Unit 1 - Bronchoscopy

Bronchial Thermoplasty

- A nonpharmacologic treatment modality for asthma - Uses thermal energy to reduce the airway smooth muscle, thus minimizing bronchoconstriction - The thermal energy is delivered via the Alair system, which is a radiofrequency catheter

Narrow Band Imaging (NBI)

- A technique that uses specialized filters to separate wavelengths of white light and selectively emits red, green, and blue bands - The intensification of the blue band detects vessel growth and complex vessel networks in the bronchial mucosa; May be useful to detect early malignant lesions

Complications of Transbronchial Biopsy: Pneumothorax

- Adequate sedation and cough suppression are important to reduce this risk - use of fluoroscopy should be used to guide the TBBx - The risk for developing is 3x higher in mechanically ventilated patients * PEEP should be maintained < 5 cmH2O during procedure * chest tube kit made available

The Role of the Respiratory Therapist: Pre-procedure

- Assist in the application of the topical anesthesia to the upper airways - Identify patient and perform pre-procedure "time-out" - Mechanically ventilated patients/bedside bronchoscopy * establish adequacy of the length and the diameter of the artificial airway * ensure a bite-block is in place to avoid equipment damage * adjust ventilator settings for the safety of the procedure while maintaining proper oxygenation

Diagnostic Bronchoscopy

- Begins with the examination of the upper airways: nasal passages, pharyngeal, and laryngeal structures - Next, the lower airways are examined at least until the firth or sixth-generation bornchi; examing bronchi deeper than this depends on the diameter of the bronchoscope - Several different types of specimens can be collected through the working channel of the bronchoscope

Electromagnetic Navigational Bronchoscopy (ENB)

- CT imaging technology combined with an electromagnetic navigation system to guide the biopsy of PPNs that lie beyond the reach of standard flexible bronchoscopy - Low complication rate of bleeding and pneumothorax - Uses low-frequency electromagnetic waves transmitted from a magnetic board placed below that patient's chest; as a result, the lesion can be visualized in real time with computer-generated guidance in three dimensions

Bronchoscopy can be diagnostic and/or therapeutic

- Can inspect the airway - Can remove objects from the airway - Can collect samples from the airway - Can place devices in the airway (airway stents)

The Role of the Respiratory Therapist: Post-procedure

- Determine adequate oxygenation and ventilation and respond to adverse reactions - Disinfect and properly store equipment - Document procedure and relevant details

Endobronchial Stents

- Devices designed for internal splinting of the airway lumen - Help reduce airway obstruction form malignant or benign processes that compress the airway form the outside - Two major types of airway stents are metallic and silicone

Ultra-thin Bronchoscope uses:

- Diagnosing PPNs - Inspecting peripheral airways - Examining the airway beyond a pathologic airway narrowing

Obtaining Specimens: Endobronchial Biopsy (EBBx)

- Flexible forceps are used to obtain a tissue sample from a visible endobronchial lesion - EBBx has been shown to successfully diagnose 51 - 97% of neoplasms - Endobronchial biopsy of a highly vascularized lesion may lead to significant bleeding and must be undertaken with caution. * the physician may take precautions such as instilling ice cold saline or using the transbronchial needle aspiration (TBNA) approach

The Procedure: Providing Sedations

- Goal is to improve the patient's comfort during the procedure * decrease the changes of the manipulation of the airway causing coughing, hypoxemia, vomiting, bleeding, laryngospasm, and bronchospasm - Conscious sedation is Most common * the patients can respond to verbal stimuli and demonstrat preserved protective airway reflexes * the combination of a benzodiazepine [midazolam (versed) or lorazepam (ativan)] and an opioid (morphine sulfate or fentanyl) has been shown to be safe and effective

Flexible Bronchoscopy

- Has become a standard procedure because of its diagnostic value, safety, and ease of performance - The procedure can be done in an outpatient setting, under local anesthesia and moderate (or conscious) sedation

The Role of Respiratory Therapist: Pre-procedure

- Help identify potential need for a bronchoscopy - Verify physician's order or protocol and review medical record for contraindications - Prepare/ensure proper function of equipment - Outline plan for adequate oxygenation during the procedure - Evaluate patient for bronchospasm and administer aerosolized bronchodilators if needed

Bronchoscopy during Mechanical Ventilation - Discuss the possible causes and interventions of:

- High peak pressure alarm and pressure cycling - Intrinsic PEEP - Leaks leading to VT loss - Hypoxemia - Acute Hypercarbia and Acidosis - Heart rate changes and cardiac arrhythmias - Alterations in BP and cardiac output

