Medical Oxygen, Basic Airway Management, and COPD

Medical Oxygen Systems and Cylinder Safety

Introduction to Medical Oxygen

Oxygen (O₂) is essential for normal aerobic metabolism and cellular function.

At sea level, ambient air contains approximately 20.9% oxygen.

In many situations, the body is able to obtain enough oxygen from normal breathing. However, during certain medical emergencies, chronic illnesses, respiratory conditions, or exposure to high altitude, supplemental oxygen may be necessary to improve oxygen delivery to the tissues.

This EMT study guide reviews the equipment used to store and deliver medical oxygen in the prehospital setting. It also covers the basic situations in which oxygen therapy may be indicated and when unnecessary oxygen administration should be avoided.

Oxygen Cylinders

Medical oxygen is stored in cylinders that come in several different sizes.

In the prehospital environment, commonly encountered cylinders include:

Different EMS systems may use other cylinder sizes depending on their equipment and operational needs.

Measuring Cylinder Pressure

The amount of pressure inside an oxygen cylinder is measured in pounds per square inch (PSI).

The pressure reading helps EMS providers estimate how much oxygen remains inside the cylinder.

A pressure regulator is attached to the cylinder to reduce the extremely high tank pressure to a level that can safely be delivered through oxygen equipment.

Oxygen Cylinder Safety

Medical oxygen cylinders contain gas stored under very high pressure.

Because of this, cylinders must always be handled carefully and secured properly.

High-Pressure Hazards

A damaged oxygen cylinder can become a serious projectile hazard.

If the valve or regulator is broken, compressed oxygen can escape rapidly and potentially propel the cylinder with tremendous force.

To reduce this risk:

Fire and Combustion Safety

Oxygen itself does not burn, but it strongly supports combustion.

Materials can ignite more easily and burn much more rapidly in an oxygen-rich environment.

For this reason:

Oil, grease, and petroleum-based products should also be kept away from oxygen equipment because they can create a serious fire hazard when exposed to concentrated oxygen.

Key Safety Principle

Oxygen is an important medical therapy, but it must be treated as both a medication and a high-pressure compressed gas.

Safe oxygen use requires providers to understand:

Proper handling of oxygen equipment protects both the patient and the EMS crew while ensuring that oxygen can be delivered safely and effectively when needed.

Oxygen Delivery Methods

The method used to administer supplemental oxygen depends on the patient’s respiratory status, oxygen needs, and ability to breathe effectively.

Oxygen flow is generally measured in liters per minute (L/min or LPM).

Different oxygen-delivery devices provide different concentrations of oxygen and levels of respiratory support.

Nasal Cannula

A nasal cannula is a low-flow oxygen device that delivers oxygen through two small prongs placed in the patient’s nostrils.

It is commonly used for patients who:

Compared with other common EMS oxygen devices, the nasal cannula provides lower-flow oxygen and is often more comfortable for patients who do not require high concentrations.

Non-Rebreather Mask

A non-rebreather mask (NRB) is used when a spontaneously breathing patient requires a higher concentration of supplemental oxygen.

The mask includes a reservoir bag that fills with oxygen.

Before placing the mask on the patient, the reservoir bag should be adequately inflated.

A high oxygen flow rate is used to keep the reservoir from collapsing significantly during inspiration.

An NRB can provide a substantially higher oxygen concentration than a nasal cannula when it is fitted and used properly.

Bag-Valve Mask

A bag-valve mask (BVM) provides positive-pressure ventilation to patients who are not breathing adequately on their own.

When connected to supplemental oxygen and an appropriately filled reservoir, a BVM can deliver a high concentration of oxygen.

The BVM may be used when a patient:

Unlike a nasal cannula or non-rebreather mask, a BVM does more than simply provide oxygen. It also mechanically moves air into the lungs through positive-pressure ventilation.

Nebulizer

A nebulizer converts liquid medication into a fine aerosol that the patient can inhale.

In the prehospital setting, oxygen or compressed gas may be used to drive the nebulizer and aerosolize medications such as albuterol.

Nebulizers are commonly used to treat bronchospasm associated with conditions such as:

The nebulizer’s primary purpose is to deliver inhaled medication rather than serve as the patient’s main oxygen-delivery device.

For patients who require both nebulized medication and supplemental oxygen, some systems allow the nebulizer to be incorporated into other respiratory equipment.

Depending on available equipment and local protocol, nebulized medication may be administered:

Selecting the Appropriate Device

Choosing an oxygen-delivery method should be based on the patient’s overall respiratory condition rather than on oxygen saturation alone.

Important factors include:

A patient who is breathing adequately may only require supplemental oxygen.

