Airway, Respiration, and Ventilation

COPD can also be caused by other issues including:

• commonly is known to be caused by tobacco smoking, which smoke causes irreversible damage to the lungs and can also cause lung cancer.

• Exposure to dusts, chemicals, fumes, etc. (air pollution, coal mines, occupational hazards). Asthma can be a risk factor for developing COPD later in life. Genetics (uncommon genetic disorder; alpha-1 antitrypsin deficiency) .

COPD causes many different issues or conditions that can be life-threatening. These include

• Frequent cough, sputum production, and shortness of breath Bronchoconstriction Hypoxia or hypoxemia Pneumonia Respiratory distress, failure, or arrest Altered mental status Severe dyspnea upon minimal exertion or activities

The Upper Respiratory Tract:

The respiratory tract is divided into the upper and lower airways. The dividing point between the two is the larynx or the "vocal cords" The upper airway includes the mouth, throat, nasal cavity, and other surrounding structures.

Pharynx:

Encompasses the oral, nasal cavities, throat, and structures leading to the esophagus and trachea.

Oropharynx:

Mouth and throat

Nasopharynx:

Nasal cavity which connects to the back of the throat

Laryngopharynx:

Branching area deep in the throat where food/air pass through branching to either the esophagus or trachea

Larynx:

The "vocal cords" or larynx are where the upper and lower airways split. This structure provides protective mechanisms to prevent unwanted substances to get into the lower airways, allows for air to pass into the lungs, and helps produce sounds upon speaking.

Epiglottis:

This flap of elastic cartilage has the ability to open or close the opening to the lower airways to prevent aspiration upon swallowing of substances.

Vocal Cords:

Have the ability to "spasm" shut as another protective mechanism against aspiration.

Esophagus:

Muscular tube connecting the mouth and throat to the stomach allowing for passage of liquids or solids to reach the digestive tract.

The Lower Respiratory Tract:

The lower airways are what allow for the passage of air to reach the alveoli deep within the lungs where gas exchange of oxygen and carbon dioxide can occur to allow for adequate tissue perfusion within the body. The lower airway structures start after the larynx starting with the trachea:

Trachea:

"wind-pipe" or cartilaginous structure leading from the larynx down to the carina where it splits into the bronchus of the lungs. The trachea is the ONLY natural path to the lungs, thus if it is blocked, issues can occur (airway obstruction).

Carina:

Cartilaginous structure branching the lungs into the left and right sides leading to the primary bronchus.

Bronchus:

Larger, cartilage composed airways that direct airflow deeper into the lungs to multiple different pathways. Bronchi have three main branches: Primary, secondary, tertiary.

Bronchioles

Smaller, muscular airways found deep within the lungs leading to the alveolar duct and finally to the alveoli. Bronchioles are composed of smooth muscles, which have the ability like other smooth muscles to constrict or dilate.

Alveolar Duct

Smaller airways leading from the bronchioles directing airflow into the alveoli.

Alveoli:

Tiny air-sacs composed of single-layered tissues where gas exchange occurs with the ability to diffuse across this thin membrane. The thin membrane allows for gases ability to cross from the alveoli into or from the pulmonary capillaries.

Diaphragm:

Skeletal muscle beneath the lungs separating the thoracic and abdominal cavities. The diaphragm is an important muscle involved with breathing helping produce pressure changes within the thoracic cavity to allow for breathing. The diaphragm upon inhalation contracts to decrease pressures allowing air to enter the lungs (pressure becomes lower than atmospheric pressures) and is an active process done by the muscle. The diaphragm upon exhalation relaxes and returns to its resting point being (passive process) as the pressure within the lungs is greater than atmospheric pressure allowing for air to escape back outside of the body.

Ribs:

Bone structures that form around the thoracic cavity (producing the rib cage) to protect the organs within as well as have the ability to expand with breathing.

Intercostal muscles:

Skeletal muscles between the ribs, help with breathing by having the ability to expand and retract.

Pleural Cavity:

Potential "space" between the lungs and rib cage continue pleural fluid, helps aid the lungs to allow for optimal lung function. "Potential space" because air, blood, or fluids can enter the cavity although, at baseline, there is no real open "cavity".

