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Oxygen
Gas necessary for energy production
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Carbon Dioxide
Waste product of the body's metabolism
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Respiration
The exchange of gases between a living organism and it environment
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Important Airway Anatomy
- NASAL CAVITY
- -Superior, middle and inferior turbinates
- -Hard and soft palates
- NASOPHARYNX
- -Tonsils/adenoids
- -Uvula
- LARYNGOPHARYNX
- -Vallecula
- -Epiglottis
- LARYNX
- -Esophagus
- -Trachea
- -Glottic opening
- -Vocal cords
- -Thyroid cartilage
- -Cricothyroid membrane
- -Cricoid cartilage
- -Thyroid gland
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Upper Airway Components
- Nasal cavity
- Oral cavity
- Pharynx
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Septum
Cartilage that seperates the right and left nasal cavities
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Sinus
Air cavity that conducts fluids from the eustacian tuves and tear ducts to and from the nasopharynx
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Eustacian Tubes
A tube that connects the ear with the nasal cavity
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Nasolacrimal Ducts
Tubular vessels that drain tears and debris from the eyes into the nasal cavity
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Muscous Membrane
Lining in body cavities that handle air transport. Usually contains small, mucus secreting cells
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Mucus
Slippery secretion that lubricates and protects airway surfaces
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Pharynx
A muscular tube that extends verticalls from the back of the soft palate to the superior aspect of the esophagus
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Regions of the Pharynx
- Nasopharynx
- Oropharynx
- Laryngopharynx
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Gag Reflex
Mechanism that stimulates retching or striving to vomit when the soft palate is touched
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Vallecula
Depression between the epiglottis and the base of the tongue
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Intubation
Passing a tube into a body opening
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Larynx
The complex structure that joins the pharynx with the trachea
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Glottis
Liplike opening between the vocal cords
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Cricoid Pressure
Pressure applied in a posterior direction to the anterior cricoid cartilage. Occludes the esophagus
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Aspiration
Inhaling foreign material such as vomitus into the lungs
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Cricothyroid Membrane
Membrane between the cricoid and thyroid cartilages of the larynx
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Lower Airway Components
- Trachea
- Bronchi
- Alveoli
- Lung parenchyma
- Pleura
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Trachea
10-12 cm long tube that connects the larynx to the mainstem bronchi
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Bronchi
Tubes from the trachea into the lungs
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Alveoli
Microscopic air sacs where lost oxygen and carbon dioxide gas exchanges take place
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Atelectasis
Alveolar collapse
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Parenchyma
Principal or essential parts of an organ
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Pleura
Membranous connective tissue covering the lung
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Pediatric Airway
- Narowest point is the cricoid cartilage
- Greater proportion of soft tissue
- Larynx more superior and anterior
- Epiglottis rounder and floppier
- Smaller jaw
- Loosely attached mucous membranes
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Ventilation
The mechanical process that moves air into and out of the lungs
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Normal Adult Tidal Volume
500 mL
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Air Contains
- 20.94% Oxygen
- 79.01 % Nitrogen
- 0.04% Carbon Dioxide
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Partial Pressure
The pressure exerted by each component of a gas mixture
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PA
Alveolar partial pressure
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Pa
Arterial partial pressure
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Diffusion
Movement of a gas from an area of higher concentration to an area of lower concentration
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Factors Effecting SpO2
- Decrease hemoglobin
- Inadequate alveolar ventilation
- Decreased diffusion across the pulmonary membrane (COPD, Pneumonia, Edema)
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Hypoventilation
Reduction in breathing rate and depth
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Pneumothorax
Accumulation of air or gas in the pleural cavity
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Hemothorax
Accumulation of blood or fluid containing blood in the pleural cavity
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Pulmonary Embolism
Blood clot that travels to the pulmonary circulation and hinders oxygenation of the blood
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FiO2
Concentration of oxygen in inspired air
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Factors Effecting CO2 in the Blood
Hypercarbia/Hypocarbia
- Hyperventilation lowers
- Fever raises
- Muscle exertion raises
- Shivering raises
- Metabolic processes raise
- Respiratory depression by drugs
- Airway obstruction
- Impairment of respiratory muscles
- COPD, etc.
