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Bronchoscopy 

Bronchoscopy
Chapter:
Bronchoscopy
Author(s):

Stephen Chapman

, Grace Robinson

, John Stradling

, Sophie West

, and John Wrightson

DOI:
10.1093/med/9780198703860.003.0063
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date: 26 October 2021

Indications and risks

Bronchoscopy is the procedure of passing a telescope or camera into the trachea to inspect the large and medium-sized airways. It may be performed with a flexible scope, using local anaesthetic ± sedation, favoured by physicians, or under a general anaesthetic with a rigid scope, used mostly by surgeons. Airways can be visually inspected, samples taken, and therapeutic procedures can be performed. This chapter focuses on flexible bronchoscopy.

Indications for bronchoscopy

  • Suspected lung cancer Patients who have a central mass <4cm from the origin of the nearest lobar bronchus, which is likely to be accessible for biopsy at bronchoscopy

  • Suspected pulmonary infection, such as TB, in a patient who is unable to produce sputum, or in immunocompromised patients, with fever, cough, hypoxia, or CXR changes (induced sputum with hypertonic saline may be an alternative; see Bronchoscopy p. [link])

  • Suspected ILD if a TBB will provide an adequate sample for diagnostic purposes such as in sarcoid. Only indicated in a limited number of ILD, as more adequate biopsies are often obtained through open lung biopsy, which may be preferable

  • Investigation of haemoptysis

  • Investigation of stridor

  • Foreign body removal if this is located proximally

  • Therapeutic indications include central airway obstruction, sputum plugging, and possibly emphysema (endobronchial lung volume reduction; see Bronchoscopy pp. [link][link]) and asthma (bronchial thermoplasty; see Bronchoscopy p. [link]).

Relative contraindications/take care

  • If a patient has saturations below 90% on air at rest or <8kPa, the risk of significant hypoxia during bronchoscopy is increased

  • FEV1 <40% predicted

  • Blood clotting abnormalities, particularly platelet level <50, 000/mm3

  • Uraemia, PHT, SVCO, liver disease, and immunosuppression predispose to haemorrhage

  • Recent MI may be associated with cardiac ischaemia during bronchoscopy. Wait until 4 weeks after, if possible (otherwise, liaise with cardiology).

Risks associated with bronchoscopy

Flexible bronchoscopy is a safe procedure, with reported mortality rates in large series being 0.01–0.04% and major complications of 0.08–1.1%. Complications include respiratory depression, pneumonia, pneumothorax, airway obstruction, laryngospasm, cardiorespiratory arrest, arrhythmias, pulmonary oedema, vasovagal episodes, fever (especially following BAL), septicaemia, haemorrhage, nausea, and vomiting.

Bleeding and bronchoscopy

  • Significant bleeding occurs in ~0.7% of patients, due to mechanical trauma from the scope, suctioning, brushing, or biopsy, but is more common with TBB (1.6–4.4%). Patients with malignancy, immunocompromise, or uraemia have an increased bleeding tendency

  • If bleeding does not stop spontaneously, retract the bronchoscope proximally to maintain vision, and preserve the airway using suction to remove free blood (but do not disturb clot). 1mL aliquots of 1:10, 000 adrenaline solution are administered via the bronchoscope as near to the bleeding point as possible, until it stops. 5–10mL iced saline may also be useful. If bleeding does not stop, the bronchoscope should be wedged in the segmental bronchus to tamponade the bleeding for 10–15min

  • If massive haemorrhage occurs, the patient should be turned on to the side of the bleeding to protect the other lung. Balloon-tipped vascular catheter may be used to tamponade the bleeding point. If bleeding continues, emergency interventional radiology or thoracic surgery may be indicated.

