
should be maintained with the endoscopist.
Bleeding should be stopped adequately before the end of the procedure, and severe coughing or choking should be avoided as much as possible in patients recovering from anesthesia
.

(5) Bronchopulmonary lavage

Bronchopulmonary lavage is often used for the treatment
of alveolar protein deposition and pneumoconiosis.
Bronchopulmonary lavage requires general anesthesia under the premise of isolation of the two-lumen bronchial duct lung
.
The dual-lumen bronchial catheter should be accurately positioned under a fiberoptic bronchoscopy (or visible bilumen tube) with the
cuff well sealed.
The first lavage lesion of the two lungs is more severe than the side lung, and the left lung is lavaged first when the degree of lesion of the two lungs
is the same.
The key to general anesthesia management of bronchopulmonary lavage includes: maintaining appropriate anesthesia depth, deep muscle relaxation, controlling the appropriate amount and speed of lavage, ventilation strategy during bilateral lung transition during double lung lavage, PEEP selection, ventilation time, how to assess lung function after lavage, and anesthesia recovery strategy
.
Attention should be paid to patient insulation
during lavage.
The lavage fluid is warm isotonic saline and prevents leakage of lavage fluid into the contralateral lung
during surgery.
After the completion of lavage, the lavage lungs should be thoroughly attracted, and the small tidal volume lung ventilation and pulmonary retensibility manipulation should be performed to promote the re-expansion
of the lavage alveoli.
Extubation is considered until lavage lung compliance returns to lavage levels
.

(1) Respiratory depression

Respiratory depression is the most common complication of sedation / anesthesia and (bronchial) tracheoscopy diagnosis and treatment, when the apnea or respiratory rate and amplitude decrease or the patient holds breath, there may be a significant decrease in SpO2, at this time the operation should be paused, increase the concentration of inhaled oxygen and use a mask to assist breathing or control breathing, until the patient's breathing returns to normal,_SpO2 rebounds and then
resumes.
If necessary, endotracheal cannels or laryngeal hoods may be inserted to assist or control breathing until the patient's breathing is fully normal
.
If the patient is sedated with benzodiazepines, intravenous antagonist flumazenib
may be considered if necessary.

(2) Spasm of the larynx and (bronchi).

Oral endocrions directly stimulate the throat, and repeated entry of (bronchal) tracheoscopy into the sound gate induces reflexive contraction of the laryngeal muscles, resulting in laryngeal spasms
.
Insufficient anesthesia, high degree of tension or irregular operation techniques and forced stimulation of vocal cords, tracheal walls or injection of drugs and cold saline can cause tracheal or bronchospasm
.
Therefore, it is necessary to ensure a good surface anesthesia effect with an appropriate sedation/anesthesia depth, and closely observe the patient's vital signs
.
Severe laryngeal and bronchospasm occurs and all consultations
should be discontinued immediately.
When laryngospasm occurs, the mask can be pressurized with oxygen to deepen anesthesia and, if necessary, muscle relaxants
.
In case of mild bronchospasm, menstrual pressure can be given to oxygen, bronchodilators and/or intravenous corticosteroids; In severe bronchospasm, if oxygen saturation is difficult to maintain, anesthesia can be deepened and mask positive pressure ventilation can be given, and endotracheal intubation and controlled ventilation if necessary, while bronchodilators and/or intravenous corticosteroids
are given.

(3) Reflux aspiration

In the sedated state, the patient's throat reflex may be suppressed and oral secretions may be inhaled into the trachea
.
Gastrointestinal juice and gastric contents may reflux and aspiration into the respiratory tract, causing aspiration pneumonia
.
Therefore, it is necessary to strictly fast food and drink to prevent reflux aspiration
.
Once vomiting occurs, immediately cause the patient to take a lateral lying position, clasp the back, promptly clean up the vomit in the oropharynx, observe vital signs, especially oxygenation, and if necessary, insert an endotracheal catheter and, if necessary, perform endotracheal irrigation and suction
under (bronchal) endoscopy.

(4) Cardiovascular complications

Sedative/anesthetic drugs, anesthesia procedures, and (bronchial) tracheoscopy procedures may cause sharp fluctuations in the patient's heart rate and blood pressure, and even arrhythmias, cardiac arrest, etc
.
Monitoring should therefore be strengthened and related complications
identified and addressed in a timely manner.

(5) Bleeding

Bleeding is often caused
by airway injury during the procedure.
Therapeutic bronchoscopy carries a higher risk
of bleeding than diagnostic (bronchioscopy).
Light patients can not be treated, bleeding can be more local hemostasis, to ensure oxygenation microscopic hemostasis, severe cases should be intubated bronchial intubation to isolate both lungs, if necessary, interventional or surgical treatment
.
Keep in mind that airway blood buildup, clogged blood clots and other gas exchange disorders are more dangerous
than blood loss itself.
Patients are more likely to die from hemorrhagic asphyxia due to bleeding than with underlying hemorrhagic shock
.
The treatment of airway bleeding should be planned in advance; Full communication with the operating physician should be provided before the procedure begins; When managing bleeding, decisions should be made in a timely and accurate manner to avoid management difficulties
due to delays in decision-making.