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Hypercarbia
Excessive CO2 in the blood
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Respiratory Rate
Number of times a person breaths in 1 minute
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Main Respiratory Center
Medulla
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Hering-Breuer Reflex
Stretch receptors in the lung which prevent overinflation when inhaling
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Chemoreceptors
- Located in medulla and other periphal locations
- Stimulated by decreased PaO2, increased PaO2 and decreased pH
- Cerebral spinal fluid pH is the primary control of respiratory center simulation
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Hypoxemia
Decreased partial pressure of oxygen in the blood
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Hypoxic Drive
Mechanism that increases respiratory stimulation when PaO2 falls and inhibits respiratory stimulation when PaO2 climbs
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Respiratory Rate Factors
- Fever, Emotion, Pain, Hypoxia, Acidosis, Simulant drugs- increase rate
- Sleep, depressant drugs- decrease rate
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Total Lung Capacity (TLC)
Maximum lung capacity- approx 6 liters for adult male
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Tidal Volume (Vt)
Average volume of gas inhaled or exhaled in one cycle- approx 500 mL in adult male
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Minute Volume (Vmin)
Amount of gas inhaled and exhaled in 1 minute
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Upper Airway Obstruction
An interference with air movement through the upper airway
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Causes of Airway Obstruction
- Tongue- #1 cause
- Foreign bodies
- Trauma
- Laryngeal spasm and edema
- Aspiration
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Extubation
Removing a tube from a body
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ABCs
Airway, breathing, circulation
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Paradoxical Breathing
Asymmetrical chest wall movement that lessens repiratory efficiency
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Flail Chest
Defect in the chest wall that allows a segment to move freely, causing paradoxical chest motion
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Cyanosis
Bluish discoloration
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Dyspnea
An abnormalitity of breathing rate, pattern or effort
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Hypoxia
Oxygen defficiency
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Anoxia
The absence or near-absence of oxygen
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Pulsus Paradoxus
Drop in blood pressure greater than 10 torr during inspiration
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Kussmaul's Respirations
Deep, slow or rapid, gasping breathing, commonly found in diabetic ketoacidosis
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Cheyne-Stokes Respirations
Progressively deeper, faster breathing alternating gradually with shallow, slower breathing, indication brainstem injury
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Biot's Respirations
Irregular pattern of rate and depth with sudden, periodic episodes of apnea, indicating increased intracranial pressure
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Central Neurogenic Hyperventilation
Deep, rapid respirations, indicating increased intracranial pressure
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Agonal Respirations
Shallow, slow, or infrequent breathing, indicating brain anoxia
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Respiratory Distress Sounds
- Snoring-results from partial obstruction of upper aiway by tongue
- Gurgling- results from the accumlation of blood, vomitus or other secretions in the upper airway
- Stridor- a harsh, high-pitched sound heard on inhalation, associated with laryngeal edema or constriction
- Wheezing- a musical, squeaking, or whistling sound heard in inspiration and/or expiration, associated with bronchiolar constriction
- Crackles (Rhales)- a fine, bubbling sound heard on inspiration, associated with fluid in the smaller bronchioles
- Rhonchi- a coarse, rattling noise heard on inspiration, associated with inflammation, mucus, or fluid in the bronchioles
- Quiet- diminished or absent breath sounds
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Compliance
The stiffness or flexibility of the lung tissue
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Pulse Oximetry
A measurement of hemoglobin oxygen saturation in th eperipheral tissues
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Oxygen Saturation Percentage
The saturation of arterial blood with oxygen as measured by pulse oximetry expressed as a percentage
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SpO2 Findings
- 95-100%- normal
- 91-94%- mild hypoxemia
- 86-90%- moderate hypoxemia
- <85%- severe hypoxemia
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Capnography Terms
- Capnometry- Measurement of expired CO2. Provides numerical display of the partial pressure of CO2 in torr or %
- Capnography- Capnography is a graphic recording or display of the capnometry reading over time
- Capnograph- Device that measures expired CO2 levels
- Capnogram- Visual representation of expired CO2 waveform
- End-tidal CO2- Measurement of the CO2 concentration at the end of expiration
- PETCO2- Partial pressure of the end-tidal CO2 in mixed gas solution
- PaCO2- Represents the partial pressure of CO2 in the arterial blood
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Capnogram Phases
- Phase I- Baseline. Flat when no CO2 is present and corresponds to the late phase of inspiration and early part of expiration
- Phase II- Respiratory upstroke. Reflects appearance of CO2 in alveoli
- Phase III- Respiratory plateau. reflects airflow through uniformly ventilated alveoli with nearly constant CO2 level
- Phase IV- Inspiratory phase. Downstroke and returns to baseline.
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Esophageal Detector Device (EDD)
Bulb placed on end of ET tube to confirm placement. Squeeze then apply. If it returns to normal indicates correct placement.