A patient who is breathing inadequately may require positive-pressure ventilation with a BVM, regardless of the oxygen saturation reading.

Nebulizer Flow Rate

A nebulizer is commonly operated using an oxygen flow rate of approximately 6–8 L/min, depending on the device and local protocol.

The oxygen flow creates the aerosol needed to deliver medications such as albuterol into the patient’s airways.

Estimating Oxygen Supply Duration

When administering supplemental oxygen, EMS providers should understand approximately how long the available oxygen supply will last.

For many routine EMS calls, transport and patient-care times are short enough that oxygen depletion is not a major concern.

However, oxygen supply becomes especially important during situations such as:

The amount of time an oxygen cylinder can continue supplying oxygen depends on three main factors:

Larger cylinders contain more oxygen than smaller cylinders, while higher flow rates use the available oxygen more quickly.

For example, a patient receiving oxygen at a high flow rate will empty the same cylinder faster than a patient receiving oxygen through a low-flow device.

Providers should regularly check the oxygen pressure gauge during prolonged care and make sure an adequate oxygen supply is available for the anticipated duration of treatment and transport.

D-Cylinder Oxygen Supply Duration
M-Cylinder Oxygen Duration and Clinical Administration Guidelines

Oxygen Delivery Time for an M Cylinder

An M cylinder is a large oxygen tank commonly used as the main oxygen supply inside an ambulance.

The amount of time an M cylinder can provide oxygen depends on:

Higher oxygen flow rates will use the available oxygen supply more quickly.

All oxygen cylinders should be checked at the beginning of every shift to make sure an adequate supply is available.

Providers should confirm:

If a call is expected to involve a long scene time, extended transport, or high oxygen flow rate, request additional oxygen and other necessary resources early.

Do not wait until the current oxygen supply is almost empty before arranging additional resources.

When Should Oxygen Be Administered?

Supplemental oxygen should be considered a medication and should be administered according to the patient’s clinical condition.

Although oxygen can be lifesaving, unnecessary oxygen administration is not always beneficial.

Providers should evaluate the entire patient rather than relying on only one finding.

Symptoms That May Indicate a Need for Oxygen

Possible symptoms associated with inadequate oxygenation include:

These symptoms may have many different causes, so they should be considered together with the patient’s vital signs and physical examination.

Signs That May Indicate Poor Oxygenation

Clinical findings that may support the need for supplemental oxygen include:

Patients with inadequate ventilation may require more than supplemental oxygen alone.

If the patient is not breathing adequately, positive-pressure ventilation with a bag-valve mask (BVM) may be necessary.

Toxic Gas Exposure

Supplemental oxygen may also be indicated following exposure to certain toxic gases.

A common example is carbon monoxide (CO) poisoning.

Patients with suspected significant carbon monoxide exposure may require high-concentration oxygen.

Standard pulse oximetry may appear normal or falsely reassuring because a conventional pulse oximeter cannot reliably distinguish oxyhemoglobin from carboxyhemoglobin.

For this reason, a normal SpO₂ reading does not rule out carbon monoxide poisoning.

Pulse Oximetry and Oxygen Administration

Pulse oximetry provides an estimate of peripheral oxygen saturation.

An SpO₂ below approximately 94% may indicate inadequate oxygenation in many patients.

However, oxygen therapy should not be based on SpO₂ alone.

Providers should also consider:

All assessment findings should be considered together when determining whether supplemental oxygen is appropriate.

When Oxygen Should Be Titrated

Some medical conditions require more careful oxygen administration.

The goal is to provide enough oxygen to correct hypoxemia without unnecessarily exposing the patient to excessive oxygen levels.

Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) may normally have lower oxygen saturation levels than healthy adults.

COPD commonly includes:

Some patients with advanced COPD may also chronically retain carbon dioxide.

These patients should still receive oxygen when they are hypoxemic or experiencing significant respiratory distress.

Oxygen should not be withheld from a critically ill COPD patient simply because of concern about carbon dioxide retention.

However, unnecessarily high concentrations of oxygen may increase carbon dioxide levels in some susceptible COPD patients.

This is primarily related to changes in ventilation-perfusion matching and carbon dioxide transport, rather than simply causing the patient to stop breathing because of a loss of “hypoxic drive.”

For patients known to be at risk for hypercapnic respiratory failure, oxygen may be carefully titrated to a target saturation, commonly around:

SpO₂ 88–92%

The appropriate target should follow local protocols and medical direction.

If a COPD patient has no signs of hypoxemia or respiratory distress and is at their normal baseline oxygen saturation, supplemental oxygen may not be necessary.