Further information

Du Rand IA et al. British Thoracic Society guideline for diagnostic flexible bronchoscopy in adults. Thorax 2013;68:i1–i44.Find this resource:

Lee P et al. Therapeutic bronchoscopy in lung cancer. Clin Chest Med 2002;23:241–56.Find this resource:

Bungay HK et al. An evaluation of CT as an aid to diagnosing patients undergoing bronchoscopy for suspected bronchial carcinoma. Clin Radiol 2000;55(7):554–60.Find this resource:

Laroche C et al. Role of CT scanning of the thorax prior to bronchoscopy in the investigation of suspected lung cancer. Thorax 2000;55(5):359–63.Find this resource:

Patient preparation and procedure

Patient preparation

  • Information Patients should be given written information about the procedure, ideally >24h prior to the procedure. Provide an information sheet for the patient to take home following the bronchoscopy, with advice about the effects of any sedation and possible complications, as well as telephone numbers in case help is needed

  • Consent The physician performing the bronchoscopy should obtain written consent, with a description of the procedure and its associated risks

  • Consider stopping anticoagulation Safe to perform if patient is taking aspirin or prophylactic LMWH, but omit clopidogrel for 7 days prior (may require cardiology discussion), and, if on warfarin, wait until INR <1.5 (may require full-dose LMWH on days prior to bronchoscopy for high-risk conditions, e.g. mitral prosthetic metal valve, prosthetic valve and AF, AF and mitral stenosis, <3 months post-VTE, or thrombophilia syndromes)

  • Risks of sedation Consider factors which may make sedation more hazardous (see Bronchoscopy p. [link])

  • Nil by mouth Patients should have no food for 4h beforehand and clear fluids only until 2h beforehand

  • Blood tests Patients do not need routine pre-procedure blood tests, unless there are specific concerns (active bleeding, uraemia, deranged LFTs, low platelets)

  • Bedside tests Perform an ECG in patients with a history of cardiac disease. Check blood sugar in patients with diabetes

  • Prophylactic antibiotics are no longer recommended for the prevention of endocarditis, fever, or pneumonia

  • In those with asthma, a nebulized bronchodilator should be given before the bronchoscopy

  • Those at high risk of infection (TB) should be last on the list.

Procedure

  • Practices vary between centres. Some perform bronchoscopy with the patient sitting up, facing the operator; some from behind, with the patient lying flat

  • IV access should be present in all patients

  • Pulse oximetry ± ECG is monitored throughout. Nasal O2 should be administered if SaO2 falls by 4%

  • Sedatives should be offered to provide conscious sedation (verbal contact possible at all times), anxiolysis, and anterograde amnesia, provided no contraindications (see Bronchoscopy p. [link]). A benzodiazepine, such as midazolam 1–2mg, with 1mg increments as necessary, may be used with fentanyl/alfentanil. Assess and document sedation depth (see Bronchoscopy p. [link]). Some patients and operators prefer not to use sedation, due to concerns particularly in elderly patients, those with COPD, or those with cardiac disease. Midazolam can make some patients more agitated. Premedication with anticholinergics is not beneficial during bronchoscopy

  • Lidocaine Local anaesthetic 2% gel (6mL = 120mg) is applied to the nostrils, and the vocal cords are anaesthetized by three actuations of local anaesthetic spray (10% lidocaine, 10mg/spray) to the back of the throat during inspiration and time allowed to work (~3–5min)

    • Transcricoid injection may be used to administer 1% lidocaine into the trachea, or this may be anaesthetized under direct vision (‘spray-as-you-go’) through the bronchoscope

    • Aliquots of 1% lidocaine may be administered to right and left main bronchi via the bronchoscope when it is passed through the vocal cords into the trachea

    • Maximum dose of lidocaine is unclear, but symptoms of toxicity seen at ≥9.6mg/kg delivered to the airways. Use the minimal dose required for cough suppression. Toxic effects include CNS effects (confusion, blurred vision, euphoria, dizziness, myoclonus, seizures) and cardiovascular effects (arrhythmias, cardiac arrest). Risks increased with renal, hepatic, and cardiac dysfunction (see Bronchoscopy p. [link])

    • The half-life of lidocaine is 1.5–2h

  • Most access the trachea via the nasal route, as this gives increased stability when taking biopsies and allows the patient to cough and spit out secretions more easily. If this is not possible, a mouth guard is used and access obtained through the mouth

  • All sections of the bronchial tree should be visually inspected, including the cords and trachea. CXR or CT may help localize the area of concern, so specimen site can then be targeted. This increases the diagnostic yield of bronchoscopy in cases of suspected lung cancer

  • Avoid unnecessary suction, as this can increase hypoxia.

