Continuous Positive Airway Pressure (CPAP)
Washington State Department of HealthEMT Basic Curriculum
Developed by:Lynn Wittwer, MD, MPD
Marc Muhr, EMT-PTJ Bishop, EMT-PClark County EMS
Keith Wesley, MD, EMS Medical DirectorState of Wisconsin
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CPAP Curriculum – EMT Basic
Introduction
Review of Anatomy and Physiology
CPAP Overview
Pulse Oximetry
Review of Respiratory Distress
Treatment With CPAP
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What is CPAP?
Continuous Positive Airway Pressure (CPAP)
A non-invasive alternative to intubation
Does not require any sedation
It provides comfort to the patient with acute respiratory distress by reducing work of breathing
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Why CPAP?
Respiratory Distress is a common reason why people call 911!
Established therapeutic alternative
Easily applied, easily discontinued
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Key Points of CPAP
CPAP has been successfully demonstrated as an effective adjunct in the management of a variety of respiratory distress states.
CPAP may prove to be a viable alternative in many patients previously requiring endotracheal intubation by prehospital personnel.
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CPAP vs. Intubation
CPAP– Non-invasive– Easily discontinued– Easily adjusted– Use by EMT-B– Does not require
sedation– Comfortable
Intubation– Invasive– Usually don’t
extubate in field– Potential for
infection– Requires highly
trained personnel– Can require
sedation– Traumatic
Review of Anatomy & Physiology
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Elements of the Airway
UPPER AIRWAY
Nares
Nasopharynx
Oropharynx
Tongue
Epiglottis/Glottis
Vocal Cords
LOWER AIRWAY
Trachea/Esophagus
Carina
Main stem Bronchi
Secondary Bronchi
Bronchioles
Alveoli
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Upper Airway
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Pharynx
Nasopharynx– Uppermost portion of airway,
just behind nasal cavities– Nasal septum – Vestibule– Olfactory membranes– Sinuses
Oropharynx– Begins at the level of the
uvula and extends down to the epiglottis
– Opens into the oral cavity
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Larynx
Three main functions:– Air passageway between the pharynx and
lungs– Prevents solids and liquids from entering the
respiratory tree– Involved in speech production
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Larynx
An outer casing of nine cartilages– Thyroid cartilage– Cricoid cartilage
Only complete cartilaginous ring in the larynx
– Epiglottis
Hyoid bone
Cricothyroid membrane
Vocal cords
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Lower Airway
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Lungs
Principal function is respiration
Attached to heart by pulmonary arteries and veins
Separated by mediastinum and its contents
Base of each lung rests on the diaphragm
Apex extends 2.5 cm above each clavicle
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Pleural Cavity
A separate pleural cavity surrounds each lung
Two layers (visceral and parietal)
Pleural space
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Respiratory System - Physiology
The respiratory system functions as a gas exchange system
Oxygen is diffused into the bloodstream for use in cellular metabolism
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Respiratory System - Physiology
Wastes, including carbon dioxide, are excreted from the body via the respiratory system
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Ventilation
Ventilation refers to the process of air movement in and out of the lungs
The volume of air moved in each breath is the tidal volume
The volume still remaining in the chest after exhalation is the functional reserve capacity. FRC
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Inspiration and Expiration
Inspiration– Chest wall expands– Lung space increases– Pressure gradient causes gas to flow into the
lungs
Expiration– Chest wall relaxes– Elastic recoil causes thorax and lung space to
decrease in size– Pressure gradient created in thoracic cavity
causes air to move out of the chest
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Pressure Changes During Inspiration and Expiration
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Mechanics of Breathing
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Mechanics of Respiration
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Ventilation
The following must be intact for ventilation to occur:– Neurologic control to initiate ventilation– Nerves between the brainstem and the
muscles of respiration– Functional diaphragm and intercostal muscles– A patent upper airway– A functional lower airway– Alveoli that are functional and not collapsed
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Diffusion
In order for diffusion to occur, the following must be intact:– Alveolar and capillary
walls that are not thickened
– Interstitial space between the alveoli and capillary wall that is not enlarged or filled with fluid
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How does CPAP work
Splints the upper airway preventing collapse
Uses continuous oxygen flow with pressure to push air into the lungs and push the fluid into the bloodsteam
Recruits alveoli that have collapsed
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CPAP Mechanism
Increases pressure within airway.