Complications of BAL

- Hypoxemia is common - its severity generally depends upon three factors: * the volume of fluid administered * the number of segments lavaged * the duration of the procedure - O2 supplementation during BAL may mitigate the degree of O2 desaturation

TNBA Guided by Ultrasound: Endobronchial Ultrasound (EBUS)

- Improved the accuracy of TBNA dramatically - EBUS is essentially a bronchoscope with a linear ultrasound probe attached at its distal end and provides real-time ultrasonographic guidance for TBNA of target structures - In patients with potentially operable lung cancer, the diagnostic accuracy of EBUS-TBNA is far superior (98% accuracy) to either PET or CT scans of the chest - Can provide adequate tissue for genetic analysis - May also be used to restage lung cancer after chemotherapy

The Role of the Respiratory Therapist: During the Procedure

- Monitor patient during the procedure, including capnography (if available) - Help identify and respond to adverse reactions - Administer adequate amount of supplemental oxygen throughout the procedure - Provide proper positioning of the patient to maintain patency of the upper airways - Assist use of endobronchial accessories - Attend to emergent situations

Thermal Ablation of the Endobronchial Lesion

- Newer modalities used to coagulate, carbonize, or vaporize lesions that protrude into the airway lumen and obstruct the central airways - These modalities increase the temperature of the tissue

Bronchoscopy in Difficult intubations Limitations:

- Operator inexperience - Patient cooperation

Thermal Ablation Complications

- Perforation of the airway, vascular structures, or esophagus - Hypoxemia, pheumothorax, bronchopleural and bronchoesophageal fistulas

EBUS-TBNA complications

- Pneumomediastinum - Pneumothorax - Mediastinitis - Bacteremia - Rarely, death

Monitoring during the Procedure

- Pulse ox, heart rate, and blood pressure are monitored throughout the procedure - One of the most difficult parameters to monitor is the depth of sedation * keep track of the patient's responses to verbal commands or spontaneous movements * assess chest movement * the ASA also recommends capnography monitoring

Thermal Ablation Contraindicatins

- Refractory hypoxemia - Extrinsic compression of the airway without an endobronchial lesion

Two techniques of Bronchoscopy

- Rigid (only done in the OR) - Flexible (most common)

Complications of Transbronchial Biopsy: Bleeding

- Risk Factors: * renal insufficiency * pulmonary hypertension * thrombocytopenia * medications: TBBx can be safely performed in patients who are receiving aspirin or nonsteroidal inflammatory drugs; antithrombotic and anticoagulant therapies should be withheld for a specific period before TBBx - Treatment: cold saline; can wedge bronchoscope to stop the bleeding temporarily

Bronchoscopy in Difficult Intubation

- The ETT is placed over the FB, the vocal cords are visualized, and the ETT is then advanced into the trachea - Allows for awake intubations with topical anesthesia - It is useful in patients with cervical injuries, in which immobilization of the neck is crucial

Ultra-thin Bronchoscope

- The diameter of the adult FB is ~6mm; reaches the 4th or 5th order bronchi - The ultra-thin bronchoscope is ~2.8 mm in diameter; reaches up to the 8th order bronchi

Rigid Tube Bronchoscopy

- The rigid bronchoscope is an open metal tube with a distal light source and a part for attaching oxygen or ventilating equipment - The large internal diameter of this suction tube allows for aspiration of thick secretions and large mucus plugs - Grasping forceps passed through the device allows removal of foreign bodies and biopsies of airway tumors

Obtaining Specimens: Transbronchial Needle Aspiration (TBNA)

- The technique that allows sampling tissue form the mediastinum or the peripheral lung by inserting needles through the bronchial walls - TBNA can be used to determine the cause of mediastinal lesions and PPNs in a minimally invasive fashion

BAL Technique

- To minimize contamination, avoid suction while inserting the FB through the nasopharynx and central airways - The amount of lidocaine used should be minimized * prevents its bacteriostatic properties from interfering with BAL fluid cultures * avoids altering the cellular contents of the lavage fluid - The right middle lobe or left lingula is generally used to perform BAL in patients with diffuse disease - In localized lung diseases, lavage is performed from the area of the focal abnormality

BAL procedure

- To obtain the lavage fluid, the bronchoscope is wedged at the level of fourth or fifth-generation bronchus - Fluid is instilled into the appropriate bronchial segment and aspirated back manually for laboratory testing * 15 to 20 mL of BAL volume is enough to conduct lab test

Obtaining Specimens: Bronchoalveolar Lavage (BAL)