Tidal volume

Amount of air inspired with one normal breath. Normal adult male : 500 ml Normal adult female : 400 ml

Residual volume:

Amount of air remaining in the lungs after max. exhalation

Inspiratory reserve volume:

Max. amount of air that can be inspired after normal tidal volume.

Expiratory reserve volume:

Max. amount of air that can be exhaled (leaving residual volume).

Vital capacity:

Total amount of air that can be expired after max. inhalation.

Anatomic dead space:

Volumes of air that are inhaled. Does not take part in gas exchange and remain within conducting portions of airways.

Surfactant:

Released by the cells within the alveoli, the substance reduces surface tension which helps keep the alveoli from collapsing upon exhalation and makes breathing easier.

Acid-base balance:

The respiratory system is one of the ways the body helps manage or maintain the body's pH levels. The body can 8 8 manage pH levels quickly via the buffer system in the blood as well as a longer-term option via the kidneys/urinary system.

Chronic Bronchitis:

Affects the bronchial airways (bronchioles and bronchus). Chronic inflammation of bronchial airways results in excessive mucus build-up and chronic narrowing of airways causing breathing difficulties. This causes chronic airway constriction and irritation which can be exerted resulting in respiratory distress from bronchoconstriction.

Emphysema

Affects the alveoli specifically. The alveoli are damaged, resulting in loss of elasticity and the alveoli lose their shape. This can result in "air trapping" within the alveoli due to the air not being able to escape out upon exhalation. "Air trapping" continuing on can result in patients having a "barrel chest" appearance in later stages of the disease due to the lungs being overinflated chronically in which the rib cage begins to stay partially expanded all the time . Also results in damage to the walls of the alveoli resulting in fewer alveoli readily available for gas exchange. Less healthy alveoli available in certain situations result in increased difficulties with breathing as well as chances of hypoxia and bronchoconstriction occurring at times of physical exertion or exacerbation of the disease.

COPD exacerbation episodes can be caused by:

Physical exertion or increase in physical activities from baseline Smoke or other air pollution inhalation 2 Continued cigarette smoking Pulmonary infection or other illnesses

Signs and Symptoms of COPD

Difficulty breathing (dyspnea) Tachypnea Tachycardia Anxiety Nausea or vomiting Dry or productive cough. Rhonchi lung sounds may be present. Bronchoconstriction. Often is the direct cause of dyspnea due to airway narrowing. Can present with wheezing, diminished or absent lung sounds. Hypoxia or hypoxemia Central or peripheral cyanosis AMS (typically a severe sign, Chest pain, tightness, or discomfort Muscle retractions or accessory muscle use with breathing

Questions that may help COPD include:

Has this happened before? Was it different or similar to now? Have any at-home remedies or treatments been attempted? Have you seen PCP or ER for issues in the past? What was the diagnosis? How often do issues like this occur? Recent increase in exacerbation episodes? What often relieves symptoms? Is oxygen used at baseline for breathing issues? Recent illness, cough, fever, or infections?

Assessment findings for COPD

Assess lung sounds Chest wall pain upon palpation or with breathing Chest wall stability Presents of muscle retractions or accessory muscle use Presence of any external injuries to the chest

Assess for any other abnormalities that may be related to the breathing issues COPD including traumatic causes including:

Rib or sternum fracture Pulmonary contusion Clavicle fracture Pneumothorax or hemothorax (or both; hemopneumothorax)

COPD Level of consciousness (LOC):

Maybe fully alert although may only be able to respond to few word sentences (two-three word dyspnea). Level of consciousness often guides treatments needed as well.

COPD Airway

Often open/patent if conscious. Non-patent if unconscious. Assess for secretions and need for airway adjuncts.

COPD Breathing

Rate may be elevated with or without shallow depth. Decreased RR is concerning with AMS. Assess if any chest injuries or other concerning findings are present. Supplemental oxygen is often needed for hypoxia.

COPD Circulation:

Often tachycardic with peripheral pulses present. The skin may be pale, diaphoretic with or without cyanosis present. Assess for any external bleeding and treat for shock.