Airways at risk for collapse from excess fluid are stented open.
Gas exchange is maintained
Increased work of breathing is minimized
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Pulse Oximetry
Basic concept of Pulse Oximetry monitoring.– Objectively determines oxygenation status
when applied correctly.– Measures the hemoglobin saturation in the
bloodstreamvia red and infrared light, through the skin to the arterial bed.
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Pulse Oximetry
Possible invalid readings– Low blood flow states, (i.e., shock states,
hypothermic, hypovolemia) may show an inaccurate low oxygenation percent.
– Carbon monoxide poisoning may show a false high percent reading.
– Anemias and oxygen capacity carrying diseases (i.e., sickle cell) may also show a false high reading.
– Fingernail polish, excessive grease and dirt, nail-tips, or gel nails may cause a false low reading.
Review of Respiratory Distress
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Respiratory DistressWork of Breathing– Respiratory rate greater than 25/minute– The presence of retractions and/or use of
accessory muscles
Appearance = Mental Status– Pulse Oximetry < 94%– Effects of hypoxia and hypercarbia
indistinguishable
Circulation/Skin Color– Severe cyanosis– Pallor and diaphoresis
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Focused History and Physical
Ascertain the patient’s chief complaint that may include:– Dyspnea– Chest pain– Cough
ProductiveNon-productiveHemoptysis
– Wheezing– Signs of infection
Fever, chillsIncreased sputum production
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History
Previous experiences with similar/identical symptomsKnown pulmonary diagnosisMedication history– Current medications– Medication allergies– Pulmonary medications– Cardiac-related drugs
History of the present episodeExposure and smoking history
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Pulmonary Edema – Congestive Heart Failure
Defined– Fluid which collects in the lung tissue and
alveoli
Signs/Symptoms/Assessment– Anxious, Pale, Clammy, Dyspnea, Tachypnea,
Confusion, Edema, Hypertension, Diaphoretic– Rales, Ronchi, Tachycardia, JVD, Pink Frothy
Sputum, Cyanosis
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Pulmonary Edema – Congestive Heart Failure
Signs/Symptoms/Assessment– Fatigue– Nocturia– Dyspnea on exertion– Paroxysmal nocturnal dyspnea– Chest Pain– Orthopnea
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Pulmonary Edema – Congestive Heart Failure
Treatment– Focused history and physical exam– Complains of trouble breathing.
Airway control w/ adequate ventilationOxygenation
– Has a prescribed nitroglycerine available.Consult medical direction.Facilitate administration of nitroglycerine
– Baseline vital signs.– Reassess
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Chronic Obstructive Pulmonary Disease (COPD)
Defined– Lung tissue loses elasticity secondary to
destruction of the alveoli (Emphysema)– Inflammation of the bronchial tree. Diagnosed
by productive cough which lasts at least three months a year for at least two consecutive years (Chronic Bronchitis)
– Any COPD patient may have both
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Chronic Obstructive Pulmonary Disease (COPD)
Signs/Symptoms/Assessment– Exertional dyspnea– Productive cough/wheezing– Minor hemoptysis– Tachypnea/exertional muscle use– Pursed lip exhalation– May have coarse crackles– Accessory muscle use– Hyperexpansion of the thorax (diminished breath
sounds)– Excessive caloric expenditure
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Chronic Obstructive Pulmonary Disease (COPD)
Signs/Symptoms/Assessment– Tachypnea, cyanosis, agitation, tachycardia,
hypertension– Confusion, tremor, stupor, apnea
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Chronic Obstructive Pulmonary Disease (COPD)
Treatment– Focused history and physical exam– Complains of trouble breathing.
Airway control w/ adequate ventilationOxygenation
– Has a prescribed inhaler available.Consult medical direction.Facilitate administration of inhalerRepeat as indicated.