Oxygen After Return of Spontaneous Circulation

After return of spontaneous circulation (ROSC) following cardiac arrest, oxygen therapy should be adjusted once reliable oxygen saturation monitoring becomes available.

During post-cardiac-arrest care, the goal is to avoid both inadequate oxygenation and unnecessarily excessive oxygen levels.

A commonly recommended target is:

SpO₂ 92–98%

This range helps reduce the risks associated with:

During active cardiac arrest, oxygen and ventilation should be provided according to current resuscitation protocols.

Oxygen for Cardiac Chest Pain

Patients experiencing suspected cardiac chest pain or acute coronary syndrome (ACS) do not automatically require supplemental oxygen.

If the patient is breathing adequately and has an acceptable room-air oxygen saturation, routine oxygen administration may not provide additional benefit.

Supplemental oxygen is generally considered when:

Treatment decisions should follow the patient’s presentation and local EMS protocols.

Oxygen in Suspected Stroke

Patients experiencing a suspected stroke or cerebrovascular accident (CVA) require adequate oxygen delivery because brain tissue is highly sensitive to hypoxia.

Supplemental oxygen should be administered when the patient is hypoxemic.

Many EMS protocols aim to maintain an oxygen saturation of approximately:

94% or greater

while avoiding unnecessary hyperoxia.

Other important stroke interventions should continue without delay, including:

Oxygen in Head Injury

Preventing hypoxemia is extremely important in patients with significant head injuries.

Low oxygen levels can worsen secondary brain injury by decreasing oxygen delivery to damaged brain tissue.

Providers should:

If a patient with a head injury is breathing inadequately, supplemental oxygen through a mask alone is not sufficient.

The patient may require assisted ventilation with a BVM.

Key Oxygen Administration Principles

Oxygen treatment should never be determined by a single assessment finding.

When deciding whether supplemental oxygen is necessary, consider the patient’s:

Most importantly, oxygen should not be withheld from a patient who is clearly hypoxemic or experiencing significant respiratory distress because of concern about an underlying medical condition.

Once adequate oxygenation has been achieved, oxygen can be titrated to the appropriate target range.

Exact oxygen thresholds and treatment goals may vary between EMS systems. Always follow your local protocols, agency guidelines, medical direction, and authorized scope of practice.

Airway Management Principles and Techniques

Fundamentals of Basic Airway Management

Overview
Optimal Patient Positioning

Unconscious patients who need airway support or assisted ventilation are generally positioned so that the airway is as open and accessible as possible. One commonly used method is the ear-to-sternal-notch position.

Basic Manual Techniques for Opening the Airway

Manual airway maneuvers are among the most basic methods used to maintain an open airway. They require no equipment, are noninvasive, and can be very effective when performed correctly. Following the principle of using the least invasive and lowest-risk intervention first, these techniques should generally be attempted before progressing to more advanced airway procedures.

Head-Tilt/Chin-Lift Maneuver

The head-tilt/chin-lift maneuver is typically used when there is no suspected injury to the cervical spine.

Technique

Jaw-Thrust Maneuver

The jaw-thrust maneuver is generally preferred when a cervical spine injury is suspected because it can help open the airway while minimizing movement of the head and neck.

Technique

Managing Airway Obstruction, Suctioning, and Basic Airway Adjuncts

Foreign-Body Airway Obstruction

Foreign-body airway obstruction (FBAO) occurs when an object blocks airflow through the airway. According to the National Safety Council, choking remains an important cause of unintentional and accidental death, particularly among children. FBAO is generally classified as either partial/mild or complete/severe depending on the amount of airflow that remains.

Partial or Mild Airway Obstruction

With a partial obstruction, the foreign object does not completely block the airway. The patient is still able to move enough air to remain conscious and will commonly have an effective cough.

Signs and Symptoms

Management

Complete or Severe Airway Obstruction

A severe obstruction occurs when the airway is completely or nearly completely blocked. A patient who cannot speak, cough effectively, or move air should be treated as having a severe airway obstruction.

Signs and Symptoms

Management

Clearing the Airway With Suction

Airway suction equipment should be readily available when caring for patients who may have fluid or secretions obstructing the airway. Blood, vomit, mucus, and other material can interfere with ventilation and increase the risk of aspiration.

Types of Suction Catheters

Rigid Suction Catheters

Rigid suction catheters are firm devices designed to rapidly remove significant amounts of fluid and larger material from the mouth and oropharynx.

Flexible Suction Catheters

Flexible suction catheters are soft, narrow tubes available in several different sizes.

Suctioning Procedure

Basic Airway Devices

When airway obstruction is caused primarily by loss of muscle tone rather than trauma, swelling, foreign material, or excessive secretions, basic airway adjuncts can help prevent the tongue from falling backward and blocking the airway.