- Used to obtain specimens from the alveolar level of the lung - Performed by instilling NS solution (up to 50mL) deep into the airways and then suctioning the instilled liquid back - BAL fluid contains both cellular and non-cellular components of the alveolar lining fluid

Obtaining Specimens: Bronchial Washings

- Uses: * cytologic examination for cancer * microbiologic analysis to diagnose mycobacterial or fungal infections - Unlike BAL, bronchial washings are obtained from the Large Airways - Easy to perform, but not very effective in diagnosing malignancy; 22 to 29% success rate for peripheral lesions

Disadvantages of Rigid Tube Bronchoscopy

- Very uncomfortable for conscious patients - Usually requires assistance of an anesthesiologist and the use of an operating room - Cannon access the smaller airways

Mini-BAL

- a non-bronchoscopic BAL - most frequently performed on intubated patients with use of a catheter - Mini-BAL is a simple procedure for acquiring quantitative lower airway cultures in mechanically ventilated patients

Obtaining Specimens: Transbronchial Biopsy (TBBx)

- a technique of obtaining a specimen of the lung parenchyma by using flexible forceps - TBBx can be performed with or without fluoroscopic guidance (x-ray video)

Flexible Bronchoscopy Procedure

- can be performed on spontaneously breathing patients via the oral or the nasal route and occasionally through a tracheostomy stoma - FB can also be done on patient with artificial airways - most procedures are performed under moderate or deep sedation; when deep sedation is used, an advanced airway needs to be placed - rigid bronchoscopy is performed under deep sedation with muscle relaxation

Obtaining Specimens: Bronchial Brushings

- involves brushing the surface of the suspicious lesion back and forth 5-10 times while rotating the handle - much more accurate than washings - once the specimen is collected, the cells are smeared onto a slide and the end of the brush is cut off and placed in a fixative solution for cytologic examination

Absolute Contraindications to Flexible Bronchoscopy:

- refractory hypoxemia - lack of patient cooperation - lack of skilled personnel - lack of appropriate equipment and facilities - unstable angina - uncontrolled arrhythmias - increased intracranial pressure - uncorrectable bleeding diatheses

Relative contraindications to flexible bronchoscopy:

- unexplained or severe hypercarbia (increased CO2) - uncontrolled asthma attack - lack of patient cooperation - uncorrected coagulopathy - recent myocardial infarction - unstable cervical spine and impaired neck mobility - need for large tissue specimen

Flexible Fiberoptic Bronchoscopy (FB)

- uses fiberoptic bundles to illuminate the endobronchial tree - most modern FBs use video technology

Cryotherapy

A method of destroying tissue by freezing and thawing it

Brachytherapy

A method to deliver short distance radiation therapy - Involves temporary placement of encapsulated radioactive sources within or near the tumor - Advantage: a higher dose of radiation can be delivered to the tumor cells while minimizing radiation to the normal tissue - Indicated in patients with inoperable lung cancer or cancer metastatic to the airways

Thermal Ablation Techniques: Argon plasma coagulation (APC)

A non-contact technique to apply electric current to the endobronchial lesion

Thermal Ablation Techniques: Laser photocoagulation

Lasers can produce tissue reaction by thermal, photochemical, or electromagnetic effects

Major indication for Rigid Tube Bronchoscopy:

Managing central airway obstruction

Thermal Ablation Techniques: Endobronchial electrocautery

Requires use of accessories such as knives, snares, or probes

The Procedure: Applying local Anesthetic to the Airway

Techniques are used: - ~10mL of 2% viscous lidocaine, "swish and swallow" - Nebulizing 5 mL of 4% lidocaine - Nasal passage is anesthetized using 5 mL of 2% lidocaine jelly - instillation of 1-2% lidocaine directly into the lower airways through the bronchoscope in 2mL aliquots during the procedure The drug lidocaine has a very narrow therapeutic range - to help avoid unwanted hazards such as methemoglobinemia, the total dose of lidocaine should be limited to 5 to 7 mg/kg in adults

Assessing the Airway Prior to the Procedure

The Mallampati classification is used to identify individuals who may pose difficulty during intubation - assessed by having the patient open his or her mount and protrude the tongue as much as possible without phonation

Assessing the Patient Prior to the Procedure: Comorbidities

The recommendation from the American Society of Anesthesiologist (ASA) is to categorize patients based on their ASA score: - I : a normally healthy patient - II : a patient with mild systemic disease - III : a patient with systemic disease that is not incapacitating - IV: a patient with an incapacitating systemic disease that is a constant threat to life - V : a patient who is not expected to survive for 24 hours with or without operation

Bronchoscopy

one of the most common procedures performed in pulmonary medicine