Ch. 15: Altered Ventilation & Diffusion

Define Ventilation

The process of moving air into and out of the lungs to facilitate gas exchange. It involves the mechanical movement of air through the respiratory pathways (nose, trachea, bronchi, etc.) and into the alveoli.

How is the rate and volume of ventilation regulated

Respiratory control centers in the brain

Lung receptors

Chemoreceptors

Define inspiration

Acquiring oxygen

Define expiration

removing carbon dioxide

Define diffusion

The movement of gases (oxygen and carbon dioxide) across a membrane from an area of higher concentration to an area of lower concentration. In the lungs, oxygen diffuses from the alveoli into the bloodstream, and carbon dioxide diffuses from the blood into the alveoli to be exhaled.

Define perfusion

The process of blood flow through the blood vessels in the lungs, delivering oxygen to tissues and organs and removing waste products such as carbon dioxide. It ensures that oxygenated blood reaches the body’s tissues and organs.

Define respiration

The overall process of exchanging gases between the atmosphere and the cells of the body. This includes air movement, gas exchange in the lungs, and blood flow deliver oxygen to tissues.

Which of the following can be complications of impaired ventilation (select all that apply)

Hypoxemia, hypoxia, and hypercapnia

Pneumonia can be caused by inhaling items not intended for the lungs, this condition is called

Aspiration pneumonia

Chronic Obstructive Pulmonary Disease (COPD) is a generic term that describes all chronic obstructive lung problems. Which of the following is true about COPD?

COPD is one of the leading causes of death worldwide.

Because emphysema is irreversible, the goal of treatment is to maintain lung function

Define Anemia

Low red blood cell count or hemoglobin, leading to reduced oxygen supply

Define infarct

Tissue death due to lack of blood supply

What is an aneurysm

Abnormal bulging of a blood vessel due to weakened walls

Define hemorrhage

Uncontrolled bleeding from blood vessels due to injury or rupture

Define embolus

A traveling particle or clot that blocks a blood vessel

Define thrombosis

Formation of a blood clot inside a vessel, blocking blood flow.

Coronary circulation is a circulatory network that focuses on

What is atherosclerosis

A condition that can lead to lipids clogging a vessel, obstruction blood flow. Hardening and narrowing of arteries due to plaque buildup.

The nurse is caring for a patient newly diagnosed with hypertension. Which of the following is accurate regarding hypertension

What is another name for a heart attack?

Myocardial infarction

What is the common term for cerebrovascular accident?

Stroke

What two major processes occur simultaneously

1.) Oxygen is trying to get to all cells

2.) CO2 is trying to escape the body through the lungs

Why are hemoglobin molecules needed for oxygen diffusion and transport?

Hemoglobin molecules are needed because oxygen has a very low solubility in water and blood plasma, meaning plasma alone can only dissolve about 1.5% - 3% of the oxygen required by the body. 87% to 99% of the oxygen is combined with hemoglobin; remainder is found dissolved in blood plasma.

What does oxygen saturation measure?

Oxygen saturation (SaO2) refers to the amount of oxyhemoglobin; that is, the amount of hemoglobin that is saturated with oxygen. Four oxygens on one hemoglobin mean it’s saturated.

Describe impaired ventilation

A problem of blocking airflow in and out of the lungs, thereby restricting oxygen intake and CO2 removal from the body. Two major mechanisms are implemented…

1.) Compression or narrowing of the airway

2.) Disruption of the neural transmissions needed to stimulate the mechanisms of breathing.

What happens when the body cannot keep up with oxygen demands?

Hypoxemia, Hypoxia, & hypercapnia

Compare and contrast Hypercapnia and hypoxemia / Hypoxia

Hypoxemia is decreased oxygen in the arterial blood leading to a decrease in the partial pressure (PaO2). Major causes of Hypoxemia include oxygen deprivation, hypoventilation, & problems with diffusion and inadequate uptake of oxygen. It can range from mild to severe and becomes problematic when cells are deprived of oxygen, a condition referred to as Hypoxia. Hypercapnia refers to a state of increased CO2 in the blood. Carbon dioxide is much more easily diffused than oxygen, therefore hypercapnia presents only in cases of severe alveolar hypoventilation & subsequent hypoxia.

What are some general manifestations of impaired ventilation and diffusion?

Cough

Excess mucus

Hemoptysis

Dyspnea

Use of accessory muscles

Chest pain

Barrel chest

Define aspiration

Inhaling a foreign substance into the lungs.

What is sputum?

Thick mixture of mucus, saliva, & cellular debris expectorated out of the respiratory tract.

What is phlegm?

Large amounts of sputum expectorated from oropharynx.

Define hemoptysis

Coughing up blood from respiratory tract.

Define dyspnea

Subjective feeling of shortness of breath or inability to get enough air.

Define orthopnea

Physical need to sit upright / in standing position to maximize lung expansion.

Define retractions

The pulling in of accessory muscles, usually in the intercostal, substernal, and supraclavicular spaces to promote more efficient inspiration.

Define barrel chest

Changes in the chest wall shape. Rounded, enlarged chest that looks full and puffed out, similar in shape to a wooden barrel.

What is cyanosis?

Caused by a grater proportion of desaturated hemoglobin in the blood, which gives the blood a bluish hue.

Define Pneumonia

Inflammation of the lungs occurring commonly in the bronchioles, interstitial lung tissue, alveoli.

Who is at greatest risk of developing Pneumonia?

Older individuals, younger individuals, smokers, and immunosuppressed people are at the highest risk.

Pathophysiology of Pneumonia

Microorganisms, including bacteria, viruses, and fungi spread by respiratory droplets, are the most common cause. Pneumonias are often distinguished as either community acquired or hospital acquired (nosocomial) depending on where it was contracted.

Community acquired Pneumonia is caused by…

Streptococcus, pneumoniae, Haemophiles, influenza, and staphylococcus species.

What are some clinical manifestations of Pneumonia

Fever, cough, chills

Sputum production

fatigue, loss of appetite

Dyspnea

Tachypnea

Tachycardia

Pleuritic pain

Diagnostic criteria for Pneumonia

Blood work to determine WBC count

Chest radiograph

Thoracic CT

Rule out bronchiectasis

Identify causing microorganism

Gram stain culture

Treatment of Pneumonia

Restore optimal ventilation & diffusion

Antibiotic

For high-risk individuals: macrolide & antibiotics

Intravenous fluids

Chest physiotherapy

Define Emphysema

Irreversible enlargement of the airspaces beyond terminal bronchioles, most notably in the alveoli, resulting in destruction of alveolar walls & obstruction of airflow. Most common cause is chronic smoking.

Pathophysiology of Emphysema

In early or mild cases the primary source of obstruction is the development of inflammation in the small airways distal to respiratory bronchioles. If diagnosed early inflammation can be reduced. In moderate to severe cases the loss of elastic recoil in the alveoli is the primary mechanism of airflow obstruction.

Clinical manifestations of Emphysema

Chronic cough most persistent in the morning

Dyspnea / wheezing

Barrel chest

Diagnostic criteria for Emphysema

Smoking history

expiratory airflow measured

AAT levels in non smokers

Treatment of Emphysema

Irreversible, the goal is to maintain optimal lung function

Drugs to increase AAT production

Stop smoking