These devices are commonly considered in patients with a decreased level of consciousness when protective airway reflexes, particularly the gag reflex, are absent or significantly reduced.

Two commonly used basic airway adjuncts include the nasopharyngeal airway and the oropharyngeal airway.

Nasopharyngeal Airway

A nasopharyngeal airway (NPA) is a soft, hollow tube made of rubber or plastic. It is inserted through a nostril and advanced into the posterior pharynx to help maintain airway patency.

Contraindications and Precautions

Choosing the Correct Size

Insertion Procedure

Patient Tolerance

The nasopharyngeal airway is usually tolerated better than an oropharyngeal airway in patients who are semiconscious or who still retain some protective airway reflexes.

Using an Oropharyngeal Airway

An oropharyngeal airway (OPA) is a curved, hollow airway device designed to help maintain an open passage through the mouth and into the posterior pharynx. It is primarily used to prevent the tongue from falling backward and blocking the airway in an unresponsive patient without an intact gag reflex.

Selecting the Proper Size

Insertion Technique

There are two common methods for placing an OPA.

Rotation Technique

Direct Insertion Technique

Important Considerations

Scenario: Suspected Opioid Overdose With Respiratory Depression

Dispatch Information

A Basic Life Support (BLS) ambulance is sent to an alley behind a neighborhood bar for a report of CPR in progress. Dispatch advises that emergency instructions are being given to the caller before the ambulance arrives.

Scene Assessment

Patient Assessment

Initial Treatment

Transport and Reassessment

During transport to the hospital, the patient gradually begins to regain consciousness. As the patient becomes more responsive and is able to maintain the airway more effectively, the NPA is removed.

The patient is transported to the emergency department, where care is transferred to hospital staff for continued evaluation and treatment.

Managing Respiratory Emergencies

Understanding Chronic Obstructive Pulmonary Disease

Overview

Chronic Obstructive Pulmonary Disease, commonly called COPD, is a group of long-term lung diseases that restrict airflow and make breathing more difficult. More than 16 million people in the United States have been diagnosed with COPD, while many others may have the condition without knowing it.

The two most common forms of COPD are emphysema and chronic bronchitis. Although COPD cannot currently be cured, treatment can help control symptoms, improve breathing, and reduce the frequency or severity of exacerbations.

Cigarette smoking is one of the leading causes of COPD. Long-term exposure to tobacco smoke can cause permanent damage to lung tissue and may also increase the risk of lung cancer.

Other factors that may contribute to the development of COPD include:

Effects and Complications of COPD

COPD can produce several chronic symptoms and potentially life-threatening complications.

Common findings and complications may include:

COPD interferes with normal airflow because the airways may become narrowed, inflamed, or partially blocked by excess mucus. In addition, damage to the alveoli can reduce the lungs’ ability to exchange oxygen and carbon dioxide effectively.

For many patients, COPD progressively worsens over time. As the disease advances, symptoms may become more severe, physical activity may become increasingly difficult, and some patients may eventually require long-term supplemental oxygen.

Prehospital Care for Patients With COPD

Respiratory distress is a frequent reason for Emergency Medical Services (EMS) activation. Studies have estimated that approximately one in eight EMS responses, or roughly 11.7% to 12.1% of calls, involve patients experiencing some form of respiratory distress.

EMS providers play an important role in identifying and treating acute respiratory problems associated with COPD. Early recognition and appropriate intervention can significantly improve a patient’s condition and may prevent further deterioration.

Prehospital treatment may include medications, oxygen therapy, ventilatory support, and other procedures designed to improve airflow, oxygenation, and ventilation.

When treatment is provided early, EMS interventions may prevent respiratory distress from progressing to respiratory failure or respiratory arrest. This can also reduce the likelihood that the patient will require advanced airway management.

Because respiratory distress can result from many different medical conditions, providers must carefully evaluate the patient’s history, physical examination findings, vital signs, lung sounds, and overall presentation. Correctly identifying the most likely cause of the breathing difficulty helps guide the most appropriate treatment.

Core Concepts: Respiratory Anatomy in COPD

Respiratory Anatomy and Its Relationship to COPD

Understanding the anatomy and function of the respiratory system is important when evaluating patients with Chronic Obstructive Pulmonary Disease (COPD). The respiratory tract is commonly divided into two main sections: the upper airway and the lower airway.

The larynx, which contains the vocal cords, generally serves as the transition point between the upper and lower respiratory tracts.

Upper Respiratory Tract

The upper airway includes the structures responsible for carrying air from the outside environment toward the lower respiratory system. These structures include the mouth, nasal cavity, throat, and nearby anatomical passages.