COPD Disability

Assess other for AMS causing if present. Obtain CBG

COPD Exposure:

Assess for chest wall trauma for injuries and stability as applicable. Full body assessment as needed

COPD Obtain baseline vital signs:

HR, RR, BP, SpO2, temperature, CBG, ETCO2 as needed to assess waveform and capnometry. If bronchospasm or bronchoconstriction is present, a "Shark fin" ETCO2 waveform may be present indicating issues. Often 3/4-lead EKG assessed, 12-lead EKG as needed. Lung sounds should be assessed prior to treatments

COPD Obtain thorough history:

Key into history related to respiratory issues: Asthma, COPD, CHF, pulmonary edema, pulmonary embolus, pneumonia, recent chest well trauma, use of oxygen at baseline, etc. Obtain another history including cardiac and GI issues, diabetes, seizure, stroke, etc. Obtain clarification questions: Hx of issues, similarities, onset time, activity level upon onset, changes with movement/breathing/medication, past diagnosis of issues, etc.

Supplemental oxygen

For mild cases, oxygen may be enough to provide relief, especially without any significant bronchoconstriction present. Supplemental oxygen amounts vary for the situation: Nasal cannula: 2-6 LPM Non-Rebreather: 10-15 LPM Bag Valve Mask: 15-25 LPM

What happens to the diaphragm during inhalation?

It contracts and flattens.

What do the intercostal muscles do during inhalation?

They contract to lift the rib cage up and out.

How does the chest cavity change during inhalation?

It enlarges substantially.

What causes a drop in intrathoracic pressure during inhalation?

An increase in container size (chest cavity) without a change in air volume.

When does air enter the lungs?

When intrathoracic pressure drops below atmospheric pressure.

What happens to the diaphragm and intercostal muscles during exhalation?

They relax.

What happens to the chest cavity during exhalation?

It returns to its normal size.

Why does pressure increase in the chest cavity during exhalation?

Because volume decreases while the air volume remains the same.

What causes air to be expelled from the lungs during exhalation?

The increase in intrathoracic pressure above atmospheric pressure.

What marks the end of exhalation?

Air is expelled to bring pressure equilibrium with the atmosphere.

What happens to oxygen during respiration?

Oxygen moves from the lungs into the bloodstream.

What happens to carbon dioxide during respiration?

It moves from the blood into the lungs.

What structure allows gas exchange in the lungs?

Capillaries in the alveolar walls.

What is the alveolocapillary membrane?

A single-cell layer where the lungs and bloodstream meet for gas exchange

What is the most superior part of the airway?

The nasal cavity.

What forms the oral cavity?

Cheeks, hard and soft palates, and the tongue.

What is the pharynx?

A muscular tube from the soft palate to the superior esophagus.

What connects the pharynx to the trachea?

The larynx.

Where does air first enter the lower airway?

The trachea.

How long is the trachea?

10–12 cm

What keeps the trachea open?

C-shaped cartilaginous rings.

What are alveoli?

Air sacs at the end of bronchioles where gas exchange occurs.

What do pleural membranes do?

They attach the lungs to the chest wall.

What respiratory rate is considered too fast?

Greater than 20 breaths per minute.

What might a fast respiratory rate indicate?

A metabolic issue or a need for respiratory compensation.

What respiratory rate is considered too slow?

Less than 12 breaths per minute.

How can a slow respiratory rate be corrected?

Through positive pressure ventilation (PPV).

What is required if respirations are absent?

External breathing support (we breathe for them).

What are signs of inadequate ventilation?

Shallow breaths or abnormal respiratory rates.

What is used to assist inadequate ventilation?

Positive pressure ventilation (PPV).

What are examples of abnormal breathing signs?

Labored respirations, diaphragmatic breathing, adventitious sounds.

What are crackles in the lungs?

Sounds from fluid and opening/closing alveoli.

What is stridor?

A high-pitched sound indicating airway obstruction.

What is wheezing?

A sound from airway constriction.

What is rhonchi?

Gurgling/snoring from the lower airway

What is bronchospasm commonly caused by?

COPD, allergic reaction, or asthma.

What condition is often linked to pulmonary edema?

Congestive heart failure (CHF).

What infections can cause pulmonary edema?

Lower airway infections like pneumonia.