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Nasopaharyngeal Airway
Uncuffed tube that follows the natural curvature of the nasopharynx
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French
Unit of measurement approximately equal to one-third millimeter
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Oropharyngeal Airway
Semicircular device that follows the palate's curvature
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Beck Airway-Airflow Monitor (BAAM)
Used for blind nasotracheal intubations to confirm tube placement. Whistles when patient exhales
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ET Intubation Equipment
- Laryngoscope (Handle and blade)
- Endotracheal tube
- 10 mL syringe
- Stylet
- Bag-valve mask
- Suction device
- Bite block
- Magill forceps
- Tape or tube-holding device
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Burden Nasoscope
Hearing device used to confirm tube placement in blind nasotracheal intubation
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Laryngoscope
Device used for lifting the tongue and epiglottis in order to see the vocal cords
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Miller Blade
Straight blade
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Endotracheal Tube (ETT)
Tube passed into the trachea to protect and maintain the airway and to permit medication administration and deep suctioning
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Stylet
Plastic covered metal wire used to bend the ETT in order to guide it easier into the trachea
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Magill Forceps
Scissor style clamps with circular tips
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Indications for ET Intubation
- Respiratory or cardiac arrest
- Unconciousness or obtusion without gag reflex
- Risk of aspiration
- Obstruction due to foreign bodies, trauma, burns or anaphylaxis
- Respiratory extremis due to disease
- Pneumothorax, hemopneumothorax with respiratory difficulty
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Advantages of ET Intubation
- Isolates trachea
- Impedes gastric distention
- Eliminates mask seal
- Offers direct route for suctioning
- Permits medication administration
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Disadvantages of ET Intubation
- Required considerable experience and training
- Requires specialized equipment
- Requires direct visualization of vocal cords
- Bypasses upper airway's functions of warming, filtering and humidifying inhaled air
- Can lead to disease transmission
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Complications of ET Intubation
- Equipment malfunction
- Teeth breakage and soft-tissue lacerations
- Hypoxia
- Esophegeal intubation
- Endobronchial intubation
- Tension pneumothorax
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Rapid Sequence Intubation (RSI)
Giving medications to sedate (induce) and temporarily paralyze a patient to perform ET intubation
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Common Paralytic Agents
- Succinylcholine
- Vecuronium
- Atracurim
- Pancuronium
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Nasotracheal Intubation
Through the nose and into the trachea. PATIENT MUST BE BREATHING
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Indications for Nasotracheal Intubation
- Possible spinal injury
- Clenched teeth preventing opening of the mouth
- Fractured jaw, oral injuries or recent oral sugery
- Significant angioedema (facial and airway swelling)
- Obesity
- Arthiritis preventing placement in sniffing position
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Contraindications for NT Intubation
- Nasal fractures
- Basilar skull fractures
- Deviated septum or nasal obstruction
- Cardiac or respiratory arrest
- Unresponsive patient
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Advantages of NT Intubation
- Patient head can remain in position
- Does not produce as much gag reflex
- Can be secured more easily than oral tube
- Patient cannot bite the tube
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Disadvantages of NT Intubation
- More difficult and time consuming
- Potentially more traumatic
- Tube may kink or clog more easily
- Greater risk of infection
- Improper placement is more likely
- Requires patient be breathing
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Intubation Devices
- Endotracheal Tube (ETT)
- Esophogeal Tracheal Combitube (ETC)
- Laryngeal Mask Airway (LMA)
- Pharyngeal Lumen Airway (PtL)
- Esophegeal Gastric Tube (EGTA)
- Esophageal Obturator Airway (EOA)
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Needle Crichothyrotomy
Surgical airway technique that inserts a 14-gauge needle into the trachea at the thyroid membrane
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Open Crichothyrotomy
Surgical airway technique that places and ET or tracheostomy tube directly into the trachea through a surgical incision made at the crichothyroid membrane
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Stenosis
Narrowing or constriction
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Barotrauma
Injury caused by pressure within a closed space
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Difficult Airway
Clinical situation where a paramedic has difficulty with mask and/or ET intubation
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Mallampati Classification
- Four class level airway assessment for use in conscious patients defined by the ability to visualize all, part or none of the tonsillar pillars and/or the uvula
- Class 1: Entire tonsil clearly visible
- Class 2: Upper half of tonsil fossa visible
- Class 3: Soft and hard palate clearly visible
- Class 4: Only hard palate visible
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Cormack and LeHane Classification System
- Four grade level airway assessment for use in unconscious patients, defined by the ability to visualize all, part, or none of the glottic opening and/or the vocal cords.
- Grade 1: Entire glottic opening and vocal cords can be seen
- Grade 2: Epiglottis and posterior portion of glottic opening may be seen with only partial view of vocal cords
- Grade 3: Only epiglottis and (sometimes) posterior cartilages seen
- Grade 4: Neither epiglottis nor glottis seen
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POGO Classification System
Airway assessment used by some EMS personnel to rate the percentage of glottic opening (POGO) one can visualize from 0% to 100%
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High-Pressure Regulator
Regulator used to transfer oxgen at high pressures from tank to tank
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Therapy Regulator
Pressure regulator used for delivering oxygen to patients
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Nasal Cannula
Catheter placed at the nares
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Venturi Mask
High-flow face mask that uses a Venturi system to deliver relatively precise oxygen concentrations
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Ventilation Methods
- Mouth-to-mouth/mouth-to-nose
- Mouth-to-mask
- Bag-valve mask
- Demand valve device
- Automatic transport ventilator
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