Pharynx

The pharynx is the passageway that connects the oral and nasal cavities with deeper structures leading toward the trachea and esophagus. It is commonly divided into three regions.

Oropharynx

The oropharynx is the portion of the pharynx located behind the mouth. It serves as a pathway for both air and swallowed substances.

Nasopharynx

The nasopharynx is located behind the nasal cavity and connects the nose with the upper portion of the throat. Air entering through the nose passes through this region before continuing deeper into the respiratory tract.

Laryngopharynx

The laryngopharynx is the lower portion of the throat where the pathways for air and food begin to separate. From this area, air is directed toward the trachea, while food and liquids are directed toward the esophagus.

Larynx

The larynx, often associated with the vocal cords, marks the transition between the upper and lower airways.

The larynx performs several important functions:

Epiglottis

The epiglottis is a flexible flap of elastic cartilage located near the entrance to the larynx.

During swallowing, the epiglottis helps cover the opening to the lower airway, directing food and fluids toward the esophagus rather than the trachea. This action helps protect the lungs from aspiration.

Vocal Cords

The vocal cords are located within the larynx and contribute to speech production.

They can also close tightly or spasm in response to irritation or foreign material. This protective response helps prevent substances from entering the lower respiratory tract.

Esophagus

The esophagus is a muscular tube that carries swallowed food and liquids from the throat to the stomach.

Although it is part of the digestive system rather than the respiratory system, it lies close to the airway and shares part of the upper throat pathway before separating from the trachea.

Lower Respiratory Tract Structure and Function

The lower respiratory tract carries air from the larynx into the lungs and ultimately to the alveoli, where oxygen and carbon dioxide are exchanged. This gas exchange is essential for supplying oxygen to body tissues and removing carbon dioxide produced by cellular metabolism.

The lower airway begins just below the larynx and includes several structures that progressively become smaller as air moves deeper into the lungs.

Trachea

The trachea, commonly called the windpipe, is a tube supported by cartilage that extends downward from the larynx.

Carina

The carina is the cartilaginous ridge located at the point where the trachea divides.

Bronchi

The bronchi are larger airways supported by cartilage that carry air farther into the lungs.

As they travel deeper into the lungs, the bronchi divide into increasingly smaller branches.

The three major levels include:

Bronchioles

The bronchioles are smaller airways located deeper within the lungs.

Alveolar Ducts

The alveolar ducts are very small passages that connect the bronchioles with the alveoli.

Their main function is to direct inhaled air toward the alveolar sacs where gas exchange takes place.

Alveoli

The alveoli are microscopic air sacs located at the ends of the respiratory passages.

Structures Supporting Ventilation

Several additional structures work with the lungs to create the pressure changes necessary for normal breathing.

Diaphragm

The diaphragm is a large skeletal muscle located beneath the lungs that separates the thoracic cavity from the abdominal cavity.

It is one of the primary muscles responsible for breathing.

During Inhalation

During Exhalation

Ribs

The ribs form the protective framework surrounding the thoracic cavity.

Intercostal Muscles

The intercostal muscles are skeletal muscles located between the ribs.

Pleural Cavity

The pleural cavity is the potential space between the lungs and the inner surface of the chest wall.

How the Respiratory System Supports Gas Exchange

The primary function of the respiratory system is to deliver oxygen to the body’s cells while removing carbon dioxide, a waste product produced during normal cellular metabolism.

Gas exchange in the lungs and throughout the body occurs primarily through a process known as diffusion.

Diffusion

Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. This process does not require the body to actively move individual gas molecules and is essential for the exchange of oxygen and carbon dioxide.

Oxygen Exchange

During inhalation, oxygen-rich air reaches the alveoli within the lungs.

Carbon Dioxide Exchange

Carbon dioxide moves in the opposite direction.

Through this continuous exchange of oxygen and carbon dioxide, the respiratory and circulatory systems work together to support normal cellular function and maintain adequate tissue oxygenation.

Respiratory Volumes, Acid–Base Regulation, and the Effects of COPD

The Alveolar-Capillary Membrane

The walls of the alveoli and pulmonary capillaries are extremely thin, which allows oxygen and carbon dioxide to move efficiently between the lungs and bloodstream by diffusion.

Because these membranes are only about one cell layer thick, respiratory gases can cross them rapidly. Under normal conditions, the alveolar-capillary barrier carefully regulates the movement of gases and fluid so that the alveoli remain relatively dry and effective for gas exchange.

As body cells continuously use oxygen and generate carbon dioxide, circulating blood continually transports these gases between the tissues and lungs. Oxygen is picked up in the lungs and delivered to the tissues, while carbon dioxide is carried back to the lungs for removal during exhalation.

