Bronchoscopy, Sputum Induction & Sleep Studies
Objectives - Differentiate diagnostic and therapeutic bronchoscopies, identify required bronchoscopy equipment, perform sputum induction, and compare common sleep disorder tests.
Bronchoscopy
Definition
Bronchoscopy is a method for directly visualizing pathologic changes in the trachea and bronchi.
Diagnostic Bronchoscopy
Diagnostic bronchoscopy may be performed for:
- Suspicion of bronchogenic carcinoma
- Abnormal chest X-ray, such as a mass
- Symptoms such as wheezing, cough, chest pain, or dyspnea
- Positive sputum cytologic findings
- Hemoptysis
Hemoptysis can be caused by several conditions:
| Cause group | Examples |
|---|---|
| Most common causes | Chronic bronchitis and bronchiectasis |
| Second most common causes | Bronchogenic carcinoma and tuberculosis |
| Other possible causes | Pulmonary infarction, pulmonary hypertension, pneumonia, sarcoidosis, and lung abscesses |
Therapeutic Bronchoscopy
Therapeutic bronchoscopy may be performed for:
- Removal of foreign bodies
- Aspiration and removal of thick secretions
- Administration of localized medications
- Selective lavage, such as BAL
Contraindications & Hazards
Relative Contraindications
Relative contraindications include:
- Patient unable to cooperate
- Tracheal obstruction or uncontrolled asthma
- Cardiovascular instability
- Moderate to severe hypoxemia
Absolute Contraindications
Absolute contraindications include:
- Absence of signed consent
- Absence of experienced personnel
- Lack of emergency equipment
- Inability to adequately oxygenate
Hazards
Hazards include:
- Hemorrhage
- Pneumothorax
- Hypoxemia
- Cardiac arrhythmia
- Bronchospasm or laryngospasm, especially in asthmatic patients
- Reaction to topical anesthesia
Hemorrhage and pneumothorax account for the majority of deaths associated with bronchoscopy.
Bronchoscopy Equipment
Core equipment includes:
- Fiberoptic bronchoscope with a light source
- Bronchoscopy cart with necessary supplies
- Suction, either portable or wall suction
- Crash cart
- Oxygen
- Pulse oximeter and/or EKG monitor
Medications
Medication supplies may include:
| Medication | Use |
|---|---|
| Atropine | Reduces salivation, bronchial secretions, and vasovagal reflex |
| Versed or Demerol | Relaxes the patient |
| Romazicon | Reverses Versed if the patient is overmedicated |
| Narcan | Reverses Demerol if the patient is overmedicated |
| Bronchodilator | May be given to patients with asthma to prevent or minimize airway obstruction |
| Sodium chloride solution | Irrigation and injectable solution |
| Lidocaine solutions, 1-10% | Topical airway anesthesia |
| Benzocaine spray | Topical anesthesia |
| Methylene blue | Treats methemoglobinemia from overuse of benzocaine spray |
| Epinephrine 1:1000 | Reduces bleeding |
Topical anesthetic sprays may include:
- Benzocaine spray
- Ceta Caine
- Hurricaine
- Exacta Cain
- Topex
Pre-Procedure Preparation
Before bronchoscopy:
- Consent form should be signed before the procedure.
- Patient should fast for 4-8 hours before the procedure.
- Patients with pulmonary tuberculosis should have 2 weeks of effective chemotherapy before the procedure.
Basic supplies include:
- Syringes and needles to draw up and deliver medication
- Cotton-tipped applicators and 4 x 4 gauze
- Nasal cannula
- Suction canister, tubing, tonsil suction, and sputum traps
Additional supplies depend on the indication for bronchoscopy.
Diagnostic Bronchoscopy Specimens
Diagnostic bronchoscopy may include biopsies and bronchial lavage.
Lavage Specimens
| Specimen type | Handling |
|---|---|
| Microbiology | No solution added |
| Cytology | Saccomanno solution added in a 50-50 mix |
Brush Biopsy
Brush biopsy may be used for pulmonary lesions.
- Protected brush for microbiology is placed in saline solution.
- Cytology brush is spread on slides and placed in a slide holder with Saccomanno solution.
Forceps Biopsy
Forceps biopsy is used to obtain lung tissue, such as tumor specimens.
- Tissue specimen is placed in formalin.
- Transbronchial lung biopsy may be used for diffuse interstitial lung disease.
- Transbronchial lung biopsy is done with fluoroscopy.
- It carries a higher risk of hemorrhaging by the patient.
- The specimen must float, indicating alveolar tissue.
Needle Biopsy
Needle biopsy may use a Wang needle.
The needle is flushed with Hank's solution, a balanced saline.