Sampling techniques

Bronchial washings

are taken by instilling ~10mL of saline and then collecting it in a pot/trap to obtain superficial airway cells.

Bronchial brushings

are taken by inserting a covered brush into a bronchial segment, uncovering it, rubbing the bronchial wall, covering it, removing it, and wiping it on a slide. The slide is then sprayed with a cell fixing solution.

Bronchial biopsies

are taken with biopsy forceps; 5–7 should be taken to optimize yield. These may be taken blindly or from a visibly abnormal area, which gives a higher diagnostic yield than blind biopsies. They can be placed in formalin or saline solution, depending on whether they are for histology or microbiology.

BAL

is performed by instilling 60–180mL of saline through the bronchoscope when it is wedged well in a small airway. Ideally, instill fluid during inspiration, and, after allowing the fluid to dwell for 10–30s, aspirate back into the syringe during expiration or collect in a trap. Best performed in the area of abnormality on CXR or CT or non-dependent lobes such as the right middle lobe or lingula. Poor return if the patient is coughing excessively or if they have emphysema. Can cause hypoxia proportional to amount of lavage fluid used.

TBB

Technique of passing TBB forceps down a terminal bronchus until resistance is first felt and taking a sample of parenchymal tissue. Some perform with radiological screening. One technique is to locate the bronchoscope at segmental bronchus of interest and advance forceps (through working channel) as far as possible. Retract forceps by 1cm; open forceps while patients inhaling slowly, then advance and close forceps while exhaling. Take biopsy (but stop if pain felt, suggesting that forceps have gathered visceral pleura). Repeat 5–6 times.

Associated with a significant risk of bleeding in 9% and pneumothorax in 1–6%, but up to 14% if patient is mechanically ventilated. Half of all pneumothoraces require chest drains. Therefore, perform on one side only, and minimize risk by performing TBB in the lower lobes in dependent segments. Perform CXR after the bronchoscopy if patient symptomatic or clinical suspicion of pneumothorax. Pneumothorax should be managed, according to standard guidelines (see Bronchoscopy pp. [link][link]). Small pneumothoraces often resolve spontaneously, but the patient may need admission if concerns.

TBNA

(see Bronchoscopy p. [link]) is used to sample mediastinal and hilar lymph nodes in suspected malignancy, TB, or sarcoidosis (see Fig. 63.1). It is also useful in sampling extrabronchial masses or necrotic endobronchial tumour. When added to other sampling techniques in lung cancer, it increases the diagnostic yield by 18%.

Fig. 63.1 Mediastinal lymph node stations. Reproduced from Mountain, Clifton, Regional Lymph Node Classification for Lung Cancer Staging, Chest (1997) 111:6 1718-1723, with the kind permission of the American College of Chest Physicians

Fig. 63.1 Mediastinal lymph node stations. Reproduced from Mountain, Clifton, Regional Lymph Node Classification for Lung Cancer Staging, Chest (1997) 111:6 1718-1723, with the kind permission of the American College of Chest Physicians

When performing bronchoscopy

  • Wear gloves, face mask, and eye shields

  • Use particulate (duck) masks if there are concerns about TB or HIV.

Central airway obstruction

(See also section on acute upper airway obstruction, Chapter 50, Bronchoscopy p. [link].)

Central airway = trachea and main stem bronchi.

Obstruction can be:

  • Extrinsic such as tumour pressing on airway causing obstruction

  • Intrinsic such as tumour occluding airway lumen

  • Mixed, a combination of extrinsic and intrinsic.

Symptoms and signs

  • May be asymptomatic if obstruction is mild

  • Productive cough, due to mucosal swelling and mucus production

  • Wheeze, unilateral wheeze, positional wheeze

  • Stridor

  • 2° atelectasis and pneumonia

  • Dyspnoea.

Investigations

  • Flow–volume loops, FEV1

  • CXR—may be normal

  • CT chest + 3D airway reconstruction, if possible

  • Bronchoscopy to make tissue diagnosis of underlying disease.