Common Respiratory Volumes and Terms

Respiratory volumes are generally measured in liters (L) or milliliters (mL).

Tidal Volume

Tidal volume is the amount of air inhaled or exhaled during one normal, relaxed breath.

Typical resting values are approximately:

Actual tidal volume varies according to body size and other individual factors.

Residual Volume

Residual volume is the amount of air that remains inside the lungs after a person exhales as completely as possible.

This remaining air helps prevent complete collapse of the lungs between breaths.

Inspiratory Reserve Volume

Inspiratory reserve volume is the maximum additional amount of air that can be inhaled after completing a normal tidal inspiration.

Expiratory Reserve Volume

Expiratory reserve volume is the greatest additional amount of air that can be forcefully exhaled after a normal expiration.

Even after this air is expelled, residual volume remains inside the lungs.

Vital Capacity

Vital capacity is the maximum amount of air that can be exhaled after taking the deepest possible breath.

It represents the combined volume of air available through normal breathing plus additional inspiratory and expiratory reserves.

Anatomic Dead Space

Anatomic dead space refers to inhaled air that remains within the conducting portions of the respiratory tract and does not directly participate in gas exchange.

Structures contributing to anatomic dead space include areas such as the trachea, bronchi, and other conducting airways.

Surfactant

Surfactant is a substance produced by specialized cells within the alveoli.

Additional Functions of the Respiratory System

Regulation of Acid–Base Balance

The respiratory system plays an important role in maintaining the body’s normal acid–base balance and blood pH.

Several systems work together to regulate pH:

Carbon dioxide produced during cellular metabolism combines with water in the bloodstream and participates in the formation of carbonic acid.

Because carbon dioxide levels influence the amount of acid present in the blood, changes in ventilation can alter blood pH.

Increasing Ventilation

When respiratory rate or depth increases:

Decreasing Ventilation

When ventilation becomes slower or shallower:

The brainstem automatically adjusts respiratory rate and depth in response to changing physiologic conditions. Increasing either the depth or frequency of breathing can increase carbon dioxide elimination when necessary.

How COPD Changes Respiratory Function

Chronic Obstructive Pulmonary Disease (COPD) is a progressive condition in which airflow limitation and lung damage generally worsen over time.

Different forms of COPD affect different structures of the respiratory system. Two of the most common conditions associated with COPD are chronic bronchitis and emphysema.

Chronic Bronchitis

Chronic bronchitis primarily affects the bronchial airways.

Repeated and long-term inflammation can cause:

During an exacerbation, airway inflammation, mucus production, and bronchial narrowing may become more severe, resulting in significant respiratory distress.

Emphysema

Emphysema primarily damages the alveoli and supporting lung tissue.

As the disease progresses:

Air Trapping

Loss of normal lung elasticity makes it difficult for patients with emphysema to completely exhale.

Air that remains trapped inside the lungs may gradually cause chronic hyperinflation. In advanced disease, this can contribute to the characteristic appearance sometimes described as a barrel-shaped chest, in which the chest remains more expanded even between breaths.

Reduced Gas Exchange

Damage to the alveolar walls decreases the amount of healthy surface area available for oxygen and carbon dioxide exchange.

As functional lung tissue decreases, patients may experience:

Living With COPD and Recognizing Acute Exacerbations

COPD affects millions of people and, although the disease cannot be cured, modern treatment can help many patients control symptoms, maintain daily function, and reduce the risk of serious complications.

Long-term management commonly includes inhaled medications that improve airflow and reduce airway inflammation. These may include:

As COPD becomes more advanced, some patients may develop chronic hypoxemia and require supplemental oxygen at home. Certain individuals may need oxygen for extended periods each day or continuously, depending on their oxygen levels and prescribed treatment plan.

Even with regular medications and home oxygen therapy, patients can experience episodes in which their usual treatments no longer adequately control symptoms. These acute worsening episodes, known as COPD exacerbations, are a common reason for EMS activation.

Recognizing a COPD Exacerbation

Many people with COPD are able to function relatively well during their normal daily routine. However, symptoms can suddenly or gradually worsen, producing increased respiratory difficulty that may require additional treatment.

Common triggers for COPD exacerbations include:

Common Signs and Symptoms

The presentation of COPD can vary depending on the severity of the disease, the cause of the exacerbation, and any additional medical conditions present.

Possible signs and symptoms include:

Patients experiencing a typical COPD exacerbation often present with a combination of dyspnea, wheezing, and decreased oxygenation, although not every patient will display all of these findings.

Many patients with a known history of COPD recognize when their respiratory condition is worsening. They may tell EMS that their current symptoms resemble previous exacerbations or that their normal inhalers, nebulizer treatments, or supplemental oxygen are no longer providing adequate relief.

