developed by: lynn wittwer, md, mpd marc muhr, emt-p tj bishop, emt-p clark county ems

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

2Washington EMT-B CPAP Curriculum

CPAP Curriculum – EMT Basic

IntroductionReview of Anatomy and PhysiologyCPAP OverviewPulse OximetryReview of Respiratory DistressTreatment With CPAP


What is CPAP?

Continuous Positive Airway Pressure (CPAP)A non-invasive alternative to intubationDoes not require any sedationIt provides comfort to the patient with acute respiratory distress by reducing work of breathing


Why CPAP?

Respiratory Distress is a common reason why people call 911!Established therapeutic alternativeEasily applied, easily discontinued


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.


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


Elements of the Airway

UPPER AIRWAYNaresNasopharynxOropharynxTongueEpiglottis/GlottisVocal Cords

LOWER AIRWAYTrachea/EsophagusCarinaMain stem BronchiSecondary BronchiBronchiolesAlveoli


Upper Airway


PharynxNasopharynx– 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


Larynx

Three main functions:– Air passageway between the pharynx and

lungs– Prevents solids and liquids from entering the

respiratory tree– Involved in speech production


Larynx

An outer casing of nine cartilages– Thyroid cartilage– Cricoid cartilage

Only complete cartilaginous ring in the larynx– Epiglottis

Hyoid boneCricothyroid membraneVocal cords


Lower Airway


Lungs

Principal function is respirationAttached to heart by pulmonary arteries and veinsSeparated by mediastinum and its contentsBase of each lung rests on the diaphragmApex extends 2.5 cm above each clavicle


Pleural Cavity

A separate pleural cavity surrounds each lungTwo layers (visceral and parietal)Pleural space


Respiratory System - Physiology

The respiratory system functions as a gas exchange systemOxygen is diffused into the bloodstream for use in cellular metabolism


Respiratory System - Physiology

Wastes, including carbon dioxide, are excreted from the body via the respiratory system


Ventilation

Ventilation refers to the process of air movement in and out of the lungsThe volume of air moved in each breath is the tidal volumeThe volume still remaining in the chest after exhalation is the functional reserve capacity. FRC


Inspiration and Expiration

Inspiration– Chest wall expands– Lung space increases– Pressure gradient causes gas to flow into the

lungsExpiration– 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


Pressure Changes During Inspiration and Expiration


Mechanics of Breathing


Mechanics of Respiration


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


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


How does CPAP work

Splints the upper airway preventing collapseUses continuous oxygen flow with pressure to push air into the lungs and push the fluid into the bloodsteamRecruits alveoli that have collapsed


CPAP MechanismIncreases pressure within airway.Airways at risk for collapse from excess fluid are stented open.Gas exchange is maintainedIncreased work of breathing is minimized


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.


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


Respiratory DistressWork of Breathing– Respiratory rate greater than 25/minute– The presence of retractions and/or use of

accessory musclesAppearance = Mental Status– Pulse Oximetry < 94%– Effects of hypoxia and hypercarbia

indistinguishableCirculation/Skin Color– Severe cyanosis– Pallor and diaphoresis


Focused History and PhysicalAscertain the patient’s chief complaint that may include:– Dyspnea– Chest pain– Cough

ProductiveNon-productiveHemoptysis

– Wheezing– Signs of infection

Fever, chillsIncreased sputum production


HistoryPrevious 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


Pulmonary Edema – Congestive Heart Failure

Defined– Fluid which collects in the lung tissue and

alveoliSigns/Symptoms/Assessment– Anxious, Pale, Clammy, Dyspnea, Tachypnea,

Confusion, Edema, Hypertension, Diaphoretic– Rales, Ronchi, Tachycardia, JVD, Pink Frothy

Sputum, Cyanosis



Signs/Symptoms/Assessment– Fatigue– Nocturia– Dyspnea on exertion– Paroxysmal nocturnal dyspnea– Chest Pain– Orthopnea



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


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



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



Signs/Symptoms/Assessment– Tachypnea, cyanosis, agitation, tachycardia,

hypertension– Confusion, tremor, stupor, apnea



Treatment– Focused history and physical exam– Complains of trouble breathing.


– Has a prescribed inhaler available.Consult medical direction.Facilitate administration of inhalerRepeat as indicated.



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


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


AsthmaTreatment– Focused history and physical exam– Complains of trouble breathing.





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


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.


PneumoniaTreatment– Focused history and physical exam– Complains of trouble breathing.




Treatment with CPAP


Essential Components Of A CPAP System

1. CPAP Control Unit



2. Breathing Circuit and Positive Pressure Face Mask



3. Oxygen Source


Treatment With CPAPIndications– 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


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


Treatment With CPAP

Procedure– Note indications and absence of

contraindications– Equipment:

CPAP machineCPAP mask, peep valves and strapsO2 Source Pulse Oximetry


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


Treatment With CPAPProcedure (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


Treatment With CPAP

Patient improvement indicated by:– Improvement in dyspnea – Decreased respiratory rate– Improved pulse oximetry– Improved patient comfort


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


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

developed by: lynn wittwer, md, mpd marc muhr, emt-p tj bishop, emt-p clark county ems

Documents

emtptj bishop

acute respiratory distress

respiratory treeinvolved

teaching points

major structures

viable alternative

complete cartilaginous

air passageway