Treatment

  • Secure airway

  • Consider bronchoscopy—senior physician ± anaesthetist should perform. Bronchoscopy itself can cause obstruction in a compromised airway. Adrenaline administered via bronchoscope may be helpful

  • Consider endobronchial treatment—core out tumour; dilate a stenosis, or place a stent (see Bronchoscopy p. [link])

  • Consider heliox (see Bronchoscopy p. [link]).

Causes of central airway obstruction

  • Malignant

    • 1° endoluminal cancer, especially lung cancer or carcinoid

    • Metastatic cancer

    • Laryngeal cancer

    • Oesophageal cancer

    • Mediastinal tumour

    • Lymphadenopathy, lymphoma

  • Non-malignant

    • Lymphadenopathy

    • Relapsing polychondritis

    • Tracheomalacia

    • Papilloma

    • Hamartoma

    • Amyloid

    • Web

    • Goitre

    • Foreign body

    • Granulation tissue.

Further information

Ernst A et al. Central airway obstruction. Am J Respir Crit Care Med 2004;169:1278–97.Find this resource:

Janssen JP et al. Series: Interventional pulmonology. Eur Respir J 2006;27:1258–71; 28:200–18.Find this resource:

Wood DE et al. Airway stenting for malignant and benign tracheobronchial stenosis. Ann Thorac Surg 2003;76:167–74.Find this resource:

Du Rand IA et al. British Thoracic Society guideline for advanced diagnostic and therapeutic flexible bronchoscopy in adults. Thorax 2011;66:iii1–iii21.Find this resource:

Interventional bronchoscopy 1

Used particularly in the diagnosis and palliative treatment of patients with lung cancer and central airway obstruction due to local tumour growth where the relief of the obstruction will have symptomatic benefits.

Diagnostic procedures

TBNA and EBUS allow mediastinal node sampling without the surgical procedure of mediastinoscopy. Some lymph nodes are accessible for sampling in this way, which cannot be accessed via mediastinoscopy.

TBNA

Technique of inserting a biopsy needle (19–22G) blindly through the bronchial wall into an enlarged lymph node or extrabronchial mass and aspirating cells. Used to give additional staging information in lung cancer. Appropriate lymph nodes should be identified on CT first; stations 2R/L, 3P, 4R/L, 7, 10R/L, and 11R/L are accessible. Should be performed initially, so the bronchoscope is not contaminated with malignant cells from the airway, and start with the highest-stage lymph nodes first. Push sheath out through end of bronchoscope until the hub is just visible. Flex the bronchoscope so that the sheath tip lies between cartilaginous rings, directed towards the node/mass. Extend the needle so that it passes through the bronchial wall, and then apply suction. A ‘to-and-fro’ motion of the needle should allow lymph node ‘goo’ to be aspirated. Subsequently, the suction is stopped; the needle is withdrawn, and the sheath is removed to allow sample preparation. Subcarinal (7) and right lower paratracheal (4R) nodes are the easiest to sample. Aim for 5–7 needle passes. Malignancy sensitivity 39–78%. Complications rare (0.3%): pneumomediastinum, pneumothorax, minor bleeding, puncture of adjacent structures.

EBUS

Technique of visualizing the bronchial wall and the immediate surrounding structures via a convex array ultrasound probe incorporated into the tip of the bronchoscope. A balloon surrounding the probe is inflated with water, in order to achieve close circular contact and view surrounding structures. Useful to assess lymph node involvement in malignancy and for real-time guided TBNA. Possible to sample nodes ≥4mm in short axis. Mediastinal structures or masses next to the airways can be identified, the depth of bronchial wall tumour invasion assessed, or masses within the lung localized for biopsy. Malignancy sensitivity 88–100%. Oesophageal endoscopic ultrasound (EUS) is an alternative strategy, which allows examination of the posterior and inferior mediastinum (particularly useful for stations 8 and 9), the liver, the coeliac axis, and the left adrenal gland. It is more accurate at diagnosing mediastinal metastases than CT and PET.