Obtaining a Focused Patient History

A detailed history can help determine whether the patient’s symptoms are consistent with a COPD exacerbation or whether another condition may be responsible.

Useful questions may include:

The answers should be considered together with the physical examination, vital signs, oxygen saturation, and overall clinical presentation.

Physical Assessment

A complete respiratory assessment should be performed while also evaluating the patient for other possible causes of breathing difficulty.

Respiratory Assessment

Important findings include:

Lung Sounds

Auscultate lung sounds throughout both sides of the chest.

Possible findings may include:

Changes in lung sounds may provide important clues about the cause and severity of the patient’s respiratory distress.

Chest Examination

The chest should also be evaluated for findings that could suggest a traumatic or non-COPD cause of breathing difficulty.

Assess for:

Traumatic conditions that may interfere with breathing include:

Considering Other Causes of Respiratory Distress

A history of COPD should not automatically mean that every episode of shortness of breath is caused by COPD.

Several other medical conditions can cause respiratory symptoms that resemble or occur at the same time as a COPD exacerbation.

Possible conditions to consider include:

Because many of these conditions can present with similar complaints, EMS providers should avoid relying on a single symptom or the patient’s COPD history alone.

A complete assessment, appropriate history, vital signs, lung sounds, and evaluation of other body systems—including the cardiovascular, gastrointestinal, neurological, and musculoskeletal systems when indicated—can help identify the most likely cause and guide appropriate treatment.

Prehospital Evaluation and Management of COPD Exacerbations

EMS Response and Scene Considerations

Before arriving at the patient, EMS providers should consider potential scene hazards, whether additional personnel or equipment may be required, and whether the response should be handled emergently or non-emergently based on dispatch information.

Once on scene, evaluate the environment and consider what the patient was doing when the symptoms began. For example, determine whether the patient was resting, walking, performing yard work, exercising, or participating in another activity that may have contributed to the onset of respiratory distress.

Initial Impression

A rapid assessment should begin as soon as the patient is visible.

Consider the following:

These immediate observations can provide important information about the severity of the respiratory emergency.

Primary Assessment: LOC and ABCDE

Level of Consciousness

Evaluate the patient’s mental status early in the assessment.

A patient with COPD may remain completely alert but have such severe dyspnea that they can only speak in short two- or three-word phrases.

Changes in consciousness can indicate worsening hypoxia, hypercapnia, fatigue, or respiratory failure and may influence the type of intervention required.

Responsive Patient

A conscious patient who is maintaining the airway may be treated with noninvasive interventions as indicated, including:

Significantly Altered or Unresponsive Patient

A patient who can no longer adequately maintain the airway or ventilate independently may require:

Airway

Determine whether the airway is open and adequately maintained.

A conscious patient is often able to maintain their own airway, although this should never be assumed without assessment.

Evaluate for:

A patient with a significantly decreased level of consciousness may lose airway muscle tone and require immediate airway intervention.

Breathing

Evaluate the patient’s respiratory rate, depth, pattern, effort, and effectiveness.

Patients experiencing COPD exacerbations commonly have an increased respiratory rate. Breaths may also become shallow as respiratory fatigue progresses.

A decreasing respiratory rate accompanied by altered mental status or worsening respiratory effort is especially concerning because it may indicate impending respiratory failure.

Assess for:

Supplemental oxygen may be required when the patient is hypoxemic, with oxygen therapy adjusted according to the patient’s condition and local protocol.

Auscultate lung sounds before treatment whenever possible to establish a baseline. Findings such as wheezing, rhonchi, crackles, diminished breath sounds, or absent breath sounds may provide important clues regarding the cause and severity of respiratory distress.

Circulation

Patients experiencing significant respiratory distress are frequently tachycardic because of increased work of breathing, hypoxia, anxiety, medications, or other physiologic stress.

Assess:

The skin may appear pale, cool, clammy, or diaphoretic. Cyanosis may develop when oxygenation is significantly impaired.

Any major external bleeding should be controlled, and signs of shock should be recognized and treated appropriately.

Disability

Perform a neurologic assessment and evaluate for altered mental status.

If mental status is abnormal, consider possible causes in addition to respiratory disease.

Obtain a capillary blood glucose (CBG) level when indicated because hypoglycemia or hyperglycemia may contribute to altered behavior or consciousness.

Exposure

Expose and examine the chest as necessary while maintaining the patient’s privacy and body temperature.

Look for:

Perform a more complete physical examination when the patient’s condition and circumstances require it.

Diagnostic Assessment and Monitoring

Obtain baseline vital signs and repeat them throughout treatment and transport.