(6) Airway burns

Airway burns are mostly caused by fires in the airways, and are often caused by the application of scalpels or laser-guided gas ducts at high concentrations of
oxygen.
In the event of a fire in the airway, all gases should be stopped immediately, the (bronchial) tracheoscopy equipment should be removed, combustible substances (such as tracheal ducts, throat masks, etc.
) in the body should be removed, and physiological saline
should be injected.
After confirming that the flame is extinguished, the mask can be used to re-establish ventilation
.
Airway management equipment (e.
g.
, endotracheal tubes, throat masks, etc.
) should be inspected to assess for debris remaining in the
airways.
Consideration may be given to examining the airway with bronchoscopy, removing foreign bodies, and assessing injuries to determine follow-up
.

(7) Pneumothorax

Mainly seen in tracheal and bronchial foreign body removal and transtracheoscopic forcep biopsy
.
If persistent hypoxemia occurs during or after surgery, chest percussion has been cleared, and breathing sounds are weakened, then vigilance and pneumothorax should be carried out, chest X-ray should be performed, and corresponding treatment should be made after diagnosis, and in severe cases, closed chest drainage
is required.

COVID-19 is primarily transmitted through respiratory droplets, airborne, and contact
.
Combined with the characteristics of bronchoscopy operation and the relevant guidelines or consensus of relevant societies at home and abroad on carrying out (bronchoscopy) diagnosis and treatment during the prevention and control of the COVID-19 infection epidemic, the following points
should be followed when implementing sedation/anesthesia.

(1) Confirmed or suspected COVID-19 is a relative contraindication to (bronchioscopy) diagnosis and treatment; Tracheoscopy should not be used as a routine means
of diagnosing COVID-19.
During the COVID-19 epidemic, on the basis of good protection, it is necessary to limit the number of people in the examination room, and strictly grasp the indications for the diagnosis and treatment of (bronchoscopy), if it is not urgently needed, it is recommended to suspend or delay the diagnosis and treatment
.
Protection standards and equipment are carried out in strict accordance with the requirements of
hospital infection prevention and control.

(2) For ordinary patients, it can be carried out
according to the routine of sedation / anesthesia of (bronchal) tracheoscopy.
Patients who have ruled out COVID-19 infection, who have recovered from COVID-19 (≥ 2 viral tests have been negative and have been released from isolation), or who have recovered from COVID-19 infection are recommended to perform (bronchioscopy) under
sedation/anesthesia.
For people with confirmed or suspected COVID-19 infection, if it is really necessary to perform (bronchioscopy), such as severe airway obstruction and need (bronchiol) tracheoscopy to clarify the cause, rescue treatment such as (bronchial) foreign body or extreme need due to the condition, it should be operated
in a specific negative pressure ward or a well-ventilated separate room.
In order to avoid coughing and spreading of nebulized particles, it is not recommended to inhale local surface anesthetics by nebulization before operation; Intravenous anesthesia, laryngeal hood, or endotracheal intubation are recommended to establish an artificial airway
.
The use of rigid bronchoscopes should be avoided as much as possible, and if necessary, users should avoid the use of open jet ventilation, and it is recommended to use positive pressure mechanical ventilation (closing various openings near the hard mirror, while filling the mouth with gauze bandages to seal the airway gaps around the hard mirror).

Specific practical plans can refer to the Guidelines for Bronchoscopic Diagnosis and Treatment During the Prevention and Control of the Novel Coronavirus Infection in 2019 (Trial)
of the Respiratory Disease Branch of the Chinese Medical Association.

(1) All medical personnel should be vaccinated against hepatitis B and Mycobacterium tuberculosis and, where appropriate, monitor the immune status of the body; For patients with hepatitis B and suspected or confirmed tuberculosis, it is advisable to schedule a test at the end of the day's office
.
For patients with multidrug-resistant Mycobacterium tuberculosis infection or with a high suspicion of TB, healthcare workers must wear advanced anti-particulate masks
.

(2) Medical personnel engaged in (bronchioscope) sedation/anesthesia should receive knowledge training on infection control, instrument cleaning, etc.
, and be familiar with the training system and operating procedures for tracheoscopy room personnel
.
During bronchoscopy, medical personnel should wear protective equipment, including isolation gowns or waterproof aprons, masks, goggles and gloves; When performing bronchoscopy in patients with confirmed or suspected multidrug-resistant Mycobacterium tuberculosis infection, it is recommended that healthcare workers wear a protective mask
.

(3) (bronchial) tracheoscopy diagnosis and treatment operation is an amorphous surgery, so the sedation/anesthesia scheme and ventilation mode are quite different, and the anesthesiologist should flexibly grasp the use of sedation/anesthesia program and ventilation mode
on the basis of this consensus, combined with the type of operation of the (bronchial) tracheoscopy operation, equipment conditions and clinical experience.

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