Autofluorescent bronchoscopy (AFB)

Technique to differentiate central malignant areas from normal tissue, including dysplasia and pre-invasive tumours in situ. However, the progression of these abnormalities is not known, so the role of AFB is unclear. Used in conjunction with usual white light bronchoscopy. Uses blue light to induce tissue autofluorescence, which means normal and abnormal tissues appear different colours when viewed through a specialized bronchoscope. Airway trauma, however, can also cause a different mucosal appearance, and the test has low specificity. It is being used in some centres as a surveillance tool following surgical resection of lung cancer, or in patients with head and neck cancer suspected of having a lung 1°, or following positive sputum cytology. Its role is not, however, clear, and advances in standard white light bronchoscopes (such as using narrow band imaging) may be found to be as good at identifying abnormal mucosa.

Rigid bronchoscopy

Visualizes bronchial tree to level of segmental bronchi. Can remove or core out endobronchial tumours, insert a stent, dilate tracheal or bronchial stenosis, and manage massive haemoptysis. Useful to provide information regarding resectability in lung cancer by measuring airway length. Incidence of serious complications <5%: hypoxia, laryngospasm, pneumothorax, bleeding.

Interventional bronchoscopy 2

Therapeutic procedures

Bronchial laser resection, electrocautery, argon–plasma coagulation (APC), photodynamic therapy (PDT), and cryotherapy/cryoextraction

These are all procedures that can be used to debulk obstructing endobronchial lesions or coagulate a bleeding point. The use of an LMA or uncuffed endotracheal tube is recommended to achieve airway control. Electrocautery is the use of a high-frequency electrical current via a probe/snare/needle knife to heat tissue, causing coagulational vaporization, which enables cutting. Nd-YAG Laser achieves the same effect. APC is a non-contact method of electrocautery, using argon gas which causes desiccation and coagulation. These are all effective immediately. These are used predominantly for obstructing malignant lesions but may be used to remove benign lesions, e.g. papilloma, or to treat benign stenoses, e.g. due to intubation, sarcoidosis, granulomatosis with polyangiitis, trauma, etc. Avoid using FiO2 >0.4 with laser, electrocautery, and APC to minimize the fire risk. Shave skin on thigh, if necessary, before placing electrode for electrocautery, and avoid placing it over metal prosthetic joints. Cryotherapy/cryoextraction is the technique of repeatedly freezing and then thawing an area with a probe in order to destroy tissue such as an endobronchial obstructing lesion. Standard cryotherapy takes hours to days to have its effects, while cryoextraction allows the bronchoscope and cryoprobe to be removed, complete with attached tumour tissue. It can also be used to remove a foreign body, as freezing attaches foreign body to the end of the probe.

PDT IV

administration of a photosensitizer drug to the patient (selectively concentrated in tumour tissue), followed 48h later by bronchoscopic exposure of the presensitized tumour to a laser light of specific matching wavelength in order to cause tumour necrosis. Airways cleared of debris immediately after and again a few days later. Skin remains light-sensitive for 8 weeks.

Tracheobronchial stent insertion

via the bronchoscope to re-establish airway patency following endobronchial debulking or if there is extrinsic compression. Self-expanding metal airway stents (SEMAS) used in cases of external compression, such as lung cancer, for palliation of breathlessness. Length, diameter, and type of stent need careful selection prior to procedure using CT. Both uncovered stents (for extrabronchial lesions) and covered stents (for tumours with an endobronchial component) are available. These are inserted over a guidewire with flexible bronchoscopic visualization. Repositioning can be tricky after placement. Complications include stent migration or fracture, haemorrhage, mucus impaction, development of granulation tissue, bronchospasm, and even death. Silicone stents are used in mainly benign disease and are inserted via rigid bronchoscopy. They are easily removed and manoeuvred but can migrate and lead to problems with retained secretions.

Brachytherapy

Procedure of endobronchial irradiation using iridium-192 via bronchoscope for endobronchial and intramural tumours. A blind-ending catheter (the applicator) is placed within or alongside a tumour, and the bronchoscope is then removed over a long guidewire, which is then replaced by a radio-opaque graduated metal insert. CXR of the insert is used to plan placement of the radioactive source within the applicator. Treatment occurs over a few minutes. Delayed effect, requires several sessions. Complementary to other bronchoscopic therapies. Can cause radiation bronchitis, stenosis, and haemorrhage.