– Baseline vital signs.– Reassess
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Asthma
Defined– Condition which causes the bronchi to
constrict making it difficult to exhale (air trapping)
– May be caused by allergic reactions and/or emotional distress
– The most serious form, status asthmaticus, is a true life-threatening emergency
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Asthma
Signs/Symptoms/Assessment– Dyspnea, chest tightness, wheezing, and
cough– Obvious SOB, wheezing, accessory muscle
use, paradoxical respirations, hyperresonance, prolonged expiration
– Change in Mental Status: agitation, confusion, lethargy, exhaustion
– Cardiac Arrhythmias
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Asthma
Treatment– Focused history and physical exam– Complains of trouble breathing.
Airway control w/ adequate ventilationOxygenation
– Has a prescribed inhaler available.Consult medical direction.Facilitate administration of inhalerRepeat as indicated.
– Baseline vital signs.– Reassess
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Pneumonia
Defined– Inflammation of both the bronchioles and
alveoli– May be viral, bacterial, or fungal. Spread by
droplets or contact with infected person– Common cause of death in North America
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Pneumonia
Signs/Symptoms/Assessment– Acute onset of chills, fever, dyspnea, pleuritic
chest pain, cough, adventitious breath sounds.
– In geriatric patients, the primary sign may be an altered mental state.
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Pneumonia
Treatment– Focused history and physical exam– Complains of trouble breathing.
Airway control w/ adequate ventilationOxygenation
– Has a prescribed inhaler available.Consult medical direction.Facilitate administration of inhalerRepeat as indicated.
– Baseline vital signs.– Reassess
Treatment with CPAP
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Essential Components Of A CPAP System
1. CPAP Control Unit
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Essential Components Of A CPAP System
2. Breathing Circuit and Positive Pressure Face Mask
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Essential Components Of A CPAP System
3. Oxygen Source
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Treatment With CPAP
Indications– Patient in respiratory distress with signs and symptoms
consistent with: Congestive Heart Failure (CHF); Pulmonary Edema; asthma; COPD; or pneumonia
– Other measures to improve oxygenation and decrease the work of breathing have failed (i.e., 100% O2 via NRM)
– And who is:Awake and able to follow commands;Is over 12 years of age and is able to fit the CPAP mask;Has the ability to maintain an open airway;
– AndExhibits two or more:
– RR > 25 BPM– SPO2 <94% at any time– use of accessory muscles of breathing
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Treatment With CPAP
Contraindications– Patient is apneic– Patient is suspected of having a
pneumothorax– Patient is a trauma patient with injury to the
chest– Patient has a tracheostomy– Patient is actively vomiting or has upper GI
bleeding
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Treatment With CPAP
Procedure– Note indications and absence of
contraindications– Equipment:
CPAP machine
CPAP mask, peep valves and straps
O2 Source
Pulse Oximetry
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Treatment With CPAP
Procedure (cont.)– EXPLAIN THE PROCEDURE TO THE PATIENT– Ensure adequate oxygen supply to the CPAP device– Place patient on continuous pulse oximetry– Position head of bed at 45 degrees or patient position
of comfort– Place CPAP mask over mouth and nose, secure with
straps provided– Use 5 cm H2O of PEEP– Check for air leaks
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Treatment With CPAP
Procedure (cont.)– Monitor and document the patient’s respiratory response to
treatment– Check and document vitals signs every 5 minutes– Assist with appropriate PATIENT PRESCRIBED medication
(nitroglycerin tablets for CHF, nebulized Albuterol for COPD/Asthma)
– Coach patient to keep mask in place, readjust as needed– Contact Medical Control and / or responding ALS unit to advise
of CPAP initiation– Request ALS intercept if available– If respiratory status deteriorates, remove device and consider
IPPV via BVM
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Treatment With CPAP
Patient improvement indicated by:– Improvement in dyspnea – Decreased respiratory rate– Improved pulse oximetry– Improved patient comfort
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Treatment With CPAP
Removal– CPAP needs to be continuous and should not be
removed unless the patient cannot tolerate the mask or experiences respiratory arrest and/or begins to vomit
– Intermittent positive pressure ventilation (IPPV) with a BVM should be considered if CPAP is removed
– A Laryngo Tracheal Device (King Airway, Combitube, etc.) should be used with a bag valve device if the patient is in respiratory arrest
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Treatment With CPAP
Special Considerations – Do not remove CPAP until hospital therapy
is ready– Watch for gastric distention which can cause
vomiting– CPAP may be used with patients who have
POLST forms or DNR orders