Important measurements may include:

Capnography

End-tidal carbon dioxide monitoring can provide additional information about ventilation.

Patients with significant bronchospasm or airflow obstruction may display a characteristic “shark-fin” waveform on waveform capnography. This appearance reflects delayed and uneven exhalation caused by narrowed lower airways.

ETCO₂ values and waveform trends should be interpreted together with the patient’s overall clinical presentation.

Cardiac Monitoring

Depending on the patient’s symptoms and provider scope, cardiac monitoring may include:

A 12-lead ECG may be particularly important when the patient has chest discomfort, significant cardiac risk factors, unexplained dyspnea, or concern for myocardial ischemia.

Focused Medical History

A thorough history is important because many conditions can produce symptoms similar to a COPD exacerbation.

Pay particular attention to previous respiratory conditions such as:

Also investigate relevant medical conditions involving other body systems, including:

Helpful clarification questions may include:

Treatment Options

Treatment should be guided by the patient’s presentation, severity of illness, provider scope of practice, and local EMS protocols.

Supplemental Oxygen

For patients with mild respiratory distress or hypoxemia without significant bronchospasm, supplemental oxygen alone may sometimes provide meaningful improvement.

Common oxygen-delivery devices include:

Oxygen therapy should be adjusted to the patient’s clinical condition and target oxygen saturation according to local guidance.

Patients with COPD who are at risk of carbon dioxide retention may sometimes have specific oxygen-saturation targets, so oxygen should be titrated rather than withheld when hypoxemia is present.

Inhaled Bronchodilator Therapy

Bronchodilators are commonly used when bronchospasm or bronchoconstriction contributes to airflow limitation.

Albuterol and Ipratropium

A combination of albuterol and ipratropium bromide, commonly referred to as a DuoNeb, may be administered according to local protocol.

These medications help relax airway smooth muscle and increase the diameter of the lower airways, allowing air to move more effectively toward the alveoli.

Nebulizers commonly require an oxygen or gas flow sufficient to create an effective medication mist, often approximately 6–8 L/min, depending on the device.

Bronchodilator treatments may be repeated when clinically indicated and permitted by protocol.

Corticosteroid Therapy

Corticosteroids may be administered to reduce airway inflammation associated with COPD exacerbations and other obstructive respiratory conditions.

Common examples used in prehospital or emergency settings include:

Steroids do not usually produce immediate bronchodilation, but they can help decrease airway inflammation and contribute to improvement over time.

Noninvasive Positive-Pressure Ventilation

CPAP and BiPAP may be useful for selected patients experiencing moderate to severe respiratory distress from a COPD exacerbation.

Positive-pressure ventilation can:

Bronchodilator therapy may often be administered before or during noninvasive positive-pressure ventilation when bronchospasm is present and equipment permits.

Patients receiving CPAP or BiPAP should be closely monitored for tolerance, blood pressure changes, mental status changes, worsening respiratory distress, or other complications.

Additional Medication Considerations

Some EMS systems permit epinephrine for selected cases of severe bronchospasm or respiratory emergencies.

Epinephrine has beta-adrenergic activity that can produce bronchodilation, but its use in COPD is not routine in every EMS system.

Providers should follow their medical direction and local protocols when considering this medication.

Advanced Airway and Ventilatory Support

A COPD exacerbation can progress from respiratory distress to respiratory failure or respiratory arrest.

Warning signs may include:

Severe respiratory distress can exhaust the patient’s respiratory muscles until spontaneous ventilation is no longer effective.

When ventilation becomes inadequate, assist respirations with a bag-valve mask and consider advanced airway management when clinically necessary and authorized.

Advanced airway placement should generally be reserved for patients who cannot maintain adequate airway protection, oxygenation, or ventilation despite appropriate less-invasive measures.

Other treatments should continue as appropriate while airway and ventilatory support are provided.

Transport Considerations

Many emergency departments are capable of initially stabilizing patients experiencing COPD exacerbations. However, the severity of the episode may determine whether the patient requires admission, intensive monitoring, or critical care.

Patients who require endotracheal intubation and mechanical ventilation may need treatment in an intensive care unit.

Patients with advanced COPD can sometimes be difficult to remove from mechanical ventilation because their underlying lung disease may make the transition back to fully spontaneous breathing more challenging.

During transport, EMS providers should continually reassess:

For long-distance or prolonged transports, oxygen supply should also be calculated carefully. Patients receiving high-flow oxygen, nebulized medication, CPAP, or assisted ventilation may consume oxygen rapidly.

If available oxygen supplies cannot safely support the anticipated transport time, the nearest appropriate receiving facility may need to be considered.