Foreign Body Removal
Foreign body removal supplies include:
| Device | Use |
|---|---|
| Grasping basket | Two looped wires for retrieval of rounded objects |
| Snare | Single looped wire for retrieval of long, thin objects |
| V-shaped forceps | Removal of thin, flat objects |
| Rat tooth forceps | Removal of flat objects such as coins |
| Alligator jaw forceps | Holding or removing objects |
| Rubber-tipped forceps | Sharp or flat objects such as needles or pins |
| 3-prong forceps | Foreign body removal |
Bronchoscopy Procedure Support
Personal Protective Equipment
Wear proper attire:
- Gown
- Gloves
- Mask
- Goggles
If the patient is suspected of having HIV or hepatitis virus, extra care should be taken, such as using a full-face shield.
If the patient has MTB, a HEPA filter mask is required. The mask is fitted and issued through Bioenvironmental.
Airway Anesthesia
The patient's airways may be anesthetized using several methods:
| Method | Key points |
|---|---|
| Gargling | Lidocaine solution can provide analgesia of the glottis and upper airways |
| Nebulized lidocaine 2% or 4% | Provides analgesia of the upper and lower airways |
| Viscous lidocaine | Applied to nasal passages with a cotton-tipped applicator |
| Dropper instillation | Patient sits erect; mouth and pharynx are sprayed with 1-2% solution; curved adapter instills solution to the base of tongue, epiglottis, vocal cords, and trachea |
| Spray as you go | Lidocaine is instilled through the advancing bronchoscope, usually over the vocal cords, trachea, and carina |
Avoid overuse of benzocaine sprays because it can cause methemoglobinemia. No more than two 2-second sprays are recommended.
During the Procedure
The patient may be placed:
- Supine
- Reclined in a dental chair
Supportive steps include:
- Place the patient on supplemental oxygen, usually 2-3 L.
- Use a transnasal approach most commonly.
- Use a transoral approach when indicated, ensuring a bite block is used.
- Monitor patient status throughout the procedure.
Observe for:
- Topical anesthesia toxicity
- Hypoxemia
- Cardiac arrhythmias
Post-Procedure
After bronchoscopy:
- Patient should not eat or drink for 2 hours.
- Begin with small sips of water.
- Clean and disinfect equipment by placing it in glutaraldehyde for the manufacturer's required time.
- Patients suspected of having AIDS, tuberculosis, or hepatitis may require a higher level of sterilization.
Sputum Induction
Definition
Sputum induction is used to collect fresh, uncontaminated secretions from the tracheobronchial tree.
The goal is achieved when an alert patient is carefully instructed by a trained health care provider, such as an RT, on the proper collection procedure.
Procedure
The patient coughs to produce sputum.
Patients who have difficulty producing a strong productive cough may need hypertonic saline by SVN.
When sputum is produced, the sample is placed in a sterile cup and sent to the medical laboratory for testing.
If the Patient Cannot Produce Sputum
When the patient cannot produce a sample, RTs may perform or assist with:
- Tracheobronchial suctioning
- Bronchoscopic lavage
Tracheobronchial suctioning uses a sterile suction catheter connected to a suction trap, which collects the sputum sample.
Bronchoscopic lavage is performed by a physician during bronchoscopy with RT assistance. The suction device is connected to a suction trap, which collects the sputum sample.
Sleep Disorder Testing Overview
Sleep disorder tests include:
- Polysomnography
- Overnight pulse oximetry
- Ambulatory sleep tests, also called home sleep tests
- Actigraphy
- Multiple Sleep Latency Test, also called a daytime nap study
- Multiple Wakefulness Test
Polysomnography
Definition
Polysomnography, or PSG, is an overnight study required for definitive diagnosis of sleep apnea.
Throughout the night, the sleep technologist monitors the patient for sleep-disordered breathing:
- Diminishing or absent breaths
- No attempt to breathe during sleep
Indications
Polysomnography is indicated for:
- Excessive daytime sleepiness
- Sleep apnea
Sleep apnea means repeated episodes of no airflow for at least 10 seconds during sleep.
| Type | Definition |
|---|---|
| Obstructive sleep apnea | Effort is present but no airflow occurs because of upper airway obstruction |
| Central sleep apnea | CNS fails to signal respiratory effort |
Equipment and Recorded Signals
Several physiologic signals are recorded throughout the sleep study to identify the presence and extent of a sleep disorder.
Signals include:
- EEG for brain waves
- EOG for eye movement
- Chin EMG for teeth grinding
- ECG for cardiac rhythm
- Airflow at the nose and mouth
- Ventilatory effort using inductive plethysmography or piezoelectric belts
- Oxygen saturation by pulse oximetry
If sleep disturbance is present, its severity and cardiopulmonary dysfunction are monitored.
Interpretation
| Finding | Interpretation |
|---|---|
| Obstructive sleep apnea | Respiratory effort detected but no airflow, with or without desaturation |
| Central sleep apnea | No respiratory effort detected and no airflow, with or without desaturation |
| Obstructive hypopnea | Respiratory effort detected with minimal airflow, with or without desaturation |
The apnea-hypopnea index, or AHI, is the number of apneas and hypopneas per hour of sleep.
CPAP/BiPAP Titration
Definition
A titration study is an in-lab sleep study used to calibrate CPAP or BiPAP therapy.
Titrations performed in the sleep lab are ideal for determining the appropriate setting.
CPAP vs BiPAP
| Therapy | Key points |
|---|---|
| CPAP | First-line medical therapy for OSA; after OSA diagnosis, the patient needs a titration study before treatment begins |
| BiPAP | Ideal for patients who require separate pressures for inhalation and exhalation; assists in ventilation and airway splinting |
Auto-Titrating Devices
Auto-titrating devices are also called:
- Auto-CPAP
- Intelligent CPAP
- Smart CPAP
They adjust CPAP levels based on need and monitoring of:
- Snoring
- Hypopneas
- Apneas
Interpretation
Titration should stop all apneic episodes and reduce the number of hypopneas.
It should improve sleep while eliminating breathing-related EEG arousals and micro-arousals.
Patient compliance and comfort are key to CPAP/BiPAP success.
Other Sleep Tests
Overnight Pulse Oximetry
Overnight pulse oximetry uses a small device with a finger probe to measure oxygen saturation levels overnight.
It is used to determine whether treatment, such as CPAP or BiPAP, is effective.
If periodic desaturation is present, the provider may have the patient return for a titration study to overcome apnea or hypopnea.
Ambulatory Sleep Tests
Ambulatory sleep tests are also called home sleep tests, or HSTs.
They are indicated for diagnosis of obstructive sleep apnea.
Equipment is a portable device about the size of a telephone.
Actigraphy
Actigraphy is a non-invasive method of monitoring human rest/activity cycles.
It measures movement of a limb and is worn for a week or more.
Actigraphy may be indicated:
- When polysomnography is not available, to estimate total sleep time in patients with obstructive sleep apnea
- To record circadian rhythms and sleep patterns or disturbances in patients with insomnia and hypersomnia
MSLT and MWT
Multiple Sleep Latency Test
The Multiple Sleep Latency Test, or MSLT, is also called a daytime nap study.
It is indicated for:
- Excessive daytime sleepiness
- Helping diagnose narcolepsy and idiopathic hypersomnia
The full-day test consists of five 15-minute naps separated by 2-hour breaks.
It measures:
- How long it takes the patient to fall asleep
- Whether the patient enters REM sleep
If the patient does not fall asleep within 20 minutes, the nap trial ends.
MSLT Interpretation
| Finding | Interpretation |
|---|---|
| Enters REM sleep two or more times during the MSLT | Narcolepsy |
| Falls asleep quickly but does not enter REM sleep | Idiopathic hypersomnia |
Multiple Wakefulness Test
The Multiple Wakefulness Test, or MWT, measures how alert a patient is during the day.
It can determine whether a person with a sleep disorder is responding well to treatment. It is critical when a person's job involves public transportation or safety, such as pilots.
The MWT consists of four sleep trials with 2-hour breaks between them.
During each trial:
- Patient sits in bed with head supported.
- Patient tries to stay awake as long as possible.
- Trial ends if the patient does not fall asleep within 40 minutes.
- Provider reviews the test to assess the patient's level of daytime sleepiness.
Compare and Contrast
| Test | Indications | Trial structure | Main task | Trial endpoint |
|---|---|---|---|---|
| MSLT | Excessive daytime sleepiness; diagnosis of narcolepsy and idiopathic hypersomnia | Five 15-minute naps separated by 2-hour breaks | Fall asleep; test measures sleep latency and REM entry | If patient does not fall asleep within 20 minutes |
| MWT | Measures daytime alertness; assesses response to treatment | Four sleep trials separated by 2-hour breaks | Stay awake as long as possible | If patient does not fall asleep within 40 minutes |
Review
High-yield points:
- Diagnostic bronchoscopy is used for suspected bronchogenic carcinoma, abnormal chest X-ray, symptoms, positive sputum cytology, and hemoptysis.
- Therapeutic bronchoscopy can remove foreign bodies or thick secretions, administer localized medications, and perform selective lavage.
- Absolute bronchoscopy contraindications include no signed consent, no experienced personnel, no emergency equipment, and inability to oxygenate.
- Hemorrhage and pneumothorax account for most deaths associated with bronchoscopy.
- Benzocaine spray overuse can cause methemoglobinemia; no more than two 2-second sprays are recommended.
- Sputum induction collects fresh, uncontaminated secretions from the tracheobronchial tree.
- PSG is the overnight test required for definitive diagnosis of sleep apnea.
- OSA has respiratory effort without airflow; central sleep apnea has no respiratory effort and no airflow.
- CPAP is first-line medical therapy for OSA, while BiPAP helps patients needing separate inspiratory and expiratory pressures.
- MSLT asks whether the patient falls asleep and enters REM; MWT asks whether the patient can stay awake.